Silicon drift detectors in alice experiment at lhc, performance tests and simulations

International Nuclear Information System (INIS)

ALICE collaboration

2001-01-01

A brief introduction to the silicon drift detector (SDD) in ALICE experiment at LHC CERN. Excellent agreement are found between the results from the simulation code (Ali Root) and the results of the test beam data for SDD s. A study of SDD performance and double track separation capability are shown

Recent photon physics results from the ALICE experiment at the LHC

CERN Document Server

Arbor, Nicolas

2013-01-01

We present an overview of the photon analysis in pp and Pb-Pb collisions with data taken by the ALICE experiment at the LHC. The ALICE detectors reconstruct photons by using the two electromagnetic calorimeters (photon spectrometer, sampling calorimeter) and central tracking systems for photon converted e + e pairs in the material of the inner ALICE layers. In Pb-Pb collisions the direct photon calculations under- predict the data below 4 GeV / c where it is expected to have a contribution from thermal radiations. The direct photon measurement also shows evidence for a non-zero elliptic flow for 1 < p T < 3 GeV / c. The nuclear modi- fication factor of the 0 production at di erent collision centralities shows a clear pattern of strong suppression in a hot QCD medium with respect to pp collisions. Finally, parton fragmentation following hard collisions is investigated by correlating high momentum direct photons and charged hadrons with the goal of revealing new insights into medium effects in the QGP.

Improvements of the ALICE high level trigger for LHC Run 2 to facilitate online reconstruction, QA, and calibration

Energy Technology Data Exchange (ETDEWEB)

Rohr, David [Frankfurt Institute for Advanced Studies, Frankfurt (Germany); Collaboration: ALICE-Collaboration

2016-07-01

ALICE is one of the four major experiments at the Large Hadron Collider (LHC) at CERN. Its main goal is the study of matter under extreme pressure and temperature as produced in heavy ion collisions at LHC. The ALICE High Level Trigger (HLT) is an online compute farm of around 200 nodes that performs a real time event reconstruction of the data delivered by the ALICE detectors. The HLT employs a fast FPGA based cluster finder algorithm as well as a GPU based track reconstruction algorithm and it is designed to process the maximum data rate expected from the ALICE detectors in real time. We present new features of the HLT for LHC Run 2 that started in 2015. A new fast standalone track reconstruction algorithm for the Inner Tracking System (ITS) enables the HLT to compute and report to LHC the luminous region of the interactions in real time. We employ a new dynamically reconfigurable histogram component that allows the visualization of characteristics of the online reconstruction using the full set of events measured by the detectors. This improves our monitoring and QA capabilities. During Run 2, we plan to deploy online calibration, starting with the calibration of the TPC (Time Projection Chamber) detector's drift time. First proof of concept tests were successfully performed using data-replay on our development cluster and during the heavy ion period at the end of 2015.

Determination of the event collision time with the ALICE detector at the LHC

NARCIS (Netherlands)

Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S. U.; Aiola, S.; Akindinov, A.; Alam, S. N.; Albuquerque, D. S. D.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Janssen, M M; Andrei, C.; Andrews, H. A.; Andronic, A.; Anguelov, V.; Anson, C. D.; Antičić, T.; Antinori, F.; Antonioli, P.; Anwar, R.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Arnaldi, R.; Arnold, O. W.; Arsene, I. C.; Arslandok, M.; Audurier, B.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Balasubramanian, S.; Baldisseri, A.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Barth, K.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Beltran, L. G. E.; Belyaev, V.; Bencedi, G.; Beole, S.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biro, G.; Biswas, R.; Biswas, S.; Bjelogrlic, S.; Blair, J. T.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Boldizsár, L.; Bombara, M.; Bonora, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Botta, E.; Bourjau, C.; Braun-Munzinger, P.; Bregant, M.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buhler, P.; Iga Buitron, S. A.; Buncic, P.; Busch, O.; Buthelezi, Z.; Butt, J. B.; Buxton, J. T.; Cabala, J.; Caffarri, D.; Caines, H.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Carnesecchi, F.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A R; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Cerkala, J.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chauvin, A.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Cho, Sukhee; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Crkovská, J.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danisch, M. C.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; Dasgupta, S. S.; De Caro, A.; De Cataldo, G.; De Conti, C.; De Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; De Souza, R. Derradi; Deisting, A.; Deloff, A.; Deplano, C.; Dhankher, P.; Di Bari, D.; Di Mauro, A.; Di Nezza, P.; Di Ruzza, B.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, O.; Dobrin, A.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Drozhzhova, T.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Duggal, A. K.; Dupieux, P.; Ehlers, R. 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K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Goméz Coral, D. M.; Gomez Ramirez, A.; Gonzalez, A. S.; Gonzalez, V; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Graham, K. L.; Greiner, L. C.; Grelli, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grion, N.; Gronefeld, J. M.; Grosse-Oetringhaus, J. F.; Grosso, R.; Gruber, L.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, R.; Guzman, I. B.; Haake, R.; Hadjidakis, C.; Hamagaki, H.; Hamar, G.; Hamon, J. C.; Harris, J. W.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Hellbär, E.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Herrmann, F.; Hess, B. A.; Hetland, K. F.; Hillemanns, H.; Hippolyte, B.; Hladky, J.; Horak, D.; Hosokawa, R.; Hristov, P.; Hughes, C.W.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Ilkaev, R.; Inaba, M.; Ippolitov, M.; Irfan, M.; Isakov, V.; Islam, M. S.; Ivanov, M.; Ivanov, V.; Izucheev, V.; Jacak, B.; Jacazio, N.; Jacobs, P. M.; Jadhav, M. B.; Jadlovska, S.; Jadlovsky, J.; Jahnke, C.; Jakubowska, M. J.; Janik, M. A.; Jayarathna, P. H S Y; Jena, C.; Jena, S.; Jimenez Bustamante, R. T.; Jones, P. G.; Jusko, A.; Kalinak, P.; Kalweit, A.; Kang, J. H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karayan, L.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L.D.; Keil, M.; Mohisin Khan, M.; Khan, P.M.; Khan, Shfaqat A.; Khanzadeev, A.; Kharlov, Y.; Khatun, A.; Khuntia, A.; Kileng, B.; Kim, D. W.; Kim, D. J.; Kim, D.-S.; Kim, H.; Kim, J. S.; Kim, J.; Kim, M.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, C; Klein, J.; Klein-Bösing, C.; Klewin, S.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobdaj, C.; Kofarago, M.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Kondratyuk, E.; Konevskikh, A.; Kopcik, M.; Kour, M.; Kouzinopoulos, C.; Kovalenko, O.; Kovalenko, V.; Kowalski, M.L.; Koyithatta Meethaleveedu, G.; Králik, I.; Kravčáková, A.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kubera, A. M.; Kučera, V.; Kuhn, C.; Kuijer, P. G.; Kumar, A.; Kumar, J.; Kumar, L.; Kumar, S.; Kundu, Seema; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kweon, M. J.; Kwon, Y.; La Pointe, S. L.; La Rocca, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; Lapidus, K.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lazaridis, L.; Lea, R.; Leardini, L.; Lee, S.; Lehas, F.; Strunz-Lehner, Christine; Lehrbach, J.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; León Monzón, I.; Lévai, P.; Li, S.; Li, X.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Llope, W. J.; Lodato, D. F.; Loenne, P. I.; Loginov, V.; Loizides, C.; Lopez, X.; López Torres, E.; Lowe, A.; Luettig, P.; Lunardon, M.; Luparello, G.; Lupi, M.; Lutz, T. H.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal’Kevich, D.; Malzacher, P.; Mamonov, A.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.; Marín, Alicia; Markert, C.; Marquard, M.; Martin, N. A.; Martinengo, P.; Martínez, Isabel M.; Martínez García, G.; Martinez Pedreira, M.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Mastroserio, A.; Matyja, A.; mayer, C.; Mazer, J.; Mazzilli, M.; Mazzoni, M. A.; Meddi, F.; Melikyan, Y.; Menchaca-Rocha, A.; Meninno, E.; Mercado Pérez, J.; Meres, M.; Mhlanga, S.; Miake, Y.; Mieskolainen, M. M.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A. N.; Mishra, T.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.; Mohanty, B.; Molnar, L.; Montes, E.; Moreira De Godoy, D. A.; Moreno, L. A. P.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Mulligan, J. D.; Munhoz, M. G.; Münning, K.; Munzer, R. H.; Murakami, H.; Murray, S.; Musa, L.; Musinsky, J.; Myers, C. J.; Naik, B.; Nair, Rajiv; Nandi, B. K.; Nania, R.; Nappi, E.; Naru, M. U.; Natal Da Luz, H.; Nattrass, C.; Navarro, S. R.; Nayak, K.; Nayak, R.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Negrao De Oliveira, R. A.; Nellen, L.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Noferini, F.; Nomokonov, P.; Nooren, G.; Noris, J. C. C.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Ohlson, A.; Okubo, T.; Olah, L.; Oleniacz, J.; Oliveira Da Silva, A. C.; Oliver, M. H.; Onderwaater, J.; Oppedisano, C.; Orava, R.; Oravec, M.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Ozdemir, M.; Pachmayer, Y.; Pacik, V.; Pagano, D.; Pagano, P.; Paić, G.; Pal, S. K.; Palni, P.; Pan, J.; Pandey, A. K.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, J.; Park, J.-W.; Parmar, S.; Passfeld, A.; Paticchio, V.; Patra, R. N.; Paul, B.; Pei, H.; Peitzmann, T.; Peng, X.; Pereira Da Costa, H.; Peresunko, D.; Perez Lezama, E.; Peskov, V.; Pestov, Y.; Petráček, V.; Petrov, V.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pimentel, L. O. D. L.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L M; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Poonsawat, W.; Pop, A.; Poppenborg, H.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, J.; Pozdniakov, V.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Rami, F.; Rana, D. B.; Raniwala, R.; Raniwala, S.; Räsänen, S.; Rascanu, B. T.; Rathee, D.; Ratza, V.; Ravasenga, I.; Read, K. F.; Redlich, K.; Rehman, A.; Reichelt, P.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Rodríguez Cahuantzi, M.; Røed, K.; Rogochaya, E.; Rohr, D.; Röhrich, D.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Saarinen, S.; Sadhu, S.; Sadovsky, S.; Šafařík, K.; Sahlmuller, B.; Sahoo, B.; Sahoo, P.; Sahoo, R.; Sahoo, S.; Sahu, P. K.; Saini, J.; Sakai, S.; Saleh, M. 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W.; van Leeuwen, M.; Vanat, T.; Vande Vyvre, P.; Varga, D.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vauthier, A.; Vázquez Doce, O.; Vechernin, V.; Veen, A. M.; Velure, A.; Vercellin, E.; Vergara Limón, S.; Vernet, R.; Vértesi, R.; Vickovic, L.; Vigolo, S.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Villatoro Tello, A.; Vinogradov, A.; Vinogradov, L.; Virgili, T.; Vislavicius, V.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; Haller, B.; Vorobyev, I.; Voscek, D.; Vranic, D.; Vrláková, J.; Wagner, B.; Wagner, J.; Wang, H.; Wang, M.; Watanabe, D.; Watanabe, Y.; Weber, M.; Weber, S. G.; Weiser, D. F.; Wessels, J. P.; Westerhoff, U.; Whitehead, A. M.; Wiechula, J.; Wikne, J.; Wilk, G.; Wilkinson, J.; Willems, G. A.; Williams, M. C S; Windelband, B.; Winn, M.; Witt, W. E.; Yalcin, S.; Yang, P.; Yano, S.; Yin, Z.; Yokoyama, H.; Yoo, I. K.; Yoon, J. H.; Yurchenko, V.; Zaccolo, V.; Zaman, A.; Zampolli, C.; Zanoli, H. J. C.; Zaporozhets, S.; Zardoshti, N.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhang, C.; Zhang, Z.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, Y.; Zhou, Z.; Zhu, H.; Zhu, J.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zmeskal, J.

2017-01-01

Particle identification is an important feature of the ALICE detector at the LHC. In particular, for particle identification via the time-of-flight technique, the precise determination of the event collision time represents an important ingredient of the quality of the measurement. In this paper,

CERN Open Days 2013, Point 2 - ALICE: ALICE Experiment

CERN Multimedia

CERN Photolab

2013-01-01

Stand description: Visitors will be guided through the ALICE experiment, an extraordinary particle physics detector located at a depth of 80 meters below ground.  ALICE started up in 2008 to study the quark-gluon plasma, a state of matter that probably existed in the first moments of the universe. Visitors will also be able to walk inside the LHC tunnel, where superconducting magnets guide the beams of protons at unprecedented energies around the LHC. In addition to the underground visit, several ALICE physicists and engineers will be available to answer visitors' questions. On surface no restricted access  Above ground, scientific  and other kinds of shows will entertain the visitors to ALICE, even the youngest, throughout the day.

Study of the multi-strange resonance $\\Xi(1530)^{0}$ production with ALICE at the LHC energies

CERN Document Server

AUTHOR|(CDS)2080748

The primary goal of the relativistic heavy-ion physics program at Large Hadron Collider (LHC) at CERN, Geneva, Switzerland is to study the nuclear matter under extreme conditions. The measurement of resonances in ultra-relativistic heavy-ion collisions allows one to study the properties of the hadronic medium. Resonances with short lifetimes compared to the duration of the time span between chemical and kinetic freeze-out are good candidates to prove the interplay of particle re-scattering and regeneration in the hadronic phase, which result in a modification of their measured yields. The ALICE detector and its subsystem used for the analysis presented in this thesis are explained. Particle identification method and a coordinate system of ALICE are provided. Measurements of multi-strange resonance $\\Xi(1530)^{0}$ were performed with the ALICE detector in pp, p-Pb and Pb-Pb collisions at the LHC energies. The ${p_{\\mathrm{T}}}$-spectra of $\\Xi(1530)^{0}$ are obtained and compared with model predictions. The y...

Results from cosmics and first LHC beam with the ALICE HMPID detector

CERN Document Server

Volpe, Giacomo

2009-01-01

The ALICE HMPID (High Momentum Particle IDentification) detector has been designed to identify charged pions and kaons in the range 1 < p < 3 GeV/c and protons in the range 1.5 < p < 5 GeV/c. It consists of seven identical proximity focusing RICH (Ring Imaging Cherenkov) counters, covering in total 11 m2, which exploit large area MWPC equipped with CsI photocathodes for Cherenkov light imaging emitted in a liquid C6F14 radiator. The ALICE detector has been widely commissioned using cosmics and LHC beam from December 2007 until October 2008. During the cosmics data taking the HMPID detector collected a large set of data, using mainly the trigger provided by the TOF detector. We present here preliminary results of detector alignment using TPC tracking. The HMPID could be operated in a stable way, at a safe HV setting, also during LHC beam injection and circulation tests, when a very large occupancy (up to 50%) was achieved. Resulting gain mapping and overall detector performance will also be discuss...

Non prompt D-meson measurements with ALICE at the LHC

International Nuclear Information System (INIS)

Mazzilli, Marianna

2016-01-01

The production of hadrons with open heavy flavour (charm and beauty) in high-energy nucleus-nucleus collisions is a powerful tool to study the properties of the deconfined phase of strongly interacting matter known as the Quark-Gluon Plasma (QGP). The production of charm and beauty quarks occurs in hard partonic scattering processes in the early stage of the collisions. ALICE is the LHC experiment devoted to the study of heavy-ion physics. It is able to reconstruct charmed mesons in exclusive decays (e.g. D"0→K"−π"+) and beauty hadrons in semi-inclusive decays (e.g. B→eX, B→J/ψ X) . At LHC energies a significant component of the inclusive D-meson yield originates from the decay of beauty-flavoured hadrons, whose knowledge is essential to determine the production of prompt D mesons coming from charm quarks. A precise determination of the non-prompt fraction combined with the determination of the inclusive D-meson yield would allow a measurement of beauty production. A data-driven method that exploits the different shapes of the distributions of the transverse-plane impact parameter to the primary vertex of prompt and feed-down D mesons in p-Pb collisions is used in ALICE. An alternative approach based on the D-meson decay length for Pb–Pb collisions is under study.

ALICE measurements of heavy-flavour production at the LHC

CERN Multimedia

CERN. Geneva

2012-01-01

The measurement of open charm and beauty production in Pb-Pb collisions at the LHC gives access to the mechanisms of heavy-quark transport and energy loss in hot and dense QCD matter. The ALICE apparatus allows us to measure heavy flavour particles over a wide acceptance, using hadronic and electronic final states at central rapidity and muonic final states at forward rapidity, in both cases with coverage down to low transverse momentum. These measurements, in pp collisions, besides constituting the reference for the heavy-ion studies, provide acceptance-wise unique information on heavy-quark production at LHC energies. After presenting results for pp collisions at centre-of-mass energies of 2.76 and 7 TeV, we focus on the observation of the suppression of heavy-flavour production in central Pb-Pb collisions and of the azimuthal anisotropy of charmed hadrons in semi-central collisions at 2.76 TeV.

On the horizon for ALICE

CERN Multimedia

Antonella Del Rosso

2012-01-01

ALICE – the LHC experiment specifically designed to study the physics of the Quark Gluon Plasma (QGP) and, more generally, of strongly interacting matter at extreme energy densities – is planning a series of upgrades during the long shutdowns of the accelerator in the coming years. The new ALICE will have enhanced read-out capabilities and improved efficiency when tracking particles and identifying the vertex of the interactions.     Corrado Gargiulo, ALICE's Project Engineer with ITS prototype. The new ITS will consist of 7 layers of silicon sensors supported by a ultra-light carbon fibre structure.  The LHC has been operated with lead ions for only about two months, but this has been sufficient for ALICE and other LHC experiments to produce results that previous accelerators took several years of operation to produce. “Prior to the start-up of the LHC heavy-ion programme, the nature of the QGP as an almost-perfect liquid had already...

Optimisation of the muon spectrometer from the detector ALICE used for the study of the quark and gluon plasma at LHC; Optimisation du spectrometre a muons du detecteur ALICE pour l'etude du plasma de quarks et de gluons au LHC

Energy Technology Data Exchange (ETDEWEB)

Guernane, R

2001-01-01

The ALICE experiment performed at the LHC will establish and study the phase transition from hadronic matter to a matter to a state of deconfined partons called Quark Gluon Plasma (QGP). The suppression of heavy flavour resonances (J{phi},{gamma}) is the most promising probe for diagnosing the formation and early stages of the QGP in ultrarelativistic heavy ion collisions. The complete spectrum of heavy quarkonia resonances, i.e. J/{phi}, {phi}', {gamma}, {gamma}' and {phi}' will be measured via their muonic decay in a forward spectrometer with a mass resolution sufficient to separate all states. It is composed of five tracking stations, each consisting of two Cathode Pad Chambers (CPC). In this work, we developed a prototype of CPC having the original feature of parallel charge read out from one segmented cathode. The geometry and operating parameters have been optimized for station 3. The expected multi-hit rate and multi-hit deconvolution have been evaluated with a complete detailed simulation and an efficient method to disentangle close hits has been proposed. The magnetic field effect on the intrinsic spatial resolution of the chambers has also been estimated. The simulated performance of the CPC's is confirmed by beam-test results obtained at CERN with prototypes. The measurement of dimuons is expected to be contaminated by beam-related background. The rate of beam-gas interactions is several orders of magnitude larger than the signal rate for p-p collisions which is the reference for further studies of p-A and A-A collisions. The ALICE Collaboration decided to equip the muon spectrometer with a level 0 trigger counter (V0) in order to validate the dimuon trigger signal in p-p mode. The various steps involved in designing the V0 scintillator hodoscope are presented in this thesis. (author)

Study of jet production in ALICE experiment at LHC collider

CERN Document Server

Jangal, Swensy

The jet is one of the probes allowing testing strong interaction theory predictions, QCD, and to extract physical properties from a particular state of nuclear matter : Quark Gluon Plasma (QGP). This PhD work is aimed to show ALICE capacities to measure jets coming from collisions produced at the Large Hadron Collider (LHC). The detection of particles constituting jets, their association with reconstruction algorithms and the construction of observables such as jet pT spectrum of Hump-Backed Plateau is a hard work. We detail these different steps from simulation allowing to estimate jet rates we could expect for our analysis and to evaluate the impact of experimental measure on final observables. We finally present pT spectrum and Hump-Backed Plateau from first p+p collisions at LHC to whom mean corrections have been applied.

Measurement of K(892)*0 resonance production in Pb-Pb collisions with the ALICE experiment at the LHC

CERN Document Server

Bellini, Francesca

The analysis of the K(892)*0 resonance production in Pb–Pb collisions at √sNN = 2.76 TeV with the ALICE detector at the LHC is presented. The analysis is motivated by the interest in the measurement of short-lived resonances production that can provide insights on the properties of the medium produced in heavy-ion collisions both during its partonic (Quark-Gluon Plasma) and hadronic phase. This particular analysis exploits particle identification of the ALICE Time-Of-Flight detector. The ALICE experiment is presented, with focus on the performance of the Time-Of-Flight system. The aspects of calibration and data quality controls are discussed in detail, while illustrating the excellent and very stable performance of the system in different collision environments at the LHC. A full analysis of the K*0 resonance production is presented: from the resonance reconstruction to the determination of the efficiency and the systematic uncertainty. The results show that the analysis strategy discussed is a valid too...

Study of {upsilon} family resonances in ultrarelativistic heavy ions collisions within the frame of the Alice experiment at CERN-LHC; Etude des resonances de la famille du {upsilon} dans les collisions d'ions lourds ultra-relativistes a 2.75 TeV/ nucleon et par faisceau sur l'experience Alice du LHC

Energy Technology Data Exchange (ETDEWEB)

Dumonteil, E

2004-09-01

Quantum Chromodynamics foresees, at high temperature and/or high energy density, a phase transition between hadronic matter and a phase where quarks and gluons are no more confined in the nucleons: the Quark Gluon Plasma (QGP). During the past fifteen years, a large experimental program has taken place at CERN and at BNL, to identify the QGP. ALICE is the LHC experiment dedicated to the study of the plasma via ultrarelativistic heavy ion collisions at 2.75 TeV/nucleon per beam. The measure of Upsilon's resonances suppression, a powerful signature of a deconfined medium, with the ALICE dimuon spectrometer, is the main topic of this thesis. The first part of the work aims at studying the multi-wires pad chambers of the dimuon arm, used to track the muons from resonances decays. The second part presents an in-beam alignment algorithm able to calculate the positions of the different chambers with a very good accuracy. Finally, the last part proposes a study to lead with the ALICE muon spectrometer, involving the measure of Upsilon and Upsilon's production ratio as a function of the transverse momentum. It has been showed that this study should allow to evidence the QGP and to extract some of its properties. (author)

Studies for dimuon measurement with ALICE

International Nuclear Information System (INIS)

Jouan, D.

1995-01-01

The idea of measuring dimuon in the ALICE detector is not new, since it already appeared in the Aachen Conference. In the meantime studies were aiming at the use of the two detectors of LHC p-p physics, CMS and ATLAS, already dedicated to dimuon measurement, for these same measurements in heavy ion collisions, whereas the detector dedicated to heavy ions physics at LHC, ALICE, was considering all the other observables. Recently, the interest for dimuon measurements in ALICE was renewed by demands from LHC committee, stiring the activities of a working group in the ALICE collaboration, also associated to a more recent move from new groups. In the following the author briefly describes the interest of measuring dimuons in heavy ion collisions, particularly in ALICE, then the experimental strategy and first estimates of the performances that could be reached with the proposed system

High-level trigger system for the LHC ALICE experiment

CERN Document Server

Bramm, R; Lien, J A; Lindenstruth, V; Loizides, C; Röhrich, D; Skaali, B; Steinbeck, T M; Stock, Reinhard; Ullaland, K; Vestbø, A S; Wiebalck, A

2003-01-01

The central detectors of the ALICE experiment at LHC will produce a data size of up to 75 MB/event at an event rate less than approximately equals 200 Hz resulting in a data rate of similar to 15 GB/s. Online processing of the data is necessary in order to select interesting (sub)events ("High Level Trigger"), or to compress data efficiently by modeling techniques. Processing this data requires a massive parallel computing system (High Level Trigger System). The system will consist of a farm of clustered SMP-nodes based on off- the-shelf PCs connected with a high bandwidth low latency network.

Open heavy–flavour and quarkonium measurements with ALICE at the LHC

CERN Document Server

INSPIRE-00249244

2013-01-01

The ALICE detector provides excellent capabilities to study heavy quark (i.e. charm and beauty) production in proton{proton (pp) and heavy{ion collisions (AA) at the Large Hadron Collider (LHC). In ALICE, open heavy{ avour hadron production is studied through the hadronic decays of D mesons at central rapidity ( j y j < 0 : 9), and in the semi{leptonic decays of charm and beauty hadrons both at mid{rapidity and at forward rapidity (2 : 5 < y < 4). Quarkonia are measured in their di{electron and di{muon decay channels in the central barrel and in the muon spectrometer respectively, reaching in both cases zero transverse momentum. The latest results on open heavy{ avour and quarkonium production in pp ( p s = 2.76 TeV and p s = 7 TeV) and PbPb ( p s NN = 2.76 TeV) collisions are presented

(Anti-)deuteron production at the LHC with the ALICE-HMPID detector

International Nuclear Information System (INIS)

Barile, F.

2015-01-01

The high center-of-mass energies delivered by the LHC during the last three years of operation led to accumulate a significant statistics of light (hyper-)nuclei in pp, p-Pb and Pb-Pb collisions. The ALICE apparatus allows for the detection of these rarely produced particles over a wide momentum range thanks to its excellent vertexing, tracking and particle identification capabilities. The last is based on the specific energy loss in the Time Projection Chamber and the velocity measurement with the Time-Of-Flight detector. The Cherenkov technique, exploited by a small acceptance detector (HMPID), has been also recently used for the most central Pb-Pb collisions to extend the identification range of the (anti-)deuteron at intermediate transverse momentum. An overview of the recent results on the (anti-)deuteron production in pp, p-Pb and Pb-Pb collisions measured with ALICE experiment are presented, giving a particular emphasis to the description of the Cherenkov technique.

(Anti-)deuteron production at the LHC with the ALICE-HMPID detector

CERN Document Server

Barile, F

2015-01-01

The high center-of-mass energies delivered by the LHC during the last three years of operation led to accumulate a significant statistics of light (hyper-)nuclei in pp, p-Pb and Pb-Pb collisions. The ALICE apparatus allows for the detection of these rarely produced particles over a wide momentum range thanks to its excellent vertexing, tracking and particle identification capabilities. The last is based on the specific energy loss in the Time Projection Chamber and the velocity measurement with the Time-Of-Flight detector. The Cherenkov tech- nique, exploited by a small acceptance detector (HMPID), has been also recently used for the most central Pb-Pb collisions to extend the identification range of the (anti-)deuteron at intermediate transverse momentum. An overview of the recent results on the (anti-)deuteron production in pp, p-Pb and Pb-Pb collisions mea- sured with ALICE experiment are presented, giving a particular emphasis to the description of the Cherenkov technique

Performance of the Alice muon spectrometer. Weak boson production and measurement in heavy-ion collisions at LHC; Performance du spectrometre a muons d'ALICE. Production et mesure des bosons faibles dans des collisions d'ions lourds aupres du LHC

Energy Technology Data Exchange (ETDEWEB)

Conesa del valle, Z

2007-07-15

Lattice QCD predicts a transition from a hadronic phase to a Quark Gluon Plasma phase, QGP, for temperatures above 10{sup 13} K. Heavy-ion collisions are proposed to recreate it in laboratory. With such a purpose, the LHC (Large Hadron Collider) will provide Pb-Pb collisions at 5.5 TeV/u, and the ALICE experiment will permit to explore them. In particular, the ALICE muon spectrometer will permit to investigate the muon related probes (quarkonia, open beauty,...). The expected apparatus performances to measure muons and dimuons are discussed. A factorization technique is employed to unravel the different contributions to the global efficiency. Results indicate that the detector should be able to measure muons up to pT {approx} 100 GeV/c with a resolution of about 10 per cent. We show that weak bosons production could be measured for the first time in heavy-ion collisions. Single muon p{sub T} and dimuons invariant mass distributions will probe W and Z production. As mainly muons from b- and c-quarks decays will populate the intermediate-p{sub T} of 5 - 25 GeV/c, heavy quark in-medium energy loss calculations indicate that the single muon spectra would be suppressed by a factor 2-4 in the most central 0 - 10% Pb-Pb collisions at 5.5 TeV. However, for p{sub T} > 35 GeV/c the weak boson decays are predominant, and no suppression is expected. Estimations indicate that the b- and W-muons crossing point shifts down in transverse momenta by 5 to 7 GeV/c in the most central 0 - 10% Pb-Pb collisions at 5.5 TeV. (author)

Calculation of Wakefields and Higher Order Modes for the New Design of the Vacuum Chamber of the ALICE Experiment for the HL-LHC

CERN Document Server

Wanzenberg, Rainer; CERN. Geneva. ATS Department

2016-01-01

The High Luminosity Large Hadron Collider (HL-LHC) project was started with the goal to extend the discovery potential of the Large Hadron Collider (LHC). The HL-LHC study implies also an upgraded dimensions of the ALICE beam pipe. The trapped monopole and dipole Higher Order Modes (HOMs) and the short range wakefields for the new design of the ALICE vacuum chamber were calculated with help of the computer codes MAFIA and ECHO2D. The results of the short range wakefields calculations and the HOMs calculations for the ALICE vacuum chamber with new dimensions are presented in this report. The short range wakefields are presented in terms of longitudinal and transverse wake potentials and also in terms of loss and kick parameters. The frequency, the loss parameter, the R/Q and the Qvalues and also power loss parameters are presented as result of the HOMs calculations and can be converted into impedance values.

Identifying Charged Hadrons on the Relativistic Rise Using the ALICE TPC at LHC

CERN Document Server

Gros, Philippe

2011-01-01

The chain from hadron collisions to the physics results requires several important links. First the outcome of the collision is measured by the detectors. Then, the signal from the detector is processed and transformed into information relevant for the study of the physics processes. The data is made available to physicists to be analysed and used to improve theories. This thesis presents work done on no most of these steps for the ALICE experiment at LHC. First a study of the main processes in the TPC detector for ALICE was done using simulation and test beam data. The results are shown in paper I. The study was deepened with the analysis of test beam data from a TPC prototype for the ILC, as shown in paper III. Concurrently, a study on the Grid – computing framework for distributed computing and storage resources – was performed. This involved the development of an interface module between the ALICE software AliEn and the ARC software developped in the Nordic countries. This work is presented in paper I...

Determination of the event collision time with the ALICE detector at the LHC

Czech Academy of Sciences Publication Activity Database

Adam, J.; Adamová, Dagmar; Bielčík, J.; Bielčíková, Jana; Brož, M.; Čepila, J.; Contreras, J. G.; Eyyubova, G.; Ferencei, Jozef; Hladký, Jan; Horák, D.; Křížek, Filip; Kučera, Vít; Kushpil, Svetlana; Mareš, Jiří A.; Petráček, V.; Pospíšil, Jan; Šumbera, Michal; Vaňát, Tomáš; Závada, Petr

2017-01-01

Roč. 132, č. 2 (2017), č. článku 99. ISSN 2190-5444 R&D Projects: GA MŠk(CZ) LG15052 Institutional support: RVO:68378271 ; RVO:61389005 Keywords : ALICE collaboration * LHC * performance Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders; BF - Elementary Particles and High Energy Physics (FZU-D) OBOR OECD: Nuclear physics; Particles and field physics (FZU-D) Impact factor: 1.753, year: 2016

Performance of the ALICE VZERO system

CERN Document Server

Abbas, E.; Adam, J.; Adamova, D.; Adare, A.M.; Aggarwal, M.M.; Aglieri Rinella, G.; Agnello, M.; Agocs, A.G.; Agostinelli, A.; Ahammed, Z.; Ahmad, N.; Masoodi, A.Ahmad; Ahmed, I.; Ahn, S.A.; Ahn, S.U.; Aimo, I.; Ajaz, M.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Molina, R.Alfaro; Alici, A.; Alkin, A.; Almaraz Avina, E.; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Altsybeev, I.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Anson, C.; Anticic, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshauser, H.; Arbor, N.; Arcelli, S.; Arend, A.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I.C.; Arslandok, M.; Asryan, A.; Augustinus, A.; Averbeck, R.; Awes, T.C.; Aysto, J.; Azmi, M.D.; Bach, M.; Badala, A.; Baek, Y.W.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baltasar Dos Santos Pedrosa, F.; Ban, J.; Baral, R.C.; Barbera, R.; Barile, F.; Barnafoldi, G.G.; Barnby, L.S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batyunya, B.; Batzing, P.C.; Baumann, C.; Bearden, I.G.; Beck, H.; Behera, N.K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bergognon, A.A.E.; Bertens, R.A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhati, A.K.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielcik, J.; Bielcikova, J.; Bilandzic, A.; Bjelogrlic, S.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Boccioli, M.; Bottger, S.; Bogdanov, A.; Boggild, H.; Bogolyubsky, M.; Boldizsar, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bossu, F.; Botje, M.; Botta, E.; Braidot, E.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T.A.; Browning, T.A.; Broz, M.; Brun, R.; Bruna, E.; Bruno, G.E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Calvo Villar, E.; Camerini, P.; Canoa Roman, V.; Cara Romeo, G.; Carena, W.; Carena, F.; Carlin Filho, N.; Carminati, F.; Casanova Diaz, A.; Castillo Castellanos, J.; Castillo Hernandez, J.F.; Casula, E.A.R.; Catanescu, V.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J.L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D.D.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C.H.; Christiansen, P.; Chujo, T.; Chung, S.U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M.E.; Contin, G.; Contreras, J.G.; Cormier, T.M.; Corrales Morales, Y.; Cortese, P.; Cortes Maldonado, I.; Cosentino, M.R.; Costa, F.; Cotallo, M.E.; Crescio, E.; Crochet, P.; Alaniz, E.Cruz; Albino, R.Cruz; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Dang, R.; Danu, A.; Das, K.; Das, I.; Das, S.; Das, D.; Dash, S.; Dash, A.; De, S.; de Barros, G.O.V.; De Caro, A.; De Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; Delagrange, H.; Deloff, A.; De Marco, N.; Denes, E.; De Pasquale, S.; Deppman, A.; Erasmo, G.D.; de Rooij, R.; Diaz Corchero, M.A.; Di Bari, D.; Dietel, T.; Di Giglio, C.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Divia, R.; Djuvsland, O.; Dobrin, A.; Dobrowolski, T.; Donigus, B.; Dordic, O.; Dubey, A.K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A.K.; Elia, D.; Emschermann, D.; Engel, H.; Erazmus, B.; Erdal, H.A.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fehlker, D.; Feldkamp, L.; Felea, D.; Feliciello, A.; Fenton-Olsen, B.; Feofilov, G.; Fernandez Tellez, A.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M.A.S.; Filchagin, S.; Finogeev, D.; Fionda, F.M.; Fiore, E.M.; Floratos, E.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Fusco Girard, M.; Gaardhoje, J.J.; Gagliardi, M.; Gago, A.; Gallio, M.; Gangadharan, D.R.; Ganoti, P.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Garishvili, I.; Gerhard, J.; Germain, M.; Geuna, C.; Gheata, M.; Gheata, A.; Ghidini, B.; Ghosh, P.; Gianotti, P.; Giubellino, P.; Gladysz-Dziadus, E.; Glassel, P.; Gomez, R.; Ferreiro, E.G.; Gonzalez-Trueba, L.H.; Gonzalez-Zamora, P.; Gorbunov, S.; Goswami, A.; Gotovac, S.; Grabski, V.; Graczykowski, L.K.; Grajcarek, R.; Grelli, A.; Grigoras, C.; Grigoras, A.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gros, P.; Grosse-Oetringhaus, J.F.; Grossiord, J.Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Guilbaud, M.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Haake, R.; Haaland, O.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Han, B.H.; Hanratty, L.D.; Hansen, A.; Harmanova-Tothova, Z.; Harris, J.W.; Hartig, M.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Hayrapetyan, A.; Heckel, S.T.; Heide, M.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Herrmann, N.; Hess, B.A.; Hetland, K.F.; Hicks, B.; Hippolyte, B.; Hori, Y.; Hristov, P.; Hrivnacova, I.; Huang, M.; Humanic, T.J.; Hwang, D.S.; Ichou, R.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Incani, E.; Innocenti, G.M.; Innocenti, P.G.; Ippolitov, M.; Irfan, M.; Ivan, C.; Ivanov, M.; Ivanov, A.; Ivanov, V.; Ivanytskyi, O.; Jacholkowski, A.; Jacobs, P.M.; Jahnke, C.; Jang, H.J.; Janik, M.A.; Jayarathna, P.H.S.Y.; Jena, S.; Jha, D.M.; Jimenez Bustamante, R.T.; Jones, P.G.; Jung, H.; Jusko, A.; Kaidalov, A.B.; Kalcher, S.; Kalinak, P.; Kalliokoski, T.; Kalweit, A.; Kang, J.H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kazantsev, A.; Kebschull, U.; Keidel, R.; Ketzer, B.; Khan, M.M.; Khan, P.; Khan, S.A.; Khan, K.H.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, M.; Kim, T.; Kim, B.; Kim, S.; Kim, M.; Kim, D.J.; Kim, J.S.; Kim, J.H.; Kim, D.W.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Klay, J.L.; Klein, J.; Klein-Bosing, C.; Kliemant, M.; Kluge, A.; Knichel, M.L.; Knospe, A.G.; Kohler, M.K.; Kollegger, T.; Kolojvari, A.; Kompaniets, M.; Kondratiev, V.; Kondratyeva, N.; Konevskikh, A.; Kovalenko, V.; Kowalski, M.; Kox, S.; Koyithatta Meethaleveedu, G.; Kral, J.; Kralik, I.; Kramer, F.; Kravcakova, A.; Krelina, M.; Kretz, M.; Krivda, M.; Krizek, F.; Krus, M.; Kryshen, E.; Krzewicki, M.; Kucera, V.; Kucheriaev, Y.; Kugathasan, T.; Kuhn, C.; Kuijer, P.G.; Kulakov, I.; Kumar, J.; Kurashvili, P.; Kurepin, A.; Kurepin, A.B.; Kuryakin, A.; Kushpil, V.; Kushpil, S.; Kvaerno, H.; Kweon, M.J.; Kwon, Y.; Ladron de Guevara, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; La Pointe, S.L.; Lara, C.; Lardeux, A.; La Rocca, P.; Lea, R.; Lechman, M.; Lee, S.C.; Lee, G.R.; Legrand, I.; Lehnert, J.; Lemmon, R.C.; Lenhardt, M.; Lenti, V.; Leon, H.; Leoncino, M.; Leon Monzon, I.; Levai, P.; Li, S.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M.A.; Ljunggren, H.M.; Lodato, D.F.; Loenne, P.I.; Loggins, V.R.; Loginov, V.; Lohner, D.; Loizides, C.; Loo, K.K.; Lopez, X.; Lopez Torres, E.; Lovhoiden, G.; Lu, X.G.; Luettig, P.; Lunardon, M.; Luo, J.; Luparello, G.; Luzzi, C.; Ma, R.; Ma, K.; Madagodahettige-Don, D.M.; Maevskaya, A.; Mager, M.; Mahapatra, D.P.; Maire, A.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manceau, L.; Mangotra, L.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Marchisone, M.; Mares, J.; Margagliotti, G.V.; Margotti, A.; Marin, A.; Markert, C.; Marquard, M.; Martashvili, I.; Martin, N.A.; Martinengo, P.; Martinez, M.I.; Martinez Garcia, G.; Martynov, Y.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Massacrier, L.; Mastroserio, A.; Matyja, A.; Mayer, C.; Mazer, J.; Mazumder, R.; Mazzoni, M.A.; Meddi, F.; Menchaca-Rocha, A.; Mercado Perez, J.; Meres, M.; Miake, Y.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A.N.; Miskowiec, D.; Mitu, C.; Mizuno, S.; Mlynarz, J.; Mohanty, B.; Molnar, L.; Montano Zetina, L.; Monteno, M.; Montes, E.; Moon, T.; Morando, M.; Moreira De Godoy, D.A.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Muhuri, S.; Mukherjee, M.; Muller, H.; Munhoz, M.G.; Murray, S.; Musa, L.; Musinsky, J.; Nandi, B.K.; Nania, R.; Nappi, E.; Nattrass, C.; Nayak, T.K.; Nazarenko, S.; Nedosekin, A.; Nicassio, M.; Niculescu, M.; Nielsen, B.S.; Niida, T.; Nikolaev, S.; Nikolic, V.; Nikulin, S.; Nikulin, V.; Nilsen, B.S.; Nilsson, M.S.; Noferini, F.; Nomokonov, P.; Nooren, G.; Nyanin, A.; Nyatha, A.; Nygaard, C.; Nystrand, J.; Ochirov, A.; Oeschler, H.; Oh, S.; Oh, S.K.; Oleniacz, J.; Oliveira Da Silva, A.C.; Onderwaater, J.; Oppedisano, C.; Ortiz Velasquez, A.; Oskarsson, A.; Ostrowski, P.; Otwinowski, J.; Oyama, K.; Ozawa, K.; Pachmayer, Y.; Pachr, M.; Padilla, F.; Pagano, P.; Paic, G.; Painke, F.; Pajares, C.; Pal, S.K.; Palaha, A.; Palmeri, A.; Papikyan, V.; Pappalardo, G.S.; Park, W.J.; Passfeld, A.; Patalakha, D.I.; Paticchio, V.; Paul, B.; Pavlinov, A.; Pawlak, T.; Peitzmann, T.; Pereira Da Costa, H.; Pereira De Oliveira Filho, E.; Peresunko, D.; Perez Lara, C.E.; Perrino, D.; Peryt, W.; Pesci, A.; Pestov, Y.; Petracek, V.; Petran, M.; Petris, M.; Petrov, P.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Pitz, N.; Piyarathna, D.B.; Planinic, M.; Ploskon, M.; Pluta, J.; Pocheptsov, T.; Pochybova, S.; Podesta-Lerma, P.L.M.; Poghosyan, M.G.; Polak, K.; Polichtchouk, B.; Poljak, N.; Pop, A.; Porteboeuf-Houssais, S.; Pospisil, V.; Potukuchi, B.; Prasad, S.K.; Preghenella, R.; Prino, F.; Pruneau, C.A.; Pshenichnov, I.; Puddu, G.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Rademakers, A.; Raiha, T.S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Raniwala, S.; Raniwala, R.; Rasanen, S.S.; Rascanu, B.T.; Rathee, D.; Rauch, W.; Rauf, A.W.; Razazi, V.; Read, K.F.; Real, J.S.; Redlich, K.; Reed, R.J.; Rehman, A.; Reichelt, P.; Reicher, M.; Reidt, F.; Renfordt, R.; Reolon, A.R.; Reshetin, A.; Rettig, F.; Revol, J.P.; Reygers, K.; Riccati, L.; Ricci, R.A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Rivetti, A.; Rodriguez Cahuantzi, M.; Rodriguez Manso, A.; Roed, K.; Rogochaya, E.; Rohr, D.; Rohrich, D.; Romita, R.; Ronchetti, F.; Rosnet, P.; Rossegger, S.; Rossi, A.; Roy, P.; Roy, C.; Rubio Montero, A.J.; Rui, R.; Russo, R.; Ryabinkin, E.; Rybicki, A.; Sadovsky, S.; Safarik, K.; Sahoo, R.; Sahu, P.K.; Saini, J.; Sakaguchi, H.; Sakai, S.; Sakata, D.; Salgado, C.A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sanchez Castro, X.; Sandor, L.; Sandoval, A.; Sano, M.; Santagati, G.; Santoro, R.; Sarkamo, J.; Sarkar, D.; Scapparone, E.; Scarlassara, F.; Scharenberg, R.P.; Schiaua, C.; Schicker, R.; Schmidt, H.R.; Schmidt, C.; Schuchmann, S.; Schukraft, J.; Schuster, T.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Scott, P.A.; Segato, G.; Selyuzhenkov, I.; Senyukov, S.; Seo, J.; Serci, S.; Serradilla, E.; Sevcenco, A.; Shabetai, A.; Shabratova, G.; Shahoyan, R.; Sharma, S.; Sharma, N.; Rohni, S.; Shigaki, K.; Shtejer, K.; Sibiriak, Y.; Sicking, E.; Siddhanta, S.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, T.; Sinha, B.C.; Sitar, B.; Sitta, M.; Skaali, T.B.; Skjerdal, K.; Smakal, R.; Smirnov, N.; Snellings, R.J.M.; Sogaard, C.; Soltz, R.; Song, M.; Song, J.; Soos, C.; Soramel, F.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Srivastava, B.K.; Stachel, J.; Stan, I.; Stefanek, G.; Steinpreis, M.; Stenlund, E.; Steyn, G.; Stiller, J.H.; Stocco, D.; Stolpovskiy, M.; Strmen, P.; Suaide, A.A.P.; Subieta Vasquez, M.A.; Sugitate, T.; Suire, C.; Suleymanov, M.; Sultanov, R.; Sumbera, M.; Susa, T.; Symons, T.J.M.; Szanto de Toledo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Takahashi, J.; Tangaro, M.A.; J.Tapia Takaki, D.; Peloni, A.Tarantola; Tarazona Martinez, A.; Tauro, A.; Tejeda Munoz, G.; Telesca, A.; Minasyan, A.Ter; Terrevoli, C.; Thader, J.; Thomas, D.; Tieulent, R.; Timmins, A.R.; Tlusty, D.; Toia, A.; Torii, H.; Toscano, L.; Trubnikov, V.; Truesdale, D.; Trzaska, W.H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T.S.; Ulery, J.; Ullaland, K.; Ulrich, J.; Uras, A.; Urciuoli, G.M.; Usai, G.L.; Vajzer, M.; Vala, M.; Valencia Palomo, L.; Vallero, S.; Vande Vyvre, P.; Van Hoorne, J.W.; van Leeuwen, M.; Vannucci, L.; Vargas, A.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vechernin, V.; Veldhoen, M.; Venaruzzo, M.; Vercellin, E.; Vergara, S.; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, Y.; Vinogradov, L.; Vinogradov, A.; Virgili, T.; Viyogi, Y.P.; Vodopyanov, A.; Volkl, M.A.; Voloshin, S.; Voloshin, K.; Volpe, G.; von Haller, B.; Vorobyev, I.; Vranic, D.; Vrlakova, J.; Vulpescu, B.; Vyushin, A.; Wagner, V.; Wagner, B.; Wan, R.; Wang, Y.; Wang, Y.; Wang, M.; Watanabe, K.; Weber, M.; Wessels, J.P.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilde, M.; Wilk, G.; Williams, M.C.S.; Windelband, B.; Winn, M.; Yaldo, C.G.; Yamaguchi, Y.; Yang, S.; Yang, P.; Yang, H.; Yasnopolskiy, S.; Yi, J.; Yin, Z.; Yoo, I.K.; Yoon, J.; Yuan, X.; Yushmanov, I.; Zaccolo, V.; Zach, C.; Zampolli, C.; Zaporozhets, S.; Zarochentsev, A.; Zavada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zelnicek, P.; Zgura, I.S.; Zhalov, M.; Zhang, Y.; Zhang, H.; Zhang, X.; Zhou, D.; Zhou, Y.; Zhou, F.; Zhu, H.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zinovjev, G.; Zoccarato, Y.; Zynovyev, M.; Zyzak, M.

2013-01-01

ALICE is an LHC experiment devoted to the study of strongly interacting matter in proton--proton, proton--nucleus and nucleus--nucleus collisions at ultra-relativistic energies. The ALICE VZERO system, made of two scintillator arrays at asymmetric positions, one on each side of the interaction point, plays a central role in ALICE. In addition to its core function as a trigger, the VZERO system is used to monitor LHC beam conditions, to reject beam-induced backgrounds and to measure basic physics quantities such as luminosity, particle multiplicity, centrality and event plane direction in nucleus--nucleus collisions. After describing the VZERO system, this publication presents its performance over more than four years of operation at the LHC.

The ALICE Inner Tracking System Upgrade

CERN Document Server

Siddhanta, Sabyasachi

2015-01-01

The long term plan of ALICE (A Large Ion Collider Experiment) at the CERN Large Hadron Collider (LHC) is a detailed investigation and characterisation of the Quark-Gluon Plasma (QGP). ALICE has devised a comprehensive upgrade strategy to enhance its physics capabilities and to exploit the LHC running conditions after the second long shutdown of the LHC scheduled in 2019-20. The upgraded ALICE will focus on high precision measurements of rare probes over a wide range of momenta, which will significantly improve the performance with respect to the present experimental set up. The upgrade strategy is based on the fact that after LS2 LHC will progressively increase its luminosity with Pb beams eventually reaching an interaction rate of about 50 kHz. To exploit the new LHC capabilities, several existing detectors will undergo a substantial upgrade and new detectors will be added. Within this upgrade strategy, the Inner Tracking System (ITS) upgrade forms an important cornerstone, providing precise measurements for...

L'aventure du grand collisionneur LHC du big bang au boson de Higgs

CERN Document Server

Denegri, Daniel; Hoecker, Andreas; Roos, Lydia; Rubbia, Carlo

2014-01-01

Qu'est-ce que la physique des particules élémentaires, le LHC, et le boson de Higgs ? Ce livre présente de manière simple le monde des quarks, des leptons et de leurs interactions, gouvernées par des symétries fondamentales de la nature, ainsi que le lien entre ce monde de l'infiniment petit et celui de l'infiniment grand. Cette conjonction entre la physique des particules élémentaires et l'évolution de la matière dans les premiers instants de l Univers qui ont suivi le Big-Bang est un des plus beaux acquis de la science de ces cinquante dernières années. Après une description du cadre théorique, le modèle standard, et de son élaboration durant la deuxième moitié du XXe siècle, l'accent est mis sur ses grands succès expérimentaux, mais aussi sur ses faiblesses ou insuffisances telles que nous les percevons aujourd'hui. La passionnante histoire du grand collisionneur de hadrons du CERN, le LHC, le plus grand projet purement scientifique jamais réalisé, est présentée à la fois sous ses...

ALICE brochure (French version)

CERN Multimedia

Lefevre, C

2012-01-01

ALICE is one of the four big experiments for the LHC, the most powerful particle accelerator in the world, which started up in 2008. ALICE will study the quark-gluon plasma, a state of matter that probably existed in the first moments of the universe.

ALICE brochure (French version)

CERN Multimedia

Lefevre, Christiane

2011-01-01

ALICE is one of the four big experiments for the LHC, the most powerful particle accelerator in the world, which started up in 2008. ALICE will study the quark-gluon plasma, a state of matter that probably existed in the first moments of the universe.

ALICE brochure (Danish version)

CERN Multimedia

Lefevre, C

2010-01-01

ALICE is one of the four big experiments for the LHC, the most powerful particle accelerator in the world, which started up in 2008. ALICE will study the quark-gluon plasma, a state of matter that probably existed in the first moments of the universe.

ALICE brochure (English version)

CERN Multimedia

Lefevre, C

2012-01-01

ALICE is one of the four big experiments for the LHC, the most powerful particle accelerator in the world, which started up in 2008. ALICE will study the quark-gluon plasma, a state of matter that probably existed in the first moments of the universe.

ALICE brochure (English version)

CERN Multimedia

Lefevre, C

2010-01-01

ALICE is one of the four big experiments for the LHC, the most powerful particle accelerator in the world, which started up in 2008. ALICE will study the quark-gluon plasma, a state of matter that probably existed in the first moments of the universe.

ALICE brochure (Italian version)

CERN Multimedia

Lefevre, C

2010-01-01

ALICE is one of the four big experiments for the LHC, the most powerful particle accelerator in the world, which started up in 2008. ALICE will study the quark-gluon plasma, a state of matter that probably existed in the first moments of the universe.

ALICE brochure (German version)

CERN Multimedia

Lefevre, C

2012-01-01

ALICE is one of the four big experiments for the LHC, the most powerful particle accelerator in the world, which started up in 2008. ALICE will study the quark-gluon plasma, a state of matter that probably existed in the first moments of the universe.

ALICE brochure (English version)

CERN Multimedia

Marcastel, Fabienne

2014-01-01

ALICE is one of the four big experiments for the LHC, the most powerful particle accelerator in the world, which started up in 2008. ALICE studies the quark-gluon plasma, a state of matter that probably existed in the first moments of the universe.

Strangeness production in Pb-Pb collisions at LHC energies with ALICE

Directory of Open Access Journals (Sweden)

Šefčík Michal

2018-01-01

Full Text Available The results on the production of strange and multi-strange hadrons (K0S, Λ, Ξ and Ω measured with ALICE in Pb-Pb collisions at the top LHC energy of SNN = 5.02 TeV are reported. Thanks to its excellent tracking and particle identification capabilities, ALICE is able to measure weakly decaying particles through the topological reconstruction of the identified hadronic decay products. Results are presented as a function of centrality and include transverse momentum spectra measured at central rapidity, pT-dependent Λ/K0S ratios and integrated yields. A systematic study of strangeness production is of fundamental importance for determining the thermal properties of the system created in ultrarelativistic heavy ion collisions. In order to study strangeness enhancement, the yields of studied particles are normalised to the corresponding measurement of pion production in the various centrality classes. The results are compared to measurements performed at lower energies, as well as to different systems and to predictions from statistical hadronization models.

Study of multi-strange baryon production with ALICE at the LHC energies

CERN Document Server

Colella, Domenico

This thesis reports on the measurement of the multi-strange baryon production in lead-lead (Pb-Pb) and proton-proton (pp) collisions at the centre-of-mass energy of 2.76 TeV per nucleon pair using the ALICE detector. The cascade identification technique, based on the topological reconstruction of weak decays into charged particles only is very effective thanks to the excellent particle identification and tracking capability of the ALICE central barrel detectors. The comparison of the transverse momentum (p$_T$) spectra for the $\\Xi^{-}$ and $\\Omega^{-}$ (and corresponding anti-particle) in Pb-Pb collisions with expectations from recent hydro models confirms the importance of an hydrodynamical approach in the description of the created system evolution. In addition, recent PYTHIA tunes results to underestimate the yields for the cascades in pp collisions. The measurements of the strangeness enhancement, one of the predicted signatures of the QGP formation, for the $\\Xi$ and $\\Omega$ at the LHC energy have been...

Gamma-hadrons and hadrons-hadrons correlation measurements in p-p collisions at 7 TeV to study jet fragmentation with ALICE at LHC

International Nuclear Information System (INIS)

Mao, Y.

2011-06-01

The ALICE experiment, which uses the ultra-relativistic heavy-ions collisions produced by the LHC at CERN, is dedicated to the study of a new state of nuclear matter, which could be composed of a Quark-Gluon Plasma (QGP). Among the probes sharing information on the medium properties, those relative to the production of high transverse momentum jets are very interesting. The analysis presented in this thesis is focused on photon-jet events, which contain one photon of high transverse momentum and one jet emitted in the opposite direction. The jet comes from the fragmentation of the initial parton, after passing through the medium. The thesis includes a simulation study of the relevant observables for the photon-hadron correlation measurement and an analysis of first data from LHC in proton-proton collisions. Preliminary results on the transverse momentum of incident partons and on the correlation function have been obtained. The layout of the thesis is as follows. In chapter 2 the author reviews the scientific background of heavy ion physics, where the experimental observables exploited so far in different experiments are listed. Jets and 2-particle correlations are described in chapter 3. The experimental apparatus of the ALICE experiment at LHC is introduced in chapter 4. In chapter 5 the approach for a feasibility study with ALICE detectors from Monte-Carlo data is fully validated, then the 2 particle correlations with γ/π 0 triggers measured by ALICE within the data collected in 2010 at the first year LHC run is presented in chapter 6. (author)

The ALICE Central Trigger Processor (CTP) upgrade

International Nuclear Information System (INIS)

Krivda, M.; Alexandre, D.; Barnby, L.S.; Evans, D.; Jones, P.G.; Jusko, A.; Lietava, R.; Baillie, O. Villalobos; Pospíšil, J.

2016-01-01

The ALICE Central Trigger Processor (CTP) at the CERN LHC has been upgraded for LHC Run 2, to improve the Transition Radiation Detector (TRD) data-taking efficiency and to improve the physics performance of ALICE. There is a new additional CTP interaction record sent using a new second Detector Data Link (DDL), a 2 GB DDR3 memory and an extension of functionality for classes. The CTP switch has been incorporated directly onto the new LM0 board. A design proposal for an ALICE CTP upgrade for LHC Run 3 is also presented. Part of the development is a low latency high bandwidth interface whose purpose is to minimize an overall trigger latency

γ-jets physics with the EMCal calorimeter in ALICE experiment at LHC

International Nuclear Information System (INIS)

Bourdaud, G.

2008-11-01

Heavy ion collisions at LHC will produce a new state of matter: the quark-gluon plasma (QGP). Photons are not sensible to the strong interaction which dominates the nuclear medium, and hence are a valuable tool to explore QGP. Gamma-jets are rare hard processes: a photon and a parton are emitted back-to-back. The parton hadronises and produces a jet of particles. These jets are quenched due to the strong interaction of the parton with the QGP. This quenching, or more precisely the re-distribution of the energy in the jet, can be measured by the modification of the distribution of the particle energy in the jet, comparing p-p and Pb-Pb collisions (fragmentation functions or hump-backed plateau distributions). For this purpose, jet energy is needed, and can be provided precisely by gamma-jet measurement. Our goal is to use EMCal to detect a photon correlated with a jet reconstructed in ALICE tracking system. Then, the jet energy distribution are compared for p-p an Pb-Pb collisions. Gamma-jet physics is first addressed, the particle identification with EMCal is introduced to isolate the direct photon, i.e. a photon and a jet emitted back-to-back. Methods of jet identification and reconstruction are developed to determine hump-backed plateau distributions. Finally, these methods are tested to evaluate ALICE and particularly EMCal capabilities for gamma-jet study at LHC and to quantify the sensibility of this probe to explore the QGP. (author)

Virtual reality visualization algorithms for the ALICE high energy physics experiment on the LHC at CERN

Science.gov (United States)

Myrcha, Julian; Trzciński, Tomasz; Rokita, Przemysław

2017-08-01

Analyzing massive amounts of data gathered during many high energy physics experiments, including but not limited to the LHC ALICE detector experiment, requires efficient and intuitive methods of visualisation. One of the possible approaches to that problem is stereoscopic 3D data visualisation. In this paper, we propose several methods that provide high quality data visualisation and we explain how those methods can be applied in virtual reality headsets. The outcome of this work is easily applicable to many real-life applications needed in high energy physics and can be seen as a first step towards using fully immersive virtual reality technologies within the frames of the ALICE experiment.

ALICE brochure (Spanish version)

CERN Multimedia

Lefevre, C

2008-01-01

ALICE is one of the four big experiments for the LHC, the most powerful particle accelerator in the world, which will start up in 2008. ALICE will study the quark-gluon plasma, a state of matter that probably existed in the first moments of the universe.

Central Diffraction in ALICE

CERN Document Server

Schicker, R

2012-01-01

The ALICE experiment at the Large Hadron Collider (LHC) at CERN consists of a central barrel, a muon spectrometer and of additional detectors for trigger and event classification purposes. The low transverse momentum threshold of the central barrel gives ALICE a unique opportunity to study the low mass sector of central production at the LHC. I will report on first analysis results of meson production in double gap events in minimum-bias proton-proton collisions at sqrt{s} = 7 TeV, and will describe a dedicated double gap trigger for future data taking.

Une force venant du futur chercherait à saboter l'expérience du LHC...

CERN Multimedia

Scappaticci, Bruno

2009-01-01

"A quelques jours de la reprise de l'expérience du LHC, on ne parle plus de la menace d'un trou noir, mais deux physicines souteinnent aujourd'hui une tout autres hypothèse: la nature, depuis le futur, va continuer de contrarier les travaux du Cern, afin d'éviter à l'Homme de mettre le doigt là où il ne faut pas..." (1.5 pages)

Le détecteur VZERO, la physique muons présente et la préparation de son futur dans l'expérience ALICE au LHC

CERN Document Server

Tieulent, Raphaël

La physique des ions lourds a pour objectif ultime d'étendre le domaine d'application du Modèle Standard de la physique des particules à des systèmes de taille finie, complexes et dynamiques. En particulier, elle vise à comprendre comment apparaissent, à partir des lois microscopiques de la physique des particules élémentaires, des phénomènes collectifs et des propriétés macroscopiques mettant en jeu un grand nombre de degrés de liberté. La réalisation de ce programme scientifique passe par une caractérisation du plasma de quarks et de gluons (QGP), l'état déconfiné de la matière nucléaire qui peut être formé à l'aide de collisions d'ions lourds accélérés à des énergies ultra relativistes. L'expérience ALICE exploite les collisions Pb-Pb, proton-Pb et proton-proton du LHC pour mesurer les propriétés fondamentales du QGP comme, par exemple, la température critique du déconfinement ou les coefficients de transport de la matière déconfinée. L'état QGP de la matière aurait �...

Light vector meson production at the LHC with the ALICE detector

CERN Document Server

Incani, Elisa

2013-01-01

The measurement of light vector meson production (\\rho, \\omega, \\phi) in pp collisions provides insight into soft Quantum Chromodynamics (QCD) processes in the LHC energy range. Calculations in this regime are based on QCD inspired phenomenological models that must be tuned to the data. Moreover, light vector meson production provides a reference for high-energy heavy-ion collisions. A measurement of the \\phi and \\omega differential cross sections as performed by the ALICE experiment in pp collisions at 7 TeV and of the \\phi cross section in pp collisions at 2.76 TeV through their decay to muon pairs and in the rapidity interval 2.5 < y < 4.

ALICE EMCal Physics Performance Report

CERN Document Server

Abeysekara, U.; Aronsson, T.; Awes, T.; Badala, A.; Baumgart, S.; Bellwied, R.; Benhabib, L.; Bernard, C.; Bianchi, N.; Blanco, F.; Bortoli, Y.; Boswell, B.; Bourdaud, G.; Bourrion, O.; Boyer, B.; Brown, C.R.; Bruna, E.; Butterworth, J.; Caines, H.; Calvo Diaz Aldagalan, D.; Capitani, G.P.; Carcagno, Y.; Casanova Diaz, A.; Cherney, M.; Conesa Balbastre, G.; Cormier, T.M.; Cosentino, M.R.; Cunqueiro Mendez, L.; Delagrange, H.; Del Franco, M.; Dialinas, M.; Di Nezza, P.; Donoghue, A.; Elnimr, M.; Enokizono, A.; Estienne, M.; Faivre, J.; Fantoni, A.; Fenton-Olsen, B.; Fichera, F.; Figueredo, M.A.S.; Foglio, B.; Fresneau, S.; Fujita, J.; Furget, C.; Gadrat, S.; Garishvili, I.; Germain, M.; Giudice, N.; Gorbunov, Y.N.; Grimaldi, A.; Guernane, R.; Hadjidakis, C.; Hamblen, J.; Harris, J.W.; Hasch, D.; Heinz, M.; Hicks, B.; Hille, P.T.; Hornback, D.; Ichou, R.; Jacobs, P.; Jangal, S.; Jayananda, K.; Kalliokoski, T.; Kharlov, Y.; Klay, J.L.; Knospe, A.G.; Kox, S.; Kral, J.; Laloux, P.; LaPointe, S.; La Rocca, P.; Lewis, S.; Li, Q.; Librizzi, F.; Ma, R.; Madagodahettige Don, D.; Mao, Y.; Markert, C.; Martashvili, I.; Mayes, B.; Milletto, T.; Mlynarz, J.; Muccifora, V.; Mueller, H.; Munhoz, M.G.; Muraz, J.F.; Newby, J.; Nattrass, C.; Noto, F.; Novitzky, N.; Nilsen, B.S.; Odyniec, G.; Orlandi, A.; Palmeri, A.; Pappalardo, G.S.; Pavlinov, A.; Pesci, W.; Petrov, V.; Petta, C.; Pichot, P.; Pinsky, L.; Ploskon, M.; Pompei, F.; Pulvirenti, A.; Putschke, J.; Pruneau, C.A.; Rak, J.; Rasson, J.; Read, K.F.; Real, J.S.; Reolon, A.R.; Riggi, F.; Riso, J.; Ronchetti, F.; Roy, C.; Roy, D.; Salemi, M.; Salur, S.; Sano, M.; Scharenberg, R.P.; Sharma, M.; Silvermyr, D.; Smirnov, N.; Soltz, R.; Sorensen, S.; Sparti, V.; Srivastava, B.K.; Stutzmann, J.S.; Symons, J.; Tarazona Martinez, A.; Tarini, L.; Thomen, R.; Timmins, A.; Turvey, A.; van Leeuwen, M.; Vieira, R.; Viticchie, A.; Voloshin, S.; Vernet, R.; Wang, D.; Wang, Y.; Ward, R.M.

2010-01-01

The ALICE detector at the LHC (A Large Ion Collider Experiment) will carry out comprehensive measurements of high energy nucleus-nucleus collisions, in order to study QCD matter under extreme conditions and the phase transtion between confined matter and the Quark-Gluon Plasma (QGP). This report presents our current state of understanding of the Physics Performance of the large acceptance Electromagnetic Calorimeter (EMCal) in the ALICE central detector. The EMCal enhances ALICE’s capabilities for jet measurements. The EMCal enables triggering and full reconstruction of high energy jets in ALICE, and augments existing ALICE capabilities to measure high momentum photons and electrons. Combined with ALICE’s excellent capabilities to track and identify particles from very low pT to high pT , the EMCal enables a comprehensive study of jet interactions in the medium produced in heavy ion collisions at the LHC.

The Time-Of-Flight detector of ALICE at LHC: construction, test and commissioning with cosmic rays

CERN Document Server

Preghenella, Roberto

2009-01-01

After several years of research and development the Time-Of-Flight detector of ALICE (A Large Ion Collider Experiment) has been constructed and is presently fully installed and operative in the experimental area located at the interaction point n.2 of the LHC (Large Hadron Collider) at CERN. Particle identification in ALICE is essential, as many observables are either mass or flavour dependent, therefore many different techniques are used to cover the largest possible momentum range. As said, the TOF (Time- Of-Flight) detector, of which a comprehensive review is given in Chapter 2, is dedicated to hadron identification at medium momenta. The detector exploits the novel technology based on the Multigap Resistive Plate Chamber (MRPC) which guarantees the excellent performance required for a very large time-of-flight array. The construction of the ALICE TOF detector has required the assembly of a large number of MRPC detectors which has been successfully carried out thanks to a careful mass production controlled...

Inclusive charged hadrons production in pp collisions with the ALICE-HMPID detector at the LHC

CERN Document Server

Barile, Francesco

The goal of this thesis is the study of the particles identification provided by a small acceptance detector: the High Momentum Particle IDentification detector. Installed during September 2006 and located at about 5 m from the primary vertex, it can contribute to several ALICE physics items using the Cherenkov radiation. This thesis is made of 5 chapters. An overview of the Heavy Ion collisions, the Quark Gluon Plasma, and the main points of the ALICE physics program are described in the first chapter. Some recent results on particles production and hadron ratios are also presented. Chapter 2 is dedicated to the LHC machine, to the ALICE apparatus and to the High Momentum Particle Detector. The layout, the principle of operation and some recent performance results of this RICH detector will be described. Chapter 3 is dedicated to the evaluation of the HMPID PID efficiency. This study exploit the unique possibility to extract the efficiency directly from data using the V$^{0}$ ’s decay. Also, it provides a ...

Strangeness production in p-Pb and Pb-Pb collisions with ALICE at LHC

CERN Document Server

Colella, Domenico

2017-01-01

The main goal of the ALICE experiment is to study the properties of the hot and dense medium created in ultra-relativistic heavy-ion collisions. The measurement of the (multi-)strange particles is an important tool to understand particle production mechanisms and the dynamics of the quark-gluon plasma (QGP). We report on the production of K$^{0}_{S}$, $\\Lambda$($\\overline{\\Lambda}$), $\\Xi^{-}$($\\overline{\\Xi}^{+}$) and $\\Omega^{-}$($\\overline{\\Omega}^{+}$) in proton-lead (p-Pb) collisions at $\\sqrt{s_{\\rm NN}}$ = 5.02 TeV and lead-lead (Pb-Pb) collisions at $\\sqrt{s_{\\rm NN}}$ = 2.76 TeV measured by ALICE at the LHC. The comparison of the hyperon-to-pion ratios in the two colliding systems may provide insight into strangeness production mechanisms, while the comparison of the nuclear modification factors helps to determine the contribution of initial state effects and the suppression from strange quark energy loss in nuclear matter.

Detección de muones atmosféricos en el experimento ALICE-LHC

CERN Document Server

Rodríguez Cahuantzi, Mario; Cuautle Flores, Eleazar

The calibration, alignment and commissioning of most of the ALICE (A Large Ion Collider Experiment at the CERN LHC) detectors have required a large amount of cosmic events during 2010, 2011, 2012 and 2013. Two main triggers were implemented to collect the atmospheric muons crossing the experiment. The first trigger, called “ACORDE trigger”, is generated by 60 scintillators located on the top three sides of the L3 magnet surrounding the central detectors, and selects single muons and bundles of atmospheric muons.
 The second trigger, called “TOF trigger”, is obtained by requiring a simultaneous signal on some pads of the Time of Flight (TOF) detector. The analysis of multi-muon events triggered by ACORDE and TOF and reconstructed using the ALICE Time Projection Chamber (TPC) is presented. A special emphasis in the study of muon bundles, with a particular attention on high muon density events is discussed. In particular the muon multiplicity distribution, that gives information on the primary cosmic ...

The VZERO detector, the present muon physics and its future with the ALICE experiment at the LHC

International Nuclear Information System (INIS)

Tieulent, R.

2013-01-01

The ALICE experiment studies the Pb-Pb or proton-Pb or proton-proton collisions at the LHC to assess the fundamental features of the quark-gluon plasma (QGP). A brief introduction to QGP and physics of heavy ions is given in the first chapter. A detector named VZERO composed of 2 hodoscopes made up of organic scintillators located on either side of the collision point has been designed. The main purpose of VZERO is to provide the triggering signal for the ALICE experiment and to provide a second triggering signal sensitive to the energy density released in the collision. VZERO is described in the second chapter. QGP can be studied through various observables. The muons is one of the most promising as the production of muons appears at any stage of the QGP evolution and the muons can be detected easily as they do interact weakly with the plasma. The muon spectrometer and its alignment system are described in the chapter 3. The vector mesons of low mass like for instance the ρ meson are sensitive to the medium effect and to the restoration of the Chiral symmetry. The Chiral symmetry is spontaneously broken in QCD at normal energy and density ranges but the restoration of the Chiral symmetry is predicted by QCD calculus at the temperatures reached by LHC. The study of low mass vector mesons is described in the fourth chapter. A new step forward for the ALICE experiment is being prepared in order to benefit fully with the increase of both luminosity and energy of the LHC in 2018. A new detector based on silicon pixels: the Muon Forward Tracker (MFT) is being designed. The experimental data of the muon spectrometer combined with those of the MFT will open a new road for muon physics. The last chapter is dedicated to the MFT

Système de PLC pour la supervision de la distribution basse tension des expériences ALICE et LHCb

CERN Document Server

Burdet, G

2004-01-01

Le groupe TS/EL étudie et réalise la distribution électrique basse tension pour alimenter les racks contenant l'électronique associée aux détecteurs dans les zones expérimentales du LHC. La distribution basse tension utilisera des tableaux récupérés des expériences du LEP pour ALICE et LHCb et un système basé sur des gaines CANALIS pour ATLAS et CMS. L'ensemble de la distribution électrique basse tension sera surveillée et contrôlée par l'intermédiaire de systèmes à base de PLC. Ce papier décrit l'infrastructure de supervision proposée pour ALICE et LHCb et son intégration au CERN Electrical Network Supervisor (ENS) et au Detector Control System (DCS).

Feasibility study for the detection of D0 → K-π+ decays in Pb-Pb collisions at LHC with ALICE

International Nuclear Information System (INIS)

Carrer, N; Dainese, A; Turrisi, R

2003-01-01

The ALICE experiment at the CERN LHC collider is devoted to the study of heavy-ion collisions at a centre of mass energy of 5.5 TeV per nucleon. The study of open charm production in nucleus-nucleus collisions at the LHC allows investigation of the mechanisms of heavy quark production and energy loss in the hot and dense medium formed in the early stage of the collision. In addition, the open charm production cross section is the natural normalization for the study of J/ψ production. The reconstruction of exclusive hadronic decays of charm particles is the only way to obtain a direct measurement of their transverse momentum distribution. We present the results of a feasibility study for the detection of D 0 → K - π + decays in Pb-Pb collisions with ALICE. (research notes from collaborations)

Heavy flavour in ALICE

CERN Document Server

Pillot, Philippe

2008-01-01

Open heavy flavours and heavy quarkonium states are expected to provide essential informa- tion on the properties of the strongly interacting system fo rmed in the early stages of heavy-ion collisions at very high energy density. Such probes are espe cially promising at LHC energies where heavy quarks (both c and b) are copiously produced. The ALICE detector shall measure the production of open heavy flavours and heavy quarkonium st ates in both proton-proton and heavy-ion collisions at the LHC. The expected performances of ALICE for heavy flavour physics is discussed based on the results of simulation studies on a s election of benchmark channels

ALICE through the phase transition

CERN Document Server

CERN. Geneva

2000-01-01

While proton-proton collisions will be the principal diet of CERN's LHC machine, heavy-ion collisions will also be on the menu. The ALICE experiment will be ready and waiting. Another of ALICE's TDRs concerns the experiment's inner tracking system (ITS). This is the innermost layer of the detector, responsible for tracking emerging particles where their density will be at its highest. ALICE physicists have been working with colleagues from fellow LHC experiment LHCb to develop silicon pixel chips for the inner two layers of the ITS.The result is a chip with 50 x 425 mu m cells; a prototype detector based on this chip is being tested this year.The ITS has six layers, all using silicon technology, and about 10 million digital and 2 million analogue readout channels to digest the huge number of particles produced in LHC lead-ion collisions. The collaboration has opted for a hybrid ITS structure combining sensors, electronics and mechanical support. Beam tests so far have indicated that the ITS should achieve pos...

Correlations in small systems with ALICE

CERN Document Server

Lakomov, Igor

2016-01-01

ALICE is dedicated to the study of the strongly interacting matter, the so-called Quark-Gluon Plasma (QGP), formed in heavy-ion collisions at the LHC. In addition, ALICE also actively participated in the pp and p–Pb collision programs. In particular, the measurements of the twoparticle azimuthal correlations in pp collisions at √ s = 7 TeV and in p–Pb collisions at √ sNN = 5.02 TeV have been performed by the ALICE Collaboration during Run I of the LHC. Similar long-range correlations in p–Pb and Pb–Pb collisions have been observed on the near and away side — also known as the double ridge. Further investigations showed the importance of the Multi-Parton Interactions (MPI) in high-multiplicity collisions in small systems. In this work the ALICE results on the correlations in small systems are presented including MPI measurements in pp collisions.

ALICE HMPID RICH

CERN Multimedia

2003-01-01

Particle identification plays a key role in the complete understanding of heavy-ion collisions in ALICE at the LHC. . The CsI Photodetector . The Radiator . The Front-End Electronics . Detector performance

Alignment of the ALICE Inner Tracking System with cosmic-ray tracks

NARCIS (Netherlands)

Aamodt, K.; Chojnacki, M.; Christakoglou, P.; de Haas, A.P.; de Rooij, R. S.; Grelli, A.|info:eu-repo/dai/nl/326052577; Ivan, C.G.|info:eu-repo/dai/nl/304847747; Kamermans, R.|info:eu-repo/dai/nl/073698733; Mischke, A.|info:eu-repo/dai/nl/325781435; Nooren, G.J.L.|info:eu-repo/dai/nl/07051349X; Oskamp, C.J.; Peitzmann, T.|info:eu-repo/dai/nl/304833959; Simili, E.; van den Brink, A.; van Leeuwen, M.|info:eu-repo/dai/nl/250599171; Verweij, M.|info:eu-repo/dai/nl/330542133

2010-01-01

ALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with

Multiplicity dependence of two-particle correlation in $\\sqrt{s}$ = 7 TeV pp collisions at LHC-ALICE experiment

CERN Document Server

Bhom, Jihyun; Esumi, Shinlchi

Early stage of universe or inside of neutron stars are supposed to be Quark Gluon Plasma (QGP) state. The QGP is a state of matter in quantum chromodynamics (QCD), which exists at extremely high temperature and/or high density. In high energy nuclear collisions experiment, hot dense matter or QGP has been studied, the collective flow of the system has been one of key issues to understand the state of matter. Large Hadron Collider (LHC) has served pp collisions at a nucleon–nucleon center-of-mass energy of 7 TeV in 2010, where the maximum charged particle multiplicity has been measured as large as 100$\\sim$200 charged particles in $|\\eta|<$2.5 in $dN/d\\eta$ like Cu-Cu collisions $\\sqrt {s_{NN}} = 200$ GeV at mid-peripheral at RHIC. A Large Ion Collider Experiment (ALICE) detector at the LHC is optimized for studying the high-temperature and high-density system called as QGP. Angular correlations between two charged particles are measured with central and forward detectors in ALICE experiment. Th...

Vector meson production in the dimuon channel in the ALICE experiment at the LHC

CERN Document Server

Massacrier, L.

2011-01-01

The purpose of the ALICE experiment at the LHC is the study of the Quark Gluon Plasma (QGP) formed in ultra-relativistic heavy-ion collisions, a state of matter in which quarks and gluons are deconfined. The properties of this state of strongly-interacting matter can be accessed through the study of light vector mesons ($\\rho$, $\\omega$ and $\\phi$). Indeed, the strange quark content ($s\\bar{s}$) of the $\\phi$ meson makes its study interesting in connection with the strangeness enhancement observed in heavy-ion collisions. Moreover, $\\rho$ and $\\omega$ spectral function studies give information on chiral symmetry restoration. Vector meson production in pp collisions is important as a baseline for heavy-ion studies and for constraining hadronic models. We present results on light vector meson production obtained with the muon spectrometer of the ALICE experiment in pp collisions at $\\sqrt{s}$=7 TeV. Production ratios, integrated and differential cross sections for $\\phi$ and $\\omega$ are presented. Those result...

Gamma-jet physics with the electro-magnetic calorimeter in the ALICE experiment at LHC

Science.gov (United States)

Bourdaud, G.

2008-05-01

The Electro-Magnetic Calorimeter (EMCal) will be fully installed for the first LHC heavy ion beam in order to improve the ALICE experiment performances in detection of high transverse momentum particles and in particular in reconstruction of γ-jet events. These events appear to be very interesting to probe the strongly interacting matter created in ultra-relativistic heavy ion collisions and the eventual Quark Gluon Plasma (QGP) state. Indeed, they may give information on the degree of medium opacity which induces the jet-quenching phenomenon: measuring the energy of the γ and comparing it to that of the associated jet may provide a unique way to quantify the jet energy loss in the dense matter. The interest of γ-jet studies in the framework of the quark gluon plasma physics will be discussed. A particular highlight will be stressed on the EMCal calorimeter. The detection of the γ-jet events will be then presented using this new ALICE detector.

A Multivariate Approach to Dilepton Analyses in the Upgraded ALICE Detector at CERN-LHC

CERN Document Server

AUTHOR|(CDS)2242451; Weber, Michael

ALICE, the dedicated heavy-ion experiment at CERN-LHC, will undergo a major upgrade in 2019/20. This work aims to assess the feasibility of conventional and multivariate analysis techniques for low-mass dielectron measurements in Pb-Pb collisions in a scenario involving the upgraded ALICE detector with a low magnetic field ($B=0.2~\\text{T}$). These electron-positron pairs are promising probes for the hot and dense medium, which is created in collisions of ultra-relativistic heavy nuclei, as they traverse the medium without significant final-state modifications. Due to their small signal-to-background ratio, high-purity dielectron samples are required. They can be provided by conventional analysis methods, which are based on sequential cuts, however at the price of low signal efficiency. This work shows that existing methods can be improved by employing multivariate approaches to reject different background sources of the dielectron invariant mass spectrum. The major background components are dielectrons from ...

The experiments ALICE

CERN Document Server

Fabjan, Christian

2009-01-01

This article documents the main design choices and the close to 20 years of preparation, detector R&D, construction and installation of ALICE, the dedicated heavy ion experiment at the CERN LHC accelerator.

ALICE electromagnetic calorimeter technical design report

NARCIS (Netherlands)

Cortese, P.; Peitzmann, T.; de Haas, A.P.; Nooren, G.J.L.; Oskamp, C.J.; van den Brink, A.; Ivan, C.G.; Kamermans, R.; Kuijer, P.G.; Botje, M.A.J.; van der Kolk, N.; Mischke, A.; van Leeuwen, M.

2008-01-01

ALICE (A Large Ion Collider Experiment) at the LHC contains a wide array of detector systems for measuring hadrons, leptons, and photons. ALICE is designed to carry out comprehensive measurements of high energy nucleus-nucleus collisions, in order to study QCD matter under extreme conditions and to

CERN: ALICE in the looking-glass

International Nuclear Information System (INIS)

Anon.

1993-01-01

While proton-proton collisions will provide the main research thrust at CERN's planned LHC high energy collider to be built in the LEP tunnel, its 27-kilometre superconducting magnet ring will also be able to handle all the other high energy beams on the CERN menu, opening up the possibility of both heavy ion and electron-proton collisions to augment the LHC research programme. A major new character in the LHC cast - ALICE (A Large Ion Collider Experiment) - has recently published a letter of intent, announcing its intention to appear on the LHC stage. Three letters of intent for major LHC proton-proton experiments were aired last year (January, page 6), and ALICE, if approved, would cohabit with the final solution for the protonproton sector (see box). Only a single major heavy ion experiment is envisaged. The protonproton detectors have some heavy ion capability, but could only look at some very specific signals. (Detailed plans for LHC's electron proton collision option are on hold, awaiting the initial exploration of this field by the new HERA collider which came into operation last year at the DESY Laboratory in Hamburg.) Describing the ALICE detector and its research aims, spokesman Jurgen Schukraft echoes T.D.Lee's observations on the state of particle physics. It is becoming increasingly clear that resolving some of today's particle puzzles require a deeper understanding of the vacuum

Study of the muon production from open heavy flavours predicted by the Color Glass Condensate model in proton-proton and proton-lead collision with the Alice muon spectrometer at LHC; Etude de la production de muons issus des saveurs lourdes predite par le modele de Color Glass Condensate dans les collisions proton-proton et proton-plomb dans l'acceptance du spectrometre a muons de l'experience Alice du LHC

Energy Technology Data Exchange (ETDEWEB)

Charpy, A

2007-10-15

The whole particle physics community is waiting for the Large Hadron Collider (LHC) commissioning at CERN. Indeed, the potential of discovery is very large in lots of themes. In particular, it will be possible to test the developments of the Quantum Chromodynamics (QCD) achieved during last years. One of these, the Colour Glass Condensate, describes the parton distributions of the nucleus in the saturation region, i.e. at small x. This theoretical description of the initial conditions of the heavy ion collisions is necessary to predict the heavy quark cross section production which evolves in a possible deconfined matter: the Quark-Gluon Plasma (PQG). ALICE is the LHC experiment mainly dedicated to the study of the PQG produced in ultra-relativistic heavy ion collisions. The measurement of J /{psi} and {upsilon} resonance suppression is a signature of this deconfined medium which is studied with the ALICE muon spectrometer. Its acceptance at large rapidity is well adapted for studying the prediction of CGC at small-x. The first part of this report presents the results of beam test experiment at CERN. It was the first time that the muon spectrometer tracking chambers were tested equipped with the final version of the front end electronics and the data acquisition system CROCUS. The relevant calibration parameters of the front end electronics were introduced in the analysis in order to improve the quality of the track reconstruction. In the second part. these parameters were used in the simulations. The last part proposes a study of the CGC with the ALICE muon spectrometer. involving the measurements of open charm and open beauty. (author)

JACoW Challenges of the ALICE Detector Control System for the LHC RUN3

CERN Document Server

Chochula, Peter; Bond, Peter; Kurepin, Alexander; Lechman, Mateusz; Lang, John; Pinazza, Ombretta

2018-01-01

The ALICE Detector Control System (DCS) has provided its services to the experiment since 10 years. During this period it ensured uninterrupted operation of the experiment and guaranteed stable conditions for the data taking. The DCS has been designed to cope with the detector requirements compatible with the LHC operation during its RUN1 and RUN2 phases. The decision to extend the lifetime of the experiment beyond this horizon requires the redesign of the DCS data flow and represents a major challenge. The major challenges of the system upgrade are presented in this paper.

An overview on the study of quark gluon plasma with Alice dimuon spectrometer; Apercu sur l'etude du plasma de Quarks et de gluons a l'aide du spectrometre dimuons d'Alice

Energy Technology Data Exchange (ETDEWEB)

Espagnon, B

2007-10-15

The Alice experiment is one of the four main LHC (Large Hadron Collider) experiments. It is dedicated to the study of a new state of matter: the quark gluon plasma, where quarks and gluons are no longer confined within hadrons. In this document, the physics issues that led to the construction of Alice dimuon spectrometer, are described. Then, the research and development on the dimuon spectrometer is presented. The different absorbers are described and experimental tests used to determine their dimensions are presented. The dimuon trigger built using the RPC (Resistive Plate Chamber) streamer mode is then described along with the associated beam and cosmic tests and results. Finally, the tracking system is described in detail and more particularly all its electronics and the first station. The physics constraints on the expected performances of all these systems are clearly defined. (author)

Study of heavy flavours from muons measured with the ALICE detector in proton-proton and heavy-ion collisions at the CERN-LHC

International Nuclear Information System (INIS)

Zhang, X.

2012-01-01

ALICE (A Large Ion Collider Experiment) is the experiment dedicated to the study of heavy-ion collisions at the LHC. ALICE also takes part in the LHC proton- proton program which is of great interest for testing perturbative QCD calculations at unprecedented low Bjorken-x values and for providing the necessary baseline for nucleus-nucleus and proton-nucleus collisions. ALICE will also collect, in the beginning of 2013, p-Pb/Pb-p collisions in order to investigate cold nuclear matter effects. ALICE measures quarkonia and open heavy flavours with (di)-electrons, (di)-muons and through the hadronic channels. This thesis work is devoted to the study of open heavy flavours in proton-proton and Pb-Pb collisions via single muons with the ALICE forward muon spectrometer. The document is organized as follows. The first chapter consists in a general introduction on heavy-ion collisions and QCD phase transitions. Chapter 2 summarizes the motivations for the study of open heavy flavours in nucleon-nucleon, nucleon-nucleus and nucleus-nucleus collisions. Chapter 3 gives an overview of the ALICE experiment with a detailed description of the forward muon spectrometer. Chapter 4 gives a short summary of the ALICE online and offline systems. Then the analysis framework (for data and simulations) and in particular the software developed for the study of open heavy flavours is detailed. Chapter 5 summarizes the performance of the ALICE muon spectrometer for the study of the production of open heavy flavours in pp collisions via single muons and dimuons. Chapters 6 to 9 are dedicated to data analysis. Chapter 6 deals with the analysis of first pp collisions at 900 GeV. The main aim was the understanding of the response of the apparatus. Chapter 7 presents the measurement of the production of heavy flavour decay muons in pp collisions at √(s) = 7 TeV. The analysis strategy is described: event and track selection, background subtraction (mainly the contribution of muons from primary

Installing the ALICE detector

CERN Multimedia

Maximilien Brice

2006-01-01

The huge iron yoke in the cavern at Point 2 in the LHC tunnel is prepared for the installation of the ALICE experiment. The yoke is being reused from the previous L3 experiment that was located at the same point during the LEP project from 1989 to 2000. ALICE will be inserted piece by piece into the cradle where it will be used to study collisions between two beams of lead ions.

Trigger system study of the dimuon spectrometer in the ALICE experiment at CERN-LHC

International Nuclear Information System (INIS)

Roig, O.

1999-12-01

This work is a contribution to the study of nucleus-nucleus collisions at the LHC with ALICE. The aim of this experiment is to search for a new phase of matter, the quark-gluon plasma (QGP). The dimuon forward spectrometer should measure one of the most promising probes of the QGP, the production of heavy quark vector mesons (J/ψ, γ, γ', γ'') through their muonic decays. The dimuon trigger selects the interesting events performing a cut on the transverse momentum of the tracks. The trigger decision is taken by a dedicated electronics using RPC (''Resistive Plate Chambers'') detector information. We have made our own R and D program on the RPC detector with various beam tests. We show the performances obtained during these tests of a low resistivity RPC operating in streamer mode. The ALICE requirements concerning the rate capability, the cluster size and the time resolution are fulfilled. We have optimised the trigger with simulations which include a complete description of the read-out planes and the trigger logic (algorithm). In particular, a technique of clustering is proposed and validated. A method called ''Ds reduction'' is introduced in order to limit the effects of combinatorial background on the trigger rates. The efficiencies and the trigger rates are calculated for Pb-Pb, Ca-Ca, p-p collisions at the LHC. Other more sophisticated cuts, on the invariant mass for example, using again the RPC information have been simulated but have not shown significant improvements of the trigger rates. (author)

On the evening of June 15, 2008, ALICE physicists saw the first tracks at LHC during the first injection test in transfer line TI 2. The Silicon Pixel detector recorded muon tracks produced in the beam dump near Point 2 of the LHC.

CERN Multimedia

Manzari, Vito

2008-01-01

On the evening of June 15, 2008, ALICE physicists saw the first tracks at LHC during the first injection test in transfer line TI 2. The Silicon Pixel detector recorded muon tracks produced in the beam dump near Point 2 of the LHC

Production of pions, kaons and protons in pp collisions at √ s = 900 GeV with ALICE at the LHC

Czech Academy of Sciences Publication Activity Database

Aamodt, K.; Abel, N.; Abeysekara, U.; Quintana, A.A.; Adamová, Dagmar; Bielčík, J.; Bielčíková, Jana; Kushpil, Svetlana; Kushpil, Vasilij; Mareš, Jiří A.; Polák, Karel; Šumbera, Michal; Tlustý, D.; Wagner, V.; Závada, Petr

2011-01-01

Roč. 71, č. 6 (2011), 1-22 ISSN 1434-6044 R&D Projects: GA MŠk LA08015 Institutional research plan: CEZ:AV0Z10100502; CEZ:AV0Z10480505 Keywords : CERN * ALICE * LHC * pp collisions Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.631, year: 2011

Measurement of heavy-flavor production in Pb-Pb collisions at the LHC with ALICE

CERN Document Server

INSPIRE-00249089

2013-01-01

A Large Ion Collider Experiment (ALICE) at the Large Hadron Collider (LHC) has been built in order to study the Quark-Gluon Plasma (QGP) created in high-energy nuclear collisions. As heavy-flavor quarks are produced at the early stage of the collision, they serve as sensitive probes for the QGP. The ALICE detector with its capabilities such as particle identification, secondary vertexing and tracking in a high multiplicity environment can address, among other measurements, the heavy-flavor sector in heavy-ion collisions. We present latest results on the measurement of the nuclear modification factor of open heavy-flavors as well as on the measurement of open heavy-flavor azimuthal anisotropy v2 in Pb-Pb collisions at sqrt(s) = 2.76 TeV. Open charmed hadrons are reconstructed in the hadronic decay channels D0->Kpi, D+->Kpipi, and D*+->D0pi applying a secondary decay-vertex topology. Complementary measurements are performed by detecting electrons (muons) from semi-leptonic decays of open heavy-flavor hadrons in...

Two-particle angular correlations in pp collisions recorded with the ALICE detector at the LHC

CERN Document Server

Janik, Małgorzata

2014-01-01

We report on the studies of two-particle angular correlations measured in proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV recorded by ALICE at the LHC. Two-particle correlations in relative azimuth ({\\Delta}{\\phi}) and pseudorapidity ({\\Delta}{\\eta}) are expected to exhibit several structures which arise from different physics mechanisms and allow us to study the wide landscape of correlations. The results include the dependence of the correlation function on the event multiplicity, the charge combination and species (pions, kaons or protons) of particles in the pair.

Strangeness Production in Jets with ALICE at the LHC

Science.gov (United States)

Smith, Chrismond; Harton, Austin; Garcia, Edmundo; Alice Collaboration

2016-03-01

The study of strange particle production is an important tool for understanding the properties of the hot and dense QCD medium created in heavy-ion collisions at ultra-relativistic energies. The study of strange particles in these collisions provides information on parton fragmentation, a fundamental QCD process. While measurements at low and intermediate pT, are already in progress at the LHC, the study of high momentum observables is equally important for a complete understanding of the QCD matter, this can be achieved by studying jet interactions. We propose the measurement of the characteristics of the jets containing strange particles. Starting with proton-proton collisions, we have calculated the inclusive pTJet spectra and the spectra for jets containing strange particles (K-short or lambda), and we are extending this analysis to lead-lead collisions. In this talk the ALICE experiment will be described, the methodology used for the data analysis and the available results will be discussed. This material is based upon work supported by the National Science Foundation under Grants PHY-1305280 and PHY-1407051.

Open-charm production measurements in pp, 1 p-Pb and Pb-Pb collisions with ALICE at the LHC

Directory of Open Access Journals (Sweden)

Meninno Elisa

2017-01-01

Full Text Available ALICE (A Large Ion Collider Experiment is designed to study the strongly in teracting matter, the Quark-Gluon Plasma (QGP, created in heavy-ion collisions at LHC energies. Charm and beauty quarks are powerful probes to study the QGP. Produced in hard partonic scattering processes on a short time scale, they are expected to traverse the QCD medium, interacting with its constituents and losing energy through radiative and collisional processes. In ALICE, open-charm production is studied through the reconstruction of the hadronic decays of D0, D+, D*+ and Ds+ mesons at mid-rapidity. High precision tracking, good vertexing capabilities and excellent particle identification offered by ALICE allow for the measurement of particles containing heavy quarks (particularly D mesons in a wide transverse momentum range in pp, p-Pb and Pb-Pb collisions. A review of the main results on D-meson production in pp collisions at √s = 7 TeV, p-Pb collisions at √sNN = 5.02 TeV and Pb-Pb collisions at √sNN = 2.76 TeV will be presented.

Photoproduction of $\\rho^0$ in ultra--peripheral nuclear collisions at ALICE

CERN Document Server

Skjerdal, Kyrre

2013-01-01

Photoproduction of $\\rho^0$ mesons in ultra-peripheral Pb+Pb collisions has been studied by the ALICE Collaboration at the CERN LHC. The strong photon flux associated with relativistic charged nuclei leads to a very large cross section for exclusive photoproduction of $\\rho^0$ meson in interactions of the type $Pb + Pb \\rightarrow Pb + Pb + \\rho^0$. For a $\\rho^0$ produced at mid-rapidity at the LHC, the photon-nucleus center of mass energy is higher than in any previous experiment. The ALICE detector is a general purpose detector dedicated to study heavy--ion collisions. ALICE has excellent performance in the low $p_T$ region, and can reconstruct charged particle tracks with 0.1 GeV/c $\\leq p_T \\leq 100$ GeV/c. In this analysis all tracks were required to be within ALICE's central barrel. Analysis of data from the first heavy ion run at the LHC in 2010 will be discussed in this paper.

Overview of results from ALICE

International Nuclear Information System (INIS)

Płoskoń, Mateusz

2014-01-01

ALICE is a dedicated experiment for measurements of heavy-ion collisions at the Large Hadron Collider (LHC). A wealth of experimental data recorded in 2010, 2011 and 2012 suggests that a strongly interacting de-confined medium is created in collisions of lead ions at a centre-of-mass energy √S_N_N = 2.76 TeV. In order to quantify the properties of this hot and dense matter, measurements were performed in smaller systems, such as proton-proton and proton-lead, where effects related to the medium are expected to be negligible. We present an overview of recent measurements of particle production and particle correlations in proton-proton, Pb-Pb and p-Pb collisions at the LHC by ALICE Collaboration.

Rapport final de la Collaboration CERN-CNRS pour la construction du LHC Accord Technique d'Exécution No 2 Cryostats et assemblage des sections droites courtes (SSS) du LHC

CERN Document Server

Bergot, JB; Poncet, A; Rohmig, P; Roy, E; Vincent, D

2006-01-01

Depuis 1995 et suite à la signature du protocole de Collaboration, le CERN, le CEA et le CNRS ont étroitement collaboré dans le cadre de la contribution exceptionnelle de la France à la construction du LHC. Pour le CNRS, l'Institut de Physique Nucléaire d'Orsay a pris en charge deux Accords Techniques d'Exécution. Le premier concerne la conception et l'assemblage des Sections Droites Courtes de la machine, et le deuxième, l'étalonnage des thermomètres cryogéniques du LHC. Dans le cadre de l'Accord Technique d'Exécution N°2, le Bureau d'Etudes de la Division Accélérateur de l'IPNO et le groupe AT-CRI du CERN ont travaillé de concert pour mener à bien la conception des SSS (Short Straight Section) et de tous les équipements nécessaires à l'assemblage. Ce rapport a donc pour objectif de dresser, en termes d'historique, d'organisation, de résultats quantitatifs et qualitatifs et de moyens mis en ?uvre, un tableau aussi complet que possible du déroulement de cette Collaboration entre le CERN e...

The ALICE TPC Upgrad

Science.gov (United States)

Castro, Andrew; Alice-Usa Collaboration; Alice-Tpc Collaboration

2017-09-01

The Time Projection Chamber (TPC) currently used for ALICE (A Large Ion Collider Experiment at CERN) is a gaseous tracking detector used to study both proton-proton and heavy-ion collisions at the Large Hadron Collider (LHC) In order to accommodate the higher luminosit collisions planned for the LHC Run-3 starting in 2021, the ALICE-TPC will undergo a major upgrade during the next LHC shut down. The TPC is limited to a read out of 1000 Hz in minimum bias events due to the intrinsic dead time associated with back ion flow in the multi wire proportional chambers (MWPC) in the TPC. The TPC upgrade will handle the increase in event readout to 50 kHz for heavy ion minimum bias triggered events expected with the Run-3 luminosity by switching the MWPCs to a stack of four Gaseous Electron Multiplier (GEM) foils. The GEM layers will combine different hole pitches to reduce the dead time while maintaining the current spatial and energy resolution of the existing TPC. Undertaking the upgrade of the TPC represents a massive endeavor in terms of design, production, construction, quality assurance, and installation, thus the upgrade is coordinated over a number of institutes worldwide. The talk will go over the physics motivation for the upgrade, the ALICE-USA contribution to the construction of Inner Read Out Chambers IROCs, and QA from the first chambers built in the U.S

ALICE upgrades its powerful eyes

CERN Multimedia

Yuri Kharlov, ALICE Collaboration

2013-01-01

The ALICE Photon Spectrometer (PHOS) is a high-resolution photon detector that measures the photons coming out of the extremely hot plasma created in the lead-lead collisions at the LHC. Taking advantage of the long accelerator shut-down, the ALICE teams are now repairing and upgrading the existing modules and getting ready to install the brand-new module in time for the next run. The upgraded PHOS detector will be faster and more stable with wider acceptance and improved photon identification.   PHOS crystal matrix during repair. The key feature and the main complexity of the ALICE PHOS detector is that it operates at a temperature of -25°C, which makes it the second-coldest equipment element at the LHC after the cryogenic superconducting magnets. Since 2009 when it was installed, the PHOS detector, with its cold and warm volumes, has been immersed in airtight boxes to avoid condensation in the cold volumes. The 10,752 lead tungstate crystals of the PHOS were completely insulated fr...

Microstrip detector for the ALICE experiment

CERN Multimedia

Laurent Guiraud

1996-01-01

This photo shows a close up of one of the silicon microstrip detectors that will be installed on the ALICE experiment at the LHC. 1698 double-sided modules of these silicon microstrips will be installed in the two outermost layers of the ALICE inner tracking system. The microstrips have to be specially designed to withstand the high resolution levels at the heart of the detector.

ALICE : the LHC experiment devoted to heavy ions Conference MT17

CERN Multimedia

2001-01-01

The object of High Energy Heavy Ion Physics is the study of strongly interacting matter at extreme energy densities and large volumes. QCD predicts that, under such conditions (high densities and large volume), hadronic matter turns into a plasma of deconfined quarks and gluons [Quark Gluon Plasma: (QGP)]. Physicists believe that matter in the Universe existed in this state up to the time when hadronization occurred i.e.10 ms after the Big Bang. Today QGP might exist in the core of neutron stars. The study of the phase diagram of matter is a new approach to investigate QCD at its natural scale, L QCD, and to address the fundamental question of confinement and chiral-symmetry breaking. The ALICE Collaboration will study QGP by observing lead nuclei colliding in the LHC at energies 30 times larger than presently available at RHIC, as well as proton-proton collisions.

Two particle correlations with photon triggers to study hot QCD medium in ALICE at LHC

CERN Document Server

Yaxian, Mao; Shou, Daicui; Schutz, Yves

2011-01-01

With the advent of the Large Hadron Collider (LHC)at the end of 2009, the new accelerator at CERN collides protons and heavy-ions at unprecedented high energies. ALICE , one of the major experiment installed at LHC, is dedicated to the study of nuclear matter under extreme conditions of energy density with the opportunity of creating a partonic medium called the Quark- Gluon-Plasma (QGP). This new experimental facility opens new avenues for the understanding of fundamental properties of the strong interaction and its vacuum. To reach the objectives of this scientific program, it is required to select a set of appropriate probes carrying relevant information on the properties of the medium created in ultra-relativistic heavy-ion collisions. Based on the information delivered by all the observables and guided by modelization of the fundamental principles in action, a coherent picture will emerge to interpret the observed phenomena. In the first part of the present document I describe the context of the scientif...

ALICE: Physics Performance Report, Volume II

International Nuclear Information System (INIS)

Alessandro, B; Antinori, F; Belikov, J A

2006-01-01

ALICE is a general-purpose heavy-ion experiment designed to study the physics of strongly interacting matter and the quark-gluon plasma in nucleus-nucleus collisions at the LHC. It currently involves more than 900 physicists and senior engineers, from both the nuclear and high-energy physics sectors, from over 90 institutions in about 30 countries. The ALICE detector is designed to cope with the highest particle multiplicities above those anticipated for Pb-Pb collisions (dN ch /dy up to 8000) and it will be operational at the start-up of the LHC. In addition to heavy systems, the ALICE Collaboration will study collisions of lower-mass ions, which are a means of varying the energy density, and protons (both pp and pA), which primarily provide reference data for the nucleus-nucleus collisions. In addition, the pp data will allow for a number of genuine pp physics studies. The detailed design of the different detector systems has been laid down in a number of Technical Design Reports issued between mid-1998 and the end of 2004. The experiment is currently under construction and will be ready for data taking with both proton and heavy-ion beams at the start-up of the LHC. Since the comprehensive information on detector and physics performance was last published in the ALICE Technical Proposal in 1996, the detector, as well as simulation, reconstruction and analysis software have undergone significant development. The Physics Performance Report (PPR) provides an updated and comprehensive summary of the performance of the various ALICE subsystems, including updates to the Technical Design Reports, as appropriate. The PPR is divided into two volumes. Volume I, published in 2004 (CERN/LHCC 2003-049, ALICE Collaboration 2004 J. Phys. G: Nucl. Part. Phys. 30 1517-1763), contains in four chapters a short theoretical overview and an extensive reference list concerning the physics topics of interest to ALICE, the experimental conditions at the LHC, a short summary and update

First Physics Results from ALICE

International Nuclear Information System (INIS)

Peressounko, Dmitri; Castillo Castellanos, Javier; Belikov, Iouri

2010-01-01

ALICE is the LHC experiment dedicated to the study of heavy-ion collisions. The main purpose of ALICE is to investigate the properties of a state of deconfined nuclear matter, the Quark Gluon Plasma. Heavy flavour measurements will play a crucial role in this investigation. The physics programme of ALICE has started by studying proton-proton collisions at unprecedented high energies. We will present the first results on open heavy flavour and quarkonia in proton-proton collisions at √s = 7 TeV measured by the ALICE experiment at both mid- and forward-rapidities. We will conclude with the prospects for heavy flavour and quarkonium measurements in both proton-proton and nucleus-nucleus collisions. Also presented are first results of neutral meson reconstruction and its perspectives, as well as further physics studies. (author)

ALICE: Simulated lead-lead collision

CERN Multimedia

2003-01-01

This track is an example of simulated data modelled for the ALICE detector on the Large Hadron Collider (LHC) at CERN, which will begin taking data in 2008. ALICE will focus on the study of collisions between nuclei of lead, a heavy element that produces many different particles when collided. It is hoped that these collisions will produce a new state of matter known as the quark-gluon plasma, which existed billionths of a second after the Big Bang.

Leading lead through the LHC

CERN Multimedia

2011-01-01

Three of the LHC experiments - ALICE, ATLAS and CMS - will be studying the upcoming heavy-ion collisions. Given the excellent results from the short heavy-ion run last year, expectations have grown even higher in experiment control centres. Here they discuss their plans:   ALICE For the upcoming heavy-ion run, the ALICE physics programme will take advantage of a substantial increase of the LHC luminosity with respect to last year’s heavy-ion run.  The emphasis will be on the acquisition of rarely produced signals by implementing selective triggers. This is a different operation mode to that used during the first low luminosity heavy-ion run in 2010, when only minimum-bias triggered events were collected. In addition, ALICE will benefit from increased acceptance coverage by the electromagnetic calorimeter and the transition radiation detector. In order to double the amount of recorded events, ALICE will exploit the maximum available bandwidth for mass storage at 4 GB/s and t...

LHC France 2013: French Meeting on High Energy Physics at the LHC

CERN Document Server

2013-01-01

Cette 1ère édition des rencontres françaises sur la physique des hautes énergies au Large Hadron Collider réunira près de 300 physiciens membres des laboratoires IN2P3-CNRS et IRFU-CEA, participants aux collaborations Atlas, CMS, LHCb et Alice. La rencontre LHC France, aura lieu à une période particulièrement cruciale pour la discipline, les derniers résultats des expériences LHC, basés sur toutes les données collectées en 2011 et 2012 y seront présentés et discutés. Elle sera l'occasion de faire le point et le bilan des avancées des diverses thématiques de recherche: boson de Higgs, les interactions électrofaibles, le quark top, la Supersymétrie, les saveurs lourdes, la violation de CP et le Plasma de Quarks et de Gluons. Elle sera aussi l'occasion de discuter des plans d'amélioration des détecteurs en vue des futures phases de fonctionnement du LHC ainsi que les perspectives pour la physique. Cette rencontre se veut un moment d'échange privilégié pour la communauté française des ...

Bose-Einstein correlations in pp and PbPb collisions with ALICE at the LHC

CERN Multimedia

CERN. Geneva

2011-01-01

We report on the results of identical pion femtoscopy at the LHC. The Bose-Einstein correlation analysis was performed on the large-statistics ALICE p+p at sqrt{s}= 0.9 TeV and 7 TeV datasets collected during 2010 LHC running and the first Pb+Pb dataset at sqrt{s_NN}= 2.76 TeV. Detailed pion femtoscopy studies in heavy-ion collisions have shown that emission region sizes ("HBT radii") decrease with increasing pair momentum, which is understood as a manifestation of the collective behavior of matter. 3D radii were also found to universally scale with event multiplicity. In p+p collisions at 7 TeV one measures multiplicities which are comparable with those registered in peripheral AuAu and CuCu collisions at RHIC, so direct comparisons and tests of scaling laws are now possible. We show the results of double-differential 3D pion HBT analysis, as a function of multiplicity and pair momentum. The results for two collision energies are compared to results obtained in the heavy-ion collisions at similar multipl...

Open-charm production measurements with ALICE at the LHC

International Nuclear Information System (INIS)

Pagano, P.

2016-01-01

The LHC heavy-ion physics program aims at investigating the properties of strongly-interacting matter under extreme conditions of temperature and energy density where the formation of the Quark-Gluon Plasma (QGP) is expected. Heavy-flavour hadrons, containing charm and beauty quarks, are considered efficient probes to investigate the properties of the QGP produced in heavy-ion collisions. Heavy quarks are produced in hard partonic scattering processes in the initial stage of hadronic collisions and propagate through the hot and dense medium created in the collision losing energy interacting with the medium via radiative and collisional processes. The high precision tracking, good vertexing capabilities and excellent particle identification offered by the ALICE experiment allow us to measure particles containing heavy quarks in a wide transversemomentum range in pp, p-Pb and Pb-Pb collisions. A review of the main results on prompt D-mesons production, reconstructed via their hadronic decays at mid-rapidity, in pp collisions at √s = 7 TeV, p-Pb collisions at √s_N_N = 5.02 TeV and Pb-Pb collisions at √s_N_N = 2.76 TeV will be shown

The Alice experiment for the study of ultra relativistic heavy ion collisions; Experience ALICE pour l'etude des collisions d'ions lourds ultra-relativistes au CERN-LHC

Energy Technology Data Exchange (ETDEWEB)

Forestier, B

2003-12-01

Alice is the detector dedicated to the study of heavy ions at the LHC (large hadron collider). It will allow scientists to investigate all the signatures of quark-gluon plasma (QGP). The spectrometer of the dimuon arm of Alice has been designed to study the production of high mass resonances through their dimuon decay. The first chapter is dedicated to some aspects of the physics of ultra-relativistic heavy ion: confinement and de-confinement of quarks, the absence of heavy resonances as a signature for the presence of QGP. The second chapter presents Alice and its ancillary detectors. The third chapter deals with the trigger system of the dimuon spectrometer, a detailed algorithm of this system is given. A method for the optimization of the trigger response is presented in the fourth chapter. The fifth chapter describes the testing of a prototype of the trigger system, this testing with muons has shown that the efficiency of the track reconstruction of the trigger system and the efficiency of the resistive plate chamber reach 98%.In the sixth chapter the author comments the simulations of the production of heavy resonances from Pb-Pb collisions as a function of centrality. (A.C.)

Very high Momentum Particle Identification detector for ALICE at the LHC

International Nuclear Information System (INIS)

Garcia, Edmundo

2009-01-01

The anomalies observed at RHIC for the baryon-meson ratios have prompted a number of theoretical works on the nature of the hadrochemistry in the hadronisation stage of the pp collisions and in the evolution of the dense system formed in heavy ion collisions. Although the predictions differ in the theoretical approach, generally a substantial increase in the baryon production is predicted in the range 10-30 GeV/c. This raises the problem of baryon identification to much higher momenta than originally planned in the LHC experiments. After a review of the present status of theoretical predictions we will present the possibilities of a gas ring imaging Cherenkov detector of limited acceptance which would be able to identify track-by-track protons until 26 GeV/c. The physics capabilities of such a detector in conjunction with the ALICE experiment will be contemplated as well as the triggering options to enrich the sample of interesting events with a dedicated trigger or/and using the ALICE Electromagnetic Calorimeter. The use of the electromagnetic calorimeter opens interesting possibility to distinguish quark and gluon jets in gamma--jet events and subsequently the study of the probability of fragmentation in proton, kaon and pion or triggering on jets in the EMCAL. Such a detector would be identify pions until 14 GeV/c kaons from 9 till 14 GeV/c and protons from 18 till 24/GeV/c in a positive way and by absence of signal from 9-18 GeV/c.

ALICE Diffractive Detector Control System for RUN-II in the ALICE Experiment

CERN Document Server

INSPIRE-00522336; Martinez, M.I.; Monzon, I. Leon

2016-01-01

This paper describes general characteristics of the deployment and commissioned of the Detector Control System (DCS) AD0 for the second phase of the Large Hadron Collider (LHC). The AD0 detector is installed in the ALICE experiment to provide a better selection of diffractive events.

ALICE tests its digital chain

CERN Multimedia

2007-01-01

During its 7th data challenge, ALICE successfully tested the infrastructure of its data acquisition, transfer and storage system. The ALICE experiment will need a rock-solid data acquisition, selection, transfer, storage and handling system to analyse the billions of bits of data that will be generated every second. The heavy ion collisions at the LHC will generate 10 times more data per second than proton collisions. The ALICE teams have therefore been hard at it for several years designing a cutting-edge informatics system, whose reliability is regularly put to the test in the annual data challenges. Last December, groups from the Collaboration and the IT Department joined forces, or rather cables, in the 7th of these challenges. The teams of ALICE DAQ (data acquisition), ALICE Offline (data handling), IT-CS-IO (network) and IT-FIO (CASTOR and data storage) all took part in testing the various components of the infrastructure, from data acquisition to transfer and storage. Working in close collaboration,...

Precision measurement of the mass difference between light nuclei and anti-nuclei with ALICE at the LHC

CERN Multimedia

CERN. Geneva

2015-01-01

is produced in the central pseudorapidity region allowing for a precise investigation of their properties. Mass and binding energy are expected to be the same in nuclei and anti-nuclei as long as the CPT invariance holds for the nuclear force, a remnant of the underlying strong interaction between quarks and gluons. The measurements of the difference in mass-to-charge ratio between deuteron and anti-deuteron, and 3He and 3\\bar{He} nuclei performed with the ALICE detector at the LHC is presented. The ALICE measurements improve by one to two orders of magnitude previous analogous direct measurements. Given the equivalence between mass and energy, the results improve by a factor two the constraints on CPT invariance inferred from measurements in the (anti-)deuteron system. The binding energy difference has been determined for the first time in the case of (anti-)3He, with a precision comparable to the one obtained in the...

The ALICE TPC, a high resolution device for ultra-high particle multiplicities. Past, present and future

Energy Technology Data Exchange (ETDEWEB)

Ivanov, Marian [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH (Germany); Collaboration: ALICE-Collaboration

2015-07-01

The Time Projection Chamber (TPC) of the ALICE apparatus is a large 3-dimensional tracking and particle identification device for ultra-high multiplicity collision events. It has been operated successfully at the Large Hadron Collider (LHC) at CERN, recording data from pp, p-Pb, and Pb-Pb collisions. Presently, LHC is in its first long shutdown (LS1), the next round of data taking will start in summer 2015 at or close to the LHC design energy and luminosity. During the second long shutdown (LS2), LHC will undergo a further increase in the Pb-Pb luminosity together with a major upgrade of ALICE. After the upgrade, the ALICE TPC will operate with Pb-Pb collisions at an interaction rate of 50 kHz. We present the performance in operation, calibration and reconstruction with the ALICE TPC together with ongoing work and plans for the near future and the coming 10 years.

ALICE A Large Ion Collider Experiment

CERN Multimedia

Mager, M; Rohr, D M; Suljic, M; Miskowiec, D C; Donigus, B; Mercado-perez, J; Lohner, D; Bertelsen, H; Kox, S; Cheynis, B; Sambyal, S S; Usai, G; Agnello, M; Toscano, L; Miake, Y; Inaba, M; Maldonado cervantes, I A; Fernandez tellez, A; Kulibaba, V; Zinovjev, G; Martynov, Y; Usenko, E; Pshenichnov, I; Nikolaev, S; Vasiliev, A; Vinogradov, A; Moukhanova, T; Vasilyev, A; Kozlov, Y; Voloshin, K; Kiselev, S; Kirilko, Y; Lyublev, E; Kondratyeva, N; Gameiro munhoz, M; Alarcon do passo suaide, A; Lagana fernandes, C; Carlin filho, N; Yin, Z; Zhu, J; Luo, J; Pikna, M; Bombara, M; Pastircak, B; Marangio, G; Gianotti, P; Muccifora, V; Sputowska, I A; Ilkiv, I; Christiansen, P; Dodokhov, V; Yurevich, V; Fedunov, A; Malakhov, A; Efremov, A; Feofilov, G; Vinogradov, L; Asryan, A; Kovalenko, V; Piyarathna, D; Myers, C J; Martashvili, I; Oh, H; Cherney, M G; D'erasmo, G; Wagner, V; Smakal, R; Sartorelli, G; Xaplanteris karampatsos, L; Mlynarz, J; Murray, C J; Oh, S; Becker, B; Zbroszczyk, H P; Feldkamp, L; Pappalardo, G; Khlebnikov, A; Basmanov, V; Punin, V; Demanov, V; Naseer, M A; Gotovac, S; Zgura, S I; Yang, H; Vernet, R; Son, C; Shtejer diaz, K; Hwang, S; Alfaro molina, J R; Jahnke, C; Richter, M R; Garcia-solis, E J; Hitchcock, T M; Bazo alba, J L; Utrobicic, A; Brun, R; Divia, R; Hillemanns, H; Schukraft, J; Riedler, P; Eulisse, G; Von haller, B; Kushpil, V; Ivanov, M; Malzacher, P; Schweda, K O; Renfordt, R A E; Reygers, K J; Pachmayer, Y C; Gaardhoeje, J J; Bearden, I G; Porteboeuf, S J; Borel, H; Pereira da costa, H D A; Faivre, J; Germain, M; Schutz, Y R; Delagrange, H; Batigne, G; Stocco, D; Estienne, M D; Bergognon, A A E; Zoccarato, Y D; Jones, P G; Levai, P; Bencedi, G; Khan, M M; Mahapatra, D P; Ghosh, P; Das, T K; Cicalo, C; De falco, A; Mazzoni, A M; Cerello, P; De marco, N; Riccati, L; Saavedra san martin, O; Paic, G; Ovchynnyk, V; Karavicheva, T; Kucheryaeva, M; Skuratovskiy, O; Mal kevich, D; Bogdanov, A; Pereira, L G; Cai, X; Zhu, X; Wang, M; Kar, S; Fan, F; Sitar, B; Cerny, V; Aggarwal, M M; Bianchi, N; Torii, H; Hori, Y; Tsuji, T; Herrera corral, G A; Kowalski, M; Rybicki, A; Deloff, A; Petrovici, A; Nomokonov, P; Parfenov, A; Koshurnikov, E; Shahaliyev, E; Rogochaya, E; Kondratev, V; Oreshkina, N; Tarasov, A; Norenberg, M; Bodnya, E; Bogolyubskiy, M; Symons, T; Blanco, F; Madagodahettige don, D M; Umaka, E N; Schaefer, B; De pasquale, S; Fusco girard, M; Kim, J; Jeon, H; Nandi, B K; Kumar, J; Sarkar - sinha, T; Arcelli, S; Scapparone, E; Shevel, A; Nikulin, V; Komkov, B; Voloshin, S; Hille, P T; Kannan, S; Dainese, A; Matynia, R M; Dabala, L B; Zimmermann, M B; Vinogradov, Y; Vikhlyantsev, O; Telnov, A; Tumkin, A; Van leeuwen, M; Erdal, H A; Keidel, R; Rui, R; Yeo, I; Vilakazi, Z; Klay, J L; Boswell, B D; Lindenstruth, V; Tveter, T S; Batzing, P C; Breitner, T G; Sahoo, R; Roy, A; Musa, L; Perini, D; Vande vyvre, P; Fuchs, U; Oberegger, M; Aglieri rinella, G; Salgueiro domingues da silva, R M; Kalweit, A P; Greco, V; Bellini, F; Bond, P M; Mohammadi, N; Marin, A M; Glassel, P; Schicker, R M; Staley, F M; Castillo castellanos, J E; Furget, C; Real, J; Martino, J F; Evans, D; Sahu, P K; Sahu, S K; Ahammed, Z; Saini, J; Bala, R; Gupta, R; Di bari, D; Biasotto, M; Nappi, G; Esumi, S; Sano, M; Roehrich, D; Lonne, P; Drakin, Y; Manko, V; Nikulin, S; Yushmanov, I; Kozlov, K; Kerbikov, B; Stavinskiy, A; Sultanov, R; Raniwala, R; Zhou, D; Zhu, H; Meres, M; Kralik, I; Parmar, S; Rizzi, V; Orlandi, A; Lea, R; Kuijer, P G; Figiel, J; Gorlich, L M; Shabratova, G; Lobanov, V; Zaporozhets, S; Ivanov, A; Iglovikov, V; Ochirov, A; Petrov, V; Jacobs, P M; De gruttola, D; Corsi, F; Varma, R; Nania, R; Wilkinson, J J; Samsonov, V; Pruneau, C A; Caines, H L; Aronsson, T; Adare, A M; Zwick, S M; Fearick, R W; Ostrowski, P K; Kulasinski, K; Heine, N; Wilk, A; Ilkaev, R; Ilkaeva, L; Pavlov, V; Mikhaylyukov, K; Rybin, A; Naumov, N; Mudnic, E; Cortese, P; Listratenko, O; Stan, I; Nooren, G; Song, J; Krawutschke, T; Kim, S Y; Hwang, D S; Lee, S H; Leon monzon, I; Vorobyev, I; Skaali, B; Wikne, J; Dordic, O; Yan, Y; Mazumder, R; Shahoyan, R; Kluge, A; Pellegrino, F; Safarik, K; Tauro, A; Foka, P; Frankenfeld, U M; Masciocchi, S; Schwarz, K E; Bailhache, R M; Anguelov, V; Hansen, A; Vulpescu, B; Baldisseri, A; Aphecetche, L B; Berenyi, D; Sahoo, S; Nayak, T K; Muhuri, S; Patra, R N; Adhya, S P; Potukuchi, B; Masoni, A; Scomparin, E; Beole, S; Mizuno, S; Enyo, H; Cuautle flores, E; Gonzalez zamora, P; Djuvsland, O; Altinpinar, S; Wagner, B; Fehlker, D; Velure, A; Potin, S; Kurepin, A; Ryabinkin, E; Kiselev, I; Pestov, Y; Hayrapetyan, A; Manukyan, N; Lutz, J; Belikov, I; Roy, C S; Takahashi, J; Araujo silva figueredo, M; Tang, S; Szarka, I; Kapusta, S; Hasko, J; Putis, M; Sandor, L; Vrlakova, J; Das, S; Hayashi, S; Van rijn, A J; Siemiarczuk, T; Petrovici, M; Petris, M; Stenlund, E A; Malinina, L; Fateev, O; Kolozhvari, A; Altsybeev, I; Sadovskiy, S; Soloviev, A; Ploskon, M A; Mayes, B W; Sorensen, S P; Mazer, J A; Awes, T; Virgili, T; Pagano, P; Krus, M; Sett, P; Bhatt, H; Sinha, B; Khan, P; Antonioli, P; Scioli, G; Sakaguchi, H; Volkov, S; Khanzadeev, A; Malaev, M; Lisa, M A; Loggins, V R; Schuster, T R; Scharenberg, R P; Turrisi, R; Debski, P R; Oleniacz, J; Westerhoff, U; Yanovskiy, V; Domrachev, S; Smirnova, Y; Zimmermann, S; Veldhoen, M; Van der maarel, J; Kileng, B; Seo, J; Lopez torres, E; Camerini, P; Jang, H J; Buthelezi, E Z; Suleymanov, M K O; Belmont moreno, E; Zhao, C; Perales, M; Kobdaj, C; Spyropoulou-stassinaki, M; Roukoutakis, F; Keil, M; Morsch, A; Rademakers, A; Soos, C; Zampolli, C; Grigoras, C; Chibante barroso, V M; Schuchmann, S; Grigoras, A G; Lafuente mazuecos, A; Wegrzynek, A T; Bielcikova, J; Kushpil, S; Braun-munzinger, P; Andronic, A; Zimmermann, A; Rosnet, P; Ramillien barret, V; Lopez, X B; Arbor, N; Erazmus, B E; Pichot, P; Pillot, P; Grossiord, J; Boldizsar, L; Khan, S; Puddu, G; Marras, D; Siddhanta, S; Costanza, S; Botta, E; Gallio, M; Masera, M; Simonetti, L; Prino, F; Oppedisano, C; Vargas trevino, A D; Nystrand, J I; Ullaland, K; Haaland, O S; Huang, M; Naumov, S; Zinovjev, M; Trubnikov, V; Alkin, A; Ivanytskyi, O; Guber, F; Karavichev, O; Nyanin, A; Sibiryak, Y; Peresunko, D Y; Patarakin, O; Aleksandrov, D; Blau, D; Yasnopolskiy, S; Chumakov, M; Vetlitskiy, I; Nedosekin, A; Selivanov, A; Okorokov, V; Grigoryan, A; Papikyan, V; Kuhn, C C; Wan, R; Cajko, F; Siska, M; Mares, J; Zavada, P; Ceballos sanchez, C; Reolon, A R; Gunji, T; Snellings, R; Mayer, C; Klusek-gawenda, M J; Schiaua, C C; Andrei, C; Herghelegiu, A I; Soegaard, C; Panebrattsev, Y; Penev, V; Efimov, L; Zanevskiy, Y; Vechernin, V; Zarochentsev, A; Kolevatov, R; Agapov, A; Polishchuk, B; Nattrass, C; Anticic, T; Kwon, Y; Kim, M; Moon, T; Seger, J E; Petran, M; Sahoo, B; Das bose, L; Hushnud, H; Hatzifotiadou, D; Shigaki, K; Jha, D M; Murray, S; Badala, A; Putevskoy, S; Shapovalova, E; Haiduc, M; Mitu, C M; Mischke, A; Grelli, A; Hetland, K F; Rachevski, A; Menchaca-rocha, A A; De cuveland, J; Hutter, D; Langhammer, M; Dahms, T; Watkins, E P; Gago medina, A M; Planinic, M; Riegler, W; Telesca, A; Knichel, M L; Lazaridis, L; Ferencei, J; Martin, N A; Appelshaeuser, H; Heckel, S T; Windelband, B S; Nielsen, B S; Chojnacki, M; Baldit, A; Manso, F; Crochet, P; Espagnon, B; Uras, A; Lietava, R; Lemmon, R C; Agocs, A G; Viyogi, Y; Pal, S K; Singhal, V; Khan, S A; Alam, S N; Rodriguez cahuantzi, M; Maslov, M; Kurepin, A; Ippolitov, M; Lebedev, V; Tsvetkov, A; Klimov, A; Agafonov, G; Martemiyanov, A; Loginov, V; Kononov, S; Hnatic, M; Kalinak, P; Trzaska, W H; Raha, S; Canoa roman, V; Cruz albino, R; Botje, M; Gladysz-dziadus, E; Marszal, T; Oskarsson, A N E; Otterlund, I; Tydesjo, H; Ljunggren, H M; Vodopyanov, A; Akichine, P; Kuznetsov, A; Vedeneyev, V; Naumenko, P; Bilov, N; Rogalev, R; Evdokimov, S; Braidot, E; Bellwied, R; De caro, A; Kang, J H; Gorbunov, Y; Lee, J; Pachr, M; Dash, S; Roy, P K; Cifarelli, L; Laurenti, G; Margotti, A; Sugitate, T; Ivanov, V; Zhalov, M; Salzwedel, J S N; Pavlinov, A; Harris, J W; Caballero orduna, D; Fiore, E M; Pluta, J M; Kisiel, A R; Wrobel, D; Klein-boesing, C; Grimaldi, A; Zhitnik, A; Nazarenko, S; Zavyalov, N; Miroshnikov, D; Kuryakin, A; Vyushin, A; Mamonov, A; Vickovic, L; Niculescu, M; Fragiacomo, E; Ahn, S U; Ahn, S; Foertsch, S V; Brown, C R; Lovhoiden, G; Harton, A V; Khosonthongkee, K; Langoy, R; Schmidt, H R; Betev, L; Buncic, P; Di mauro, A; Martinengo, P; Gargiulo, C; Grosse-oetringhaus, J F; Costa, F; Baltasar dos santos pedrosa, F; Laudi, E; Adamova, D; Lippmann, C; Schmidt, C J; Book, J H; Grajcarek, R; Christensen, C H; Dupieux, P; Bastid, N; Rakotozafindrabe, A M; Conesa balbastre, G; Martinez-garcia, G; Suire, C P; Ducroux, L; Tieulent, R N; Jusko, A; Barnafoldi, G G; Pochybova, S; Hussain, T; Dubey, A K; Acharya, S; Gupta, A; Ricci, R A; Meddi, F; Vercellin, E; Chujo, T; Watanabe, K; Onishi, H; Akiba, Y; Vergara limon, S; Tejeda munoz, G; Skjerdal, K; Svistunov, S; Reshetin, A; Maevskaya, A; Antonenko, V; Mishustin, N; Meleshko, E; Korsheninnikov, A; Balygin, K; Zagreev, B; Akindinov, A; Mikhaylov, K; Gushchin, O; Grigoryev, V; Gulkanyan, H; Sanchez castro, X; Peretti pezzi, R; Oliveira da silva, A C; Harmanova, Z; Vokal, S; Beitlerova, A; Rak, J; Ghosh, S K; Bhati, A K; Spiriti, E; Ronchetti, F; Casanova diaz, A O; Kuzmin, N; Melkumov, G; Zinchenko, A; Shklovskaya, A; Bunzarov, Z I; Chernenko, S; Rogachevskiy, O; Toulina, T; Kompaniets, M; Titov, A; Kharlov, Y; Dantsevich, G; Stolpovskiy, M; Porter, R J; Datskova, O V; Kim, D S; Jung, W W; Kim, H; Bielcik, J; Pospisil, V; Cepila, J; Das, D; Williams, C; Pesci, A; Roshchin, E; Grounds, A; Humanic, T; Steinpreis, M D; Yaldo, C G; Smirnov, N; Heinz, M T; Connors, M E; Barile, F; Lunardon, M; Orzan, G; Wielanek, D H; Servais, E L J; Patecki, M; Passfeld, A; Zhelezov, S; Morkin, A; Zabelin, O; Hobbs, D A; Gul, M; Ramello, L; Van den brink, A; Bertens, R A; Lodato, D F; Haque, M R; Kim, E J; Coccetti, F; Margagliotti, G V; Rauf, A W; Sandoval, A; Berger, M E; Munzer, R H; Qvigstad, H; Lindal, S; Cervantes jr, M; Kebschull, U W; Engel, H; Karasu uysal, A; Lien, J A; Hess, B A; Calvo villar, E; Augustinus, A; Carena, W; Chochula, P; Chapeland, S; Dobrin, A F; Reidt, F; Bock, F; Festanti, A; Galdames perez, A; Sumbera, M; Averbeck, R P; Garabatos cuadrado, J; Reichelt, P S; Marquard, M; Stachel, J; Wang, Y; Boggild, H; Gulbrandsen, K H; Hansen, J C; Charvet, J F; Shabetai, A; Hadjidakis, C M; Krivda, M; Vertesi, R; Mitra, J; Altini, V; Ferretti, A; Gagliardi, M; Sakata, D; Niida, T; Martinez hernandez, M I; Yang, S; Karpechev, E; Veselovskiy, A; Konevskikh, A; Finogeev, D; Fokin, S; Karadzhev, K; Kucheryaev, Y; Plotnikov, V; Ryabinin, M; Golubev, A; Kaplin, V; Ter-minasyan, A; Abramyan, A; Raniwala, S; Hippolyte, B; Strmen, P; Krivan, F; Kalliokoski, T E A; Chang, B; De cataldo, G; Paticchio, V; Fantoni, A; Gomez jimenez, R; Christakoglou, P; Cyz, A; Wilk, G A; Kurashvili, P; Pop, A; Arefiev, V; Batyunya, B; Lioubochits, V; Zryuev, V; Sokolov, M; Patalakha, D; Pinsky, L; Timmins, A R; Petracek, V; Krelina, M; Chattopadhyay, S; Basile, M; Falchieri, D; Miftakhov, N; Garner, R M; Konyushikhin, M; Joseph, N; Srivastava, B K; Cleymans, J W A; Dietel, T; Soramel, F; Pawlak, T J; Kucinski, M; Janik, M A; Surma, K D; Wessels, J P; Riggi, F; Ivanov, A; Selin, I; Budnikov, D; Filchagin, S; Sitta, M; Gheata, M; Danu, A; Peitzmann, T; Reicher, M; Helstrup, H; Subasi, M; Mathis, A M; Nilsson, M S; Rist, J A S; Jena, C; Lara martinez, C E; Vasileiou, M

2002-01-01

%title\\\\ \\\\ALICE is a general-purpose heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma in nucleus-nucleus collisions at the LHC. It currently includes more than 750~physicists and $\\sim$70 institutions in 27 countries.\\\\ \\\\The detector is designed to cope with the highest particle multiplicities anticipated for Pb-Pb reactions (dN/dy~$\\approx$~8000) and it will be operational at the start-up of the LHC. In addition to heavy systems, the ALICE Collaboration will study collisions of lower-mass ions, which are a means of varying the energy density, and protons (both pp and p-nucleus), which provide reference data for the nucleus-nucleus collisions.\\\\ \\\\ALICE consists of a central part, which measures event-by-event hadrons, electrons and photons, and a forward spectrometer to measure muons. The central part, which covers polar angles from 45$^{0} $ to 135$^{0} $ ($\\mid \\eta \\mid $ < 0.9) over the full azimuth, is embedded in the large L3 solenoidal mag...

Status of the Grid Computing for the ALICE Experiment in the Czech Republic

International Nuclear Information System (INIS)

Adamova, D; Hampl, J; Chudoba, J; Kouba, T; Svec, J; Mendez, Lorenzo P; Saiz, P

2010-01-01

The Czech Republic (CR) has been participating in the LHC Computing Grid project (LCG) ever since 2003 and gradually, a middle-sized Tier-2 center has been built in Prague, delivering computing services for national HEP experiments groups including the ALICE project at the LHC. We present a brief overview of the computing activities and services being performed in the CR for the ALICE experiment.

29 November 2013 - U. Humphrey Orjiako Nigerian Ambassador Extraordinary and Plenipotentiary Permanent Mission to the United Nations Office and other international organisations in Geneva signing the Guest Book with Head of International Relations R. Voss, visiting the LHC tunnel at Point 2 and the ALICE cavern with ALICE Collaboration Deputy Spokesperson Y. Schutz.

CERN Multimedia

Noemi Caraban

2013-01-01

29 November 2013 - U. Humphrey Orjiako Nigerian Ambassador Extraordinary and Plenipotentiary Permanent Mission to the United Nations Office and other international organisations in Geneva signing the Guest Book with Head of International Relations R. Voss, visiting the LHC tunnel at Point 2 and the ALICE cavern with ALICE Collaboration Deputy Spokesperson Y. Schutz.

Study of the strange baryons and mesons production (Λ and Ks0) in proton-proton collisions with the ALICE experiment at the LHC

International Nuclear Information System (INIS)

Ricaud, H.

2008-11-01

The ALICE experiment at LHC is dedicated to the investigation of the transition of matter from the hadron gas to the Quark and Gluons Plasma in which partons are deconfined. Ultra-relativistic heavy-ion collisions offer indeed the possibility to create extreme temperature and pressure conditions which are required to reach a deconfined phase. Elementary collisions such as proton-proton are of great importance since they are regarded as the hadronic reference. The aim of this thesis was to prepare the analysis of strange baryon and meson production mechanisms in proton-proton collisions at the LHC energies by the detection of Λ and K s 0 particles with ALICE. Strange particles are a major tool to probe the matter created. The behaviour of the Λ/K s 0 ratio at intermediate transverse momentum in high energy proton-proton collisions, that we have studied with several theoretical models, could also sign the presence of collective phenomena. Up to now, these phenomena have been observed only in heavy-ion collisions. (author)

Overview of recent ALICE results

CERN Document Server

Gunji, Taku

2016-01-01

The ALICE experiment explores the properties of strongly interacting QCD matter at extremely high temperatures created in Pb-Pb collisions at LHC and provides further insight into small-system physics in (high-multiplicity) pp and p-Pb collisions. The ALICE collaboration presented 27 parallel talks, 50 posters, and 1 flash talk at Quark Matter 2015 and covered various topics including collective dynamics, correlations and fluctuations, heavy flavors, quarkonia, jets and high $p_{\\rm T}$ hadrons, electromagnetic probes, small system physics, and the upgrade program. This paper highlights some of the selected results.

Overview of recent ALICE results

Energy Technology Data Exchange (ETDEWEB)

Gunji, Taku

2016-12-15

The ALICE experiment explores the properties of strongly interacting QCD matter at extremely high temperatures created in Pb-Pb collisions at LHC and provides further insight into small-system physics in (high-multiplicity) pp and p-Pb collisions. The ALICE collaboration presented 27 parallel talks, 50 posters, and 1 flash talk at Quark Matter 2015 and covered various topics including collective dynamics, correlations and fluctuations, heavy flavors, quarkonia, jets and high p{sub T} hadrons, electromagnetic probes, small system physics, and the upgrade program. This paper highlights some of the selected results.

ALICE HLT Run 2 performance overview.

Science.gov (United States)

Krzewicki, Mikolaj; Lindenstruth, Volker; ALICE Collaboration

2017-10-01

For the LHC Run 2 the ALICE HLT architecture was consolidated to comply with the upgraded ALICE detector readout technology. The software framework was optimized and extended to cope with the increased data load. Online calibration of the TPC using online tracking capabilities of the ALICE HLT was deployed. Offline calibration code was adapted to run both online and offline and the HLT framework was extended to support that. The performance of this schema is important for Run 3 related developments. An additional data transport approach was developed using the ZeroMQ library, forming at the same time a test bed for the new data flow model of the O2 system, where further development of this concept is ongoing. This messaging technology was used to implement the calibration feedback loop augmenting the existing, graph oriented HLT transport framework. Utilising the online reconstruction of many detectors, a new asynchronous monitoring scheme was developed to allow real-time monitoring of the physics performance of the ALICE detector, on top of the new messaging scheme for both internal and external communication. Spare computing resources comprising the production and development clusters are run as a tier-2 GRID site using an OpenStack-based setup. The development cluster is running continuously, the production cluster contributes resources opportunistically during periods of LHC inactivity.

ALICE takes its ITS to heart

CERN Multimedia

2007-01-01

In the study of heavy-ion events, the ALICE Inner Tracking System must use the most delicate materials. A hundred physicists and engineers from around the world witnessed its impressive journey to the centre of the ALICE experiment. ALICE's ITS on its way into the TCP. On 15 March, after 15 years of development, construction, commissioning and testing, the Inner Tracking System (ITS) finally reached its ultimate destination at the heart of ALICE. With almost five square meters of double-sided silicon strip detectors and over one square meter of silicon drift detectors, ALICE's ITS is the largest system built for either type of silicon detector. In ALICE's search for heavy-ion events at the LHC, it is necessary for the ITS to be extremely lightweight and delicate. For this reason the ITS was designed and built using the smallest amounts of only the lightest materials, with the design team developing innovative construction and assembly systems. The team prepared in detail for the final transport from the fi...

Investigation of baryons with strangeness and search for weakly decaying exotics with ALICE at the LHC

CERN Document Server

Dönigus, Benjamin; Braun-Munzinger, P

Within this work data are analysed which have been taken with the ALICE apparatus (A Large Ion Collider Experiment) at the Large Hadron Collider (LHC). The unique properties and the excellent performance of the LHC made it possible to take data for proton-proton collisions (pp) in the last three years at several center-of-mass energies (0.9 TeV, 2.36 TeV, 2.76 TeV, 7 TeV and 8 TeV). It was further possible to aquire data in two of the three years of lead–lead collisions (Pb–Pb) at sqrt(s_NN) = 2.76TeV and recently a short pilot run of proton–lead collisions (pPb) at sqrt(s_NN) = 5.01TeV was recorded. It will be continued as a full run in January/February this year. The high energies and at the same time low baryo-chemical potential (mu_B around 0) in Pb–Pb collisions at the LHC allow the production of strangeness, charm and bottom quarks in up to now unseen quantities. The particles created, either in the initial hard collision (charm and bottom) or in the quark-gluon plasma, end up in hadrons or ligh...

Commissioning of the ALICE-LHC online data quality monitoring framework

International Nuclear Information System (INIS)

Roukoutakis, Filimon; Haller, Barthelemy von

2009-01-01

ALICE is one of the experiments installed at CERN Large Hadron Collider, dedicated to the study of heavy-ion collisions. The final ALICE data acquisition system has been installed and is being used for the testing and commissioning of detectors. Data Quality Monitoring (DQM) is an important aspect of the online procedures for a HEP experiment. In this presentation we overview the commissioning and the integration of ALICE's AMORE (Automatic MOnitoRing Environment), a custom-written distributed application aimed at providing DQM services in a large, experiment-wide scale.

ALICE: The best is yet to come

CERN Multimedia

CERN Bulletin

2010-01-01

The ALICE wonderland is the ion-ion collisions. However, the proton run was intensely used by the collaboration to get to know its detector in detail and to produce its first results in QCD-related matters. This very successful preparatory phase will now allow ALICE to enter the uncharted territory of the quark-gluon plasma at the extreme energies provided by the LHC.   The ALICE detector is optimized to study ion-ion collisions in which quark-gluon plasma may be formed. This type of matter, which existed a few moments after the Big Bang and appears when quarks and gluons are deconfined to form a highly dense and hot soup, has been studied at CERN’s SPS in the 1990s and later, from 2000 onwards, at much higher energy at RHIC in the US. Now it’s ALICE’s turn. “Quark-gluon plasma is created at very high temperatures but starts to cool down very quickly to become normal matter again. The high energy of the LHC puts us much higher above the threshold of its for...

Performance of the ALICE Experiment at the CERN LHC

CERN Document Server

Abelev, Betty Bezverkhny; Adam, Jaroslav; Adamova, Dagmar; Aggarwal, Madan Mohan; Agnello, Michelangelo; Agostinelli, Andrea; Agrawal, Neelima; Ahammed, Zubayer; Ahmad, Nazeer; Ahmad, Arshad; Ahmed, Ijaz; Ahn, Sang Un; Ahn, Sul-Ah; Aimo, Ilaria; Aiola, Salvatore; Ajaz, Muhammad; Akindinov, Alexander; Aleksandrov, Dmitry; Alessandro, Bruno; Alexandre, Didier; Alici, Andrea; Alkin, Anton; Alme, Johan; Alt, Torsten; Altini, Valerio; Altinpinar, Sedat; Altsybeev, Igor; Alves Garcia Prado, Caio; Andrei, Cristian; Andronic, Anton; Anguelov, Venelin; Anielski, Jonas; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Aphecetche, Laurent Bernard; Appelshaeuser, Harald; Arbor, Nicolas; Arcelli, Silvia; Armesto Perez, Nestor; Arnaldi, Roberta; Aronsson, Tomas; Arsene, Ionut Cristian; Arslandok, Mesut; Augustinus, Andre; Averbeck, Ralf Peter; Awes, Terry; Azmi, Mohd Danish; Bach, Matthias Jakob; Badala, Angela; Baek, Yong Wook; Bagnasco, Stefano; Bailhache, Raphaelle Marie; Bala, Renu; Baldisseri, Alberto; Baltasar Dos Santos Pedrosa, Fernando; Baral, Rama Chandra; Barbera, Roberto; Barile, Francesco; Barnafoldi, Gergely Gabor; Barnby, Lee Stuart; Ramillien Barret, Valerie; Bartke, Jerzy Gustaw; Basile, Maurizio; Bastid, Nicole; Basu, Sumit; Bathen, Bastian; Batigne, Guillaume; Batyunya, Boris; Batzing, Paul Christoph; Baumann, Christoph Heinrich; Bearden, Ian Gardner; Beck, Hans; Bedda, Cristina; Behera, Nirbhay Kumar; Belikov, Iouri; Bellini, Francesca; Bellwied, Rene; Belmont Moreno, Ernesto; Bencedi, Gyula; Beole, Stefania; Berceanu, Ionela; Bercuci, Alexandru; Berdnikov, Yaroslav; Berenyi, Daniel; Berger, Martin Emanuel; Bertens, Redmer Alexander; Berzano, Dario; Betev, Latchezar; Bhasin, Anju; Bhati, Ashok Kumar; Bhattacharjee, Buddhadeb; Bhom, Jihyun; Bianchi, Livio; Bianchi, Nicola; Bianchin, Chiara; Bielcik, Jaroslav; Bielcikova, Jana; Bilandzic, Ante; Bjelogrlic, Sandro; Blanco, Fernando; Blau, Dmitry; Blume, Christoph; Bock, Friederike; Bogdanov, Alexey; Boggild, Hans; Bogolyubskiy, Mikhail; Boehmer, Felix Valentin; Boldizsar, Laszlo; Bombara, Marek; Book, Julian Heinz; Borel, Herve; Borissov, Alexander; Bossu, Francesco; Botje, Michiel; Botta, Elena; Boettger, Stefan; Braun-Munzinger, Peter; Bregant, Marco; Breitner, Timo Gunther; Broker, Theo Alexander; Browning, Tyler Allen; Broz, Michal; Bruna, Elena; Bruno, Giuseppe Eugenio; Budnikov, Dmitry; Buesching, Henner; Bufalino, Stefania; Buncic, Predrag; Busch, Oliver; Buthelezi, Edith Zinhle; Caffarri, Davide; Cai, Xu; Caines, Helen Louise; Caliva, Alberto; Calvo Villar, Ernesto; Camerini, Paolo; Canoa Roman, Veronica; Carena, Francesco; Carena, Wisla; Castillo Castellanos, Javier Ernesto; Casula, Ester Anna Rita; Catanescu, Vasile Ioan; Cavicchioli, Costanza; Ceballos Sanchez, Cesar; Cepila, Jan; Cerello, Piergiorgio; Chang, Beomsu; Chapeland, Sylvain; Charvet, Jean-Luc Fernand; Chattopadhyay, Subhasis; Chattopadhyay, Sukalyan; Cherney, Michael Gerard; Cheshkov, Cvetan Valeriev; Cheynis, Brigitte; Chibante Barroso, Vasco Miguel; Dobrigkeit Chinellato, David; Chochula, Peter; Chojnacki, Marek; Choudhury, Subikash; Christakoglou, Panagiotis; Christensen, Christian Holm; Christiansen, Peter; Chujo, Tatsuya; Chung, Suh-Urk; Cicalo, Corrado; Cifarelli, Luisa; Cindolo, Federico; Cleymans, Jean Willy Andre; Colamaria, Fabio Filippo; Colella, Domenico; Collu, Alberto; Colocci, Manuel; Conesa Balbastre, Gustavo; Conesa Del Valle, Zaida; Connors, Megan Elizabeth; Contreras Nuno, Jesus Guillermo; Cormier, Thomas Michael; Corrales Morales, Yasser; Cortese, Pietro; Cortes Maldonado, Ismael; Cosentino, Mauro Rogerio; Costa, Filippo; Crochet, Philippe; Cruz Albino, Rigoberto; Cuautle Flores, Eleazar; Cunqueiro Mendez, Leticia; Dainese, Andrea; Dang, Ruina; Danu, Andrea; Das, Debasish; Das, Indranil; Das, Kushal; Das, Supriya; Dash, Ajay Kumar; Dash, Sadhana; De, Sudipan; Delagrange, Hugues; Deloff, Andrzej; Denes, Ervin Sandor; D'Erasmo, Ginevra; De Caro, Annalisa; De Cataldo, Giacinto; De Cuveland, Jan; De Falco, Alessandro; De Gruttola, Daniele; De Marco, Nora; De Pasquale, Salvatore; De Rooij, Raoul Stefan; Diaz Corchero, Miguel Angel; Dietel, Thomas; Divia, Roberto; Di Bari, Domenico; Di Liberto, Sergio; Di Mauro, Antonio; Di Nezza, Pasquale; Djuvsland, Oeystein; Dobrin, Alexandru Florin; Dobrowolski, Tadeusz Antoni; Domenicis Gimenez, Diogenes; Donigus, Benjamin; Dordic, Olja; Dorheim, Sverre; Dubey, Anand Kumar; Dubla, Andrea; Ducroux, Laurent; Dupieux, Pascal; Dutt Mazumder, Abhee Kanti; Ehlers Iii, Raymond James; Elia, Domenico; Engel, Heiko; Erazmus, Barbara Ewa; Erdal, Hege Austrheim; Eschweiler, Dominic; Espagnon, Bruno; Esposito, Marco; Estienne, Magali Danielle; Esumi, Shinichi; Evans, David; Evdokimov, Sergey; Fabris, Daniela; Faivre, Julien; Falchieri, Davide; Fantoni, Alessandra; Fasel, Markus; Fehlker, Dominik; Feldkamp, Linus; Felea, Daniel; Feliciello, Alessandro; Feofilov, Grigory; Ferencei, Jozef; Fernandez Tellez, Arturo; Gonzalez Ferreiro, Elena; Ferretti, Alessandro; Festanti, Andrea; Figiel, Jan; Araujo Silva Figueredo, Marcel; Filchagin, Sergey; Finogeev, Dmitry; Fionda, Fiorella; Fiore, Enrichetta Maria; Floratos, Emmanouil; Floris, Michele; Foertsch, Siegfried Valentin; Foka, Panagiota; Fokin, Sergey; Fragiacomo, Enrico; Francescon, Andrea; Frankenfeld, Ulrich Michael; Fuchs, Ulrich; Furget, Christophe; Fusco Girard, Mario; Gaardhoeje, Jens Joergen; Gagliardi, Martino; Gago Medina, Alberto Martin; Gallio, Mauro; Gangadharan, Dhevan Raja; Ganoti, Paraskevi; Garabatos Cuadrado, Jose; Garcia-Solis, Edmundo Javier; Gargiulo, Corrado; Garishvili, Irakli; Gerhard, Jochen; Germain, Marie; Gheata, Andrei George; Gheata, Mihaela; Ghidini, Bruno; Ghosh, Premomoy; Ghosh, Sanjay Kumar; Gianotti, Paola; Giubellino, Paolo; Gladysz-Dziadus, Ewa; Glassel, Peter; Gomez Jimenez, Ramon; Gomez Ramirez, Andres; Gonzalez Zamora, Pedro; Gorbunov, Sergey; Gorlich, Lidia Maria; Gotovac, Sven; Graczykowski, Lukasz Kamil; Grajcarek, Robert; Grelli, Alessandro; Grigoras, Alina Gabriela; Grigoras, Costin; Grigoryev, Vladislav; Grigoryan, Ara; Grigoryan, Smbat; Grynyov, Borys; Grion, Nevio; Grosse-Oetringhaus, Jan Fiete; Grossiord, Jean-Yves; Grosso, Raffaele; Guber, Fedor; Guernane, Rachid; Guerzoni, Barbara; Guilbaud, Maxime Rene Joseph; Gulbrandsen, Kristjan Herlache; Gulkanyan, Hrant; Gunji, Taku; Gupta, Anik; Gupta, Ramni; Khan, Kamal; Haake, Rudiger; Haaland, Oystein Senneset; Hadjidakis, Cynthia Marie; Haiduc, Maria; Hamagaki, Hideki; Hamar, Gergoe; Hanratty, Luke David; Hansen, Alexander; Harris, John William; Hartmann, Helvi; Harton, Austin Vincent; Hatzifotiadou, Despina; Hayashi, Shinichi; Heckel, Stefan Thomas; Heide, Markus Ansgar; Helstrup, Haavard; Herghelegiu, Andrei Ionut; Herrera Corral, Gerardo Antonio; Hess, Benjamin Andreas; Hetland, Kristin Fanebust; Hicks, Bernard Richard; Hippolyte, Boris; Hladky, Jan; Hristov, Peter Zahariev; Huang, Meidana; Humanic, Thomas; Hutter, Dirk; Hwang, Dae Sung; Ilkaev, Radiy; Ilkiv, Iryna; Inaba, Motoi; Innocenti, Gian Michele; Ionita, Costin; Ippolitov, Mikhail; Irfan, Muhammad; Ivanov, Marian; Ivanov, Vladimir; Ivanytskyi, Oleksii; Jacholkowski, Adam Wlodzimierz; Jacobs, Peter Martin; Jahnke, Cristiane; Jang, Haeng Jin; Janik, Malgorzata Anna; Pahula Hewage, Sandun; Jena, Satyajit; Jimenez Bustamante, Raul Tonatiuh; Jones, Peter Graham; Jung, Hyungtaik; Jusko, Anton; Kalcher, Sebastian; Kalinak, Peter; Kalweit, Alexander Philipp; Kamin, Jason Adrian; Kang, Ju Hwan; Kaplin, Vladimir; Kar, Somnath; Karasu Uysal, Ayben; Karavichev, Oleg; Karavicheva, Tatiana; Karpechev, Evgeny; Kebschull, Udo Wolfgang; Keidel, Ralf; Ketzer, Bernhard Franz; Khan, Mohammed Mohisin; Khan, Palash; Khan, Shuaib Ahmad; Khanzadeev, Alexei; Kharlov, Yury; Kileng, Bjarte; Kim, Beomkyu; Kim, Do Won; Kim, Dong Jo; Kim, Jinsook; Kim, Mimae; Kim, Minwoo; Kim, Se Yong; Kim, Taesoo; Kirsch, Stefan; Kisel, Ivan; Kiselev, Sergey; Kisiel, Adam Ryszard; Kiss, Gabor; Klay, Jennifer Lynn; Klein, Jochen; Klein-Boesing, Christian; Kluge, Alexander; Knichel, Michael Linus; Knospe, Anders Garritt; Kobdaj, Chinorat; Kofarago, Monika; Kohler, Markus Konrad; Kollegger, Thorsten; Kolozhvari, Anatoly; Kondratev, Valerii; Kondratyeva, Natalia; Konevskikh, Artem; Kovalenko, Vladimir; Kowalski, Marek; Kox, Serge; Koyithatta Meethaleveedu, Greeshma; Kral, Jiri; Kralik, Ivan; Kramer, Frederick; Kravcakova, Adela; Krelina, Michal; Kretz, Matthias; Krivda, Marian; Krizek, Filip; Krus, Miroslav; Kryshen, Evgeny; Krzewicki, Mikolaj; Kucera, Vit; Kucheryaev, Yury; Kugathasan, Thanushan; Kuhn, Christian Claude; Kuijer, Paulus Gerardus; Kulakov, Igor; Kumar, Jitendra; Kurashvili, Podist; Kurepin, Alexander; Kurepin, Alexey; Kuryakin, Alexey; Kushpil, Svetlana; Kweon, Min Jung; Kwon, Youngil; Ladron De Guevara, Pedro; Lagana Fernandes, Caio; Lakomov, Igor; Langoy, Rune; Lara Martinez, Camilo Ernesto; Lardeux, Antoine Xavier; Lattuca, Alessandra; La Pointe, Sarah Louise; La Rocca, Paola; Lea, Ramona; Lee, Graham Richard; Legrand, Iosif; Lehnert, Joerg Walter; Lemmon, Roy Crawford; Lenhardt, Matthieu Laurent; Lenti, Vito; Leogrande, Emilia; Leoncino, Marco; Leon Monzon, Ildefonso; Levai, Peter; Li, Shuang; Lien, Jorgen Andre; Lietava, Roman; Lindal, Svein; Lindenstruth, Volker; Lippmann, Christian; Lisa, Michael Annan; Ljunggren, Hans Martin; Lodato, Davide Francesco; Lonne, Per-Ivar; Loggins, Vera Renee; Loginov, Vitaly; Lohner, Daniel; Loizides, Constantinos; Lopez, Xavier Bernard; Lopez Torres, Ernesto; Lu, Xianguo; Luettig, Philipp Johannes; Lunardon, Marcello; Luo, Jiebin; Luparello, Grazia; Luzzi, Cinzia; Ma, Rongrong; Maevskaya, Alla; Mager, Magnus; Mahapatra, Durga Prasad; Maire, Antonin; Majka, Richard Daniel; Malaev, Mikhail; Maldonado Cervantes, Ivonne Alicia; Malinina, Liudmila; Mal'Kevich, Dmitry; Malzacher, Peter; Mamonov, Alexander; Manceau, Loic Henri Antoine; Manko, Vladislav; Manso, Franck; Manzari, Vito; Marchisone, Massimiliano; Mares, Jiri; Margagliotti, Giacomo Vito; Margotti, Anselmo; Marin, Ana Maria; Markert, Christina; Marquard, Marco; Martashvili, Irakli; Martin, Nicole Alice; Martinengo, Paolo; Martinez Hernandez, Mario Ivan; Martinez-Garcia, Gines; Martin Blanco, Javier; Martynov, Yevgen; Mas, Alexis Jean-Michel; Masciocchi, Silvia; Masera, Massimo; Masoni, Alberto; Massacrier, Laure Marie; Mastroserio, Annalisa; Matyja, Adam Tomasz; Mayer, Christoph; Mazer, Joel Anthony; Mazzoni, Alessandra Maria; Meddi, Franco; Menchaca-Rocha, Arturo Alejandro; Meninno, Elisa; Mercado-Perez, Jorge; Meres, Michal; Miake, Yasuo; Mikhaylov, Konstantin; Milano, Leonardo; Milosevic, Jovan; Mischke, Andre; Mishra, Aditya Nath; Miskowiec, Dariusz Czeslaw; Mitu, Ciprian Mihai; Mlynarz, Jocelyn; Mohanty, Bedangadas; Molnar, Levente; Montano Zetina, Luis Manuel; Montes Prado, Esther; Morando, Maurizio; Moreira De Godoy, Denise Aparecida; Moretto, Sandra; Morreale, Astrid; Morsch, Andreas; Muccifora, Valeria; Mudnic, Eugen; Muhuri, Sanjib; Mukherjee, Maitreyee; Muller, Hans; Gameiro Munhoz, Marcelo; Murray, Sean; Musa, Luciano; Musinsky, Jan; Nandi, Basanta Kumar; Nania, Rosario; Nappi, Eugenio; Nattrass, Christine; Nayak, Tapan Kumar; Nazarenko, Sergey; Nedosekin, Alexander; Nicassio, Maria; Niculescu, Mihai; Nielsen, Borge Svane; Nikolaev, Sergey; Nikulin, Sergey; Nikulin, Vladimir; Nilsen, Bjorn Steven; Noferini, Francesco; Nomokonov, Petr; Nooren, Gerardus; Nyanin, Alexander; Nystrand, Joakim Ingemar; Oeschler, Helmut Oskar; Oh, Saehanseul; Oh, Sun Kun; Okatan, Ali; Olah, Laszlo; Oleniacz, Janusz; Oliveira Da Silva, Antonio Carlos; Onderwaater, Jacobus; Oppedisano, Chiara; Ortiz Velasquez, Antonio; Oskarsson, Anders Nils Erik; Otwinowski, Jacek Tomasz; Oyama, Ken; Sahoo, Pragati; Pachmayer, Yvonne Chiara; Pachr, Milos; Pagano, Paola; Paic, Guy; Painke, Florian; Pajares Vales, Carlos; Pal, Susanta Kumar; Palmeri, Armando; Pant, Divyash; Papikyan, Vardanush; Pappalardo, Giuseppe; Pareek, Pooja; Park, Woojin; Parmar, Sonia; Passfeld, Annika; Patalakha, Dmitry; Paticchio, Vincenzo; Paul, Biswarup; Pawlak, Tomasz Jan; Peitzmann, Thomas; Pereira Da Costa, Hugo Denis Antonio; Pereira De Oliveira Filho, Elienos; Peresunko, Dmitry Yurevich; Perez Lara, Carlos Eugenio; Pesci, Alessandro; Pestov, Yury; Petracek, Vojtech; Petran, Michal; Petris, Mariana; Petrovici, Mihai; Petta, Catia; Piano, Stefano; Pikna, Miroslav; Pillot, Philippe; Pinazza, Ombretta; Pinsky, Lawrence; Piyarathna, Danthasinghe; Ploskon, Mateusz Andrzej; Planinic, Mirko; Pluta, Jan Marian; Pochybova, Sona; Podesta Lerma, Pedro Luis Manuel; Poghosyan, Martin; Pohjoisaho, Esko Heikki Oskari; Polishchuk, Boris; Poljak, Nikola; Pop, Amalia; Porteboeuf, Sarah Julie; Porter, R Jefferson; Pospisil, Vladimir; Potukuchi, Baba; Prasad, Sidharth Kumar; Preghenella, Roberto; Prino, Francesco; Pruneau, Claude Andre; Pshenichnov, Igor; Puccio, Maximiliano; Puddu, Giovanna; Punin, Valery; Putschke, Jorn Henning; Qvigstad, Henrik; Rachevski, Alexandre; Raha, Sibaji; Rak, Jan; Rakotozafindrabe, Andry Malala; Ramello, Luciano; Raniwala, Rashmi; Raniwala, Sudhir; Rasanen, Sami Sakari; Rascanu, Bogdan Theodor; Rathee, Deepika; Rauf, Aamer Wali; Razazi, Vahedeh; Read, Kenneth Francis; Real, Jean-Sebastien; Redlich, Krzysztof; Reed, Rosi Jan; Rehman, Attiq Ur; Reichelt, Patrick Simon; Reicher, Martijn; Reidt, Felix; Renfordt, Rainer Arno Ernst; Reolon, Anna Rita; Reshetin, Andrey; Rettig, Felix Vincenz; Revol, Jean-Pierre; Reygers, Klaus Johannes; Riabov, Viktor; Ricci, Renato Angelo; Richert, Tuva Ora Herenui; Richter, Matthias Rudolph; Riedler, Petra; Riegler, Werner; Riggi, Francesco; Rivetti, Angelo; Rocco, Elena; Rodriguez Cahuantzi, Mario; Rodriguez Manso, Alis; Roeed, Ketil; Rogochaya, Elena; Sharma, Rohni; Rohr, David Michael; Roehrich, Dieter; Romita, Rosa; Ronchetti, Federico; Ronflette, Lucile; Rosnet, Philippe; Rossegger, Stefan; Rossi, Andrea; Roukoutakis, Filimon; Roy, Ankhi; Roy, Christelle Sophie; Roy, Pradip Kumar; Rubio Montero, Antonio Juan; Rui, Rinaldo; Russo, Riccardo; Ryabinkin, Evgeny; Ryabov, Yury; Rybicki, Andrzej; Sadovskiy, Sergey; Safarik, Karel; Sahlmuller, Baldo; Sahoo, Raghunath; Sahu, Pradip Kumar; Saini, Jogender; Salgado Lopez, Carlos Alberto; Salzwedel, Jai Samuel Nielsen; Sambyal, Sanjeev Singh; Samsonov, Vladimir; Sanchez Castro, Xitzel; Sanchez Rodriguez, Fernando Javier; Sandor, Ladislav; Sandoval, Andres; Sano, Masato; Santagati, Gianluca; Sarkar, Debojit; Scapparone, Eugenio; Scarlassara, Fernando; Scharenberg, Rolf Paul; Schiaua, Claudiu Cornel; Schicker, Rainer Martin; Schmidt, Christian Joachim; Schmidt, Hans Rudolf; Schuchmann, Simone; Schukraft, Jurgen; Schulc, Martin; Schuster, Tim Robin; Schutz, Yves Roland; Schwarz, Kilian Eberhard; Schweda, Kai Oliver; Scioli, Gilda; Scomparin, Enrico; Scott, Patrick Aaron; Scott, Rebecca Michelle; Segato, Gianfranco; Seger, Janet Elizabeth; Selyuzhenkov, Ilya; Seo, Jeewon; Serradilla Rodriguez, Eulogio; Sevcenco, Adrian; Shabetai, Alexandre; Shabratova, Galina; Shahoyan, Ruben; Shangaraev, Artem; Sharma, Natasha; Sharma, Satish; Shigaki, Kenta; Shtejer Diaz, Katherin; Sibiryak, Yury; Siddhanta, Sabyasachi; Siemiarczuk, Teodor; Silvermyr, David Olle Rickard; Silvestre, Catherine Micaela; Simatovic, Goran; Singaraju, Rama Narayana; Singh, Ranbir; Singha, Subhash; Singhal, Vikas; Sinha, Bikash; Sarkar - Sinha, Tinku; Sitar, Branislav; Sitta, Mario; Skaali, Bernhard; Skjerdal, Kyrre; Smakal, Radek; Smirnov, Nikolai; Snellings, Raimond; Soegaard, Carsten; Soltz, Ron Ariel; Song, Jihye; Song, Myunggeun; Soramel, Francesca; Sorensen, Soren Pontoppidan; Spacek, Michal; Sputowska, Iwona Anna; Spyropoulou-Stassinaki, Martha; Srivastava, Brijesh Kumar; Stachel, Johanna; Stan, Ionel; Stefanek, Grzegorz; Steinpreis, Matthew Donald; Stenlund, Evert Anders; Steyn, Gideon Francois; Stiller, Johannes Hendrik; Stocco, Diego; Stolpovskiy, Mikhail; Strmen, Peter; Alarcon Do Passo Suaide, Alexandre; Subieta Vasquez, Martin Alfonso; Sugitate, Toru; Suire, Christophe Pierre; Suleymanov, Mais Kazim Oglu; Sultanov, Rishat; Sumbera, Michal; Susa, Tatjana; Symons, Timothy; Szanto De Toledo, Alejandro; Szarka, Imrich; Szczepankiewicz, Adam; Szymanski, Maciej Pawel; Takahashi, Jun; Tangaro, Marco-Antonio; Tapia Takaki, Daniel Jesus; Tarantola Peloni, Attilio; Tarazona Martinez, Alfonso; Tarzila, Madalina-Gabriela; Tauro, Arturo; Tejeda Munoz, Guillermo; Telesca, Adriana; Terrevoli, Cristina; Ter-Minasyan, Astkhik; Thaeder, Jochen Mathias; Thomas, Deepa; Tieulent, Raphael Noel; Timmins, Anthony Robert; Toia, Alberica; Torii, Hisayuki; Trubnikov, Victor; Trzaska, Wladyslaw Henryk; Tsuji, Tomoya; Tumkin, Alexandr; Turrisi, Rosario; Tveter, Trine Spedstad; Ulery, Jason Glyndwr; Ullaland, Kjetil; Uras, Antonio; Usai, Gianluca; Vajzer, Michal; Vala, Martin; Valencia Palomo, Lizardo; Vallero, Sara; Vande Vyvre, Pierre; Vannucci, Luigi; Van Der Maarel, Jasper; Van Hoorne, Jacobus Willem; Van Leeuwen, Marco; Diozcora Vargas Trevino, Aurora; Varma, Raghava; Vasileiou, Maria; Vasiliev, Andrey; Vechernin, Vladimir; Veldhoen, Misha; Velure, Arild; Venaruzzo, Massimo; Vercellin, Ermanno; Vergara Limon, Sergio; Vernet, Renaud; Verweij, Marta; Vickovic, Linda; Viesti, Giuseppe; Viinikainen, Jussi Samuli; Vilakazi, Zabulon; Villalobos Baillie, Orlando; Vinogradov, Alexander; Vinogradov, Leonid; Vinogradov, Yury; Virgili, Tiziano; Vislavicius, Vytautas; Viyogi, Yogendra; Vodopyanov, Alexander; Volkl, Martin Andreas; Voloshin, Kirill; Voloshin, Sergey; Volpe, Giacomo; Von Haller, Barthelemy; Vorobyev, Ivan; Vranic, Danilo; Vrlakova, Janka; Vulpescu, Bogdan; Vyushin, Alexey; Wagner, Boris; Wagner, Jan; Wagner, Vladimir; Wang, Mengliang; Wang, Yifei; Watanabe, Daisuke; Weber, Michael; Weber, Steffen Georg; Wessels, Johannes Peter; Westerhoff, Uwe; Wiechula, Jens; Wikne, Jon; Wilde, Martin Rudolf; Wilk, Grzegorz Andrzej; Wilkinson, Jeremy John; Williams, Crispin; Windelband, Bernd Stefan; Winn, Michael Andreas; Xiang, Changzhou; Yaldo, Chris G; Yamaguchi, Yorito; Yang, Hongyan; Yang, Ping; Yang, Shiming; Yano, Satoshi; Yasnopolskiy, Stanislav; Yi, Jungyu; Yin, Zhongbao; Yoo, In-Kwon; Yushmanov, Igor; Zaccolo, Valentina; Zach, Cenek; Zaman, Ali; Zampolli, Chiara; Zaporozhets, Sergey; Zarochentsev, Andrey; Zavada, Petr; Zavyalov, Nikolay; Zbroszczyk, Hanna Paulina; Zgura, Sorin Ion; Zhalov, Mikhail; Zhang, Haitao; Zhang, Xiaoming; Zhang, Yonghong; Zhao, Chengxin; Zhigareva, Natalia; Zhou, Daicui; Zhou, Fengchu; Zhou, You; Zhu, Hongsheng; Zhu, Jianhui; Zhu, Xiangrong; Zichichi, Antonino; Zimmermann, Alice; Zimmermann, Markus Bernhard; Zinovjev, Gennady; Zoccarato, Yannick Denis; Zynovyev, Mykhaylo; Zyzak, Maksym

2014-01-01

ALICE is the heavy-ion experiment at the CERN Large Hadron Collider. The experiment continuously took data during the first physics campaign of the machine from fall 2009 until early 2013, using proton and lead-ion beams. In this paper we describe the running environment and the data handling procedures, and discuss the performance of the ALICE detectors and analysis methods for various physics observables.

The ALICE data quality monitoring

International Nuclear Information System (INIS)

Haller, B von; Roukoutakis, F; Chapeland, S; Carena, F; Carena, W; Barroso, V Chibante; Costa, F; Divia, R; Fuchs, U; Makhlyueva, I; Schossmaier, K; Soos, C; Vyvre, P Vande; Altini, V

2010-01-01

ALICE is one of the four experiments installed at the CERN Large Hadron Collider (LHC), especially designed for the study of heavy-ion collisions. The online Data Quality Monitoring (DQM) is an important part of the data acquisition (DAQ) software. It involves the online gathering, the analysis by user-defined algorithms and the visualization of monitored data. This paper presents the final design, as well as the latest and coming features, of the ALICE's specific DQM software called AMORE (Automatic MonitoRing Environment). It describes the challenges we faced during its implementation, including the performances issues, and how we tested and handled them, in particular by using a scalable and robust publish-subscribe architecture.We also review the on-going and increasing adoption of this tool amongst the ALICE collaboration and the measures taken to develop, in synergy with their respective teams, efficient monitoring modules for the sub-detectors. The related packaging and release procedure needed by such a distributed framework is also described. We finally overview the wide range of usages people make of this framework, and we review our own experience, before and during the LHC start-up, when monitoring the data quality on both the sub-detectors and the DAQ side in a real-world and challenging environment.

14 November 2013 - Director of Indian Institute of Technology Indore P. Mathur with members of the Indian community working at CERN; visiting the LHC tunnel at Point 2, the ALICE experimental area and SM18 with ALICE Collaboration Spokesperson, Istituto Nazionale Fisica Nucleare P. Giubellino and Technology Department, Accelerator Beam Transfer Group Leader V. Mertens

CERN Multimedia

Jean-Claude Gadmer

2013-01-01

14 November 2013 - Director of Indian Institute of Technology Indore P. Mathur with members of the Indian community working at CERN; visiting the LHC tunnel at Point 2, the ALICE experimental area and SM18 with ALICE Collaboration Spokesperson, Istituto Nazionale Fisica Nucleare P. Giubellino and Technology Department, Accelerator Beam Transfer Group Leader V. Mertens

Light hyper- and anti-nuclei production at the LHC measured with ALICE

CERN Multimedia

CERN. Geneva

2014-01-01

The high collision energies reached at the LHC lead to significant production yields of light (anti-) and hyper-nuclei in proton-proton, proton-lead and, in particular, lead-lead collisions. The excellent particle identification capabilities of the ALICE apparatus, based on the specific energy loss in the Time Projection Chamber and the velocity information obtained with the Time-Of-Flight detector, allow for the detection of these rarely produced particles. Furthermore, the Inner Tracking System gives the possibility to separate primary nuclei from those originating from the decay of hyper-nuclei. One example is the hypertriton which is reconstructed in the decay channel 3LambdaH -> 3H + pi. We present results on the production of stable nuclei and anti-nuclei in Pb--Pb and lighter collision systems. Hypernuclei production rates in Pb--Pb will also be shown. All results are compared with predictions for the production in thermal (statistical) models and alternatives which are based on coalescence mech...

Identified charged hadron production in Pb-Pb collisions at $\\sqrt{s_{NN}}$ = 2.76 TeV with the ALICE experiment at the LHC

CERN Document Server

Milano, Leonardo; Prino, Francesco; Wessels, Johannes

Quark Gluon Plasma (QGP) is an unavoidable consequence of Quantum Chromodynamics (QCD). High-energy heavy-ion collisions offer the unique possibility to reproduce in the laboratory the conditions expected during the very first stages of the evolution of the universe. The ALICE (A Large Ion Collider Experiment) experiment at the Large Hadron Collider (LHC) allows the study of the dense nuclear environment created in nucleus-nucleus collisions. Particle Identification (PID) is one of the point of strength of the ALICE experiment. Identified particle spectra represent a crucial tool to understand the behaviour of the matter created in high-energy heavy-ion collisions. The transverse momentum $p_{ m T}$ distributions of identified hadrons contain informations about the transverse expansion of the system and constrain the freeze-out properties of the system. The ALICE Inner Tracking System (ITS) can be used as a standalone tracker with a dedicated tracking algorithm. This allows the reconstruction of particles tha...

Jet physics in ALICE

International Nuclear Information System (INIS)

Loizides, C.A.

2005-01-01

The ALICE experiment is one of the experiments currently prepared for the Large Hadron Collider (LHC) at CERN, Geneva, starting operation end of 2007. ALICE is dedicated to the research on nucleus-nucleus collisions at ultra-relativistic energies, which addresses the properties of strongly interacting matter under varying conditions of high density and temperature. The conditions provided at the LHC allow significant qualitative improvement with respect to previous studies. In particular, energetic probes, light quarks and gluons, will be abundantly produced. These probes might be identified by their fragmentation into correlated particles, so called jets, of high enough energy to allow full reconstruction of jet properties; even in the underlying heavy-ion environment. Understanding the dependence of high-energy jet production and fragmentation influenced by the dense medium created in the collision region is an open field of active research. Generally, one expects energy loss of the probes due to medium-induced gluon radiation. It is suggested that hadronization products of these, rather soft gluons may be contained within the jet emission cone, resulting in a modification of the characteristic jet fragmentation, as observed via longitudinal and transverse momentum distributions with respect to the direction of the initial parton, as well as of the multiplicity distributions arising from the jet fragmentation. Particle momenta parallel to the jet axis are softened (jet quenching), while transverse to it increased (transverse heating). The present thesis studies the capabilities of the ALICE detectors to measure these jets and quantifies obtainable rates and the quality of jet reconstruction, in both proton-proton and lead-lead collisions at the LHC. In particular, it is addressed whether modification of the jet fragmentation can be detected within the high-particle-multiplicity environment of central lead-lead collisions. (orig.)

ALICE moves into warp drive.

CERN Multimedia

CERN. Geneva

2012-01-01

A Large Ion Collider Experiment (ALICE) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). Since its successful start-up in 2010, the LHC has been performing outstandingly, providing to the experiments long periods of stable collisions and an integrated luminosity that greatly exceeds the planned targets. To fully explore these privileged conditions, we aim at maximizing the experiment's data taking productivity during stable collisions. We present in this paper the evolution of the online systems in order to spot reasons of inefficiency and address new requirements. This paper describes the features added to the ALICE Electronic Logbook (eLogbook) to allow the Run Coordination team to identify, prioritize, fix and follow causes of inefficiency in the experiment. Thorough monitoring of the data taking efficiency provides reports for the collaboration to portray its evolution and evaluate the measures (fix...

Study of the production of nuclei and anti-nuclei at the LHC with the ALICE experiment

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00508690; Bufalino, Stefania

In the ultra-relativistic lead-lead collisions at the CERN Large Hadron Collider (LHC), a state of matter called Quark Gluon Plasma (QGP) is created. A typical signature of a heavy ion collision (HIC) correlated to the production of the QGP is the large number of particles produced ($\\mathrm{d} N_{\\mathrm{ch}}/\\mathrm{d}\\eta$ up to 2000 in Pb-Pb collisions at $\\sqrt{s_{\\mathrm{NN}}}=5.02$ TeV). This high multiplicity environment poses a tremendous experimental challenge on the experiments that have to cope with the high density of signals in their sensitive volume. A Large Ion Collider Experiment (ALICE) has been designed to deal with the harsh environment of a HIC and to study in details the characteristics of the QGP. Among the particles produced in a HIC, light nuclei and their anti-matter companions are of special interest since the production mechanism of such loosely bound states is not clear in high energy collisions. The production rate at the LHC for the lightest of these objects, the deuteron, is a...

Probing the Quark-Gluon Plasma from bottomonium production at forward rapidity with ALICE at the LHC

CERN Document Server

Marchisone, Massimiliano

The main goal of ultrarelativistic heavy-ion collisions is the study of the properties of the matter at very high temperatures and energy densities. Quantum chromodynamics (QCD) predicts in these conditions the existence of a new phase of the matter whose components are deconfined in a Quark-Gluon Plasma (QGP). Heavy quarks (charm e bottom) are produced in the first stages of the collisions, before to interact with the medium. Therefore, the measurement of the quarkonia (cc and bb mesons) is of particular interest for the study of the QGP: their dissociation mainly due to the colour screening is sensible to the initial temperature of the medium. Previous measurements at the SPS and RHIC allowed to understand some characteristics of the system produced, but they also opened many questions. With an energy 14 times higher than RHIC, the LHC (Large Hadron Collider) at CERN opened a new era for the study of the QGP properties. ALICE (A Large Ion Collider Experiment) is the LHC experiment fully dedicated to the stu...

Technical design report for the upgrade of the ALICE inner tracking system

NARCIS (Netherlands)

Abelev, B.; Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agostinelli, A.; Agrawal, N.; Ahammed, Z.; Ahmad, N.; Ahmad Masoodi, A.; Ahmed, I.; Ahn, S. U.; Ahn, S. A.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Anderssen, E. C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arbor, N.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bairathi, V.; Bala, R.; Baldisseri, A.; Baltasar Dos Santos Pedrosa, F.; Bán, J.; Baral, R. C.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastian Van Beelen, J.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Battistin, M.; Batyunya, B.; Batzing, P. C.; Baudot, J.; Baumann, C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Bencedi, G.; Benettoni, M.; Benotto, F.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Berger, M. E.; Bertens, R. A.|info:eu-repo/dai/nl/371577810; Berzano, D.; Besson, A.; Betev, L.; Bhasin, A.; Bhati, A. K.; Bhatti, A.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.|info:eu-repo/dai/nl/371578248; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bjelogrlic, S.|info:eu-repo/dai/nl/355079615; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Boehmer, F. V.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bornschein, J.; Borshchov, V. N.; Bortolin, C.; Bossú, F.; Botje, M.|info:eu-repo/dai/nl/070139032; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Caliva, A.|info:eu-repo/dai/nl/411885812; Calvo Villar, E.; Camerini, P.; Canoa Roman, V.; Carena, F.; Carena, W.; Cariola, P.; Carminati, F.; Casanova Díaz, A.; Castillo Castellanos, J.; Casula, E. A R; Catanescu, V.; Caudron, T.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Chojnacki, M.|info:eu-repo/dai/nl/411888056; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Claus, G.; Cleymans, J.; Colamaria, F.; Colella, D.; Coli, S.; Colledani, C.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa Del Valle, Z.; Connors, M. E.; Contin, G.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Dang, R.; Danu, A.; Da Riva, E.; Das, D.; Das, I.; Das, K.; Das, S.; Dash, A.; Dash, S.; De, S.; Decosse, C.; Delagrange, H.; Delo, A.; Dénes, E.; D'Erasmo, G.; De Barros, G. O V; De Caro, A.; De Cataldo, G.; De Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; De Robertis, G.; De Roo, K.; De Rooij, R.|info:eu-repo/dai/nl/315888644; Diaz Corchero, M. A.; Dietel, T.; Divià, R.; Di Bari, D.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Djuvsland, O.; Dobrin, A.|info:eu-repo/dai/nl/372618715; Dobrowolski, T.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Dorheim, S.; Dorokhov, A.; Doziere, G.; Dubey, A. K.; Dubla, A.|info:eu-repo/dai/nl/355502488; Ducroux, L.; Dulinski, W.; Dupieux, P.; Dutta Majumdar, A. K.; Ehlers, R. J.; Elia, D.; Engel, H.; Erazmus, B.; Erdal, H. A.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fehlker, D.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A S; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Fiorenza, G.; Floratos, E.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Franco, M.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gajanana, D.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Garishvili, I.; Gerhard, J.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubilato, P.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez, R.; Gomez Marzoa, M.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Graczykowski, L. K.; Grajcarek, R.; Greiner, L. C.; Grelli, A.|info:eu-repo/dai/nl/326052577; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grondin, D.; Grosse-Oetringhaus, J. F.; Grossiord, J. Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Guilbaud, M.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Khan, K. H.; Haake, R.; Haaland, I.M.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hanratty, L. D.; Hansen, A.; Harris, J. W.; Hartmann, H.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Heide, M.; Helstrup, H.; Hennes, E.; Herghelegiu, A.; Herrera Corral, G.; Hess, B. A.; Hetland, K. F.; Hicks, B.; Hillemanns, H.; Himmi, A.; Hippolyte, B.; Hladky, J.; Hristov, P.; Huang, M.; Hu-Guo, C.; Humanic, T. J.; Hutter, D.; Hwang, D. S.; Igolkin, S.; Ijzermans, P.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Incani, E.; Innocenti, G. M.; Ionita, C.; Ippolitov, M.; Irfan, M.; Ivanov, M.; Ivanov, V.; Ivanytskyi, O.; Jacho lkowski, A.; Jadlovsky, J.; Jahnke, C.; Jang, H. J.; Janik, M. A.; Jayarathna, P. H S Y; Jena, S.; Jimenez Bustamante, R. T.; Jones, P. G.; Jung, H.; Junique, A.; Jusko, A.; Kalcher, S.; Kalinak, P.; Kalweit, A.; Kamin, J.; Kang, J. H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keil, M.; Ketzer, B.; Khan, M. Mohisin; Khan, P.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, B.; Kim, D.; Kim, D. W.; Kim, D. J.; Kim, J. S.; Kim, M.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, J.; Klein-Bösing, C.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobdaj, C.; Kofarago, M.; Köhler, M. K.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Konevskikh, A.; Kovalenko, V.; Kowalski, M.; Kox, S.; Koyithatta Meethaleveedu, G.; Kral, J.; Králik, I.; Kramer, F.; Kravčáková, A.; Krelina, M.; Kretz, M.; Krivda, M.; Krizek, F.; Krus, M.; Krymov, E. B.; Kryshen, E.; Krzewicki, M.|info:eu-repo/dai/nl/362845670; Kučera, V.; Kucheriaev, Y.; Kugathasan, T.; Kuhn, C.; Kuijer, P. G.|info:eu-repo/dai/nl/074064975; Kulakov, I.; Kumar, J.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kushpil, V.; Kweon, M. J.; Kwon, Y.; Ladron De Guevara, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; Lara, C.; Lardeux, A.; Lattuca, A.; La Pointe, S. L.|info:eu-repo/dai/nl/355080192; La Rocca, P.; Lea, R.; Lee, G. R.; Legrand, I.; Lehnert, J.; Lemmon, R. C.; Lenhardt, M.; Lenti, V.; Leogrande, E.; Leoncino, M.; León Monzón, I.; Lesenechal, Y.; Lévai, P.; Li, S.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Listratenko, O. M.; Ljunggren, H. M.; Lodato, D. F.; Loddo, F.; Loenne, P. I.; Loggins, V. R.; Loginov, V.; Lohner, D.; Loizides, C.; Lopez, X.; López Torres, E.; Lu, X. G.; Luettig, P.; Lunardon, M.; Luo, J.; Luparello, G.|info:eu-repo/dai/nl/355080400; Luzzi, C.; M. Gago, A.; M. Jacobs, P.; Ma, R.; Maevskaya, A.; Mager, M.; Mahapatra, D. P.; Maire, A.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal'Kevich, D.; Maltsev, N. A.; Malzacher, P.; Mamonov, A.; Manceau, L.; Manko, V.; Manso, F.; Manzari, V.; Mapelli, A.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Marín, A.; Marin Tobon, C. A.; Markert, C.; Marquard, M.; Marras, D.; Martashvili, I.; Martin, N. A.; Martinengo, P.; Martínez, M. I.; Martínez García, G.; Martin Blanco, J.; Martynov, Y.; Mas, A.; Masciocchi, S.; Masera, M.; Maslov, M.; Masoni, A.; Massacrier, L.; Mastroserio, A.; Mattiazzo, S.; Matyja, A.; Mayer, C.; Mazer, J.; Mazumder, R.; Mazza, G.; Mazzoni, M. A.; Meddi, F.; Menchaca-Rocha, A.; Mercado Pérez, J.; Meres, M.; Miake, Y.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.|info:eu-repo/dai/nl/325781435; Mishra, A. N.; Miśkowiec, D.; Mitu, C. M.; Mlynarz, J.; Mohanty, B.; Molnar, L.; Mongelli, M.; Montaño Zetina, L.; Montes, E.; Morando, M.; Moreira De Godoy, D. A.; Morel, F.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Muhammad Bhopal, F.; Muhuri, S.; Mukherjee, M.; Müller, H.; Munhoz, M. G.; Murray, S.; Musa, L.; Musinsky, J.; Nandi, B. K.; Nania, R.; Nappi, E.; Nattrass, C.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Nicassio, M.; Niculescu, M.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Nilsen, B. S.; Noferini, F.; Nomokonov, P.; Nooren, G.|info:eu-repo/dai/nl/07051349X; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Oh, S. K.; Okatan, A.; Olah, L.; Oleniacz, J.; Oliveira Da Silva, A. C.|info:eu-repo/dai/nl/323375618; Onderwaater, J.; Oppedisano, C.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Pachmayer, Y.; Pachr, M.; Pagano, P.; Paić, G.; Painke, F.; Pajares, C.; Pal, S. K.; Palmeri, A.; Panati, S.; Pant, D.; Pantano, D.; Papikyan, V.; Pappalardo, G. S.; Park, W. J.; Passfeld, A.; Pastore, C.; Patalakha, D. I.; Paticchio, V.; Paul, B.; Pawlak, T.; Peitzmann, T.|info:eu-repo/dai/nl/304833959; Pereira Da Costa, H.; Pereira De Oliveira Filho, E.; Peresunko, D.; Pérez Lara, C. E.; Peryt, W.; Pesci, A.; Pestov, Y.; Petagna, P.; Petráček, V.; Petran, M.; Petris, M.; Petrovici, M.; Petta, C.; Pham, H.; Piano, S.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Poskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L M; Poghosyan, M. G.; Pohjoisaho, E. H O; Polichtchouk, B.; Poljak, N.; Pop, A.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, V.; Potukuchi, B.; Prasad, S. K.; Preghenella, R.; Prino, F.; Protsenko, M. A.; Pruneau, C. A.; Pshenichnov, I.; Puddu, G.; Puggioni, C.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rasson, J. E.; Rathee, D.; Rauf, A. W.; Razazi, V.; Read, K. F.; Real, J. S.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reicher, M.|info:eu-repo/dai/nl/32823219X; Reidt, F.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J. P.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Rivetti, A.; Rocco, E.; Rodríguez Cahuantzi, M.; Rodriguez Manso, A.; Røed, K.; Rogochaya, E.; Rohni, S.; Rohr, D.; Röhrich, D.; Romita, R.; Ronchetti, F.; Ronette, L.; Rosnet, P.; Rossegger, S.; Rossewij, M. J.; Rossi, A.; Roudier, S.; Rousset, J.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Sacchetti, M.; Sadovsky, S.; Šafařík, K.; Sahlmuller, B.; Sahoo, R.; Sahu, P. K.; Saini, J.; Salgado, C. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sanchez Castro, X.; Sánchez Rodríguez, F. J.; Šándor, L.; Sandoval, A.; Sano, M.; Santagati, G.; Santoro, R.; Sarkar, D.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schipper, J. D.; Schmidt, C.; Schmidt, H. R.; Schuchmann, S.; Schukraft, J.; Schulc, M.; Schuster, T.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, P. A.; Scott, R.; Segato, G.; Seger, J. E.; Selyuzhenkov, I.; Senyukhov, S.; Seo, J.; Serradilla, E.; Sevcenco, A.; Sgura, I.; Shabetai, A.; Shabratova, G.; Shahoyan, R.; Shangaraev, A.; Sharma, N.; Sharma, S.; Shigaki, K.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Skjerdal, K.; Smakal, R.; Smirnov, N.; Snellings, R. J M|info:eu-repo/dai/nl/165585781; Snoeys, W.; Søgaard, C.; Soltz, R.; Song, J.; Song, M.; Sooden, V.; Soramel, F.; Sorensen, S.; Spacek, M.; Špalek, J.; Spiriti, E.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stefanek, G.; Steinpreis, M.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Stolpovskiy, M.; Strmen, P.; Suaide, A. A P; Subieta Vasquez, M. A.; Sugitate, T.; Suire, C.; Suleymanov, M.; Šuljić, M.; Sultanov, R.; Šumbera, M.; Sun, X.; Susa, T.; Symons, T. J M; Szanto De Toledo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Takahashi, J.; Tangaro, M. A.; Tapia Takaki, J. D.; Tarantola Peloni, A.; Tarazona Martinez, A.; Tauro, A.; Tejeda Muñoz, G.; Telesca, A.; Terrevoli, C.; Ter Minasyan, A.; Thäder, J.; Thomas, D.; Tieulent, R.; Timmins, A. R.; Toia, A.; Torii, H.; Trubnikov, V.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turchetta, R.; Turrisi, R.; Tveter, T. S.; Tymchuk, I. T.; Ulery, J.; Ullaland, K.; Uras, A.; Usai, G. L.; Vajzer, M.; Vala, M.; Valencia Palomo, L.; Valentino, V.; Valin, I.; Vallero, S.; Vande Vyvre, P.; Vannucci, L.; Van Der Maarel, J.|info:eu-repo/dai/nl/412860996; Van Hoorne, J. W.; Van Leeuwen, M.; Vargas, A.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vasta, P.; Vechernin, V.; Veldhoen, M.; Velure, A.; Venaruzzo, M.; Vercellin, E.; Vergara Limón, S.; Verlaat, B.; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Viyogi, Y. P.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; Von Haller, B.; Vorobyev, I.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Vyushin, A.; Wagner, B.; Wagner, J.; Wagner, V.; Wang, M.; Wang, Y.; Watanabe, D.; Weber, M.; Wessels, J. P.; Westerho, U.; Wiechula, J.; Wikne, J.; Wilde, M.; Wilk, G.; Wilkinson, J.; Williams, M. C S; Windelband, B.; Winn, M.; Winter, M.; Xiang, C.; Yaldo, C. G.; Yamaguchi, Y.; Yang, H.; Yang, P.; Yang, S.; Yano, S.; Yasnopolskiy, S.; Yi, J.; Yin, Z.; Yoo, I. K.; Yushmanov, I.; Zaccolo, V.; Zach, C.; Zaman, A.; Zampolli, C.; Zaporozhets, S.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zgura, I. S.; Zhalov, M.; Zhang, F.; Zhang, H.; Zhang, X.; Zhang, Y.|info:eu-repo/dai/nl/352841931; Zhao, C.; Zherebchevsky, V. I.; Zhou, D.; Zhou, F.; Zhou, Y.; Zhu, H.; Zhu, J.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zoccarato, Y.; Zynovyev, M.; Zyzak, M.

2014-01-01

ALICE (A Large Ion Collider Experiment) is studying the physics of strongly interacting matter, and in particular the properties of the Quark-Gluon Plasma (QGP), using proton-proton, proton-nucleus and nucleus-nucleus collisions at the CERN LHC (Large Hadron Collider). The ALICE Collaboration is

GEM Foil Quality Assurance For The ALICE TPC Upgrade

Science.gov (United States)

Brücken, Erik; Hildén, Timo

2018-02-01

The ALICE (A Large Ion Collider Experiment) experiment at the Large Hadron Collider (LHC) at CERN is dedicated to heavy ion physics to explore the structure of strongly interacting matter. The Time Projection Chamber (TPC) of ALICE is a tracking detector located in the central region of the experiment. It offers excellent tracking capabilities as well as particle identification. After the second long shutdown (LS2) the LHC will run at substantially higher luminosities. To be able to increase the data acquisition rate by a factor of 100, the ALICE TPC experiment has to replace the Multi-Wire Proportional Chamber (MWPC) -based readout chambers. The MWPC are operated with gating grid that limits the rate to O(kHz). The new ReadOut Chamber (ROC) design is based on Gas Electron Multiplier (GEM) technology operating in continuous mode. The current GEM productions scheme foresees the production of more than 800 GEM foils of different types. To fulfill the requirements on the performance of the GEM TPC readout, necessitates thorough Quality Assurance (QA) measures. The QA scheme, developed by the ALICE collaboration, will be presented in detail.

GEM Foil Quality Assurance For The ALICE TPC Upgrade

Directory of Open Access Journals (Sweden)

Brücken Erik

2018-01-01

Full Text Available The ALICE (A Large Ion Collider Experiment experiment at the Large Hadron Collider (LHC at CERN is dedicated to heavy ion physics to explore the structure of strongly interacting matter. The Time Projection Chamber (TPC of ALICE is a tracking detector located in the central region of the experiment. It offers excellent tracking capabilities as well as particle identification. After the second long shutdown (LS2 the LHC will run at substantially higher luminosities. To be able to increase the data acquisition rate by a factor of 100, the ALICE TPC experiment has to replace the Multi-Wire Proportional Chamber (MWPC –based readout chambers. The MWPC are operated with gating grid that limits the rate to O(kHz. The new ReadOut Chamber (ROC design is based on Gas Electron Multiplier (GEM technology operating in continuous mode. The current GEM productions scheme foresees the production of more than 800 GEM foils of different types. To fulfill the requirements on the performance of the GEM TPC readout, necessitates thorough Quality Assurance (QA measures. The QA scheme, developed by the ALICE collaboration, will be presented in detail.

submitter LHC experiments

CERN Document Server

Tanaka, Shuji

2001-01-01

Large Hadron Collider (LHC) is under construction at the CERN Laboratory in Switzerland. Four experiments (ATLAS, CMS, LHCb, ALICE) will try to study the new physics by LHC from 2006. Its goal to explore the fundamental nature of matter and the basic forces. The PDF file of the transparency is located on http://www-atlas.kek.jp/sub/documents/lepsymp-stanaka.pdf.

Study of Υ family resonances in ultrarelativistic heavy ions collisions within the frame of the Alice experiment at CERN-LHC

International Nuclear Information System (INIS)

Dumonteil, E.

2004-09-01

Quantum Chromodynamics foresees, at high temperature and/or high energy density, a phase transition between hadronic matter and a phase where quarks and gluons are no more confined in the nucleons: the Quark Gluon Plasma (QGP). During the past fifteen years, a large experimental program has taken place at CERN and at BNL, to identify the QGP. ALICE is the LHC experiment dedicated to the study of the plasma via ultrarelativistic heavy ion collisions at 2.75 TeV/nucleon per beam. The measure of Upsilon's resonances suppression, a powerful signature of a deconfined medium, with the ALICE dimuon spectrometer, is the main topic of this thesis. The first part of the work aims at studying the multi-wires pad chambers of the dimuon arm, used to track the muons from resonances decays. The second part presents an in-beam alignment algorithm able to calculate the positions of the different chambers with a very good accuracy. Finally, the last part proposes a study to lead with the ALICE muon spectrometer, involving the measure of Upsilon and Upsilon's production ratio as a function of the transverse momentum. It has been showed that this study should allow to evidence the QGP and to extract some of its properties. (author)

A fast high-voltage current-peak detection system for the ALICE transition radiation detector

Energy Technology Data Exchange (ETDEWEB)

Verclas, Robert [Physikalisches Institut, Ruprecht-Karls-Universitaet Heidelberg (Germany); Collaboration: ALICE-Collaboration

2016-07-01

During LHC operation in run 1, the gaseous detectors of ALICE occasionally experienced simultaneous trips in their high voltage which affected the majority of the high voltage channels. These trips are caused by large anode currents in the detector and are potentially related to LHC machine operations. We developed and installed a fast current-peak detection system for the ALICE Transition Radiation Detector. This system is based on FPGA technology and monitors 144 out 522 high voltage channels minimally invasively at a maximum readout rate of 2 MHz. It is an integral part of the LHC beam monitoring system. We report on the latest status.

30 janvier 2015 - Monsieur Mouïn Hamzé, Secrétaire général Conseil National pour la Recherche Scientifique, République libanaise

CERN Document Server

Gadmer, Jean-Claude

2015-01-01

en visite au Centre de Contrôle du CERN avec L. Ponce du Département Faisceaux; à la caverne de l'expérience ALICE avec J.-P. Revol, R. Guernane et K. Safarik de la collaboration ALICE; au hall d’assemblage des aimants supraconducteurs du LHC avec L. Tavian du Département Technologie puis lors de la signature du livre d'or avec le directeur général du CERN, R. Heuer. P. Fassnacht, Conseiller MENA, Bureau des relations internationales présent tout au long de la visite.

Charm production in proton-proton collisions at the LHC with the ALICE detector

CERN Document Server

Rossi, Andrea

The ALICE experiment at CERN will study the medium formed in very high energy lead-lead collisions at the LHC. According to the Quantum Chromo Dynamics theory of the strong interaction, a phase transition to a state where quarks and gluons are not confined into hadrons (Quark-Gluon Plasma) can occur in these collisions. Heavy quarks (charm and beauty) are produced in hard scattering processes in the first stages of the collisions. While travelling through the medium they can lose energy by means of gluon radiation. This affects the momentum spectra of the hadrons produced in the subsequent hadronization. To study the energy loss mechanism and its dependence on the parton nature (quark/gluon) and mass (light/heavy quark), hadron momentum spectra observed in heavy-ion collisions are compared to the same spectra observed in proton-proton collisions, where the formation of a thermalized medium is not expected. In this thesis, the measurement of charm production in proton-proton collisions via the exclusive recons...

Charm production at the LHC via $D^{0} -> K^{-} \\pi^{+}$ reconstruction in ALICE:cross section in pp collisions and first flow measurement in Pb-Pb collisions

CERN Document Server

Bianchin, Chiara; Dainese, Andrea

ALICE (A Large Hadron Collider Experiment) is one of the CERN-LHC (Large Hadron Collider) experiments. The main goal of ALICE is investigating the properties of the state of matter formed in ultra-relativistic heavy-ion collisions, the strongly-interacting quark-gluon plasma (QGP). The extremely high-energy-density and high-temperature matter produced in Pb--Pb collisions at centre-of-mass-energy of 2.76 TeV at the LHC is similar to the state of the matter that constituted the Universe few microseconds after the Big Bang. Nucleus-nucleus collisions have been carried out for the last 20 years by the Super Proton Synchrotron at CERN and by the Relativistic Heavy Ion Collider at Brookhaven to study this state of matter in a laboratory. The experimental results confirm the production of a deconfined system that reaches a thermal equilibrium and behaves like an almost perfect fluid, following the equations of hydrodynamics, until it cools down and hadrons are produced again. The properties of such a medium can be ...

Protecting detectors in ALICE

International Nuclear Information System (INIS)

Lechman, M.; Augustinus, A.; Chochula, P.; Di Mauro, A.; Stig Jirden, L.; Rosinsky, P.; Schindler, H.; Cataldo, G. de; Pinazza, O.; Kurepin, A.; Moreno, A.

2012-01-01

ALICE (A Large Ion Collider Experiment) is one of the big LHC (Large Hadron Collider) experiments at CERN in Geneva. It is composed of many sophisticated and complex detectors mounted very compactly around the beam pipe. Each detector is a unique masterpiece of design, engineering and construction and any damage to it could stop the experiment for months or even for years. It is therefore essential that the detectors are protected from any danger and this is one very important role of the Detector Control System (DCS). One of the main dangers for the detectors is the particle beam itself. Since the detectors are designed to be extremely sensitive to particles they are also vulnerable to any excess of beam conditions provided by the LHC accelerator. The beam protection consists of a combination of hardware interlocks and control software and this paper will describe how this is implemented and handled in ALICE. Tools have also been developed to support operators and shift leaders in the decision making related to beam safety. The gained experiences and conclusions from the individual safety projects are also presented. (authors)

Light vector meson production at forward rapidity in pp collisions at the LHC with the ALICE detector

CERN Document Server

Incani, Elisa; Usai, Gianluca

Low-mass vector mesons ($\\rho$, $\\omega$ and $\\phi$) give us information on the hot and dense state of strongly interacting matter produced in heavy ion collisions. In fact, in the QGP an enhancement of the strange particle production should be present (strangeness enhancement), which means a N$\\phi$ /N$\\rho+\\omega$ ratio increasing in A-A collisions with respect to pp collisions; pp collisions provide a reference for these studies. Vector meson production in pp collisions is also useful by itself, to study soft Quantum ChromoDynamics (QCD) in the LHC energy range, since calculations in this regime are based on QCD inspired phenomenological models that must be tuned to the data. The ALICE experiment at the LHC can access vector mesons produced at forward rapidity through their decays in muon pairs. We will show the ratio $N\\phi$ /N$\\rho+\\omega$ vs pT, the ratios $\\sigma_\\rho/\\sigma_\\omega$ and $\\sigma_\\phi/\\sigma_\\omega$, and the $\\phi$ and $\\omega$ pT and rapidity differential cross sections for the data sam...

The ALICE Experiment at the LHC and the Mexican Contribution

International Nuclear Information System (INIS)

Herrera Corral, G.

2007-01-01

The final installation of the detectors that form ALICE has started on year 2005. The first device of ALICE that was completed and set up to work was the Cosmic Ray Detector. The V0A detector will be installed and commissioned on the summer of 2007. These two detectors were designed and built in Mexico. Here we give a very general description of these two devices

ALICE Upgrades: Plans and Potentials

CERN Document Server

Tieulent, Raphael

2015-01-01

The ALICE collaboration consolidated and completed the installation of current detectors during LS1 with the aim to accumulate 1 nb$^{-1}$ of Pb-Pb collisions during Run 2 corresponding to about 10 times the Run 1 integrated luminosity. In parallel, the ALICE experiment has a rich detector upgrade programme scheduled during the second LHC long shutdown (LS2, 2018-2019) in order to fully exploit the LHC Runs 3 and 4. The main objectives of this programme are: improving the tracking precision and enabling the read-out of all Pb-Pb interactions at a rate of up to 50 kHz, with the goal to record an integrated luminosity of 10 nb$^{-1}$ after LS2 in minimum-bias trigger mode. This sample would represent an increase by a factor of one hundred with respect to the minimum-bias sample expected during Run 2. The implementation of this upgrade programme, foreseen in LS2, includes: a new low-material Inner Tracking System at central rapidity with a forward rapidity extension to add vertexing capabilities to the current M...

AliEn: ALICE environment on the GRID

International Nuclear Information System (INIS)

Bagnasco, S; Betev, L; Buncic, P; Carminati, F; Cirstoiu, C; Grigoras, C; Hayrapetyan, A; Harutyunyan, A; Peters, A J; Saiz, P

2008-01-01

Starting from mid-2008, the ALICE detector at CERN LHC will collect data at a rate of 4PB per year. ALICE will use exclusively distributed Grid resources to store, process and analyse this data. The top-level management of the Grid resources is done through the AliEn (ALICE Environment) system, which is in continuous development since year 2000. AliEn presents several original solutions, which have shown their viability in a number of large exercises of increasing complexity called Data Challenges. This paper describes the AliEn architecture: Job Management, Data Management and UI. The current status of AliEn will be illustrated, as well as the performance of the system during the data challenges. The paper also describes the future AliEn development roadmap

AliEn: ALICE Environment on the GRID

CERN Multimedia

Bagnasco, S; Buncic, P; Carminati, F; Cirstoiu, C; Grigoras, C; Hayrapetyan, A; Harutyunyan, A; Peters, A J; Saiz, P

2007-01-01

Starting from mid-2008, the ALICE detector at CERN LHC will collect data at a rate of 4PB per year. ALICE will use exclusively distributed Grid resources to store, process and analyse this data. The top-level management of the Grid resources is done through the AliEn (ALICE Environment) system, which is in continuous development since year 2000. AliEn presents several original solutions, which have shown their viability in a number of large exercises of increasing complexity called Data Challenges. This paper describes the AliEn architecture: Job Management, Data Management and UI. The current status of AliEn will be illustrated, as well as the performance of the system during the data challenges. The paper also describes the future AliEn development roadmap.

ALICE HLT Cluster operation during ALICE Run 2

Science.gov (United States)

Lehrbach, J.; Krzewicki, M.; Rohr, D.; Engel, H.; Gomez Ramirez, A.; Lindenstruth, V.; Berzano, D.; ALICE Collaboration

2017-10-01

ALICE (A Large Ion Collider Experiment) is one of the four major detectors located at the LHC at CERN, focusing on the study of heavy-ion collisions. The ALICE High Level Trigger (HLT) is a compute cluster which reconstructs the events and compresses the data in real-time. The data compression by the HLT is a vital part of data taking especially during the heavy-ion runs in order to be able to store the data which implies that reliability of the whole cluster is an important matter. To guarantee a consistent state among all compute nodes of the HLT cluster we have automatized the operation as much as possible. For automatic deployment of the nodes we use Foreman with locally mirrored repositories and for configuration management of the nodes we use Puppet. Important parameters like temperatures, network traffic, CPU load etc. of the nodes are monitored with Zabbix. During periods without beam the HLT cluster is used for tests and as one of the WLCG Grid sites to compute offline jobs in order to maximize the usage of our cluster. To prevent interference with normal HLT operations we separate the virtual machines running the Grid jobs from the normal HLT operation via virtual networks (VLANs). In this paper we give an overview of the ALICE HLT operation in 2016.

Production of (anti-)(hyper-)nuclei at LHC energies with ALICE

Science.gov (United States)

Puccio, Maximiliano

2018-02-01

The ALICE experiment at the LHC has measured a variety of (anti-)(hyper-)nuclei produced in Pb-Pb collisions at = 5.02 TeV and at 2.76 TeV. In addition, a large sample of high quality data was collected in pp collisions at √s = 7 TeV and 13 TeV and in p-Pb collisions at = 5.02 TeV. These data are used to study the production of different (anti-)(hyper-)nuclei in the collisions, namely (anti-)deuteron, (anti-)3He, (anti-)alpha and (anti-)3ΛH. The identification of these (anti-)(hyper-)nuclei is based on the energy loss measurement in the Time Projection Chamber and the velocity measurement in the Time-Of-Flight detector. In addition, the Inner Tracking System is used to distinguish secondary vertices originating from weak decays from the primary vertex. New results on deuteron production as a function of multiplicity in pp, p-Pb and Pb-Pb collisions will be presented, as well as the measurement of 3He in p-Pb and Pb- Pb collisions. Special emphasis will be given to the new results of the (anti-)3ΛH in its charged-two-body decay mode. The large variety of measurements at different energies and system sizes constrains the production models of light flavour baryon clusters, in particular those based on coalescence and the statistical hadronisation approaches.

Managing Information Flow in ALICE

CERN Document Server

Augustinus, A; Moreno, A; Kurepin, A N; De Cataldo, G; Pinazza, O; Rosinský, P; Lechman, M; Jirdén, L S

2011-01-01

ALICE is one of the experiments at the Large Hadron Collider (LHC) at CERN in Geneva, Switzerland. The ALICE detector control system is an integrated system collecting 18 different detectors’ controls and general services. Is implemented using the commercial SCADA package PVSS. Information of general interest, such as beam and condition data, and data related to shared plants or systems, are made available to all the subsystems via the distribution capabilities of PVSS. Great care has been taken to build a modular and hierarchical system, limiting the interdependencies of the various subsystems. Accessing remote resources in a PVSS distributed environment is very simple and can be initiated unilaterally. In order to improve the reliability of distributed data and to avoid unforeseen and unwished dependencies, the ALICE DCS group has enforced the centralization of global data required by the subsystems. A tool has been developed to monitor the level of interdependency and to understand the ...

Upgrade of the ALICE Inner Tracking System

OpenAIRE

Reidt, Felix; Collaboration, for the ALICE

2014-01-01

During the Long Shutdown 2 of the LHC in 2018/2019, the ALICE experiment plans the installation of a novel Inner Tracking System. It will replace the current six layer detector system with a seven layer detector using Monolithic Active Pixel Sensors. The upgraded Inner Tracking System will have significantly improved tracking and vertexing capabilities, as well as readout rate to cope with the expected increased Pb-Pb luminosity of the LHC. The choice of Monolithic Active Pixel Sensors has be...

The ALICE silicon pixel detector system

International Nuclear Information System (INIS)

Kapusta, S.

2009-01-01

The Large Hadron Collider (LHC) is again reaching its startup phase at the European Organization for Particle Physics (CERN). The LHC started its operation on the 10 th of September, 2008 with huge success managing to sent the the first beam successfully around the entire ring in less than an hour after the first injection in one direction, and later that day in the opposite direction. Unfortunately, on the 19 th of September, an accident occurred during the 5.5 TeV magnet commissioning in Sector 34, which will significantly delay the operation of the LHC. The ALICE experiment will exploit the collisions of accelerated ions produced at the LHC to study strongly interacting matter at extreme densities and high temperatures. e ALICE Silicon Pixel Detector (SPD) represents the two innermost layers of the ALICE Inner Traing System (ITS) located at radii of 3.9 cm and 7.6 cm from the Interaction Point (IP). One of the main tasks of the SPD is to provide precise traing information. is information is fundamental for the study of weak decays of heavy flavor particles, since the corresponding signature is a secondary vertex separated from the primary vertex only by a few hundred micrometers. e tra density could be as high as 80 tracks per cm 2 in the innermost SPD layer as a consequence of a heavy ion collision. The SPD will provide a spatial resolution of around ≅12 μm in the rφ direction and ≅70 μm in the z direction. The expected occupancy of the SPD ranges from 0.4% to 1.5% which makes it an excellent charged particle multiplicity detector in the pseudorapidity region |η| < 2. Furthermore, by combining all possible hits in the SPD, one can get a rough estimate of the position of the primary interaction. One of the challenges is the tight material budget constraint (<1% radiation length per layer) in order to limit the scattering of the traversing particles. e silicon sensor and its readout chip have a total thickness of only 350 μm and the signal lines from the

Probing the quark-gluon plasma from bottomonium production at forward rapidity with ALICE at the LHC

International Nuclear Information System (INIS)

Marchisone, M.

2013-01-01

The main goal of ultrarelativistic heavy-ion collisions is the study of the properties of the matter at very high temperatures and energy densities. Quantum chromodynamics (QCD) predicts in these conditions the existence of a new phase of the matter whose components are deconfined in a Quark- Gluon Plasma (QGP). Heavy quarks are produced in the first stages of the collisions, before interacting with the medium. Therefore, the measurement of the quarkonia (cc-bar and bb-bar mesons) is of particular interest for the study of the QGP: their dissociation mainly due to the colour screening is sensible to the initial temperature of the medium. Previous measurements at the SPS and RHIC allowed to understand some characteristics of the system produced, but they also opened many questions. With an energy 14 times higher than RHIC, the LHC (Large Hadron Collider) at CERN opened a new era for the study of the QGP properties. ALICE (A Large Ion Collider Experiment) is the LHC experiment fully dedicated to the study of the Quark-Gluon Plasma produced in Pb-Pb collisions at an energy of 2.76 TeV per nucleon. The experiment also participates to the proton-proton data taking in order to obtain the fundamental reference for the study of ion-ion and proton-ion collisions and for testing the predictions at very small Bjorken-x values of the perturbative QCD. Quarkonia, D and B mesons and light vector mesons are measured at forward rapidity by a Muon Spectrometer exploiting their (di)muonic decay. This detector is composed of a front absorber, a dipole magnet, five stations for tracking (Muon Tracking) and two stations for triggering (Muon Trigger). The work presented in this thesis has been carried out from 2011 to 2013 during the first period of data collecting of ALICE. After a detailed introduction of the heavy-ion physics and a description of the experimental setup, the performance of the Muon Trigger in Pb-Pb collisions are shown. A particular attention is devoted to the

Data science in ALICE

CERN Multimedia

CERN. Geneva

2015-01-01

ALICE is the LHC experiment dedicated to the study of Heavy Ion collisions. In particular, the detector features low momentum tracking and vertexing, and comprehensive particle identification capabilities. In a single central heavy ion collision at the LHC, thousands of particles per unit rapidity are produced, making the data volume, track reconstruction and search of rare signals particularly challenging. Data science and machine learning techniques could help to tackle some of the challenges outlined above. In this talk, we will discuss some early attempts to use these techniques for the processing of detector signals and for the physics analysis. We will also highlight the most promising areas for the application of these methods.

The Fast Interaction Trigger Upgrade for ALICE

CERN Document Server

Garcia-Solis, Edmundo

2016-01-01

The ALICE Collaboration is preparing a major detector upgrade for the second LHC long shutdown (2019–20). The LHC heavy-ion luminosity and collision rate from 2021 onwards will considerably exceed the design parameters of the present ALICE forward trigger detectors. Furthermore, the introduction of a new Muon Forward Tracker (MFT) will significantly reduce the space available for the upgraded trigger detectors. To comply with these conditions a Fast Interaction Trigger (FIT) has been designed. FIT will be the primary forward trigger, luminosity, and collision time measurement detector. The FIT will be capable of triggering at an interaction rate of 50 kHz, with a time resolution better than 30 ps, with 99% efficiency. It will also determine multiplicity, centrality, and reaction plane. FIT will consist of two arrays of Cherenkov radiators with MCP-PMT sensors and of a single, large-size scintillator ring. The arrays will be placed on both sides of the interaction point (IP). Because of the presence of the h...

Performance du spectrometre a muons d’ALICE. Production et mesure des bosons faibles dans des collisions d’ions lourds aupres du LHC

CERN Document Server

Conesa Del Valle, Zaida; Moreno, F Fernandez

2007-01-01

Nucleus-nucleus collisions are the unique tool available to investigate the QCD matter phase diagram in the laboratory. A lot of work has been devoted to explore it in different domains in the last 3 decades, and the forthcoming LHC collider will contribute to such research increasing the collision center-of-mass energy by a factor 30 and the energy densities by a factor 1-10 with respect to the RHIC collider [C+04, A+06].Only a comprehensive analysis of a wide spectrum of experimental observables can help to fully characterize the prospected matter. In particular, valuable information is expected from charm and beauty production, the situation from SPS and RHIC charmonia data being puzzling [GdC07, Lei07, A+00a, Sco07], and the c¯c (b¯b) yields per central nucleon-nucleon collision being increased from 10 (0.1) to 110 (5) from RHIC to LHC [C+04, MG07]. Whether quarkonia will thermalize, will develop collective motion, will be further suppressed or regenerated are still open questions that LHC data might re...

The ALICE muon spectrometer: trigger detectors and quarkonia detection in p-p collisions

CERN Document Server

Gagliardi, Martino

This work was carried out in the context of the optimisation of the performances of the muon spectrometer of the forthcoming ALICE experiment at the Large Hadron Collider (LHC, CERN). The aim of ALICE is the study of nuclear matter at the highest energy densities ever accessed experimentally. More in detail, the focus is on the expected phase transition to a deconfined phase of matter where the degrees of freedom are those of quarks and gluons: the Quark-Gluon Plasma. The conditions for QGP formation are expected to be achieved in highly relativistic heavy ion collisions. The energy in the centre of mass of Pb-Pb collisions at the LHC will be 5.5 TeV per nucleon pair. The ALICE physics program also includes data-taking in p-p collisions at the centre-of-mass-energy of 14 TeV. The ALICE muon spectrometer has been designed for the detection of heavy quarkonia through their muon decay: both theoretical predictions and experimental data obtained at SPS and RHIC indicate that the production of these resonances sho...

Multi-strange baryon production in pp, p-Pb and Pb-Pb collisions at LHC measured with ALICE

CERN Document Server

Colella, Domenico

2015-01-01

Transverse momentum spectra and yields of charged $\\Xi$ and $\\Omega$ at mid-rapidity in pp, p-Pb and Pb-Pb collisions at the LHC have been measured by the ALICE Collaboration. These baryons are identified by reconstruction of their weak decay topology, in modes with only charged decay products, using the excellent tracking and particle identification capabilities of the detector. The recent measurements of the multi-strange baryon production relative to non-strange particles in p-Pb collisions are presented: this would help to understand the change in relative strangeness production from pp collisions to Pb-Pb collisions. Results on the nuclear modification factors for the charged $\\Xi$ and $\\Omega$ particles, compared with those for other light particles, are also reported.

Round Two for Three ALICE Industrial Awards

CERN Multimedia

2004-01-01

Excellency in industrial collaboration with the LHC experimental teams is one important contribution to the successful development and realization of the experiments. A few weeks ago the ALICE collaboration presented a second round of awards to industrial collaborators for their novel and remarkable contributions to major detector systems.

The ALICE Transition Radiation Detector: construction, operation, and performance

OpenAIRE

Acharya, Shreyasi; Adam, Jaroslav; Ahmad, Nazeer; Bhattacharjee, Buddhadeb; Turrisi, Rosario; Tveter, Trine Spedstad; Ullaland, Kjetil; Umaka, Ejiro Naomi; Uras, Antonio; Usai, Gianluca; Utrobicic, Antonija; Vala, Martin; Van Der Maarel, Jasper; Van Hoorne, Jacobus Willem; Bhom, Jihyun

2018-01-01

The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 G...

Detector performance of the ALICE silicon pixel detector

CERN Document Server

Cavicchioli, C

2011-01-01

The ALICE Silicon Pixel Detector (SPD) forms the two innermost layers of the ALICE Inner Tracking System (ITS). It consists of two barrel layers of hybrid silicon pixel detectors at radii of 39 and 76 mm. The physics targets of the ALICE experiment require that the material budget of the SPD is kept within approximate to 1\\%X(0) per layer. This has set some stringent constraints on the design and construction of the SPD. A unique feature of the ALICE SPD is that it is capable of providing a prompt trigger signal, called Fast-OR, which contributes to the L0 trigger decision. The pixel trigger system allows to apply a set of algorithms for the trigger selection, and its output is sent to the Central Trigger Processor (CTP). The detector has been installed in the experiment in summer 2007. During the first injection tests in June 2008 the SPD was able to record the very first sign of life of the LHC by registering secondary particles from the beam dumped upstream the ALICE experiment. In the following months the...

The upgrade of the ALICE Inner Tracking System

CERN Document Server

Ravasenga, Ivan

2017-01-01

In 2021, for the third run of the CERN Large Hadron Collider (LHC), Pb-Pb collisions will be performed at a centre-of-mass energy per nucleon of 5.5 TeV, with an integrated luminosity of $6 \\times 10^{27}$ cm$^{-2}$ s$^{-1}$ and at an unprecedented interaction rate up to 50 kHz. To fulfil the requirements of the ALICE physics program for Run 3, the ALICE experiment at LHC is planning a major upgrade during the Long Shutdown 2 of LHC in 2019-2020. One of the key elements, is the construction of a new ultra-light and high-resolution Inner Tracking System (ITS). The upgraded ITS will significantly enhance the determination of the distance of closest approach to the primary vertex, the tracking efficiency at low transverse momenta, and the read-out rate capabilities, with respect to what can be achieved with the current detector. It will consist of seven layers equipped with silicon Monolithic Active Pixel Sensors (MAPS) with a pixel size of the order of $30 \\times 30 \\mu m^2$. They will be produced by Towerjazz ...

Modeling and simulation of critical parameters of the first chamber of the dimuon arm spectrometer of the Alice experiment; Modelisation et simulation de parametres critiques de la premiere station du spectrometre dimuons d'ALICE

Energy Technology Data Exchange (ETDEWEB)

Guez, D

2003-10-01

The Alice experiment that is dedicated to the study of ultra-relativistic heavy ion collisions, will take place in the future large hadron collider (LHC) at CERN. The dimuon arm spectrometer of the Alice experiment is devoted to the search of a new signature of the existence of the quark gluon plasma (QGP). The first chapter is dedicated to the physics notions linked to the study of QGP, a few signatures are proposed for the detection of QGP, particularly the signature concerning the production rate of quarkonium. The second chapter deals with particle detection involved in Alice experiment, the dimuon arm spectrometer is a detector dedicated to the track reconstruction of muons issued from the decay of heavy mesons from J/{psi} and {upsilon} families. The third and the fourth chapters present the studies made to integrate a reliable model of the dimuon arm in the global simulation code of Alice (Aliroot). The fifth chapter presents the software TB{sup 2} that has been developed within the framework of this thesis in order to check and control the output data when the detector is tested with a real particle beam. The sixth chapter presents the results of the tests that have been performed with a 7 GeV/c pion beam. These tests have shown that the electronic noise is coherent with the specifications of Alice experiment. A factor 1,8 between the highest and the weakest values of the gain has been measured in the chamber. The detection efficiency of the chamber has been estimated to 99% in the different cases studied. (A.C.)

ALICE TRD results from prototype tests

CERN Document Server

Andronic, A; Blume, C; Braun-Munzinger, P; Bucher, D; Catanescu, G; Ciobanu, M; Daues, H W; Devismes, A; Finck, C; Herrmann, N; Lister, T A; Mahmoud, Tariq; Peitzmann, Thomas; Petrovici, M; Reygers, K; Santo, R; Schicker, R; Sedykha, S; Simon, R S; Stachel, J; Stelzer, H; Wessels, J P; Winkelmann, O; Windelband, B; Xu, C

2002-01-01

We present results from tests of a prototype of the TRD for the ALICE experiment at LHC. We investigate the performance-of different radiator types, composed of foils, fibres and foams. The pion rejection performance for different methods of analysis over a momentum range from 0.7 to 2 GeV/c is presented. (8 refs).

Search for (exotic) strange matter in the Star and Alice experiments with the ultra-relativistic heavy ion colliders RHIC and LHC; Recherche de matiere etrange (exotique) dans les experiences STAR et ALICE aupres des collisionneurs d'ions lourds ultra-relativistes RHIC et LHC

Energy Technology Data Exchange (ETDEWEB)

Vernet, R

2006-02-15

Ultra-relativistic heavy ion collisions offer the possibility to create conditions of temperature and density that could lead nuclear matter to a state of deconfined partons, the quark-gluon plasma. Strange baryon production is one of the essential observables to understand the mechanisms involved in the medium. Furthermore, theories predict a possible production of strange dibaryons, still hypothetical particles, from which one could draw important inferences in nuclear physics and astrophysics. The experiments STAR at RHIC, and, soon, ALICE at LHC, allow one to search for strange baryons and dibaryons. The STAR sensitivity to the metastable dibaryon H{sup 0} in the {lambda}p{pi}{sup -} decay mode was calculated thanks to a dedicated simulation. The search for the H{sup 0}, and for the {xi}{sup -}p resonance as well, was performed in the STAR Au+Au data at {radical}(s{sub NN}) = 62.4 and 200 GeV energies. Within the framework of the preparation of ALICE to the first Pb+Pb data, the detector ability to identify strange baryons {lambda}, {xi} and {omega}, was estimated via several simulations. So as to favour the reconstruction efficiency in a large range of transverse momentum while keeping a reasonable S/B ratio, the influence of the geometrical selections and the size of the reconstruction zone was emphasized. The ALICE sensitivities to the metastable strange dibaryons H{sup 0} and ({xi}{sup 0}p){sub b} and to the {lambda}{lambda} resonance were calculated as well. (author)

Muon probe and connected instrumentation for the study of quark-gluon plasma in ALICE experiment; Sonde muonique et instrumentation associee pour l'etude du plasma de quarks et de gluons dans l'experience ALICE

Energy Technology Data Exchange (ETDEWEB)

Guerin, Fabien [Ecole Doctorale des Sciences Fondamentales, Universite Blaise Pascal, U.F.R de Recherches Scientifiques et Techniques, 34, avenue Carnot - BP 185, 63006 Clermont-Ferrand Cedex (France)

2006-11-15

ALICE (A Large Ion Collider Experiment) is the LHC detector dedicated to the study of ultra-relativistic heavy ion collisions. The main goal of ALICE is the study of a new phase of the nuclear matter predicted by the Quantum Chromodynamics theory (QCD): the Quark-Gluon Plasma (QGP). One of the possible signatures is a suppression of quarkonia yields by color screening in the heavy ion collisions, in which the formation of the QGP is expected. The muon spectrometer will allow measuring of the quarkonia yields (J/{psi}, {upsilon}) in heavy ion collisions via their dimuon decay. A fast trigger, associated to muon spectrometer, has to select events with at least one muon or one dimuon by using a track search algorithm. The study of muon trigger performance will be presented with emphasis on the trigger efficiency and rates in Ar-Ar and Pb-Pb collisions. We will also present the reconstruction of unlike-sign dimuon mass spectrum with the ALICE muon spectrometer. The expected yields of Upsilon states will be extracted from a simulation based on a fit of this spectrum for one month running for Pb-Pb collisions and for different collision centralities. (author)

Members of the LHC Resources Review Boards

CERN Multimedia

Maximilien Brice

2002-01-01

Photo 01: Members of the LHCRRB visiting Point 2, hosting the ALICE experiment From l. to r. : W. Korda, Head of the VIP Office; P. Rimmer, CERN public relations, J. Seed, Member of the LHCRRB, J.-P. Revol, ALICE CERN Team Leader; J. Bartke, Member of the LHCRRB; F. Suransky, Member of the LHCRRB; J. Schukraft, Spokesperson, ALICE experiment and S. Molinari, VIP Office. Photo 02: Members of the LHC Resources Review Boards visiting the ALICE magnet at Point 2. L. to. r.: O. Dines-Hansen, H. Boggild, S. Irgens-Jensens, H.A. Gustafsson Photo 03: Members of the LHCRRB visiting Point 2, hosting the ALICE experiment From l. t to r.: J.Richter, Member of the LHCRRB; H. Gutbrod, Deputy Spokesperson, ALICE experiment; G. Paic, ALICE experiment; D. Muller, Member of the LHCRRB; P. Brau-Munzinger, ALICE experiment; R. Santo, Member of the LHCRRB, A. Van Rijn, Member of the LHCRRB; J. Engelen, Member of the LHCRRB.

Open charm analysis with the ALICE detector in pp collisions at LHC

NARCIS (Netherlands)

Ivan, C.G.|info:eu-repo/dai/nl/304847747

2009-01-01

The upcoming ALICE experiment, at the Large Hadron Collider located at CERN, is designed to investigate the physics of strongly interacting matter at very high energy densities. In this thesis we present an analysis strategy for the feasibility of reconstructing open charm mesons with ALICE via the

J/ψ production in proton-proton collisions at √ s = 2.76 and 7 TeV in the ALICE forward muon spectrometer at LHC

International Nuclear Information System (INIS)

Geuna, C.

2012-01-01

Quarkonia are meson states whose constituents are a charm or bottom quark and its corresponding antiquark (Q-Q-bar). The study of the production of such bound states in high-energy hadron collisions represents an important test for the Quantum Chromo-Dynamics. Despite the fact that the quarkonium saga has already a 40-year history, the quarkonium production mechanism is still an open issue. Therefore, measurements at the new CERN Large Hadron Collider (LHC) energy regimes are extremely interesting. In this thesis, the study of inclusive J/Ψ production in proton-proton (pp) collisions at √ = 2.76 and 7 TeV, obtained with the ALICE experiment, is presented. J/Ψ mesons are measured at forward rapidity (2.5 ≤ y ≤ 4), down to zero pT, via their decay into muon pairs (μ + μ - ). Quarkonium resonances also play an important role in probing the properties of the strongly interacting hadronic matter created, at high energy densities, in heavy-ion collisions. Under such extreme conditions, the created system, according to QCD, undergoes a phase transition from ordinary hadronic matter to a new state of deconfined quarks and gluons, called Quark Gluon Plasma (QGP). The ALICE experiment at CERN LHC has been specifically designed to study this state of matter. Quarkonia, among other probes, represents one of the most promising tools to prove the QGP formation. In order to correctly interpret the measurements of quarkonium production in heavy-ion collisions, a solid baseline is provided by the analogous results obtained in pp collisions. Hence, the work discussed in this thesis, concerning the inclusive J/Ψ production in pp collisions, also provides the necessary reference for the corresponding measurements performed in Pb-Pb collisions which were collected, by the ALICE experiment, at the very same center-of-mass energy per nucleon pair (√ = 2.76 TeV). (author) [fr

ALICE gives its first thesis awards

CERN Multimedia

2008-01-01

For the first time the ALICE collaboration has given two of its doctoral students awards for their outstanding theses. Winners Christian Holm Christensen and Zaida Conesa del Valle holding their awards.On 29 October the ALICE collaboration honoured two students for their outstanding theses at a ceremony held at CERN. The two awards, one of which was given for a physics thesis and the other for a technical thesis, went to Zaida Conesa Del Valle (Laboratoire de physique subatomique et des technologies associées) and Christian Holm Christensen (Niels Bohr Institute) respectively. "It is very gratifying to see that the collaboration appreciates our work," said Zaida Conesa del Valle, winner of the physics award for her thesis: Performance of the ALICE Muon Spectrometer. Weak Boson Production and Measurement in Heavy Ion Collisions at the LHC. "I also feel specially thankful to all the people who worked with me," she added. "It was pl...

Studies for the ALICE Inner Tracking System Upgrade

CERN Document Server

AUTHOR|(CDS)2079168; Musa, Luciano

The ALICE experiment at the CERN LHC identifies D0 mesons via secondary-vertex reconstruction and topological cuts to reduce the corresponding combinatorial background in heavy-ion collisions. The D0 meson is produced promptly in initial, hard scatterings via the strong interaction or as feed-down from weakly decaying B hadrons. Within this thesis, a novel method for the separation of prompt and feed-down D0 mesons using cut variations was implemented and applied to data from p–Pb collisions at $\\sqrt(s_\\mathrm{NN})=5.02$ TeV. The effectiveness of the secondary-vertex reconstruction strongly depends on the performance and in particular the pointing resolution of the Inner Tracking System. The upgrade of the ALICE Inner Tracking System for the Long Shutdown 2 of the LHC in 2019/2020 will significantly improve its vertex-reconstruction and tracking capabilities. It will be equipped with Monolithic Active Pixel Sensors manufactured using the TowerJazz 180nm CMOS process on wafers with a high-resistivity epitax...

Beam test results of the irradiated Silicon Drift Detector for ALICE

OpenAIRE

Kushpil, S.; Crescio, E.; Giubellino, P.; Idzik, M.; Kolozhvari, A.; Kushpil, V.; Martinez, M. I.; Mazza, G.; Mazzoni, A.; Meddi, F.; Nouais, D.; Petracek, V.; Piemonte, C.; Rashevsky, A.; Riccati, L.

2005-01-01

The Silicon Drift Detectors will equip two of the six cylindrical layers of high precision position sensitive detectors in the ITS of the ALICE experiment at LHC. In this paper we report the beam test results of a SDD irradiated with 1 GeV electrons. The aim of this test was to verify the radiation tolerance of the device under an electron fluence equivalent to twice particle fluence expected during 10 years of ALICE operation.

Managing information flow in ALICE

International Nuclear Information System (INIS)

Pinazza, O.; Augustinus, A.; Chochula, P.Ch.; Jirden, L.S.; Lechman, M.; Rosinsky, P.; Cataldo, G. de; Kurepin, A.N.; Moreno, A.

2012-01-01

ALICE is one of the experiments at the Large Hadron Collider (LHC) at CERN in Geneva, Switzerland. The ALICE detector control system (DCS) is an integrated system collecting 18 different detectors' controls and general services. DCS is implemented using the commercial SCADA package PVSS. Information of general interest, such as beam and condition data, and data related to shared plants or systems, are made available to all the subsystems via the distribution capabilities of PVSS. Great care has been taken to build a modular and hierarchical system, limiting the inter-dependencies of the various subsystems. Accessing remote resources in a PVSS distributed environment is very simple and can be initiated unilaterally. In order to improve the reliability of distributed data and to avoid unforeseen and unwished dependencies, the ALICE DCS group has enforced the centralization of global data required by the subsystems. A tool has been developed to monitor the level of inter-dependency and to understand the optimal layout of the distributed connections, allowing for an interactive visualization of the distribution topology. (authors)

arXiv GEM Foil Quality Assurance For The ALICE TPC Upgrade

CERN Document Server

INSPIRE-00019412; Hildén, Timo

2018-01-01

The ALICE (A Large Ion Collider Experiment) experiment at the Large Hadron Collider (LHC) at CERN is dedicated to heavy ion physics to explore the structure of strongly interacting matter. The Time Projection Chamber (TPC) of ALICE is a tracking detector located in the central region of the experiment. It offers excellent tracking capabilities as well as particle identification. After the second long shutdown (LS2) the LHC will run at substantially higher luminosities. To be able to increase the data acquisition rate by a factor of 100, the ALICE TPC experiment has to replace the Multi-Wire Proportional Chamber (MWPC) –based readout chambers. The MWPC are operated with gating grid that limits the rate to O(kHz). The new ReadOut Chamber (ROC) design is based on Gas Electron Multiplier (GEM) technology operating in continuous mode. The current GEM productions scheme foresees the production of more than 800 GEM foils of different types. To fulfill the requirements on the performance of the GEM TPC readout, nec...

Kalibration des ALICE Übergangsstrahlungsdetektors und ein Studium der Z-Boson und schwere Quarks Produktion in pp Kollisionen an der LHC

CERN Document Server

Bailhache, Raphaëlle

2008-01-01

The ALICE Experiment is one of the four experiments installed at the Large Hadron Collider (LHC). One of its detector-systems, the Transition Radiation Detector (TRD), is a gas detector designed for electron identification and charged particle tracking. The charged particle ionizes the gas along its path and electrons drift in an uniform field of 700 V/cm over 3 cm before being amplified. We implemented procedures to calibrate the drift velocity of the electrons, the time-offset of the signal, the amplification factor and the width of the Pad Response Function (PDF) characterizing the sharing of the deposited charge over adjacent pads. Physics events (pp and PbPb collisions) will be used. The performances of the algorithms were tested on simulated pp collisions at √s=14 TeV and on first real data taken with cosmic-rays in the ALICE setup. The calibration software was installed on the Data Acquisition System at CERN and executed continuously during the cosmic-ray data taking in 2008, providing a first determ...

Transverse momentum spectra of charged particles in proton-proton collisions at $\\sqrt{s}$ = 900 GeV with ALICE at the LHC

CERN Document Server

Aamodt, K; Abeysekara, U; Abrahantes Quintana, A; Abramyan, A; Adamov, D; Aggarwal, M M; Aglieri Rinella, G; Agocs, A G; Aguilar Salazar, S; Ahammed, Z; Ahmad, A; Ahmad, N; Ahn, S U; Akimoto, R; Akindinov, A; Aleksandrov, D; Alessandro, B; Alfaro Molina, R; Alici, A; Almarz Avia, E; Alme, J; Alt, T; Altini, V; Altinpinar, S; Andrei, C; Andronic, A; Anelli, G; Angelov, V; Anson, C; Anticic, T; Antinori, F; Antinori, S; Antipin, K; Antonczyk, D; Antonioli, P; Anzo, A; Aphecetche, L; Appelshuser, H; Arcelli, S; Arceo, R; Arend, A; Armesto, N; Arnaldi, R; Aronsson, T; Arsene, I C; Asryan, A; Augustinus, A; AverbecK, R; Awes, T C; yst, J; Azmi, M D; Bablok, S; Bach, M; Badal, A; Baek, Y W; Bagnasco, S; Bailhache, R; Bala, R; Baldisseri, A; Baldit, A; Bn, J; Barbera, R; Barnafldi, G G; Barnby, L S; Barret, V; Bartke, J; Barile, F; Basile, M; Basmanov, V; Bastid, N; Bathen, B; Batigne, G; Batyunya, B; Baumann, C; Bearden, I G; Becker, B; Belikov, I; Bellwied, R; Belmont-Moreno, E; Belogianni, A; 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Nazarov, G; Nedosekin, A; Nendaz, F; Newby, J; Nianine, A; Nicassio, M; Nielsen, B S; Nikolaev, S; Nikolic, V; Nikulin, S; Nikulin, V; Nilsen, B S; Nilsson, M S; Noferini, F; Nomokonov, P; Nooren, G; Novitzky, N; Nyatha, A; Nygaard, C; Nyiri, A; Nystrand, J; Ochirov, A; Odyniec, G; Oeschler, H; Oinonen, M; Okada, K; Okada, Y; Oldenburg, M; Oleniacz, J; Oppedisano, C; Orsini, F; Ortiz Velasquez, A; Ortona, G; Oskarsson, A; Osmic, F; sterman, L; Ostrowski, P; Otterlund, I; Otwinowski, J; Øvrebekk, G; Oyama, K; Ozawa, K; Pachmayer, Y; Pachr, M; Padilla, F; Pagano, P; Paic, G; Painke, F; Pajares, C; Pal, S; Pal, S K; Palaha, A; Palmeri, A; Panse, R; Papikyan, V; Pappalardo, G S; Park, W J; Pastirck, B; Pastore, C; Paticchio, V; Pavlinov, A; Pawlak, T; Peitzmann, T; Pepato, A; Pereira, H; Peressounko, D; Prez, C; Perini, D; Perrino, D; Peryt, W; Peschek, J; Pesci, A; Peskov, V; Pestov, Y; Peters, A J; Petrcek, V; Petridis, A; Petris, M; Petrov, P; Petrovici, M; Petta, C; Peyr, J; Piano, S; Piccotti, A; Pikna, M; Pillot, P; Pinazza, O; Pinsky, L; Pitz, N; Piuz, F; Platt, R; Ploskon, M; Pluta, J; Pocheptsov, T; Pochybova, S; Podesta Lerma, P L M; Poggio, F; Poghosyan, M.G.; Polk, K; Polichtchouk, B; Polozov, P; Polyakov, V; Pommeresch, B; Pop, A; Posa, F; Pospsil, V; Potukuchi, B; Pouthas, J; Prasad, S K; Preghenella, R; Prino, F; Pruneau, C A; Pshenichnov, I; Puddu, G; Pujahari, P; Pulvirenti, A; Punin, A; Punin, V; Putis, M; Putschke, J; Quercigh, E; Rachevski, A; Rademakers, A; Radomski, S; Rih, T S; Rak, J; Rakotozafindrabe, A; Ramello, L; Ramrez Reyes, A; Rammler, M; Raniwala, R; Raniwala, S; Rsnen, S S; Rashevskaya, I; Rath, S; Read, K F; Real, J S; Redlich, K; Renfordt, R; Reolon, A R; Reshetin, A; Rettig, F; Revol, J P; Reygers, K; Ricaud, H; Riccati, L; Ricci, R A; Richter, M; Riedler, P; Riegler, W; Riggi, F; Rivetti, A; Rodriguez Cahuantzi, M; Red, K; Rhrich, D; Romn Lopez, S; Romita, R; Ronchetti, F; Rosinsk, P; Rosnet, P; Rossegger, S; Rossi, A; Roukoutakis, F; Rousseau, S; Roy, C; Roy, P; Rubio-Montero, A J; Rui, R; Rusanov, I; Russo, G; Ryabinkin, E; Rybicki, A; Sadovsky, S; Safark, K; Sahoo, R; Saini, J; Saiz, P; Sakata, D; Salgado, C A; Salgueiro Domingues da Silva, R; Salur, S; Samanta, T; Sambyal, S; Samsonov, V; Sndor, L; Sandoval, A; Sano, M; Sano, S; Santo, R; Santoro, R; Sarkamo, J; Saturnini, P; Scapparone, E; Scarlassara, F; Scharenberg, R P; Schiaua, C; Schicker, R; Schindler, H; Schmidt, C; Schmidt, H R; Schossmaier, K; Schreiner, S; Schuchmann, S; Schukraft, J; Schutz, Y; Schwarz, K; Schweda, K; Scioli, G; Scomparin, E; Scott, P A; Segato, G; Semenov, D; Senyukov, S; Seo, J; Serci, S; Serkin, L; Serradilla, E; Sevcenco, A; Sgura, I; Shabratova, G; Shahoyan, R; Sharkov, G; Sharma, N; Sharma, S; Shigaki, K; Shimomura, M; Shtejer, K; Sibiriak, Y; Siciliano, M; Sicking, E; Siddi, E; Siemiarczuk, T; Silenzi, A; Silvermyr, D; Simili, E; Simonetti, G; Singaraju, R; Singh, R; Singhal, V; Sinha, B C; Sinha, T; Sitar, B; Sitta, M; Skaali, T B; Skjerdal, K; Smakal, R; Smirnov, N; Snellings, R; Snow, H; Sgaard, C; Soloviev, A; Soltveit, H K; Soltz, R; Sommer, W; Son, C W; Son, H; Song, M; Soos, C; Soramel, F; Soyk, D; Spyropoulou-Stassinaki, M; Srivastava, B K; Stachel, J; Staley, F; Stan, E; Stefanek, G; Stefanini, G; Steinbeck, T; Stenlund, E; Steyn, G; Stocco, D; Stock, R; Stolpovsky, P; Strmen, P; Suaide, A A P; Subieta Vsquez, M A; Sugitate, T; Suire, C; Sumbera, M; Susa, T; Swoboda, D; Symons, J; Szanto de Toledo, A; Szarka, I; Szostak, A; Szuba, M; Tadel, M; Tagridis, C; Takahara, A; Takahashi, J; Tanabe, R; Tapia Takaki, J D; Taureg, H; Tauro, A; Tavlet, M; Tejeda Muoz, G; Telesca, A; Terrevoli, C; Thader, J; Tieulent, R; Tlusty, D; Toia, A; Tolyhy, T; Torcato de Matos, C; Torii, H; Torralba, G; Toscano, L; Tosello, F; Tournaire, A; Traczyk, T; Tribedy, P; Trger, G; Truesdale, D; Trzaska, W H; Tsiledakis, G; Tsilis, E; Tsuji, T; Tumkin, A; Turrisi, R; Turvey, A; Tveter, T S; Tydesj, H; Tywoniuk, K; Ulery, J; Ullaland, K; Uras, A; Urbn, J; Urciuoli, G M; Usai, G L; Vacchi, A; Vala, M; Valencia Palomo, L; Vallero, S; van der Kolk, N; Vande Vyvre, P; van Leeuwen, M; Vannucci, L; Vargas, A; Varma, R; Vasiliev, A; Vassiliev, I; Vasileiou, M; Vechernin, V; Venaruzzo, M; Vercellin, E; Vergara, S; Vernet, R; Verweij, M; Vetlitskiy, I; Vickovic, L; Viesti, G; Vikhlyantsev, O; Vilakazi, Z; Villalobos Baillie, O; Vinogradov, A; Vinogradov, L; Vinogradov, Y; Virgili, T; Viyogi, Y P; Vodopianov, A; Voloshin, K; Voloshin, S; Volpe, G; von Haller, B; Vranic, D; Vrlkov, J; Vulpescu, B; Wagner, B; Wagner, V; Wallet, L; Wan, R; Wang, D; Wang, Y; Wang, Y; Watanabe, K; Wen, Q; Wessels, J; Westerhoff, U; Wiechula, J; Wikne, J; Wilk, A; Wilk, G; Williams, M C S; Willis, N; Windelband, B; Xu, C; Yang, C; Yang, H; Yasnopolskiy, S; Yermia, F; Yi, J; Yin, Z; Yokoyama, H; Yoo, I K; Yuan, X; Yurevich, V; Yushmanov, I; Zabrodin, E; Zagreev, B; Zalite, A; Zampolli, C; Zanevsky, Yu; Zaporozhets, S; Zarochentsev, A; Zvada, P; Zbroszczyk, H; Zelnicek, P; Zenin, A; Zepeda, A; Zgura, I; Zhalov, M; Zhang, X; Zhou, D; Zhou, S; Zhu, J; Zichichi, A; Zinchenko, A; Zinovjev, G; Zoccarato, Y; Zychcek, V; Zynovyev, M

2010-01-01

The inclusive charged particle transverse momentum distribution is measured in proton-proton collisions at $\\sqrt{s} = 900$~GeV at the LHC using the ALICE detector. The measurement is performed in the central pseudorapidity region $(|\\eta|_{\\rm INEL}=0.483\\pm0.001$~(stat.)~$\\pm0.007$~(syst.)~GeV/$c$ and $\\left_{\\rm NSD}=0.489\\pm0.001$~(stat.)~$\\pm0.007$~(syst.)~GeV/$c$, respectively. The data exhibit a slightly larger $\\left$ than measurements in wider pseudorapidity intervals. The results are compared to simulations with the Monte Carlo event generators PYTHIA and PHOJET.

Quarkonium in ALICE: results on p-Pb and Pb-Pb collisions from LHC Run 2

CERN Multimedia

CERN. Geneva

2017-01-01

In 1986, the modification of quarkonium production was first proposed as a signature of the formation of a Quark Gluon Plasma. While the central role of quarkonium in the understanding of the QGP is indisputable, the direct link between the expected sequential suppression, in a very hot medium, and the experimental observations is not yet completely settled. Several other mechanisms, related to either the formation of a hot medium, such as quarkonium regeneration, or to the presence of cold nuclear matter, are well-known key effects in the interpretation of the results. This talk reviews very recent LHC Run 2 results obtained with the ALICE detector, which is designed to study quarkonium in two rapidity ranges,  at mid-rapidity ($|y|<0.9$) in the dielectron decay channel and at forward rapidity ($2.5

Upgrade of the ALICE Inner Tracking System

CERN Document Server

INSPIRE-00246160

2015-05-20

{During the Long Shutdown 2 (LS2) of the LHC in 2018/2019, the ALICE experiment plans the installation of a novel Inner Tracking System (ITS). The upgraded detector will fully replace the current ITS having six layers by seven layers of Monolithic Active Pixel Sensors (MAPS). The upgraded ITS will have significantly improved tracking and vertexing capabilities, as well as readout rate to cope with the expected increased Pb-Pb luminosity in LHC. The choice of MAPS has been driven by the specific requirements of ALICE as a heavy ion experiment dealing with rare probes at low $p_\\mathrm{T}$. This leads to stringent requirements on the material budget of 0.3$\\%~X/X_{0}$ per layer for the three innermost layers. Furthermore, the detector will see large hit densities of $\\sim 19~\\mathrm{cm}^{-2}/\\mathrm{event}$ on average for minimum-bias events in the inner most layer and has to stand moderate radiation loads of 700 kRad TID and $1\\times 10^{13}$ 1 MeV n$_\\mathrm{eq}/\\mathrm{cm}^{2}$ NIEL at maximum. The MAPS dete...

LHC an unprecedented technological challenge

International Nuclear Information System (INIS)

Baruch, J.O.

2002-01-01

This article presents the future LHC (large hadron collider) in simple terms and gives some details concerning radiation detectors and supra-conducting magnets. LHC will take the place of the LEP inside the 27 km long underground tunnel near Geneva and is scheduled to operate in 2007. 8 years after its official launching the LHC project has piled up 2 year delay and has exceeded its initial budget (2 milliard euros) by 18%. Technological challenges and design difficulties are the main causes of these shifts. The first challenge has been carried out successfully, it was the complete clearing out of the LEP installation. In order to release 14 TeV in each proton-proton collision, powerful magnetic fields (8,33 Tesla) are necessary. 1248 supra-conducting 15 m-long bipolar magnets have to be built. 30% of the worldwide production of niobium-titanium wires will be used each year for 5 years in the design of these coils. The global cryogenic system will be gigantic and will use 94 tons of helium. 4 radiation detectors are being built: ATLAS (a toroidal LHC apparatus), CMS (compact muon solenoid), ALICE (a large ion collider experiment) and LHC-b (large hadron collider beauty). The 2 first will search after the Higgs boson, ALICE will be dedicated to the study of the quark-gluon plasma and LHC-b will gather data on the imbalance between matter and anti-matter. (A.C.)

Fibre optic cables for the ALICE experiment

CERN Multimedia

Maximilien Brice

2003-01-01

These thin fibres will transmit the signal received in detectors at the ALICE experiment when it starts up with the LHC in 2008. The analogue signals produced in the detectors are first converted into digital pulse, which are transported in light down such fibres. Computers then read this digital signal to produce the final set of data.

Development of the digital read-out system for the CERN Alice pixel detector

CERN Document Server

Grassi, Tullio

In order to gain new experimental insight at the TeV energy scale, CERN (Geneva) will build the Large Hadron Collider (LHC), a new collider machine operating at a maximum center-of-mass energy of 14 TeV (in the p+/p+ interactions). The accelerator can operate in a heavy ion collision mode achieving a center-of-mass energy of ~5.5 TeV. The experimental environment at LHC is characterized by a high crossing rate of the particle bunches (one every 25 ns for p+/p+) and high levels of radiation. Therefore stringent requirements are imposed on the performance of detectors at LHC. Such a particle physics environment calls for dedicated hardware/software solutions with specific constraints, such as radiation tolerance, limited amount of material and limited power dissipation. One of the particle physics experiments carried out in LHC is ALICE (A Large Ion Collider Experiment). The ALICE detector will face a very high density of tracks of particles (a multiplicity of 8000 charged particles per unit of rapidity, that i...

21 March 2011 - South African Ministry of Science and Technology, Department of Science and Technology (DST) Director General P. Mjwara signing the guest with Head of International Relations F. Pauss and Adviser J. Ellis and ALICE Collaboration Spokesperson P. Giubellino and J. Cleymans; in the CERN control centre with R. Steerenberg; visiting ALICE surface exhibition with P. Giubellino and LHC superconducting magnet test hall with L. Bottura.

CERN Multimedia

Maximilien Brice

2011-01-01

21 March 2011 - South African Ministry of Science and Technology, Department of Science and Technology (DST) Director General P. Mjwara signing the guest with Head of International Relations F. Pauss and Adviser J. Ellis and ALICE Collaboration Spokesperson P. Giubellino and J. Cleymans; in the CERN control centre with R. Steerenberg; visiting ALICE surface exhibition with P. Giubellino and LHC superconducting magnet test hall with L. Bottura.

Search for (exotic) strange matter in the Star and Alice experiments with the ultra-relativistic heavy ion colliders RHIC and LHC

International Nuclear Information System (INIS)

Vernet, R.

2006-02-01

Ultra-relativistic heavy ion collisions offer the possibility to create conditions of temperature and density that could lead nuclear matter to a state of deconfined partons, the quark-gluon plasma. Strange baryon production is one of the essential observables to understand the mechanisms involved in the medium. Furthermore, theories predict a possible production of strange dibaryons, still hypothetical particles, from which one could draw important inferences in nuclear physics and astrophysics. The experiments STAR at RHIC, and, soon, ALICE at LHC, allow one to search for strange baryons and dibaryons. The STAR sensitivity to the metastable dibaryon H 0 in the Λpπ - decay mode was calculated thanks to a dedicated simulation. The search for the H 0 , and for the Ξ - p resonance as well, was performed in the STAR Au+Au data at √(s NN ) = 62.4 and 200 GeV energies. Within the framework of the preparation of ALICE to the first Pb+Pb data, the detector ability to identify strange baryons Λ, Ξ and Ω, was estimated via several simulations. So as to favour the reconstruction efficiency in a large range of transverse momentum while keeping a reasonable S/B ratio, the influence of the geometrical selections and the size of the reconstruction zone was emphasized. The ALICE sensitivities to the metastable strange dibaryons H 0 and (Ξ 0 p) b and to the ΛΛ resonance were calculated as well. (author)

LHC 2008 lectures "Une nouvelle vision du monde"

CERN Multimedia

2008-01-01

The history of the science of the Universe and the science of matter have been marked by a small number of "revolutions" that have turned our understanding of the infinitesimally large and the infinitesimally small on its head. New ways of looking at the world have come about sometimes through conceptual advances and sometimes through innovations in scientific instrumentation. How do things stand at the beginning of the 21st century? Will today’s large-scale machine projects like the LHC and gravitational wave detectors pave the way for a new scientific revolution? Thursday, 15 May 2008 at 8.00 p.m. Une nouvelle vision du monde Jean-Pierre Luminet, Research Director at the CNRS The Globe, first floor No specialist knowledge required. Entrance free. To reserve call + 41 (0) 22 767 76 76 http://www.cern.ch/globe

Measurement of $\\Lambda_{\\rm c}$ Baryon production in the decay channel $\\Lambda_{\\rm c} \\rightarrow p \\rm K^{0}_{\\rm S}~$ in proton-proton and proton-lead collisions with ALICE detector at LHC

CERN Document Server

Meninno, Elisa

This thesis describes the study of the production of the charmed baryon $\\Lambda_{\\rm c}^{+}$ in proton-proton and proton-lead collisions with the ALICE experiment, operating at the Large Hadron Collider (LHC) at CERN. ALICE was built to study hadronic collisions (pp and A-A) and, in particular, aims to investigate the $Quark-Gluon Plasma$ (QGP), state of the matter during the first instants of life of the universe. When two ultra-relativistic heavy nuclei collide, the extreme conditions of temperature and pressure, necessary for the QGP formation, can be created. In particular, heavy quarks (charm and beauty) are produced in hard scattering processes during the first stages of the hadronic collision. The measurement of hadrons with heavy quarks in pp collisions at the LHC energies is a powerful test for perturbative quantum cromodynamics (pQCD) in this energy domain. Moreover, these studies are the necessary reference for studying the production of heavy quarks in nucleus-nucleus collisions. Results from pp ...

Studies of characteristics of triple GEM detector for the ALICE-TPC upgrade

International Nuclear Information System (INIS)

Patra, Rajendra Nath; Singaraju, R.N.; Ahammed, Z.; Nayak, T.K.; Biswas, S.

2015-01-01

Gas Electron Multiplier (GEM) is a novel gas detector in the field of radiation detection. GEM detectors have tremendous advantages over other types gas detectors like high rate handling capability with high efficiency and very low ion back flow (IBF). These detectors are most suitable for the use in the future experiments in high-energy proton-proton and heavy-ion collisions at the Large Hadron Collider (LHC) at CERN and Facility for Antiproton and Ion Research (FAIR) at GSI. A Large Ion Collider Experiment (ALICE) at the LHC is a dedicated experiment for the study of Quark Gluon Plasma (QGP). In few years, the data taking rate for Pb-Pb collisions will increase by 100 times to 50 KHz. The ALICE Time Projection Chamber (TPC) is the main tracking detector in ALICE. It is planned that by the year 2018, GEM detectors will replace the present readout planes of TPC. The goal of the present study is to characterize the GEM detector to achieve the performance goal of the TPC

Onia, open heavy flavours, meson decays and combinatorial effects in muon pairs measurements, in ALICE at LHC

International Nuclear Information System (INIS)

Zhou, D.C.; Jouan, D.

1996-01-01

The ALICE collaboration has proposed to build a detector dedicated to nucleus-nucleus collisions at LHC. The aim is to study strongly interacting matter at extreme energy densities and particularly to search for evidence of the predicted QCD phase transition to quark-gluon plasma (QGP). The suppression of heavy quark resonances, J/ψ and υ, is one of the most promising signatures of the quark-gluon plasma. This work gives out results of a simulation of signals and backgrounds in muon pairs measurements with a forward spectrometer, including the dimuon production from resonances, open charm, open beauty and meson decay in Pb-Pb, Ca-Ca and P-P collisions. The effect of the nature of the absorber on the mass resolution is discussed, and a comparison with measurement in the central region is also made. (author)

The readout system for the ALICE zero degree calorimeters

CERN Document Server

Siddhanta, S; De Falco, A; Floris, M; Masoni, A; Puddu, G; Serci, S; Uras, A; Usai, G; Arnaldi, R; Bianchi, L; Bossu, F; Chiavassa, E; De Marco, N; Ferretti, A; Gagliardi, M; Gallio, M; Luparello, G; Musso, A; Oppedisano, C; Piccotti, A; Scomparin, E; Vercellin, E; Cortese, P; Dellacasa, G

2011-01-01

ALICE at the CERN LHC will investigate the physics of strongly interacting matter at extreme energy densities where the formation of the Quark Gluon Plasma is expected. Its properties can be studied from observations like the production of mesons w ith charm and beauty quarks. These signals have to be studied as a function of energy density, which is determined by the centrality of collisions. One of the physics observables that is closely related with the centrality of the collision is the number o f spectator nucleons that can be measured by the Zero Degree Calorimeters (ZDC). Having a direct geometric interpretation allows to extract the impact parameter with minimal model assumptions. This paper describes the readout system of the ZDC. The ZDC re adout consists of a VME system with a ZDC Readout Card, a VME Processor, Discriminators, a ZDC Trigger Card, scalers, QDCs and TDCs. The system was successfully tested during the 2009 ALICE data taking and is currently operational at the LHC.

Study of the muon production from open heavy flavours predicted by the Color Glass Condensate model in proton-proton and proton-lead collision with the Alice muon spectrometer at LHC

International Nuclear Information System (INIS)

Charpy, A.

2007-10-01

It will be possible to test the latest developments of the Quantum Chromodynamics (QCD) in the new LHC (large hadron collider) machine. One of these, the Colour Glass Condensate (CGC), describes the parton distributions of the nucleus in the saturation region, i.e. at small x. This theoretical description of the initial conditions of the heavy ion collisions is necessary to predict the heavy quark cross section production which evolves in a possible deconfined matter: the Quark-Gluon Plasma (PQG). Alice is the LHC experiment mainly dedicated to the study of the PQG produced in ultra-relativistic heavy ion collisions. The measurement of J/Psi and Upsilon resonance suppression is a signature of this deconfined medium which is studied with the Alice muon spectrometer. Its acceptance at large rapidity is well adapted for studying the prediction of CGC at small-x. The first part of this report presents the results of beam test experiment at CERN. It was the first time that the muon spectrometer tracking chambers were tested equipped with the final version of the front end electronics and the data acquisition system Crocus. The relevant calibration parameters of the front end electronics were introduced in the analysis in order to improve the quality of the track reconstruction. In the second part, these parameters were used in the simulations. The last part proposes a study of the CGC with the Alice muon spectrometer, involving the measurements of open charm and open beauty. (author)

Measurements of ion mobility and GEM discharge studies for the upgrade of the ALICE time projection chamber

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00507268

2018-02-20

ALICE is one of the four experiments at the Large Hadron Collider (LHC). The quark-gluon plasma, which is predominantly produced in lead-lead collisions at LHC, is of particular interest for ALICE. After the long shut-down 2 (2019-2021) the LHC will provide lead-lead collisions at an increased interaction rate of 50 kHz. In order to examine every event at this interaction rate the ALICE Time Projection Chamber (TPC) needs to be upgraded. The TPC’s ReadOut Chambers (ROCs) are currently multi-wire proportional chambers. To prevent space charge build-up of slow ions, drifting from the ROCs into the TPC, a gating grid is used. The corresponding closure time imposes a dead time on the TPC read out, which prohibits data taking at a readout rate higher than 3 kHz. New ROCs have therefore been designed, relying on stacks of Gas Electron Multiplier (GEM) foils for the gas amplification, allowing for continuous readout. With the new ROCs, a certain fraction of ions will be drifting at all time into the TPC. Knowing t...

JACoW ADAPOS: An architecture for publishing ALICE DCS conditions data

CERN Document Server

Lång, John; Bond, Peter; Chochula, Peter; Kurepin, Alexander; Lechman, Mateusz; Pinazza, Ombretta

2018-01-01

ALICE Data Point Service (ADAPOS) is a software architecture being developed for the RUN3 period of LHC, as a part of the effort to transmit conditions data from ALICE Detector Control System (DCS) to Event Processing Network (EPN), for distributed processing. The key processes of ADAPOS, Engine and Terminal, run on separate machines, facing different networks. Devices connected to DCS publish their state as DIM services. Engine gets updates to the services, and converts them into a binary stream. Terminal receives it over 0MQ, and maintains an image of the DCS state. It sends copies of the image, at regular intervals, over another 0MQ connection, to a readout process of ALICE Data Acquisition.

Probe station for testing of ALICE silicon drift detectors

CERN Document Server

Humanic, T J; Piemonte, C; Rashevsky, A; Sugarbaker, E R; Vacchi, A

2003-01-01

Large area, 7.25 cm multiplied by 8.76 cm silicon drift detectors have been developed and are in production for the ALICE experiment at LHC. An active area of the detector of more than 50 cm**2 imposes high demands on the quality of processing and raw material. Automated testing procedures have been developed to test detectors before mounting them on the ladders. Probe stations for ALICE SDD testing were designed and built at INFN, Trieste and Ohio State University (OSU). Testing procedures, detector selection criteria and some details of the OSU probe station design are discussed.

Diffraction in ALICE and trigger efficiencies

CERN Document Server

Navin, Sparsh; Lietava, Roman

ALICE is built to measure the properties of strongly interacting matter created in heavy-ion collisions. In addition, taking advantage of the low pT acceptance in the central barrel, ALICE is playing an important role in understanding pp collisions with minimum bias triggers at LHC energies. The work presented in this thesis is based on pp data simulated by the ALICE collaboration and early data collected at a center-of-mass energy of 7 TeV. A procedure to calculate trigger efficiencies and an estimate of the systematic uncertainty due to the limited acceptance of the detector are shown. A kinematic comparison between Monte Carlo event generators, PYTHIA 6, PYTHIA 8 and PHOJET is also presented. To improve the description of diffraction in PYTHIA, a hard diffractive component was added to PYTHIA 8 in 2009, which is described. Finally a trigger with a high efficiency for picking diffractive events is used to select a sample with an enhanced diffractive component from pp data. These data are compared to Monte ...

ALICE's first vacuum bakeout a success

CERN Multimedia

2007-01-01

At the beginning of April, the ALICE central beryllium beam pipe and absorber beam pipes were successfully conditioned. The installation and bakeout shell surround the beam pipe (lower left), running through the middle of the ITS and TPC. Notice the high-tech cooling system, an additional precaution to avoid overheating the ALICE detection equipment.One end of the vacuum sector during the bakeout and pure gas refill. It is unusual for a vacuum sector to end as it does in the middle of a non-accessible detector and made the installation and cabling of the bakeout equipment a more difficult procedure. Just before Easter, the first bakeout and NEG activation of experimental chambers in the LHC was carried out, followed by ultra pure gas refill. The bakeout consisted of externally heating the chambers under vacuum in order to lower their outgassing. This same heating process also activates the NEG, a coating on the inside surface of the beam vacuum chambers, which pumps the residual gas. ALICE's bakeout was pa...

23 octobre 2012 - Le Président du Conseil général de la Haute-Savoie C. Monteil signe le livre d'or en présence du Directeur général R. Heuer, la chef des Relations Internationales F. Pauss, le chef du département Physique P. Bloch et le chef du département Technologie F. Bordry; visite du hall de test des aimants supraconducteurs du LHC avec F. Bordry.

CERN Multimedia

Maximilien Brice

2012-01-01

23 octobre 2012 - Le Président du Conseil général de la Haute-Savoie C. Monteil signe le livre d'or en présence du Directeur général R. Heuer, la chef des Relations Internationales F. Pauss, le chef du département Physique P. Bloch et le chef du département Technologie F. Bordry; visite du hall de test des aimants supraconducteurs du LHC avec F. Bordry.

Performance of the ALICE experiment at the CERN LHC

NARCIS (Netherlands)

Meddi, F.; Menchaca-Rocha, A.; Meninno, E.; Mercado Pérez, J.; Meres, M.; Miake, Y.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A. N.; Mis̈kowiec, D.; Mitu, C. M.; Mlynarz, J.; Mohanty, B.; Molnar, L.; Montano Zetina, L.; Montes, E.; Morando, M.; Moreira De Godoy, D. A.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Muhuri, S.; Mukherjee, M.; Müller, H.; Munhoz, M. G.; Murray, S.; Musa, L.; Musinsky, J.; Nandi, B. K.; Nania, R.; Nappi, E.; Nattrass, C.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Nicassio, M.; Niculescu, M.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Nilsen, B. S.; Noferini, F.; Nomokonov, P.; Nooren, G.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Oh, S. K.; Okatan, A.; Olah, L.; Oleniacz, J.; Oliveira Da Silva, A. C.; Onderwaater, J.; Oppedisano, C.; Ortiz Velasquez, A.; Oskarsson, A.; Twinowski, J.; Oyama, K.; Sahoo, P.; Pachmayer, Y.; Pachr, M.; Pagano, P.; Paić, G.; Painke, F.; Pajares, C.; Pal, S. K.; Palmeri, A.; Pant, D.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, W. J.; Parmar, S.; Passfeld, A.; Patalakha, D. I.; Paticchio, V.; Paul, B.; Pawlak, T.; Peitzmann, T.; Pereira Da Costa, H.; Pereira De Oliveira Filho, E.; Peresunko, D.; Pérez Lara, C. E.; Pesci, A.; Pestov, Y.; Petráček, V.; Petran, M.; Petris, M.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Ploskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L M; Poghosyan, M. G.; Pohjoisaho, E. H O; Polichtchouk, B.; Poljak, N.; Pop, A.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, V.; Potukuchi, B.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Rauf, A. W.; Razazi, V.; Read, K. F.; Real, J. S.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reicher, M.; Reidt, F.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J. P.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Rivetti, A.; Rocco, E.; Rodríguez Cahuantzi, M.; Rodriguez Manso, A.; Rd, K.; Rogochaya, E.; Rohni, S.; Rohr, D.; Röhrich, D.; Romita, R.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossegger, S.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Sadovsky, S.; Safarík, K.; Sahlmuller, B.; Sahoo, R.; Sahu, P. K.; Saini, J.; Salgado, C. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sanchez Castro, X.; Sánchez Rodríguez, F. J.; Sándor, L.; Sandoval, A.; Sano, M.; Santagati, G.; Sarkar, D.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schuchmann, S.; Schukraft, J.; Schulc, M.; Schuster, T.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, P. A.; Scott, R.; Segato, G.; Seger, J. E.; Selyuzhenkov, I.; Seo, J.; Serradilla, E.; Sevcenco, A.; Shabetai, A.; Shabratova, G.; Shahoyan, R.; Shangaraev, A.; Sharma, N.; Sharma, S.; Shigaki, K.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, C. B.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Skjerdal, K.; Smakal, R.; Smirnov, N.; Snellings, R. J M; Saard, C.; Soltz, R.; Song, J.; Song, M.; Soramel, F.; Sorensen, S.; Spacek, M.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stefanek, G.; Steinpreis, M.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Stolpovskiy, M.; Strmen, P.; Suaide, A. A P; Subieta Vasquez, M. A.; Sugitate, T.; Suire, C.; Suleymanov, M.; Sultanov, R.; Sumbera, M.; Susa, T.; Symons, T. J M; Szanto De Toledo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Takahashi, J.; Tangaro, M. A.; Tapia Takaki, J. D.; Tarantola Peloni, A.; Tarazona Martinez, A.; Tarzila, M. G.; Tauro, A.; Tejeda Muñoz, G.; Telesca, A.; Terrevoli, C.; Ter Minasyan, A.; Thäder, J.; Thomas, D.; Tieulent, R.; Timmins, A. R.; Toia, A.; Torii, H.; Trubnikov, V.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ulery, J.; Ullaland, K.; Uras, A.; Usai, G. L.; Vajzer, M.; Vala, M.; Valencia Palomo, L.; Vallero, S.; Vande Vyvre, P.; Vannucci, L.; Van Der Maarel, J.; Van Hoorne, J. W.; Van Leeuwen, M.; Vargas, A.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vechernin, V.; Veldhoen, M.; Velure, A.; Venaruzzo, M.; Vercellin, E.; Vergara Limón, S.; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Vislavicius, V.; Viyogi, P. Y.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; Von Haller, B.; Vorobyev, I.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Vyushin, A.; Wagner, B.; Wagner, J.; Wagner, V.; Wang, M.; Wang, Y.; Watanabe, D.; Weber, M.; Weber, S. G.; Wessels, J. P.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilde, M.; Wilk, G.; Wilkinson, J.; Williams, M. C S; Windelband, B.; Winn, M.; Xiang, C.; Yaldo, C. G.; Yamaguchi, Y.; Yang, H.; Yang, P.; Yang, S.; Yano, S.; Yasnopolskiy, S.; Yi, J.; Yin, Z.; Yoo, I. K.; Yushmanov, I.; Zaccolo, V.; Zach, C.; Zaman, A.; Zampolli, C.; Zaporozhets, S.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zgura, I. S.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, F.; Zhou, Y.; Zhu, H.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zoccarato, Y.; Zynovyev, M.; Zyzak, M.

2014-01-01

ALICE is the heavy-ion experiment at the CERN Large Hadron Collider. The experiment continuously took data during the first physics campaign of the machine from fall 2009 until early 2013, using proton and lead-ion beams. In this paper we describe the running environment and the data handling

ALICE installs new hardware in preparation for the 2012 run

CERN Multimedia

CERN Bulletin and ALICE Matters

2012-01-01

2011 was a fantastic year for the heavy-ion run at ALICE despite unprecedented challenges and difficult conditions. The data collected is at least one order of magnitude greater than the 2010 data. Thanks to a planned upgrade to two subdetectors during the 2011/2012 winter shutdown and a reorganisation of ALICE’s Physics Working Groups that should allow them to better deal with the greater challenges imposed by the LHC, the collaboration is confident that the 2011 run will allow ALICE to extend its physics reach and improve its performance.   Photograph of ALICE taken by Antonio Saba during this year's winter shutdown. The annual winter shutdown has been a very intense period for the ALICE collaboration. In conjunction with the general maintenance, modifications and tests of the experiment, two major projects – the installation of 3 supermodules of the Transition Radiation Detector (TRD) and 2 supermodules of the Electromagnetic Calorimeter (EMCal) – hav...

Start of run2 physics at the Large Hadron Collider (LHC)

CERN Multimedia

Brice, Maximilien

2015-01-01

Images from the CERN Control Centre (CCC), where operators control the LHC, and from the control rooms of the ALICE, ATLAS, CMS and LHCb experiments, where operators control huge detectors that capture data from collisions between beams of protons in the LHC.

Ré-imaginer Alice au pays des merveilles

Directory of Open Access Journals (Sweden)

Florence Cheron

2016-12-01

Full Text Available Alice’s Adventures in Wonderland fait l’objet d’adaptations cinématographiques dès les débuts du cinéma. De nombreuses analyses soulèvent, et ce dès les années 1990, le lien tacite entre les films de Tim Burton et les aventures d’Alice. Que ce soient les personnages, les univers ou encore l’absurdité des situations, il semblait évident que le cinéaste en viendrait un jour à filmer sa vision des écrits de Lewis Carroll, comme l’aboutissement d’une idée qui serait en germe depuis toujours. Le réalisateur rendant hommage aux premières illustrations mais aussi aux différentes adaptations d’Alice au cinéma, effectue une synthèse visuelle et narrative de l’ensemble de ces œuvres comme si son Alice in Wonderland devait être une transposition-somme.

Le futur du project LHC

CERN Multimedia

Heyoka

2007-01-01

Since 2004, and specitally during the long study in 2005, we used the results of the LHC Project to evaluate differents parameters of the machiene (LHC). The final choices for the design of the machine are based partly on these results. (1,5 page)

Upgrade of the ALICE Experiment: Letter of Intent

CERN Document Server

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Beck, H; Bedda, C; Behera, N K; Belikov, I; Bellini, F; Bellwied, R; Belmont-Moreno, E; Bencedi, G; Benettoni, M; Benotto, F; Beole, S; Berceanu, I; Bercuci, A; Berdnikov, Y; Berenyi, D; Berger, M E; Bertens, R A; Berzano, D; Besson, A; Betev, L; Bhasin, A; Bhati, A K; Bhatti, A; Bhattacharjee, B; Bhom, J; Bianchi, L; Bianchi, N; Bianchin, C; Bielcík, J; Bielcíková, J; Bilandzic, A; Bjelogrlic, S; Blanco, F; Blau, D; Blume, C; Bock, F; Boehmer, F V; Bogdanov, A; Boggild, H; Bogolyubsky, M; Boldizsár, L; Bombara, M; Book, J; Borel, H; Borissov, A; Bornschein, J; Borshchov, V N; Bortolin, C; Bossú, F; Botje, M; Botta, E; Böttger, S; Braun-Munzinger, P; Breitner, T; Broker, T A; Browning, T A; Broz, M; Bruna, E; Bruno, G E; Budnikov, D; Buesching, H; Bufalino, S; Buncic, P; Busch, O; Buthelezi, Z; Caffarri, D; Cai, X; Caines, H; Caliva, A; Calvo Villar, E; Camerini, P; Canoa Roman, V; Carena, F; Carena, W; Cariola, P; Carminati, F; Casanova Díaz, A; Castillo Castellanos, J; Casula, E A R; 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Hwang, D S; Igolkin, S; Ijzermans, P; Ilkaev, R; Ilkiv, I; Inaba, M; Incani, E; Innocenti, G M; Ionita, C; Ippolitov, M; Irfan, M; Ivanov, M; Ivanov, V; Ivanytskyi, O; Jacholkowski, A; Jadlovsky, J; Jahnke, C; Jang, H J; Janik, M A; Jayarathna, P H S Y; Jena, S; Jimenez Bustamante, R T; Jones, P G; Jung, H; Junique, A; Jusko, A; Kalcher, S; Kalinak, P; Kalweit, A; Kamin, J; Kang, J H; Kaplin, V; Kar, S; Karasu Uysal, A; Karavichev, O; Karavicheva, T; Karpechev, E; Kebschull, U; Keidel, R; Keil, M; Ketzer, B; Khan, M Mohisin; Khan, P; Khan, S A; Khanzadeev, A; Kharlov, Y; Kileng, B; Kim, B; Kim, D; Kim, D W; Kim, D J; Kim, J S; Kim, M; Kim, M; Kim, S; Kim, T; Kirsch, S; Kisel, I; Kiselev, S; Kisiel, A; Kiss, G; Klay, J L; Klein, J; Klein-Bösing, C; Kluge, A; Knichel, M L; Knospe, A G; Kobdaj, C; Kofarago, M; Köhler, M K; Kollegger, T; Kolojvari, A; Kondratiev, V; Kondratyeva, N; Konevskikh, A; Kovalenko, V; Kowalski, M; Kox, S; Koyithatta Meethaleveedu, G; Kral, J; Králik, I; Kramer, F; 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Maltsev, N A; Malzacher, P; Mamonov, A; Manceau, L; Manko, V; Manso, F; Manzari, V; Mapelli, A; Marchisone, M; Mares, J; Margagliotti, G V; Margotti, A; Marín, A; Marin Tobon, C A; Markert, C; Marquard, M; Marras, D; Martashvili, I; Martin, N A; Martinengo, P; Martínez, M I; Martínez García, G; Martin Blanco, J; Martynov, Y; Mas, A; Masciocchi, S; Masera, M; Maslov, M; Masoni, A; Massacrier, L; Mastroserio, A; Mattiazzo, S; Matyja, A; Mayer, C; Mazer, J; Mazumder, R; Mazza, G; Mazzoni, M A; Meddi, F; Menchaca-Rocha, A; Mercado Pérez, J; Meres, M; Miake, Y; Mikhaylov, K; Milano, L; Milosevic, J; Mischke, A; Mishra, A N; Miskowiec, D; Mitu, C M; Mlynarz, J; Mohanty, B; Molnar, L; Mongelli, M; Montaño Zetina, L; Montes, E; Morando, M; Moreira De Godoy, D A; Morel, F; Moretto, S; Morreale, A; Morsch, A; Muccifora, V; Mudnic, E; Muhammad Bhopal, F; Muhuri, S; Mukherjee, M; Müller, H; Munhoz, M G; Murray, S; Musa, L; Musinsky, J; Nandi, B K; Nania, R; Nappi, E; Nattrass, C; Nayak, T K; Nazarenko, S; Nedosekin, A; Nicassio, M; Niculescu, M; Nielsen, B S; Nikolaev, S; Nikulin, S; Nikulin, V; Nilsen, B S; Noferini, F; Nomokonov, P; Nooren, G; Nyanin, A; Nystrand, J; Oeschler, H; Oh, S; Oh, S K; Okatan, A; Olah, L; Oleniacz, J; Oliveira Da Silva, A C; Onderwaater, J; Oppedisano, C; Ortiz Velasquez, A; Oskarsson, A; Otwinowski, J; Oyama, K; Pachmayer, Y; Pachr, M; Pagano, P; Paic, G; Painke, F; Pajares, C; Pal, S K; Palmeri, A; Panati, S; Pant, D; Pantano, D; Papikyan, V; Pappalardo, G S; Park, W J; Passfeld, A; Pastore, C; Patalakha, D I; Paticchio, V; Paul, B; Pawlak, T; Peitzmann, T; Pereira Da Costa, H; Pereira De Oliveira Filho, E; Peresunko, D; Pérez Lara, C E; Peryt, W; Pesci, A; Pestov, Y; Petagna, P; Petrácek, V; Petran, M; Petris, M; Petrovici, M; Petta, C; Pham, H; Piano, S; Pikna, M; Pillot, P; Pinazza, O; Pinsky, L; Piyarathna, D B; Ploskon, M; Planinic, M; Pluta, J; Pochybova, S; Podesta-Lerma, P L M; Poghosyan, M G; Pohjoisaho, E H O; Polichtchouk, B; Poljak, N; Pop, A; Porteboeuf-Houssais, S; Porter, J; Pospisil, V; Potukuchi, B; Prasad, S K; Preghenella, R; Prino, F; Protsenko, M A; Pruneau, C A; Pshenichnov, I; Puddu, G; Puggioni, C; Punin, V; Putschke, J; Qvigstad, H; Rachevski, A; Raha, S; Rak, J; Rakotozafindrabe, A; Ramello, L; Raniwala, R; Raniwala, S; Räsänen, S S; Rascanu, B T; Rasson, J E; Rathee, D; Rauf, A W; Razazi, V; Read, K F; Real, J S; Redlich, K; Reed, R J; Rehman, A; Reichelt, P; Reicher, M; Reidt, F; Renfordt, R; Reolon, A R; Reshetin, A; Rettig, F; Revol, J -P; Reygers, K; Riabov, V; Ricci, R A; Richert, T; Richter, M; Riedler, P; Riegler, W; Riggi, F; Rivetti, A; Rocco, E; Rodríguez Cahuantzi, M; Rodriguez Manso, A; Roed, K; Rogochaya, E; Rohni, S; Rohr, D; Röhrich, D; Romita, R; Ronchetti, F; Ronflette, L; Rosnet, P; Rossegger, S; Rossewij, M J; Rossi, A; Roudier, S; Rousset, J; Roy, A; Roy, C; Roy, P; Rubio Montero, A J; Rui, R; Russo, R; Ryabinkin, E; Ryabov, Y; Rybicki, A; Sacchetti, M; Sadovsky, S; Safarík, K; Sahlmuller, B; 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Zinovjev, G; Zoccarato, Y; Zynovyev, M; Zyzak, M; CERN. Geneva. The LHC experiments Committee; LHCC

2014-01-01

The long term goal of the ALICE experiment is to provide a precise characterization of the high-density, high-temperature phase of strongly interacting matter. To achieve this goal, high-statistics precision measurement are required. The general upgrade strategy for the ALICE detector is conceived to deal with this challenge with expected Pb-Pb interaction rates of up to 50 kHz aiming at an integrated luminosity of the order of 10 nb^-1. With the proposed timeline, starting the high-rate operation progressively after 2018 shutdown, the goals set up in our upgrade plans should be achieved collecting data until mid-2020's. In this document we present the main physics motivations for running the LHC with heavy ions at high luminosities and discuss the modifications and replacements needed in the ALICE detectors, the online systems and offline system. The schedule, cost estimate and organization of the upgrade programme are presented as well.

Successful beam tests for ALICE Transition Radiation Detector

CERN Multimedia

2002-01-01

Another round of beam tests of prototypes for the Transition Radiation Detector (TRD) for ALICE has been completed and there are already some good results. Mass production of the components of the detector will start early next year.   Top view of the setup for the Transition Radiation Detector prototype tests at CERN.On the left, can be seen the full-scale TRD prototype together with four smaller versions. These are busy days for the TRD (Transition Radiation Detector) team of ALICE. Twenty people - mainly from Germany, but also from Russia and Japan - were working hard during the beam tests this autumn at CERN to assess the performance of their detector prototypes. Analysis of the data shows that the TRD can achieve the desired physics goal even for the highest conceivable multiplicities in lead-lead collisions at the LHC. In its final configuration in the ALICE experiment, the TRD will greatly help in identifying high-momentum electrons, which are 'needles in a haystack' that consists mostly of...

The ALICE High Level Trigger: status and plans

CERN Document Server

Krzewicki, Mikolaj; Gorbunov, Sergey; Breitner, Timo; Lehrbach, Johannes; Lindenstruth, Volker; Berzano, Dario

2015-01-01

The ALICE High Level Trigger (HLT) is an online reconstruction, triggering and data compression system used in the ALICE experiment at CERN. Unique among the LHC experiments, it extensively uses modern coprocessor technologies like general purpose graphic processing units (GPGPU) and field programmable gate arrays (FPGA) in the data flow. Realtime data compression is performed using a cluster finder algorithm implemented on FPGA boards. These data, instead of raw clusters, are used in the subsequent processing and storage, resulting in a compression factor of around 4. Track finding is performed using a cellular automaton and a Kalman filter algorithm on GPGPU hardware, where both CUDA and OpenCL technologies can be used interchangeably. The ALICE upgrade requires further development of online concepts to include detector calibration and stronger data compression. The current HLT farm will be used as a test bed for online calibration and both synchronous and asynchronous processing frameworks already before t...

A Bayesian approach to particle identification in ALICE

CERN Multimedia

CERN. Geneva

2016-01-01

Among the LHC experiments, ALICE has unique particle identification (PID) capabilities exploiting different types of detectors. During Run 1, a Bayesian approach to PID was developed and intensively tested. It facilitates the combination of information from different sub-systems. The adopted methodology and formalism as well as the performance of the Bayesian PID approach for charged pions, kaons and protons in the central barrel of ALICE will be reviewed. Results are presented with PID performed via measurements of specific energy loss (dE/dx) and time-of-flight using information from the TPC and TOF detectors, respectively. Methods to extract priors from data and to compare PID efficiencies and misidentification probabilities in data and Monte Carlo using high-purity samples of identified particles will be presented. Bayesian PID results were found consistent with previous measurements published by ALICE. The Bayesian PID approach gives a higher signal-to-background ratio and a similar or larger statist...

Investigating heavy-ion collisions with neutral mesons in the ALICE calorimeters

Energy Technology Data Exchange (ETDEWEB)

Sahlmueller, Baldo [Goethe-Universitaet Frankfurt (Germany); Collaboration: ALICE-Collaboration

2015-07-01

One of the main purposes of the LHC is the investigation of the quark-gluon plasma produced in heavy-ion collisions. In order to interpret such measurements, the initial state of such collisions, i.e. the lead nucleus, and its effects on observables such as the modification of hadron transverse momentum spectra have to be understood. This initial state is studied in p-Pb collisions. Furthermore, pp collisions function as baseline measurement for the aforementioned larger systems and are necessary to extract fundamental parameters such as fragmentation functions. The π{sup 0} and η mesons can be measured in electromagnetic calorimeters via their two-photon decays. In the first run of the LHC, ALICE comprised two different calorimeters, PHOS and EMCAL, that offer different advantages and the possibility of two independent measurements of the same observables such as the transverse momentum distribution of neutral mesons. We present the status of ALICE measurements of neutral mesons with the EMCAL and PHOS detectors. The focus is on technical aspects of the analyses and present results from pp and p-Pb collisions. Furthermore, we give an outlook to future measurements in the second LHC run that will start in 2015.

Measurement of the J/ψ production in pp, p-Pb and Pb-Pb collisions with ALICE at LHC

Energy Technology Data Exchange (ETDEWEB)

Book, Julian [Institut fuer Kernphysik, Goethe-Universitaet Frankfurt am Main (Germany); Collaboration: ALICE-Collaboration

2015-07-01

The investigation of the properties of strongly interacting matter under extreme conditions is the aim of the ALICE experiment. Quarkonia, i.e. bound states of heavy (charm or bottom) quarks such as the J/ψ, are expected to be produced in initial hard scattering processes in hadronic collisions. Thus they will provide insights into the earliest and hottest stages of nucleus-nucleus collisions where the formation of a Quark-Gluon Plasma is expected. We present final results of J/ψ production in pp, p-Pb and Pb-Pb collisions performed by ALICE at the LHC in the first 4 years of data taking. Measurements in p-Pb and pp collisions help to decouple cold nuclear matter effects from hot nuclear effects in Pb-Pb collisions and serve as reference for the interpretation and evaluation of medium induced effects, such as color screening and recombination. Measurements differential in p{sub T} and centrality of J/ψ decaying into e{sup +}e{sup -} obtained at mid-rapidity (vertical stroke y vertical stroke < 0.9) for the different collisions systems are shown. Clearly less suppression with respect to SPS and RHIC results can be seen in Pb-Pb collisons at √(s{sub NN})=2.76 TeV. Results for J/ψ decaying into μ{sup +}μ{sup -} measured at forward rapidities (2.5

Future Upgrade and Physics Perspectives of the ALICE TPC

CERN Document Server

INSPIRE-00033137

The ALICE experiment at the Large Hadron Collider (LHC) proposes major detector upgrades to fully exploit the increase of the luminosity of the LHC in RUN~3 and to extend the physics reach for rare probes at low transverse momentum. The Time Projection Chamber (TPC) is one of the main tracking and PID devices in the central barrel of ALICE. The maximum trigger rate of the TPC is currently limited to about 3.5 kHz by the operation of a gating grid system. In order to make full use of the luminosity in RUN 3, the TPC is foreseen to be operated in an ungated mode with continuous readout. The existing MWPC readout will be replaced by a Micro-Pattern Gaseous Detector (MPGD) based readout, which provides intrinsic ion capture capability without gating. Extensive detector R\\&D employing Gas Electron Multiplier (GEM) and Micro-Mesh Gaseous detector (Micromegas) technologies, and simulation studies to advance the techniques for the corrections of space-charge distortions have been performed since 2012. In this pap...

LS1 Report: ALICE ups the ante

CERN Multimedia

Katarina Anthony

2014-01-01

SPS up and running... LHC almost cold... CCC Operators back at their desks... all telltale signs of the start of Run 2! For the experiments, that means there are just a few short months left for them to prepare for beams. The CERN Bulletin will be checking in with each of the Big Four to see how they are getting on during these closing months...   It has been a long road for the ALICE LS1 team. From major improvements to the 19 sub-detectors to a full re-cabling and replacement of LEP-era electrical infrastructure, no part of the ALICE cavern has gone untouched.* With the experiment set to close in early December, the teams are making finishing touches before turning their focus towards re-commissioning and calibration. "Earlier this week, we installed the last two modules of the di-jet calorimeter," explains Werner Riegler, ALICE technical coordinator. "These are the final parts of a 60 degree calorimeter extension that is installed opposite the present calorimeter, c...

Heavy-ion physics with the ALICE experiment at the CERN Large Hadron Collider.

Science.gov (United States)

Schukraft, J

2012-02-28

After close to 20 years of preparation, the dedicated heavy-ion experiment A Large Ion Collider Experiment (ALICE) took first data at the CERN Large Hadron Collider (LHC) accelerator with proton collisions at the end of 2009 and with lead nuclei at the end of 2010. After a short introduction into the physics of ultra-relativistic heavy-ion collisions, this article recalls the main design choices made for the detector and summarizes the initial operation and performance of ALICE. Physics results from this first year of operation concentrate on characterizing the global properties of typical, average collisions, both in proton-proton (pp) and nucleus-nucleus reactions, in the new energy regime of the LHC. The pp results differ, to a varying degree, from most quantum chromodynamics-inspired phenomenological models and provide the input needed to fine tune their parameters. First results from Pb-Pb are broadly consistent with expectations based on lower energy data, indicating that high-density matter created at the LHC, while much hotter and larger, still behaves like a very strongly interacting, almost perfect liquid.

First proton-proton collisions at the LHC as observed with the ALICE detector measurement of the charged particle pseudorapidity density at $\\sqrt{s}$ = 900 GeV

CERN Document Server

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Zenin, A; Zepeda, A; Zgura, I; Zhalov, M; Zhang, X; Zhou, D; Zhou, S; Zhu, J; Zichichi, A; Zinchenko, A; Zinovjev, G; Zinovjev, M; Zoccarato, Y; Zychácek, V; Ploskon, M

2010-01-01

On 23rd November 2009, during the early commissioning of the CERN Large Hadron Collider (LHC), two counter-rotating proton bunches were circulated for the first time concurrently in the machine, at the LHC injection energy of 450 GeV per beam. Although the proton intensity was very low, with only one pilot bunch per beam, and no systematic attempt was made to optimize the collision optics, all LHC experiments reported a number of collision candidates. In the ALICE experiment, the collision region was centred very well in both the longitudinal and transverse directions and 284 events were recorded in coincidence with the two passing proton bunches. The events were immediately reconstructed and analyzed both online and offline. We have used these events to measure the pseudorapidity density of charged primary particles in the central region. In the range |eta| < 0.5, we obtain dNch/deta = 3.10 +- 0.13 (stat.) +- 0.22 (syst.) for all inelastic interactions, and dNch/deta = 3.51 +- 0.15 (stat.) +- 0.25 (syst.)...

Building a large-area GEM-based readout chamber for the upgrade of the ALICE TPC

CERN Document Server

Gasik, Piotr

2017-01-01

A large Time Projection Chamber (TPC) is the main device for tracking and charged-particle identification in the ALICE experiment at the CERN LHC. After the second long shutdown in 2019-2020, the LHC will deliver Pb beams colliding at an interaction rate up to 50 kHz, which is about a factor of 100 above the present read-out rate of the TPC. To fully exploit the LHC potential the TPC will be upgraded based on the Gas Electron Multiplier (GEM) technology. A prototype of an ALICE TPC Outer Read-Out Chamber (OROC) was equipped with twelve large-size GEM foils as amplification stage to demonstrate the feasibility of replacing the current Multi Wire Proportional Chambers with the new technology. With a total area of $\\sim$0.76 m$^2$ it is the largest GEM-based detector built to date. The GEM OROC was installed within a test field cage and commissioned with radioactive sources.

Building a large-area GEM-based readout chamber for the upgrade of the ALICE TPC

Energy Technology Data Exchange (ETDEWEB)

Gasik, P. [Physik Department E62, Technische Universität München, Garching (Germany); Excellence Cluster ‘Origin and Structure of the Universe’, Garching (Germany)

2017-02-11

A large Time Projection Chamber (TPC) is the main device for tracking and charged-particle identification in the ALICE experiment at the CERN LHC. After the second long shutdown in 2019–2020, the LHC will deliver Pb beams colliding at an interaction rate up to 50 kHz, which is about a factor of 100 above the present read-out rate of the TPC. To fully exploit the LHC potential the TPC will be upgraded based on the Gas Electron Multiplier (GEM) technology. A prototype of an ALICE TPC Outer Read-Out Chamber (OROC) was equipped with twelve large-size GEM foils as amplification stage to demonstrate the feasibility of replacing the current Multi Wire Proportional Chambers with the new technology. With a total area of ∼0.76 m{sup 2} it is the largest GEM-based detector built to date. The GEM OROC was installed within a test field cage and commissioned with radioactive sources.

Building a large-area GEM-based readout chamber for the upgrade of the ALICE TPC

International Nuclear Information System (INIS)

Gasik, P.

2017-01-01

A large Time Projection Chamber (TPC) is the main device for tracking and charged-particle identification in the ALICE experiment at the CERN LHC. After the second long shutdown in 2019–2020, the LHC will deliver Pb beams colliding at an interaction rate up to 50 kHz, which is about a factor of 100 above the present read-out rate of the TPC. To fully exploit the LHC potential the TPC will be upgraded based on the Gas Electron Multiplier (GEM) technology. A prototype of an ALICE TPC Outer Read-Out Chamber (OROC) was equipped with twelve large-size GEM foils as amplification stage to demonstrate the feasibility of replacing the current Multi Wire Proportional Chambers with the new technology. With a total area of ∼0.76 m 2 it is the largest GEM-based detector built to date. The GEM OROC was installed within a test field cage and commissioned with radioactive sources.

Alignment of the ALICE Inner Tracking System with cosmic-ray tracks

CERN Document Server

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Gebelein, J; Gemme, R; Germain, M; Gheata, A; Gheata, M; Ghidini, B; Ghosh, P; Giraudo, G; Giubellino, P; Gladysz-Dziadus, E; Glasow, R; Glässel, P; Glenn, A; Gomez, R; González Santos, H; González-Trueba, L H; González-Zamora, P; Gorbunov, S; Gorbunov, Y; Gotovac, S; Gottschlag, H; Grabski, V; Grajcarek, R; Grelli, A; Grigoras, A; Grigoras, C; Grigoriev, V; Grigoryan, A; Grinyov, B; Grion, N; Gros, P; Grosse-Oetringhaus, J F; Grossiord, J Y; Grosso, R; Guarnaccia, C; Guber, F; Guernane, R; Guerzoni, B; Gulbrandsen, K; Gulkanyan, H; Gunji, T; Gupta, A; Gupta, R; Gustafsson, H A; Gutbrod, H; Haaland, Ø; Hadjidakis, C; Haiduc, M; Hamagaki, H; Hamar, G; Hamblen, J; Han, B H; Harris, J W; Hartig, M; Harutyunyan, A; Hasch, D; Hasegan, D; Hatzifotiadou, D; Hayrapetyan, A; Heide, M; Heinz, M; Helstrup, H; Herghelegiu, A; Hernández, C; Herrera Corral, G; Herrmann, N; Hetland, K F; Hicks, B; Hiei, A; Hille, P T; Hippolyte, B; Horaguchi, T; Hori, Y; Hristov, P; Hrivnácová, I; Huber, S; Humanic, T J; Hu, S; Hutter, D; Hwang, D S; Ichou, R; Ilkaev, R; Ilkiv, I; Innocenti, P G; Ippolitov, M; Irfan, M; Ivan, C; Ivanov, A; Ivanov, M; Ivanov, V; Iwasaki, T; Jachokowski, A; Jacobs, P; Jancurová, L; Jangal, S; Janik, R; Jayananda, K; Jena, C; Jena, S; Jirden, L; Jones, G T; Jones, P G; Jovanovic, P; Jung, H; Jung, W; Jusko, A; Kaidalov, A B; Kalcher, S; Kalinák, P; Kalliokoski, T; Kalweit, A; Kamal, A; Kamermans, R; Kanaki, K; Kang, E; Kang, J H; Kapitan, J; Kaplin, V; Kapusta, S; Karavicheva, T; Karpechev, E; Kazantsev, A; Kebschull, U; Keidel, R; Khan, M M; Khan, S A; Khanzadeev, A; Kharlov, Y; Kikola, D; Kileng, B; Kim, D J; Kim, D S; Kim, D W; Kim, H N; Kim, J H; Kim, J; Kim, J S; Kim, M; Kim, M; Kim, S H; Kim, S; Kim, Y; Kirsch, S; Kiselev, S; Kisel, I; Kisiel, A; Klay, J L; Klein-Bösing, C; Klein, J; Kliemant, M; Klovning, A; Kluge, A; Kniege, S; Koch, K; Kolevatov, R; Kolojvari, A; Kondratiev, V; Kondratyeva, N; Konevskih, A; Kornas, E; Kour, R; Kowalski, M; Kox, S; Kozlov, K; Králik, I; Kral, J; Kramer, F; Kraus, I; Kravcáková, A; Krawutschke, T; Krivda, M; Krumbhorn, D; Krus, M; Kryshen, E; Krzewicki, M; Kucheriaev, Y; Kuhn, C; Kuijer, P G; Kumar, L; Kumar, N; Kupczak, R; Kurashvili, P; Kurepin, A; Kurepin, A N; Kuryakin, A; Kushpil, S; Kushpil, V; Kutouski, M; Kvaerno, H; Kweon, M J; Kwon, Y; Lackner, F; Ladrón de Guevara, P; Lafage, V; Lal, C; Lara, C; La Rocca, P; Larsen, D T; Laurenti, G; Lazzeroni, C; Le Bornec, Y; Le Bris, N; Lee, H; Lee, K S; Lee, S C; Lefèvre, F; Lehnert, J; Leistam, L; Lenhardt, M; Lenti, V; León, H; León Monzón, I; León Vargas, H; Lévai, P; Lietava, R; Lindal, S; Lindenstruth, V; Lippmann, C; Lisa, M A; Listratenko, O; Liu, L; Li, Y; Loginov, V; Lohn, S; López Noriega, M; López-Ramírez, R; López Torres, E; Lopez, X; Løvhøiden, G; Lozea Feijo Soares, A; Lunardon, M; Luparello, G; Luquin, L; Lu, S; Lutz, J R; Luvisetto, M; Madagodahettige-Don, D M; Maevskaya, A; Mager, M; Mahajan, A; Mahapatra, D P; Maire, A; Makhlyueva, I; Ma, K; Malaev, M; Maldonado Cervantes, I; Malek, M; Mal'Kevich, D; Malkiewicz, T; Malzacher, P; Mamonov, A; Manceau, L; Mangotra, L; Manko, V; Manso, F; Manzari, V; Mao, Y; Mares, J; Margagliotti, G V; Margotti, A; Marín, A; Martashvili, I; Martinengo, P; Martínez Davalos, A; Martínez García, G; Martínez, M I; Maruyama, Y; Ma, R; Marzari Chiesa, A; Masciocchi, S; Masera, M; Masetti, M; Masoni, A; Massacrier, L; Mastromarco, M; Mastroserio, A; Matthews, Z L; Mattos Tavares, B; Matyja, A; Mayani, D; Mazza, G; Mazzoni, M A; Meddi, F; Menchaca-Rocha, A; Mendez Lorenzo, P; Meoni, M; Mercado Pérez, J; Mereu, P; Miake, Y; Michalon, A; Miftakhov, N; Milosevic, J; Minafra, F; Mischke, A; Miskowiec, D; Mitu, C; Mizoguchi, K; Mlynarz, J; Mohanty, B; Molnar, L; Mondal, M M; Montaño Zetina, L; Monteno, M; Montes, E; Morando, M; Moretto, S; Morsch, A; Moukhanova, T; Muccifora, V; Mudnic, E; Muhuri, S; Müller, H; Munhoz, M G; Munoz, J; Musa, L; Musso, A; Nandi, B K; Nania, R; Nappi, E; Navach, F; Navin, S; Nayak, T K; Nazarenko, S; Nazarov, G; Nedosekin, A; Nendaz, F; Newby, J; Nianine, A; Nicassio, M; Nielsen, B S; Nikolaev, S; Nikolic, V; Nikulin, S; Nikulin, V; Nilsen, B S; Nilsson, M S; Noferini, F; Nomokonov, P; Nooren, G; Novitzky, N; Nyatha, A; Nygaard, C; Nyiri, A; Nystrand, J; Ochirov, A; Odyniec, G; Oeschler, H; Oinonen, M; Okada, K; Okada, Y; Oldenburg, M; Oleniacz, J; Oppedisano, C; Orsini, F; Ortíz Velázquez, A; Ortona, G; Oskamp, C; Oskarsson, A; Osmic, F; Österman, L; Ostrowski, P; Otterlund, I; Otwinowski, J; Øvrebekk, G; Oyama, K; Ozawa, K; Pachmayer, Y; Pachr, M; Padilla, F; Pagano, P; Paic, G; Painke, F; Pajares, C; Palaha, A; Palmeri, A; Pal, S K; Pal, S; Panse, R; Pappalardo, G S; Park, W J; Pastircák, B; Pastore, C; Paticchio, V; Pavlinov, A; Pawlak, T; Peitzmann, T; Pepato, A; Pereira, H; Peressounko, D; Pérez, C; Perini, D; Perrino, D; Peryt, W; Peschek, J; Pesci, A; Peskov, V; Pestov, Y; Peters, A J; Petrácek, V; Petridis, A; Petris, M; Petrovici, M; Petrov, P; Petta, C; Peyré, J; Piano, S; Piccotti, A; Pikna, M; Pillot, P; Pinsky, L; Pitz, N; Piuz, F; Platt, R; Pluta, J; Pocheptsov, T; Pochybova, S; Podesta Lerma, P L M; Poggio, F; Poghosyan, M G; Poghosyan, T; Polák, K; Polichtchouk, B; Polozov, P; Polyakov, V; Pommeresch, B; Pop, A; Posa, F; Poskon, M; Pospisil, V; Potukuchi, B; Pouthas, J; Prasad, S K; Preghenella, R; Prino, F; Pruneau, C A; Pshenichnov, I; Puddu, G; Pujahari, P; Pulvirenti, A; Punin, A; Punin, V; Putis, M; Putschke, J; Quercigh, E; Rachevski, A; Rademakers, A; Radomski, S; Räihä, T S; Rak, J; Rakotozafindrabe, A; Ramello, L; Ramírez Reyes, A; Rammler, M; Raniwala, R; Raniwala, S; Räsänen, S; Rashevskaya, I; Rath, S; Read, K F; Real, J; Redlich, K; Renfordt, R; Reolon, A R; Reshetin, A; Rettig, F; Revol, J P; Reygers, K; Ricaud, H; Riccati, L; Ricci, R A; Richter, M; Riedler, P; Riegler, W; Riggi, F; Rivetti, A; Rodriguez Cahuantzi, M; Røed, K; Röhrich, D; Román López, S; Romita, R; Ronchetti, F; Rosinský, P; Rosnet, P; Rossegger, S; Rossi, A; Roukoutakis, F; Rousseau, S; Roy, C; Roy, P; Rubio-Montero, A J; Rui, R; Rusanov, I; Russo, G; Ryabinkin, E; Rybicki, A; Sadovsky, S; Safarík, K; Sahoo, R; Saini, J; Saiz, P; Sakata, D; Salgado, C A; Salgueiro Dominques da Silva, R; Salur, S; Samanta, T; Sambyal, S; Samsonov, V; Sándor, L; Sandoval, A; Sano, M; Sano, S; Santo, R; Santoro, R; Sarkamo, J; Saturnini, P; Scapparone, E; Scarlassara, F; Scharenberg, R P; Schiaua, C; Schicker, R; Schindler, H; Schmidt, C; Schmidt, H R; Schossmaier, K; Schreiner, S; Schuchmann, S; Schukraft, J; Schutz, Y; Schwarz, K; Schweda, K; Scioli, G; Scomparin, E; Segato, G; Semenov, D; Senyukov, S; Seo, J; Serci, S; Serkin, L; Serradilla, E; Sevcenco, A; Sgura, I; Shabratova, G; Shahoyan, R; Sharkov, G; Sharma, N; Sharma, S; Shigaki, K; Shimomura, M; Shtejer, K; Sibiriak, Y; Siciliano, M; Sicking, E; Siddi, E; Siemiarczuk, T; Silenzi, A; Silvermyr, D; Simili, E; Simonetti, G; Singaraju, R; Singhal, V; Singh, R; Sinha, B C; Sinha, T; Sitar, B; Sitta, M; Skaali, T B; Skjerdal, K; Smakal, R; Smirnov, N; Snellings, R; Snow, H; Søgaard, C; Sokolov, O; Soloviev, A; Soltveit, H K; Soltz, R; Sommer, W; Son, C W; Song, M; Son, H S; Soos, C; Soramel, F; Soyk, D; Spyropoulou-Stassinaki, M; Srivastava, B K; Stachel, J; Staley, F; Stan, I; Stefanek, G; Stefanini, G; Steinbeck, T; Stenlund, E; Steyn, G; Stocco, D; Stock, R; Stolpovsky, P; Strmen, P; Suaide, A A P; Subieta Vásquez, M A; Sugitate, T; Suire, C; Sumbera, M; Susa, T; Swoboda, D; Symons, J; Szanto de Toledo, A; Szarka, I; Szostak, A; Szuba, M; Tadel, M; Tagridis, C; Takahara, A; Takahashi, J; Tanabe, R; Tapia Takaki, J D; Taureg, H; Tauro, A; Tavlet, M; Tejeda Muñoz, G; Telesca, A; Terrevoli, C; Thäder, J; Tieulent, R; Tlusty, D; Toia, A; Tolyhy, T; Torcato de Matos, C; Torii, H; Torralba, G; Toscano, L; Tosello, F; Tournaire, A; Traczyk, T; Tribedy, P; Tröger, G; Truesdale, D; Trzaska, W H; Tsiledakis, G; Tsilis, E; Tsuji, T; Tumkin, A; Turrisi, R; Turvey, A; Tveter, T S; Tydesjö, H; Tywoniuk, K; Ulery, J; Ullaland, K; Uras, A; Urbán, J; Urciuoli, G M; Usai, G L; Vacchi, A; Vala, M; Valencia Palomo, L; Vallero, S; van den Brink, A; van der Kolk, N; Vande Vyvre, P; van Leeuwen, M; Vannucci, L; Vargas, A; Varma, R; Vasiliev, A; Vassiliev, I; Vassiliou, M; Vechernin, V; Venaruzzo, M; Vercellin, E; Vergara, S; Vernet, R; Verweij, M; Vetlitskiy, I; Vickovic, L; Viesti, G; Vikhlyantsev, O; Vilakazi, Z; Villalobos Baillie, O; Vinogradov, A; Vinogradov, L; Vinogradov, Y; Virgili, T; Viyogi, Y P; Vodopianov, A; Voloshin, K; Voloshin, S; Volpe, G; von Haller, B; Vranic, D; Vrláková, J; Vulpescu, B; Wagner, B; Wagner, V; Wallet, L; Wan, R; Wang, D; Wang, Y; Watanabe, K; Wen, Q; Wessels, J; Wiechula, J; Wikne, J; Wilk, A; Wilk, G; Williams, M C S; Willis, N; Windelband, B; Xu, C; Yang, C; Yang, H; Yasnopolsky, A; Yermia, F; Yi, J; Yin, Z; Yokoyama, H; Yoo, I-K; Yuan, X; Yushmanov, I; Zabrodin, E; Zagreev, B; Zalite, A; Zampolli, C; Zanevsky, Yu; Zaporozhets, Y; Zarochentsev, A; Závada, P; Zbroszczyk, H; Zelnicek, P; Zenin, A; Zepeda, A; Zgura, I; Zhalov, M; Zhang, X; Zhou, D; Zhou, S; Zhu, J; Zichichi, A; Zinchenko, A; Zinovjev, G; Zinovjev, M; Zoccarato, Y; Zychácek, V

2010-01-01

ALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 micron in some cases (pixels). The sources of alignment information include survey measurements, and the reconstructed tracks from cosmic rays and from proton-proton collisions. The main track-based alignment method uses the Millepede global approach. An iterative local method was developed and used as well. We present the results obtained for the ITS alignment using about 10^5 charged tracks from cosmic rays that h...

Particle correlations at ALICE

Energy Technology Data Exchange (ETDEWEB)

Erazmus, B.; Lednicky, R.; Lyuboshitz, V.; Martin, L.; Mikhailov, K.; Pluta, J.; Sinyukov, Yu.; Stavinsky, A.; Werner, K

1998-12-31

The ability of the ALICE detector for determination of the space-time characteristics of particle production in heavy-ion collisions at LHC from measurements of the correlation functions of identical and non-identical particles at small relative velocities is discussed. The possibility to use the correlations of non-identical particles for a direct determination of the delays in emission of various particle species at time scales as small as 10{sup -23} s is demonstrated. The influence of the multi-boson effects on pion multiplicities, single-pion spectra and two-pion correlation functions is discussed. (author) 63 refs.

Study of D-mesons using hadronic decay channels with the ALICE detector

CERN Document Server

Bala, Renu

2010-01-01

At LHC energy, heavy quarks will be abundantly produced and the design of the ALICE Experiment will allow us to study their production using several channels. We investigate the feasibility of the study of D mesons reconstructed in their exclusive hadronic decay channel. After reviewing the ALICE potential for such studies, we will present some results for the two more promising decay channels i.e D0->KPi and D+ -> K-Pi+Pi+ obtained with 7 TeV pp data and 5.5 A TeV Pb-Pb Monte Carlo data .

The ALICE Workload Management System: Status before the real data taking

International Nuclear Information System (INIS)

Bagnasco, S; Betev, L; Buncic, P; Carminati, F; Furano, F; Grigoras, A; Grigoras, C; Lorenzo, P Mendez; Peters, A J; Saiz, P

2010-01-01

With the startup of LHC, the ALICE detector will collect data at a rate that, after two years, will reach 4PB per year. To process such a large amount of data, ALICE has developed AliEn, a distributed computing environment, integrated with the WLCG environment. The ALICE environment presents several original solutions, which have shown their viability in a number of large exercises of increasing complexity called ALICE Data Challenges. Within the ALICE distributed computing environment, the AliEn Workload Management Structure was created to submit to the WLCG infrastructure, and has played a crucial role to achieve the mentioned results. ALICE has more than 80 sites distributed all over the world and this WMS together with the operations management structure defined by the experiment has demonstrated a reliability and performance level ready to begin the data taking at the end of the year. In this talk we will focus on the description and current status of the AliEn WMS, emphasizing the last functionalities that have been included to handle from a single entry point the different matchmaking services of WLCG (lcg-RB, gLite WMS) and also the CREAM Computing Element; the latter has been extensively tested by the experiment during summer 2008.

The ALICE Glance Shift Accounting Management System (SAMS)

Science.gov (United States)

Martins Silva, H.; Abreu Da Silva, I.; Ronchetti, F.; Telesca, A.; Maidantchik, C.

2015-12-01

ALICE (A Large Ion Collider Experiment) is an experiment at the CERN LHC (Large Hadron Collider) studying the physics of strongly interacting matter and the quark-gluon plasma. The experiment operation requires a 24 hours a day and 7 days a week shift crew at the experimental site, composed by the ALICE collaboration members. Shift duties are calculated for each institute according to their correlated members. In order to ensure the full coverage of the experiment operation as well as its good quality, the ALICE Shift Accounting Management System (SAMS) is used to manage the shift bookings as well as the needed training. ALICE SAMS is the result of a joint effort between the Federal University of Rio de Janeiro (UFRJ) and the ALICE Collaboration. The Glance technology, developed by the UFRJ and the ATLAS experiment, sits at the basis of the system as an intermediate layer isolating the particularities of the databases. In this paper, we describe the ALICE SAMS development process and functionalities. The database has been modelled according to the collaboration needs and is fully integrated with the ALICE Collaboration repository to access members information and respectively roles and activities. Run, period and training coordinators can manage their subsystem operation and ensure an efficient personnel management. Members of the ALICE collaboration can book shifts and on-call according to pre-defined rights. ALICE SAMS features a user profile containing all the statistics and user contact information as well as the Institutes profile. Both the user and institute profiles are public (within the scope of the collaboration) and show the credit balance in real time. A shift calendar allows the Run Coordinator to plan data taking periods in terms of which subsystems shifts are enabled or disabled and on-call responsible people and slots. An overview display presents the shift crew present in the control room and allows the Run Coordination team to confirm the presence

27 February 2012 - First Lady of Mexico, M. Zavala Gómez del Campo, welcomed by Adviser J. Salicio Diez withe ALICE Management and Mexican Users at LHC Point 2 and signing the guest book with CERN Director-General R. Heuer.

CERN Multimedia

Maximilien Brice

2012-01-01

27 February 2012 - First Lady of Mexico, M. Zavala Gómez del Campo, welcomed by Adviser J. Salicio Diez withe ALICE Management and Mexican Users at LHC Point 2 and signing the guest book with CERN Director-General R. Heuer.

Fragmentation of jets into hadrons with strangeness in Pb-Pb collisions in ALICE at the LHC

Energy Technology Data Exchange (ETDEWEB)

Zimmermann, Alice [Physikalisches Institut Heidelberg (Germany); Collaboration: ALICE-Collaboration

2014-07-01

The research programme of the ALICE experiment at the LHC focuses on the so-called Quark-Gluon Plasma, a state of matter where quarks and gluons are deconfined. The measurement of particle jets from fragmentation of hard scatterings of partons in the colliding nuclei allows to study parton energy loss in the hot and dense medium and constrains the modelling of such a phenomenon. By measuring yields of particles like K{sup 0}{sub s}, Λ and anti Λ of low to intermediate momenta within jet cones, fragmentation into strange hadrons, as well as the baryon-meson ratio in jets can be studied. In this contribution we present first results on K{sup 0}{sub s}, Λ and anti Λ production in jets in Pb-Pb collisions at √(s{sub NN}) = 2.76 TeV. The analysis is further performed in different centrality classes, representing collisions with different impact parameters. The strangeness identified fragmentation distributions are compared to first results on inclusive fragmentation in Pb-Pb collisions.

LHC Report: The beam is back at the LHC

CERN Multimedia

Reyes Alemany

2015-01-01

A series of sector beam tests paved the way for the start-up of the LHC in 2008 and 2009. These tests and the follow-up of the issues that arose were part of the process that led to a smooth start-up with beam.   Given this experience, sector tests were scheduled to take place several weeks before the 2015 start-up. On the weekend of 6-9 March, beam from the SPS was injected into both LHC injection regions, followed by a first pass through the downstream LHC sectors. For the clockwise LHC beam (called “beam 1”) this meant passing through ALICE and into Sector 2-3, while the anticlockwise beam (called “beam 2”) was threaded through LHCb and all the way from Point 8 to Point 6, where it was extracted by the beam dump kickers onto the beam dump block. The dry runs in the previous weeks were mainly targeted at preparation for the sector tests. The systems tested included: injection, timing, synchronisation and beam instrumentation. The beam interlock ...

Development of high $\\beta^*$-optics for ALICE

CERN Document Server

Hermes, Pascal Dominik; Wessels, Johannes Peter

This thesis describes a feasibility study for a special optical configuration in Insertion Region 2 (IR2) of the Large Hadron Collider (LHC), which is host of the ALICE detector. This configuration allows the study of elastic and diffractive scattering during LHC high-intensity proton operation, in parallel to the nominal physics studies in all LHC experiments at the design energy of 7 TeV per beam. Such measurements require the instal- lation of additional Roman Pot (RP) detectors in the very forward region, at longitudinal distances of 150 m to 220 m from the Interaction Point (IP). Apart from being adjusted for a specific betatron phase advance between the IP and the RP detectors, such a configuration must be optimized for the largest possible $\\beta^*$ -value, to be sensitive for the smallest possible four-momentum transfer $|t|$. A value of $\\beta^*$ = 18 m is compatible with a bunch spacing of 25 ns, considering the LHC design emittance of N = 3.75 μm rad, and a required bunch-bunch separation of $12 \\...

Study of the muon production from open heavy flavours predicted by the Color Glass Condensate model in proton-proton and proton-lead collision with the Alice muon spectrometer at LHC

International Nuclear Information System (INIS)

Charpy, A.

2007-10-01

The whole particle physics community is waiting for the Large Hadron Collider (LHC) commissioning at CERN. Indeed, the potential of discovery is very large in lots of themes. In particular, it will be possible to test the developments of the Quantum Chromodynamics (QCD) achieved during last years. One of these, the Colour Glass Condensate, describes the parton distributions of the nucleus in the saturation region, i.e. at small x. This theoretical description of the initial conditions of the heavy ion collisions is necessary to predict the heavy quark cross section production which evolves in a possible deconfined matter: the Quark-Gluon Plasma (PQG). ALICE is the LHC experiment mainly dedicated to the study of the PQG produced in ultra-relativistic heavy ion collisions. The measurement of J /Ψ and Υ resonance suppression is a signature of this deconfined medium which is studied with the ALICE muon spectrometer. Its acceptance at large rapidity is well adapted for studying the prediction of CGC at small-x. The first part of this report presents the results of beam test experiment at CERN. It was the first time that the muon spectrometer tracking chambers were tested equipped with the final version of the front end electronics and the data acquisition system CROCUS. The relevant calibration parameters of the front end electronics were introduced in the analysis in order to improve the quality of the track reconstruction. In the second part. these parameters were used in the simulations. The last part proposes a study of the CGC with the ALICE muon spectrometer. involving the measurements of open charm and open beauty. (author)

The ALICE Transition Radiation Detector: Construction, operation, and performance

Science.gov (United States)

Alice Collaboration

2018-02-01

The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/ c in p-Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction. The triggering capability is demonstrated both for jet, light nuclei, and electron selection.

The ALICE Silicon Pixel Detector Control and Calibration Systems

CERN Document Server

Calì, Ivan Amos; Manzari, Vito; Stefanini, Giorgio

2008-01-01

The work presented in this thesis was carried out in the Silicon Pixel Detector (SPD) group of the ALICE experiment at the Large Hadron Collider (LHC). The SPD is the innermost part (two cylindrical layers of silicon pixel detec- tors) of the ALICE Inner Tracking System (ITS). During the last three years I have been strongly involved in the SPD hardware and software development, construction and commissioning. This thesis is focused on the design, development and commissioning of the SPD Control and Calibration Systems. I started this project from scratch. After a prototyping phase now a stable version of the control and calibration systems is operative. These systems allowed the detector sectors and half-barrels test, integration and commissioning as well as the SPD commissioning in the experiment. The integration of the systems with the ALICE Experiment Control System (ECS), DAQ and Trigger system has been accomplished and the SPD participated in the experimental December 2007 commissioning run. The complex...

Inclusive production at LHC energies

International Nuclear Information System (INIS)

Merino, C.; Pajares, C.; Shabelski, Yu.M.

2011-01-01

We consider the first LHC data for pp collisions in the framework of Regge theory. The integral cross sections and inclusive densities of secondaries are determined by the Pomeron exchange, and we present the corresponding predictions for them. The first measurements of inclusive densities in the midrapidity region are in agreement with these predictions. The contribution of the baryon-number transfer due to String Junction diffusion in the rapidity space is at the origin of the differences in the inclusive spectra of particle and antiparticle in the central region, and this effect could be significant at LHC energies. We discuss the first data of ALICE and LHCb collaborations on the baryon/antibaryon asymmetry at LHC. (orig.)

ALICE distributed analysis of the K*(892)0 signal in pp events with the AliEn package

International Nuclear Information System (INIS)

Badala, A.; Barbera, R.; Lo Re, G.; Palmeri, A.; Pappalardo, G.S.; Pulvirenti, A.; Riggi, F.

2004-01-01

A simulation study concerning the K*(892)0 resonance was carried out within the ALICE Collaboration, in order to evaluate the capability of the detector in the reconstruction of this signal in pp collisions at the Large Hadron Collider (LHC) energy. A description of the analysis procedure which makes use of AliEn, the ALICE package for distributed computing, is given together with the obtained results

ALICE distributed analysis of the $K^{*}(892)^{0}$ signal in pp events with the AliEn package

CERN Document Server

Badalà, A; Palmeri, A; Pappalardo, G S; Pulvirenti, A; Lo Re, G; Riggi, F

2004-01-01

A simulation study concerning the K*(892)**0 resonance was carried out within the ALICE Collaboration, in order to evaluate the capability of the detector in the reconstruction of this signal in pp collisions at the Large Hadron Collider (LHC) energy. A description of the analysis procedure which makes use of AliEn, the ALICE package for distributed computing, is given together with the obtained results.

Le LHC, un tunnel cosmique

CERN Multimedia

CERN. Geneva

2009-01-01

Et si la lumière au bout du tunnel du LHC était cosmique ? En d’autres termes, qu’est-ce que le LHC peut nous apporter dans la connaissance de l’Univers ? Car la montée en énergie des accélérateurs de particules nous permet de mieux appréhender l’univers primordial, chaud et dense. Mais dans quel sens dit-on que le LHC reproduit des conditions proches du Big bang ? Quelles informations nous apporte-t-il sur le contenu de l’Univers ? La matière noire est-elle détectable au LHC ? L’énergie noire ? Pourquoi l’antimatière accumulée au CERN est-elle si rare dans l’Univers ? Et si le CERN a bâti sa réputation sur l’exploration des forces faibles et fortes qui opèrent au sein des atomes et de leurs noyaux, est-ce que le LHC peut nous apporter des informations sur la force gravitationnelle qui gouverne l’évolution cosmique ? Depuis une trentaine d’années, notre compréhension de l’univers dans ses plus grandes dimensions et l’appréhension de son comportement aux plus peti...

Performance of the Alice muon spectrometer. Weak boson production and measurement in heavy-ion collisions at LHC

International Nuclear Information System (INIS)

Conesa del valle, Z.

2007-07-01

Lattice QCD predicts a transition from a hadronic phase to a Quark Gluon Plasma phase, QGP, for temperatures above 10 13 K. Heavy-ion collisions are proposed to recreate it in laboratory. With such a purpose, the LHC (Large Hadron Collider) will provide Pb-Pb collisions at 5.5 TeV/u, and the ALICE experiment will permit to explore them. In particular, the ALICE muon spectrometer will permit to investigate the muon related probes (quarkonia, open beauty,...). The expected apparatus performances to measure muons and dimuons are discussed. A factorization technique is employed to unravel the different contributions to the global efficiency. Results indicate that the detector should be able to measure muons up to pT ∼ 100 GeV/c with a resolution of about 10 per cent. We show that weak bosons production could be measured for the first time in heavy-ion collisions. Single muon p T and dimuons invariant mass distributions will probe W and Z production. As mainly muons from b- and c-quarks decays will populate the intermediate-p T of 5 - 25 GeV/c, heavy quark in-medium energy loss calculations indicate that the single muon spectra would be suppressed by a factor 2-4 in the most central 0 - 10% Pb-Pb collisions at 5.5 TeV. However, for p T > 35 GeV/c the weak boson decays are predominant, and no suppression is expected. Estimations indicate that the b- and W-muons crossing point shifts down in transverse momenta by 5 to 7 GeV/c in the most central 0 - 10% Pb-Pb collisions at 5.5 TeV. (author)

The Readout Control Unit of the ALICE TPC

CERN Document Server

Lien, J A; Musa, L

2004-01-01

The ALICE Time Projection Chamber (TPC) is the main tracking detector of the central barrel of the ALICE (A Large Ion Collider) Experiment at the Large Hadron Collider (LHC), being constructed at CERN, Geneva. It is a 88 m$^{3}$ cylinder filled with gas and divided into two drift regions by the central electrode located at its axial center. The readout chambers of the TPC are multi-wire proportional chambers with cathode pad readout. About 570 000 pads are read-out by an electronics chain of amplification, digitalization and pre-processing. One of the challenges in designing the TPC for ALICE is the design of Front End Electronics (FEE) to cope with the data rates and the channel occupancy. The Readout Control Unit (RCU), which is presented in this work, is designed to control and monitor the Front End Electronics, and to collect and ship data to the High Level Trigger and the Data Acquisition System, via the Detector Data Link (DDL - optical fibre). The RCU must be capable of reading out up to 200 Mbytes/s f...

A Dashboard for the Italian Computing in ALICE

Science.gov (United States)

Elia, D.; Vino, G.; Bagnasco, S.; Crescente, A.; Donvito, G.; Franco, A.; Lusso, S.; Mura, D.; Piano, S.; Platania, G.; ALICE Collaboration

2017-10-01

A dashboard devoted to the computing in the Italian sites for the ALICE experiment at the LHC has been deployed. A combination of different complementary monitoring tools is typically used in most of the Tier-2 sites: this makes somewhat difficult to figure out at a glance the status of the site and to compare information extracted from different sources for debugging purposes. To overcome these limitations a dedicated ALICE dashboard has been designed and implemented in each of the ALICE Tier-2 sites in Italy: in particular, it provides a single, interactive and easily customizable graphical interface where heterogeneous data are presented. The dashboard is based on two main ingredients: an open source time-series database and a dashboard builder tool for visualizing time-series metrics. Various sensors, able to collect data from the multiple data sources, have been also written. A first version of a national computing dashboard has been implemented using a specific instance of the builder to gather data from all the local databases.

Coordination de la sécurité de l'installation du LHC et de ses expériences

CERN Document Server

Vadon, M

2005-01-01

La coordination de sécurité pour l'installation du LHC et de ses expériences a été mise en place lors du démantèlement du LEP. Depuis, les contractants et les surveillants de chantier ont fait beaucoup de progrès en matière de sécurité et les procédures en vigueur sont maintenant suivies. Néanmoins, des accidents et incidents se produisent encore et pourraient être facilement évités. Un incident important, des dommages sérieux aux équipements, ou pire un accident mortel affecteraient sérieusement le projet LHC. L'analyse des causes des accidents récents révèle toujours une marge d'amélioration, en particulier en ce qui concerne l'analyse à priori des procédures l'installation et des méthodes de travail. L'intégration des aspects de sécurité dès la phase de conception et l'application stricte des règles dans tout le projet sont les clefs pour une meilleure sécurité des chantiers. Ceci ne peut être réalisable que si la sécurité est abordée de la même manière que la qualit...

Characteristics of triple GEM detector for the ALICE TPC upgrade at CERN

International Nuclear Information System (INIS)

Patra, Rajendra Nath; Singaraju, R.N.; Ahammed, Z.; Nayak, T.K.; Viyogi, Y.P.; Biswas, S.

2016-01-01

Gas Electron Multiplier (GEM) detector, introduced by F. Sauliin 1997 and has been widely improved in last two decades for applications to high energy physics experiments and imaging. GEM detectors have several advantages, like good spatial resolution (∼100 μm), high detection efficiency (>98%), high rate handling capability (∼105 Hz/mm"2 ) and reasonable time response (∼5 ns). The unique features of the GEM detector make it suitable for experiments at Large Hadron Collider (LHC) at CERN and FAIR at GSI. With the increase of beam luminosity of LHC for its next phase of running from the year 2020, the ALICE experiment is planning to take data for PbPb collisions at a rate of 50 kHz. The ALICE Time Projection Chamber (TPC) will be upgraded by GEM based read-out to fulfil this future goal. In this report, results of a thorough test in the laboratory using a newly developed online data monitoring system are discussed

LHC data and cosmic ray coplanarity at superhigh energies

Directory of Open Access Journals (Sweden)

Mukhamedshin R.A.

2017-01-01

Full Text Available A new phenomenological model FANSY 2.0 is designed, which makes it possible to simulate hadron interactions via traditional and coplanar generation of most energetic particles as well as to reproduce a lot of LHC (ALICE, ATLAS, CMS, TOTEM, LHCf data. Features of the model are compared with LHC data. Problems of coplanarity are considered and a testing experiment is proposed.

Commissioning and initial experience with the ALICE on-line

International Nuclear Information System (INIS)

Altini, V; Anticic, T; Carena, F; Carena, W; Chapeland, S; Barroso, V Chibante; Costa, F; Divia, R; Fuchs, U; Makhlyueva, I; Roukoutakis, F; Schossmaier, K; Soos, C; Vyvre, P Vande; Haller, B von; Denes, E; Kiss, T

2010-01-01

ALICE (A Large Ion Collider Experiment) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). A large bandwidth and flexible Data Acquisition System (DAQ) has been designed and deployed to collect sufficient statistics in the short running time available per year for heavy ions and to accommodate very different requirements originated from the 18 sub-detectors. This paper will present the large scale tests conducted to assess the standalone DAQ performances, the interfaces with the other online systems and the extensive commissioning performed in order to be fully prepared for physics data taking. It will review the experience accumulated since May 2007 during the standalone commissioning of the main detectors and the global cosmic runs and the lessons learned from this exposure on the b attle field . It will also discuss the test protocol followed to integrate and validate each sub-detector with the online systems and it will conclude with the first results of the LHC injection tests and startup in September 2008. Several papers of the same conference present in more details some elements of the ALICE DAQ system.

Commissioning and initial experience with the ALICE on-line

Science.gov (United States)

Altini, V.; Anticic, T.; Carena, F.; Carena, W.; Chapeland, S.; Chibante Barroso, V.; Costa, F.; Dénes, E.; Divià, R.; Fuchs, U.; Kiss, T.; Makhlyueva, I.; Roukoutakis, F.; Schossmaier, K.; Soós, C.; Vande Vyvre, P.; von Haller, B.; ALICE Collaboration

2010-04-01

ALICE (A Large Ion Collider Experiment) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). A large bandwidth and flexible Data Acquisition System (DAQ) has been designed and deployed to collect sufficient statistics in the short running time available per year for heavy ions and to accommodate very different requirements originated from the 18 sub-detectors. This paper will present the large scale tests conducted to assess the standalone DAQ performances, the interfaces with the other online systems and the extensive commissioning performed in order to be fully prepared for physics data taking. It will review the experience accumulated since May 2007 during the standalone commissioning of the main detectors and the global cosmic runs and the lessons learned from this exposure on the "battle field". It will also discuss the test protocol followed to integrate and validate each sub-detector with the online systems and it will conclude with the first results of the LHC injection tests and startup in September 2008. Several papers of the same conference present in more details some elements of the ALICE DAQ system.

Open heavy-flavour measurements in Pb-Pb collisions with ALICE at the LHC

CERN Document Server

Mischke, André

2017-01-01

The ALICE experiment has measured charm and beauty production in Pb–Pb collisions at $\\sqrt{S_{\\rm{NN}}}= 2.76 \\text{ TeV}$ and $5.02 \\text{ TeV}$, via the reconstruction of hadronic D-meson decays and semi-leptonic Dand B-meson decays. In this contribution, an overview is given on current open heavy-flavour results from ALICE ranging from the nuclear modification factor to elliptic flow measurements and on the interpretation of the data by comparing with different model calculations of in-medium energy loss.

LHC Report: Positive ion run!

CERN Multimedia

Mike Lamont for the LHC Team

2011-01-01

The current LHC ion run has been progressing very well. The first fill with 358 bunches per beam - the maximum number for the year - was on Tuesday, 15 November and was followed by an extended period of steady running. The quality of the beam delivered by the heavy-ion injector chain has been excellent, and this is reflected in both the peak and the integrated luminosity.   The peak luminosity in ATLAS reached 5x1026 cm-2s-1, which is a factor of ~16 more than last year's peak of 3x1025 cm-2s-1. The integrated luminosity in each of ALICE, ATLAS and CMS is now around 100 inverse microbarn, already comfortably over the nominal target for the run. The polarity of the ALICE spectrometer and solenoid magnets was reversed on Monday, 28 November with the aim of delivering another sizeable amount of luminosity in this configuration. On the whole, the LHC has been behaving very well recently, ensuring good machine availability. On Monday evening, however, a faulty level sensor in the cooling towe...

MAPS development for the ALICE ITS upgrade

OpenAIRE

Yang, P; Aglieri, G; Cavicchioli, C; Chalmet, P L; Chanlek, N; Collu, A; Gao, C; Hillemanns, H; Junique, A; Kofarago, M; Keil, M; Kugathasan, T; Kim, D; Kim, J; Lattuca, A

2015-01-01

Monolithic Active Pixel Sensors (MAPS) offer the possibility to build pixel detectors and tracking layers with high spatial resolution and low material budget in commercial CMOS processes. Significant progress has been made in the field of MAPS in recent years, and they are now considered for the upgrades of the LHC experiments. This contribution will focus on MAPS detectors developed for the ALICE Inner Tracking System (ITS) upgrade and manufactured in the TowerJazz 180 nm CMOS imaging senso...

Event visualisation in ALICE - current status and strategy for Run 3

Science.gov (United States)

Niedziela, Jeremi; von Haller, Barthélémy

2017-10-01

A Large Ion Collider Experiment (ALICE) is one of the four big experiments running at the Large Hadron Collider (LHC), which focuses on the study of the Quark-Gluon Plasma (QGP) being produced in heavy-ion collisions. The ALICE Event Visualisation Environment (AliEve) is a tool providing an interactive 3D model of the detector’s geometry and a graphical representation of the data. Together with the online reconstruction module, it provides important quality monitoring of the recorded data. As a consequence it has been used in the ALICE Run Control Centre during all stages of Run 2. Static screenshots from the online visualisation are published on the public website - ALICE LIVE. Dedicated converters have been developed to provide geometry and data for external projects. An example of such project is the Total Event Display (TEV) - a visualisation tool recently developed by the CERN Media Lab based on the Unity game engine. It can be easily deployed on any platform, including web and mobile platforms. Another external project is More Than ALICE - an augmented reality application for visitors, overlaying detector descriptions and event visualisations on the camera’s picture. For the future Run 3 both AliEve and TEV will be adapted to fit the ALICE O2 project. Several changes are required due to the new data formats, especially so-called Compressed Time Frames.

New Fast Interaction Trigger for ALICE

Energy Technology Data Exchange (ETDEWEB)

Trzaska, Wladyslaw Henryk

2017-02-11

The LHC heavy-ion luminosity and collision rate from 2021 onwards will considerably exceed the design parameters of the present ALICE forward trigger detectors and the introduction of the Muon Forward Tracker (MFT) will significantly reduce the space available for the new trigger detectors. To comply with these conditions a new Fast Interaction Trigger (FIT) will be built. FIT will be the main forward trigger, luminometer, and interaction-time detector. It will also determine multiplicity, centrality, and reaction plane of heavy-ion collisions. FIT will consist of two arrays of Cherenkov quartz radiators with MCP-PMT sensors and of a plastic scintillator ring. By increasing the overall acceptance of FIT, the scintillator will improve centrality and event plane resolution. It will also add sensitivity for the detection of beam-gas events and provide some degree of redundancy. FIT is currently undergoing an intense R&D and prototyping period. It is scheduled for installation in ALICE during 2020.

JACoW Monitoring the new ALICE Online-Offline computing system

CERN Document Server

Wegrzynek, Adam; Vino, Gioacchino

2018-01-01

ALICE (A Large Ion Collider Experiment) is a particle detector designed to study heavy-ion collisions and the physics of strongly interacting matter and the quark–gluon plasma at the CERN LHC (Large Hadron Collider). ALICE has been successfully collecting physics data since 2010. Currently, it is in the preparations for a major upgrade of the computing system, called O$^{2}$ (Online-Offline) and scheduled to be deployed during Long Shutdown 2 in 2019–2020. The O$^{2}$ system will consist of 268 FLPs (First Level Processors) equipped with readout cards and 1500 EPNs (Event Processing Node) performing data aggregation, calibration, reconstruction and event building. The system will readout 27 Tb/s of raw data and record tens of PBs of reconstructed data per year. To allow an efficient operation of the upgraded experiment, a new Monitoring subsystem will provide a complete overview of the O$^{2}$ computing system status, detect performance degradation or component failures. The ALICE O$^{2}$ Monitoring subsy...

Successful beam test of the SPS-to-LHC transfer line TI2

CERN Multimedia

2007-01-01

Image of the first beam spot on the last BTV screen traversed by the beam during the TI 2 test.At 12:03:47 on 28 October a beam passed down the 2.7 km of the new SPS-to-LHC transfer line TI 2 at the first attempt, to within some 50 m of the LHC tunnel. After initial tuning, a range of measurements was carried out with a low intensity proton beam and preliminary analyses look good. After the test, no increase in radiation levels was found in either the LHC or ALICE, and the zones were rapidly opened again for access. As from next year TI 2 will regularly transport a beam from the SPS to the LHC injection point of Ring 1, near Point 2 (ALICE). The TI 8 transfer line, which will bring particles from the SPS to the injection point in Ring 2, near Point 8 (LHCb), was commissioned successfully with low intensity beam in 2004. The two LHC injection lines have a combined length of 5.6 km and comprise some seven hundred warm magnets. While a...

Charged-particle multiplicity at LHC energies

CERN Multimedia

CERN. Geneva

2010-01-01

The talk presents the measurement of the pseudorapidity density and the multiplicity distribution with ALICE at the achieved LHC energies of 0.9 and 2.36 TeV.An overview about multiplicity measurements prior to LHC is given and the related theoretical concepts are briefly discussed.The analysis procedure is presented and the systematic uncertainties are detailed. The applied acceptance corrections and the treatment of diffraction are discussed.The results are compared with model predictions. The validity of KNO scaling in restricted phase space regions is revisited. 

The great adventure of the LHC - From big bang to the Higgs boson

International Nuclear Information System (INIS)

Denegri, D.; Guyot, C.; Hoecker, A.; ); Roos, L.; Rubbia, C.

2014-03-01

This book presents what has been the biggest scientific equipment ever designed on earth: the LHC (large hadron collider) and its associated experiments (ATLAS, CMS, LHCb and ALICE) that led to the discovery of the Higgs boson in 2012. About 10.000 physicists and engineers from 50 countries have taken part into the project that began in 1989. This book is composed of the following chapters: 1) the standard model (SM) of particle physics, 2) the experimental success of SM, 3) the shortfalls of SM, 4) the new physics, 5) the original big bang, 6) the LHC, 7) particle detection, 8) ATLAS and CMS experiments, 9) the first data from LHC, 10) data analysis, 11) the quest for the Higgs boson, 12) the search for new physics, 13) LHCb and ALICE experiments, and 14) future prospects

The ALICE TPC

CERN Document Server

Garabatos, C

2004-01-01

We describe the ALICE TPC, with emphasis on the design features which are driven by the physics requirements of the detector. In particular, the gas choice and composition, Ne-CO/sub 2/ Ý90-10¿, as well as the unprecedentedly high gain for a TPC (2*10/sup 40/), are direct consequences of the expected performance in the high- multiplicity environment of heavy-ion collisions at the LHC. The characteristics of this mixture are discussed and a viable way of improving the stability of detectors working under these conditions, namely the addition of nitrogen into the mixture, is presented. This results in a more effective Penning transfer of neon excited states onto ionisation of the quencher at no penalty for the charge transport and amplification properties.

The ALICE data acquisition system

CERN Document Server

Carena, F; Chapeland, S; Chibante Barroso, V; Costa, F; Dénes, E; Divià, R; Fuchs, U; Grigore, A; Kiss, T; Simonetti, G; Soós, C; Telesca, A; Vande Vyvre, P; Von Haller, B

2014-01-01

In this paper we describe the design, the construction, the commissioning and the operation of the Data Acquisition (DAQ) and Experiment Control Systems (ECS) of the ALICE experiment at the CERN Large Hadron Collider (LHC). The DAQ and the ECS are the systems used respectively for the acquisition of all physics data and for the overall control of the experiment. They are two computing systems made of hundreds of PCs and data storage units interconnected via two networks. The collection of experimental data from the detectors is performed by several hundreds of high-speed optical links. We describe in detail the design considerations for these systems handling the extreme data throughput resulting from central lead ions collisions at LHC energy. The implementation of the resulting requirements into hardware (custom optical links and commercial computing equipment), infrastructure (racks, cooling, power distribution, control room), and software led to many innovative solutions which are described together with ...

Two-pion Bose-Einstein correlations in Pb-Pb collisions at $\\sqrt{s_{NN}}$ = 2.76 TeV measured with the ALICE experiment

CERN Document Server

Gramling, Johanna Lena

2012-01-01

The measurement of pion source radii in Pb-Pb collisions with the ALICE experiment at LHC is presented. By the analysis of Bose-Einstein enhancement in the correlation function of identical pions information on the size and evolution of the source region in space-time can be obtained. The source radii observed at LHC are larger than at RHIC, approximately scaling with the cube root of the particle multiplicity. A decrease of source radii with increasing pair momentum, indicating a collective expansion of the medium, was observed at RHIC and SPS and is also expected at LHC energies. The ALICE data confirm this and provide strict constraints on dynamical models describing the medium expansion. The results suggest that the created fireball has a higher temperature and a longer lifetime as compared to lower energies.

Monitoring and calibration of the ALICE time projection chamber

CERN Document Server

Larsen, Dag Toppe

The aim of the A Large Ion Collider Experiment (ALICE) experiment at CERN is to study the properties of the Quark–Gluon Plasma (QGP). With energies up to 5.5 A T eV for Pb+Pb collisions, the Large Hadron Collider (LHC) sets a new benchmark for heavy- ion collisions, and opens the door to a so far unexplored energy domain. A closer look at some of the physics topics of ALICE is given in Chapter 1. ALICE consists of several sub-detectors and other sub-systems. The various sub- detectors are designed for exploring different aspects of the particle production of an heavy-ion collision. Chapter 2 gives some insight into the design. The main tracking detector is the Time Projection Chamber (TPC). It has more than half million read-out channels, divided into 216 Read-out Partitions (RPs). Each RP is a separate Front-End Electronics (FEE) entity, as described in Chapter 3. A complex Detector Control System (DCS) is needed for configuration, monitoring and control. The heart of it on the RP side is a small embedded ...

ALICE TPC gas system is the first of the LHC experiments to be put on line

CERN Document Server

Maximilien Brice

2006-01-01

Picture 01 : the Physics Department's DT1 gas systems team in their laboratory. Picture 02 : Chilo Garabatos (ALICE) and Stefan Haider (PH-DT1-GS) in front of the gas system for the ALICE TPC which has just been put on line.

LHC Startup

CERN Document Server

AUTHOR|(CDS)2067853

2008-01-01

The Large Hadron Collider will commence operations in the latter half of 2008. The plans of the LHC experiments ALICE, ATLAS, CMS and LHCb are described. The scenario for progression of luminosity and the strategies of these 4 experiments to use the initial data are detailed. There are significant measurements possible with integrated luminosities of 1, 10 and 100 pb^-1. These measurements will provide essential calibration and tests of the detectors, understanding of the Standard Model backgrounds and a first oportunity to look for new physics.

Challenges to Software/Computing for Experimentation at the LHC

Science.gov (United States)

Banerjee, Sunanda

The demands of future high energy physics experiments towards software and computing have led the experiments to plan the related activities as a full-fledged project and to investigate new methodologies and languages to meet the challenges. The paths taken by the four LHC experiments ALICE, ATLAS, CMS and LHCb are coherently put together in an LHC-wide framework based on Grid technology. The current status and understandings have been broadly outlined.

Latest results from ALICE

CERN Document Server

Scapparone, Eugenio

2011-01-01

In this paper selected results obtained by the ALICE experiment at the LHC will be presented. Data collected during the pp runs taken at sqrt(s)=0.9, 2.76 and 7 TeV and Pb-Pb runs at sqrt(s_NN)=2.76 TeV allowed interesting studies on the properties of the hadronic and nuclear matter: proton runs gave us the possibility to explore the ordinary matter at very high energy and up to very low pt, while Pb-Pb runs provided spectacular events where several thousands of particles produced in the interaction revealed how a very dense medium behaves, providing a deeper picture on the quark gluon plasma(QGP) chemical composition and dynamics.

8th February 2011-Rector Universidad Autónoma de Sinaloa Mexico Dr Victor Antonio Corrales Burgeño-Mexico-visiting ALICE cavern and tunnel with ALICE Spokesperson P. Giubellino

CERN Multimedia

Maximilien Brice

2011-01-01

Photo 1,3-14:The delegation visiting ALICE cavern Photo 2:Dra. Beatriz E. Rodríguez Pérez\tDirectora del Centro de Políticas de Género para la igualdad entre Hombres y Mujeres,Dr Victor Antonio Corrales Burgeño,P. Giubellino Photo 15-29:The delegation visiting LHC Tunnel Photo 30-57:Signature of the Guest Book with CERN Director-General R. Heuer and Head of International Relations F. Pauss Photo 58:Adviser for Mexico J. Salicio,ALICE Collaboration Universidad Autonoma de Sinaloa I. Leon Monzon,ALICE Collaboration Centro Invest. Estudios Avanz. IPN (Cinnestav) G. Herrera Corral,R. Heuer,Dr Victor Antonio Corrales Burgeño,F. Pauss,Dra. Beatriz E. Rodríguez Pérez,Directora de Relaciones InternacionalesMC. América M. Lizárraga González

Development and characterisation of Monolithic Active Pixel Sensor prototypes for the upgrade of the ALICE Inner Tracking System

CERN Document Server

Collu, Alberto

ALICE (A Large Ion Collider Experiment) is dedicated to the study and characterisation of the Quark-­‐Gluon Plasma (QGP), exploiting the unique potential of ultrarelativistic heavy-­‐ion collisions at the CERN Large Hadron Collider (LHC). The increase of the LHC luminosity leading up to about 50 kHz Pb-­‐Pb interaction rate after the second long shutdown (in 2018-­‐2019) will offer the possibility to perform high precision measurements of rare probes over a wide range of momenta. These measurements are statistically limited or not even possible with the present experimental set up. For this reason, an upgrade strategy for several ALICE detectors is being pursued. In particular, it is foreseen to replace the Inner Tracking System (ITS) by a new detector which will significantly improve the tracking and vertexing capabilities of ALICE in the upgrade scenario. The new ITS will have a barrel geometry consisting of seven layers of Monolithic Active Pixel Sensors (MAPS) with high granularity, which will...

Commissioning and initial experience with the ALICE on-line

Energy Technology Data Exchange (ETDEWEB)

Altini, V [INFN, Dipartimento di Fisica dell' Universita and Sezione INFN Bari (Italy); Anticic, T [Ruder Botkovic Institute, Zagreb (Croatia); Carena, F; Carena, W; Chapeland, S; Barroso, V Chibante; Costa, F; Divia, R; Fuchs, U; Makhlyueva, I; Roukoutakis, F; Schossmaier, K; Soos, C; Vyvre, P Vande; Haller, B von [CERN, Physics department, Geneva (Switzerland); Denes, E; Kiss, T, E-mail: pierre.vande.vyvre@cern.c [KFKI Research Institute for Particle and Nuclear Physics, Budapest (Hungary)

2010-04-01

ALICE (A Large Ion Collider Experiment) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). A large bandwidth and flexible Data Acquisition System (DAQ) has been designed and deployed to collect sufficient statistics in the short running time available per year for heavy ions and to accommodate very different requirements originated from the 18 sub-detectors. This paper will present the large scale tests conducted to assess the standalone DAQ performances, the interfaces with the other online systems and the extensive commissioning performed in order to be fully prepared for physics data taking. It will review the experience accumulated since May 2007 during the standalone commissioning of the main detectors and the global cosmic runs and the lessons learned from this exposure on the {sup b}attle field{sup .} It will also discuss the test protocol followed to integrate and validate each sub-detector with the online systems and it will conclude with the first results of the LHC injection tests and startup in September 2008. Several papers of the same conference present in more details some elements of the ALICE DAQ system.

Critical services in the LHC computing

International Nuclear Information System (INIS)

Sciaba, A

2010-01-01

The LHC experiments (ALICE, ATLAS, CMS and LHCb) rely for the data acquisition, processing, distribution, analysis and simulation on complex computing systems, running using a variety of services, provided by the experiments, the Worldwide LHC Computing Grid and the different computing centres. These services range from the most basic (network, batch systems, file systems) to the mass storage services or the Grid information system, up to the different workload management systems, data catalogues and data transfer tools, often internally developed in the collaborations. In this contribution we review the status of the services most critical to the experiments by quantitatively measuring their readiness with respect to the start of the LHC operations. Shortcomings are identified and common recommendations are offered.

MAPS development for the ALICE ITS upgrade

Science.gov (United States)

Yang, P.; Aglieri, G.; Cavicchioli, C.; Chalmet, P. L.; Chanlek, N.; Collu, A.; Gao, C.; Hillemanns, H.; Junique, A.; Kofarago, M.; Keil, M.; Kugathasan, T.; Kim, D.; Kim, J.; Lattuca, A.; Marin Tobon, C. A.; Marras, D.; Mager, M.; Martinengo, P.; Mazza, G.; Mugnier, H.; Musa, L.; Puggioni, C.; Rousset, J.; Reidt, F.; Riedler, P.; Snoeys, W.; Siddhanta, S.; Usai, G.; van Hoorne, J. W.; Yi, J.

2015-03-01

Monolithic Active Pixel Sensors (MAPS) offer the possibility to build pixel detectors and tracking layers with high spatial resolution and low material budget in commercial CMOS processes. Significant progress has been made in the field of MAPS in recent years, and they are now considered for the upgrades of the LHC experiments. This contribution will focus on MAPS detectors developed for the ALICE Inner Tracking System (ITS) upgrade and manufactured in the TowerJazz 180 nm CMOS imaging sensor process on wafers with a high resistivity epitaxial layer. Several sensor chip prototypes have been developed and produced to optimise both charge collection and readout circuitry. The chips have been characterised using electrical measurements, radioactive sources and particle beams. The tests indicate that the sensors satisfy the ALICE requirements and first prototypes with the final size of 1.5 × 3 cm2 have been produced in the first half of 2014. This contribution summarises the characterisation measurements and presents first results from the full-scale chips.

Performance optimisations for distributed analysis in ALICE

CERN Document Server

Betev, L; Gheata, M; Grigoras, C; Hristov, P

2014-01-01

Performance is a critical issue in a production system accommodating hundreds of analysis users. Compared to a local session, distributed analysis is exposed to services and network latencies, remote data access and heterogeneous computing infrastructure, creating a more complex performance and efficiency optimization matrix. During the last 2 years, ALICE analysis shifted from a fast development phase to the more mature and stable code. At the same time, the framewo rks and tools for deployment, monitoring and management of large productions have evolved considerably too. The ALICE Grid production system is currently used by a fair share of organized and individual user analysis, consuming up to 30% or the available r esources and ranging from fully I/O - bound analysis code to CPU intensive correlations or resonances studies. While the intrinsic analysis performance is unlikely to improve by a large factor during the LHC long shutdown (LS1), the overall efficiency of the system has still to be improved by a...

The Wonderland of Operating the ALICE Experiment

CERN Document Server

Augustinus, A; Pinazza, O; Rosinský, P; Lechman, M; Jirdén, L; Chochula, P

2011-01-01

ALICE is one of the experiments at the Large Hadron Collider (LHC), CERN, Geneva, Switzerland. Composed of 18 sub-detectors each with numerous subsystems that need to be controlled and operated in a safe and efficient way. The Detector Control System (DCS) is the key to this and has been used by detector experts with success during the commissioning of the individual detectors. During the transition from commissioning to operation, more and more tasks were transferred from detector experts to central operators. By the end of the 2010 datataking campaign, the ALICE experiment was run by a small crew of central operators, with only a single controls operator. The transition from expert to non-expert operation constituted a real challenge in terms of tools, documentation and training. A relatively high turnover and diversity in the operator crew that is specific to the HEP experiment environment (as opposed to the more stable operation crews for accelerators) made this challenge even bigger. Thi...

Low-Mass Dielectron Production in pp, p-Pb and Pb-Pb Collisions with ALICE

CERN Document Server

Reichelt, Patrick

2016-01-01

The ALICE Collaboration measures the production of low-mass dielectrons in pp, p-Pb and Pb-Pb collisions at the LHC. The main detectors used in the analyses are the Inner Tracking System, Time Projection Chamber and Time-Of-Flight detector, all located at mid-rapidity. The dielectron yield in p-Pb collisions shows an overall agreement with the hadronic cocktail. The pair transverse momentum distributions are sensitive to the contributions from open heavy-flavours. In Pb-Pb collisions, uncorrected background-subtracted yields have been extracted in two centrality classes. In pp collisions the production of virtual photons relative to the inclusive yield is determined by analyzing the dielectron excess with respect to the expected hadronic sources. The direct photon cross section is then calculated and found to be in agreement with NLO pQCD calculations. A feasibility study for LHC Run 3 after the ALICE upgrade indicates the possibility for a future measurement of the early effective temperature.

Low-Mass Dielectron Production in pp, p–Pb and Pb–Pb Collisions with ALICE

Energy Technology Data Exchange (ETDEWEB)

Reichelt, Patrick

2016-12-15

The ALICE Collaboration measures the production of low-mass dielectrons in pp, p–Pb and Pb–Pb collisions at the LHC. The main detectors used in the analyses are the Inner Tracking System, Time Projection Chamber and Time-Of-Flight detector, all located at mid-rapidity. The dielectron yield in p–Pb collisions shows an overall agreement with the hadronic cocktail. The pair transverse momentum distributions are sensitive to the contributions from open heavy-flavours. In Pb–Pb collisions, uncorrected background-subtracted yields have been extracted in two centrality classes. In pp collisions the production of virtual photons relative to the inclusive yield is determined by analyzing the dielectron excess with respect to the expected hadronic sources. The direct photon cross section is then calculated and found to be in agreement with NLO pQCD calculations. A feasibility study for LHC Run 3 after the ALICE upgrade indicates the possibility for a future measurement of the early effective temperature.

The ALICE data quality monitoring system

International Nuclear Information System (INIS)

Haller, B von; Telesca, A; Chapeland, S; Carena, F; Carena, W; Barroso, V Chibante; Costa, F; Denes, E; Divià, R; Fuchs, U; Simonetti, G; Soós, C; Vyvre, P Vande

2011-01-01

ALICE (A Large Ion Collider Experiment) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). The online Data Quality Monitoring (DQM) is a key element of the Data Acquisition's software chain. It provide shifters with precise and complete information to quickly identify and overcome problems, and as a consequence to ensure acquisition of high quality data. DQM typically involves the online gathering, the analysis by user-defined algorithms and the visualization of monitored data. This paper describes the final design of ALICE'S DQM framework called AMORE (Automatic MOnitoRing Environment), as well as its latest and coming features like the integration with the offline analysis and reconstruction framework, a better use of multi-core processors by a parallelization effort, and its interface with the eLogBook. The concurrent collection and analysis of data in an online environment requires the framework to be highly efficient, robust and scalable. We will describe what has been implemented to achieve these goals and the procedures we follow to ensure appropriate robustness and performance. We finally review the wide range of usages people make of this framework, from the basic monitoring of a single sub-detector to the most complex ones within the High Level Trigger farm or using the Prompt Reconstruction and we describe the various ways of accessing the monitoring results. We conclude with our experience, before and after the LHC startup, when monitoring the data quality in a challenging environment.

The ALICE data quality monitoring system

Science.gov (United States)

von Haller, B.; Telesca, A.; Chapeland, S.; Carena, F.; Carena, W.; Chibante Barroso, V.; Costa, F.; Denes, E.; Divià, R.; Fuchs, U.; Simonetti, G.; Soós, C.; Vande Vyvre, P.; ALICE Collaboration

2011-12-01

ALICE (A Large Ion Collider Experiment) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). The online Data Quality Monitoring (DQM) is a key element of the Data Acquisition's software chain. It provide shifters with precise and complete information to quickly identify and overcome problems, and as a consequence to ensure acquisition of high quality data. DQM typically involves the online gathering, the analysis by user-defined algorithms and the visualization of monitored data. This paper describes the final design of ALICE'S DQM framework called AMORE (Automatic MOnitoRing Environment), as well as its latest and coming features like the integration with the offline analysis and reconstruction framework, a better use of multi-core processors by a parallelization effort, and its interface with the eLogBook. The concurrent collection and analysis of data in an online environment requires the framework to be highly efficient, robust and scalable. We will describe what has been implemented to achieve these goals and the procedures we follow to ensure appropriate robustness and performance. We finally review the wide range of usages people make of this framework, from the basic monitoring of a single sub-detector to the most complex ones within the High Level Trigger farm or using the Prompt Reconstruction and we describe the various ways of accessing the monitoring results. We conclude with our experience, before and after the LHC startup, when monitoring the data quality in a challenging environment.

Measurement of inelastic, single- and double-diffraction cross sections in proton-proton collisions at the LHC with ALICE

CERN Document Server

Abelev, Betty; Adamova, Dagmar; Adare, Andrew Marshall; Aggarwal, Madan; Aglieri Rinella, Gianluca; Agocs, Andras Gabor; Agostinelli, Andrea; Aguilar Salazar, Saul; Ahammed, Zubayer; Ahmad, Nazeer; Ahmad, Arshad; Ahn, Sul-Ah; Ahn, Sang Un; Akindinov, Alexander; Aleksandrov, Dmitry; Alessandro, Bruno; Alfaro Molina, Jose Ruben; Alici, Andrea; Alkin, Anton; Almaraz Avina, Erick Jonathan; Alme, Johan; Alt, Torsten; Altini, Valerio; Altinpinar, Sedat; Altsybeev, Igor; Andrei, Cristian; Andronic, Anton; Anguelov, Venelin; Anielski, Jonas; Anson, Christopher Daniel; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Aphecetche, Laurent Bernard; Appelshauser, Harald; Arbor, Nicolas; Arcelli, Silvia; Arend, Andreas; Armesto, Nestor; Arnaldi, Roberta; Aronsson, Tomas Robert; Arsene, Ionut Cristian; Arslandok, Mesut; Asryan, Andzhey; Augustinus, Andre; Averbeck, Ralf Peter; Awes, Terry; Aysto, Juha Heikki; Azmi, Mohd Danish; Bach, Matthias Jakob; Badala, Angela; Baek, Yong Wook; Bailhache, Raphaelle Marie; Bala, Renu; Baldini Ferroli, Rinaldo; Baldisseri, Alberto; Baldit, Alain; Baltasar Dos Santos Pedrosa, Fernando; Ban, Jaroslav; Baral, Rama Chandra; Barbera, Roberto; Barile, Francesco; Barnafoldi, Gergely Gabor; Barnby, Lee Stuart; Barret, Valerie; Bartke, Jerzy Gustaw; Basile, Maurizio; Bastid, Nicole; Basu, Sumit; Bathen, Bastian; Batigne, Guillaume; Batyunya, Boris; Baumann, Christoph Heinrich; Bearden, Ian Gardner; Beck, Hans; Behera, Nirbhay Kumar; Belikov, Iouri; Bellini, Francesca; Bellwied, Rene; Belmont-Moreno, Ernesto; Bencedi, Gyula; Beole, Stefania; Berceanu, Ionela; Bercuci, Alexandru; Berdnikov, Yaroslav; Berenyi, Daniel; Bergognon, Anais Annick Erica; Berzano, Dario; Betev, Latchezar; Bhasin, Anju; Bhati, Ashok Kumar; Bhom, Jihyun; Bianchi, Livio; Bianchi, Nicola; Bianchin, Chiara; Bielcik, Jaroslav; Bielcikova, Jana; Bilandzic, Ante; Bjelogrlic, Sandro; Blanco, F; Blanco, Francesco; Blau, Dmitry; Blume, Christoph; Boccioli, Marco; Bock, Nicolas; Boettger, Stefan; Bogdanov, Alexey; Boggild, Hans; Bogolyubsky, Mikhail; Boldizsar, Laszlo; Bombara, Marek; Book, Julian; Borel, Herve; Borissov, Alexander; Bose, Suvendu Nath; Bossu, Francesco; Botje, Michiel; Botta, Elena; Boyer, Bruno Alexandre; Braidot, Ermes; Braun-Munzinger, Peter; Bregant, Marco; Breitner, Timo Gunther; Browning, Tyler Allen; Broz, Michal; Brun, Rene; Bruna, Elena; Bruno, Giuseppe Eugenio; Budnikov, Dmitry; Buesching, Henner; Bufalino, Stefania; Busch, Oliver; Buthelezi, Edith Zinhle; Caballero Orduna, Diego; Caffarri, Davide; Cai, Xu; Caines, Helen Louise; Calvo Villar, Ernesto; Camerini, Paolo; Canoa Roman, Veronica; Cara Romeo, Giovanni; Carena, Wisla; Carena, Francesco; Carlin Filho, Nelson; Carminati, Federico; Casanova Diaz, Amaya Ofelia; Castillo Castellanos, Javier Ernesto; Castillo Hernandez, Juan Francisco; Casula, Ester Anna Rita; Catanescu, Vasile; Cavicchioli, Costanza; Ceballos Sanchez, Cesar; Cepila, Jan; Cerello, Piergiorgio; Chang, Beomsu; Chapeland, Sylvain; Charvet, Jean-Luc Fernand; Chattopadhyay, Subhasis; Chattopadhyay, Sukalyan; Chawla, Isha; Cherney, Michael Gerard; Cheshkov, Cvetan; Cheynis, Brigitte; Chibante Barroso, Vasco Miguel; Chinellato, David; Chochula, Peter; Chojnacki, Marek; Choudhury, Subikash; Christakoglou, Panagiotis; Christensen, Christian Holm; Christiansen, Peter; Chujo, Tatsuya; Chung, Suh-Urk; Cicalo, Corrado; Cifarelli, Luisa; Cindolo, Federico; Cleymans, Jean Willy Andre; Coccetti, Fabrizio; Colamaria, Fabio; Colella, Domenico; Conesa Balbastre, Gustavo; Conesa del Valle, Zaida; Contin, Giacomo; Contreras, Jesus Guillermo; Cormier, Thomas Michael; Corrales Morales, Yasser; Cortese, Pietro; Cortes Maldonado, Ismael; Cosentino, Mauro Rogerio; Costa, Filippo; Cotallo, Manuel Enrique; Crescio, Elisabetta; Crochet, Philippe; Cruz Alaniz, Emilia; Cuautle, Eleazar; Cunqueiro, Leticia; Dainese, Andrea; Dalsgaard, Hans Hjersing; Danu, Andrea; Das, Kushal; Das, Indranil; Das, Debasish; Dash, Sadhana; Dash, Ajay Kumar; De, Sudipan; de Barros, Gabriel; De Caro, Annalisa; de Cataldo, Giacinto; de Cuveland, Jan; De Falco, Alessandro; De Gruttola, Daniele; Delagrange, Hugues; Deloff, Andrzej; De Marco, Nora; Denes, Ervin; De Pasquale, Salvatore; Deppman, Airton; D'Erasmo, Ginevra; de Rooij, Raoul Stefan; Diaz Corchero, Miguel Angel; Di Bari, Domenico; Dietel, Thomas; Di Giglio, Carmelo; Di Liberto, Sergio; Di Mauro, Antonio; Di Nezza, Pasquale; Divia, Roberto; Djuvsland, Oeystein; Dobrin, Alexandru Florin; Dobrowolski, Tadeusz Antoni; Dominguez, Isabel; Donigus, Benjamin; Dordic, Olja; Driga, Olga; Dubey, Anand Kumar; Dubla, Andrea; Ducroux, Laurent; Dupieux, Pascal; Dutta Majumdar, AK; Dutta Majumdar, Mihir Ranjan; Elia, Domenico; Emschermann, David Philip; Engel, Heiko; Erazmus, Barbara; Erdal, Hege Austrheim; Espagnon, Bruno; Estienne, Magali Danielle; Esumi, Shinichi; Evans, David; Eyyubova, Gyulnara; Fabris, Daniela; Faivre, Julien; Falchieri, Davide; Fantoni, Alessandra; Fasel, Markus; Fearick, Roger Worsley; Fehlker, Dominik; Feldkamp, Linus; Felea, Daniel; Fenton-Olsen, Bo; Feofilov, Grigory; Fernandez Tellez, Arturo; Ferretti, Alessandro; Ferretti, Roberta; Festanti, Andrea; Figiel, Jan; Figueredo, Marcel; Filchagin, Sergey; Finogeev, Dmitry; Fionda, Fiorella; Fiore, Enrichetta Maria; Floris, Michele; Foertsch, Siegfried Valentin; Foka, Panagiota; Fokin, Sergey; Fragiacomo, Enrico; Francescon, Andrea; Frankenfeld, Ulrich Michael; Fuchs, Ulrich; Furget, Christophe; Fusco Girard, Mario; Gaardhoje, Jens Joergen; Gagliardi, Martino; Gago, Alberto; Gallio, Mauro; Gangadharan, Dhevan Raja; Ganoti, Paraskevi; Garabatos, Jose; Garcia-Solis, Edmundo; Garishvili, Irakli; Gerhard, Jochen; Germain, Marie; Geuna, Claudio; Gheata, Mihaela; Gheata, Andrei George; Ghidini, Bruno; Ghosh, Premomoy; Gianotti, Paola; Girard, Martin Robert; Giubellino, Paolo; Gladysz-Dziadus, Ewa; Glassel, Peter; Gomez, Ramon; Gonzalez Ferreiro, Elena; Gonzalez-Trueba, Laura Helena; Gonzalez-Zamora, Pedro; Gorbunov, Sergey; Goswami, Ankita; Gotovac, Sven; Grabski, Varlen; Graczykowski, Lukasz Kamil; Grajcarek, Robert; Grelli, Alessandro; Grigoras, Alina Gabriela; Grigoras, Costin; Grigoriev, Vladislav; Grigoryan, Ara; Grigoryan, Smbat; Grinyov, Boris; Grion, Nevio; Gros, Philippe; Grosse-Oetringhaus, Jan Fiete; Grossiord, Jean-Yves; Grosso, Raffaele; Guber, Fedor; Guernane, Rachid; Guerra Gutierrez, Cesar; Guerzoni, Barbara; Guilbaud, Maxime Rene Joseph; Gulbrandsen, Kristjan Herlache; Gunji, Taku; Gupta, Ramni; Gupta, Anik; Gutbrod, Hans; Haaland, Oystein Senneset; Hadjidakis, Cynthia Marie; Haiduc, Maria; Hamagaki, Hideki; Hamar, Gergoe; Han, Byounghee; Hanratty, Luke David; Hansen, Alexander; Harmanova, Zuzana; Harris, John William; Hartig, Matthias; Hasegan, Dumitru; Hatzifotiadou, Despoina; Hayrapetyan, Arsen; Heckel, Stefan Thomas; Heide, Markus Ansgar; Helstrup, Haavard; Herghelegiu, Andrei Ionut; Herrera Corral, Gerardo Antonio; Herrmann, Norbert; Hess, Benjamin Andreas; Hetland, Kristin Fanebust; Hicks, Bernard; Hille, Per Thomas; Hippolyte, Boris; Horaguchi, Takuma; Hori, Yasuto; Hristov, Peter Zahariev; Hrivnacova, Ivana; Huang, Meidana; Humanic, Thomas; Hwang, Dae Sung; Ichou, Raphaelle; Ilkaev, Radiy; Ilkiv, Iryna; Inaba, Motoi; Incani, Elisa; Innocenti, Pier Giorgio; Innocenti, Gian Michele; Ippolitov, Mikhail; Irfan, Muhammad; Ivan, Cristian George; Ivanov, Vladimir; Ivanov, Marian; Ivanov, Andrey; Ivanytskyi, Oleksii; Jacobs, Peter; Jang, Haeng Jin; Janik, Malgorzata Anna; Janik, Rudolf; Jayarathna, Sandun; Jena, Satyajit; Jha, Deeptanshu Manu; Jimenez Bustamante, Raul Tonatiuh; Jirden, Lennart; Jones, Peter Graham; Jung, Hyung Taik; Jusko, Anton; Kaidalov, Alexei; Kakoyan, Vanik; Kalcher, Sebastian; Kalinak, Peter; Kalliokoski, Tuomo Esa Aukusti; Kalweit, Alexander Philipp; Kang, Ju Hwan; Kaplin, Vladimir; Karasu Uysal, Ayben; Karavichev, Oleg; Karavicheva, Tatiana; Karpechev, Evgeny; Kazantsev, Andrey; Kebschull, Udo Wolfgang; Keidel, Ralf; Khan, Shuaib Ahmad; Khan, Palash; Khan, Mohisin Mohammed; Khanzadeev, Alexei; Kharlov, Yury; Kileng, Bjarte; Kim, Minwoo; Kim, Se Yong; Kim, Dong Jo; Kim, Do Won; Kim, Jonghyun; Kim, Jin Sook; Kim, Taesoo; Kim, Mimae; Kim, Beomkyu; Kirsch, Stefan; Kisel, Ivan; Kiselev, Sergey; Kisiel, Adam Ryszard; Klay, Jennifer Lynn; Klein, Jochen; Klein-Bosing, Christian; Kliemant, Michael; Kluge, Alexander; Knichel, Michael Linus; Knospe, Anders Garritt; Koch, Kathrin; Kohler, Markus; Kollegger, Thorsten; Kolojvari, Anatoly; Kondratiev, Valery; Kondratyeva, Natalia; Konevskih, Artem; Kour, Ravjeet; Kowalski, Marek; Kox, Serge; Koyithatta Meethaleveedu, Greeshma; Kral, Jiri; Kralik, Ivan; Kramer, Frederick; Kraus, Ingrid Christine; Kravcakova, Adela; Krawutschke, Tobias; Krelina, Michal; Kretz, Matthias; Krivda, Marian; Krizek, Filip; Krus, Miroslav; Kryshen, Evgeny; Krzewicki, Mikolaj; Kucheriaev, Yury; Kugathasan, Thanushan; Kuhn, Christian Claude; Kuijer, Paul; Kulakov, Igor; Kumar, Jitendra; Kurashvili, Podist; Kurepin, A; Kurepin, AB; Kuryakin, Alexey; Kushpil, Vasily; Kushpil, Svetlana; Kvaerno, Henning; Kweon, Min Jung; Kwon, Youngil; Ladron de Guevara, Pedro; Lakomov, Igor; Langoy, Rune; La Pointe, Sarah Louise; Lara, Camilo Ernesto; Lardeux, Antoine Xavier; La Rocca, Paola; Lea, Ramona; Le Bornec, Yves; Lechman, Mateusz; Lee, Ki Sang; Lee, Sung Chul; Lee, Graham Richard; Lefevre, Frederic; Lehnert, Joerg Walter; Lenhardt, Matthieu Laurent; Lenti, Vito; Leon, Hermes; Leoncino, Marco; Leon Monzon, Ildefonso; Leon Vargas, Hermes; Levai, Peter; Lien, Jorgen; Lietava, Roman; Lindal, Svein; Lindenstruth, Volker; Lippmann, Christian; Lisa, Michael Annan; Liu, Lijiao; Loggins, Vera; Loginov, Vitaly; Lohn, Stefan Bernhard; Lohner, Daniel; Loizides, Constantinos; Loo, Kai Krister; Lopez, Xavier Bernard; Lopez Torres, Ernesto; Lovhoiden, Gunnar; Lu, Xianguo; Luettig, Philipp; Lunardon, Marcello; Luo, Jiebin; Luparello, Grazia; Luquin, Lionel; Luzzi, Cinzia; Ma, Ke; Ma, Rongrong; Madagodahettige-Don, Dilan Minthaka; Maevskaya, Alla; Mager, Magnus; Mahapatra, Durga Prasad; Maire, Antonin; Malaev, Mikhail; Maldonado Cervantes, Ivonne Alicia; Malinina, Ludmila; Mal'Kevich, Dmitry; Malzacher, Peter; Mamonov, Alexander; Mangotra, Lalit Kumar; Manko, Vladislav; Manso, Franck; Manzari, Vito; Mao, Yaxian; Marchisone, Massimiliano; Mares, Jiri; Margagliotti, Giacomo Vito; Margotti, Anselmo; Marin, Ana Maria; Marin Tobon, Cesar Augusto; Markert, Christina; Marquard, Marco; Martashvili, Irakli; Martinengo, Paolo; Martinez, Mario Ivan; Martinez Davalos, Arnulfo; Martinez Garcia, Gines; Martynov, Yevgen; Mas, Alexis Jean-Michel; Masciocchi, Silvia; Masera, Massimo; Masoni, Alberto; Massacrier, Laure Marie; Mastroserio, Annalisa; Matthews, Zoe Louise; Matyja, Adam Tomasz; Mayer, Christoph; Mazer, Joel; Mazzoni, Alessandra Maria; Meddi, Franco; Menchaca-Rocha, Arturo Alejandro; Mercado Perez, Jorge; Meres, Michal; Miake, Yasuo; Milano, Leonardo; Milosevic, Jovan; Mischke, Andre; Mishra, Aditya Nath; Miskowiec, Dariusz; Mitu, Ciprian Mihai; Mlynarz, Jocelyn; Mohanty, Bedangadas; Molnar, Levente; Montano Zetina, Luis Manuel; Monteno, Marco; Montes, Esther; Moon, Taebong; Morando, Maurizio; Moreira De Godoy, Denise Aparecida; Moretto, Sandra; Morsch, Andreas; Muccifora, Valeria; Mudnic, Eugen; Muhuri, Sanjib; Mukherjee, Maitreyee; Muller, Hans; Munhoz, Marcelo; Musa, Luciano; Musso, Alfredo; Nandi, Basanta Kumar; Nania, Rosario; Nappi, Eugenio; Nattrass, Christine; Navin, Sparsh; Nayak, Tapan Kumar; Nazarenko, Sergey; Nedosekin, Alexander; Nicassio, Maria; Niculescu, Mihai; Nielsen, Borge Svane; Niida, Takafumi; Nikolaev, Sergey; Nikolic, Vedran; Nikulin, Vladimir; Nikulin, Sergey; Nilsen, Bjorn Steven; Nilsson, Mads Stormo; Noferini, Francesco; Nomokonov, Petr; Nooren, Gerardus; Novitzky, Norbert; Nyanin, Alexandre; Nyatha, Anitha; Nygaard, Casper; Nystrand, Joakim Ingemar; Ochirov, Alexander; Oeschler, Helmut Oskar; Oh, Sun Kun; Oh, Saehanseul; Oleniacz, Janusz; Oppedisano, Chiara; Ortiz Velasquez, Antonio; Ortona, Giacomo; Oskarsson, Anders Nils Erik; Ostrowski, Piotr Krystian; Otwinowski, Jacek Tomasz; Oyama, Ken; Ozawa, Kyoichiro; Pachmayer, Yvonne Chiara; Pachr, Milos; Padilla, Fatima; Pagano, Paola; Paic, Guy; Painke, Florian; Pajares, Carlos; Pal, Susanta Kumar; Palaha, Arvinder Singh; Palmeri, Armando; Papikyan, Vardanush; Pappalardo, Giuseppe; Park, Woo Jin; Passfeld, Annika; Pastircak, Blahoslav; Patalakha, Dmitri Ivanovich; Paticchio, Vincenzo; Pavlinov, Alexei; Pawlak, Tomasz Jan; Peitzmann, Thomas; Pereira Da Costa, Hugo Denis Antonio; Pereira De Oliveira Filho, Elienos; Peresunko, Dmitri; Perez Lara, Carlos Eugenio; Perez Lezama, Edgar; Perini, Diego; Perrino, Davide; Peryt, Wiktor Stanislaw; Pesci, Alessandro; Peskov, Vladimir; Pestov, Yury; Petracek, Vojtech; Petran, Michal; Petris, Mariana; Petrov, Plamen Rumenov; Petrovici, Mihai; Petta, Catia; Piano, Stefano; Piccotti, Anna; Pikna, Miroslav; Pillot, Philippe; Pinazza, Ombretta; Pinsky, Lawrence; Pitz, Nora; Piyarathna, Danthasinghe; Planinic, Mirko; Ploskon, Mateusz Andrzej; Pluta, Jan Marian; Pocheptsov, Timur; Pochybova, Sona; Podesta Lerma, Pedro Luis Manuel; Poghosyan, Martin; Polak, Karel; Polichtchouk, Boris; Pop, Amalia; Porteboeuf-Houssais, Sarah; Pospisil, Vladimir; Potukuchi, Baba; Prasad, Sidharth Kumar; Preghenella, Roberto; Prino, Francesco; Pruneau, Claude Andre; Pshenichnov, Igor; Puddu, Giovanna; Pulvirenti, Alberto; Punin, Valery; Putis, Marian; Putschke, Jorn Henning; Quercigh, Emanuele; Qvigstad, Henrik; Rachevski, Alexandre; Rademakers, Alphonse; Raiha, Tomi Samuli; Rak, Jan; Rakotozafindrabe, Andry Malala; Ramello, Luciano; Ramirez Reyes, Abdiel; Raniwala, Rashmi; Raniwala, Sudhir; Rasanen, Sami Sakari; Rascanu, Bogdan Theodor; Rathee, Deepika; Read, Kenneth Francis; Real, Jean-Sebastien; Redlich, Krzysztof; Rehman, Attiq Ur; Reichelt, Patrick; Reicher, Martijn; Renfordt, Rainer Arno Ernst; Reolon, Anna Rita; Reshetin, Andrey; Rettig, Felix Vincenz; Revol, Jean-Pierre; Reygers, Klaus Johannes; Riccati, Lodovico; Ricci, Renato Angelo; Richert, Tuva; Richter, Matthias Rudolph; Riedler, Petra; Riegler, Werner; Riggi, Francesco; Rodrigues Fernandes Rabacal, Bartolomeu; Rodriguez Cahuantzi, Mario; Rodriguez Manso, Alis; Roed, Ketil; Rohr, David; Rohrich, Dieter; Romita, Rosa; Ronchetti, Federico; Rosnet, Philippe; Rossegger, Stefan; Rossi, Andrea; Roy, Christelle Sophie; Roy, Pradip Kumar; Rubio Montero, Antonio Juan; Rui, Rinaldo; Russo, Riccardo; Ryabinkin, Evgeny; Rybicki, Andrzej; Sadovsky, Sergey; Safarik, Karel; Sahoo, Raghunath; Sahu, Pradip Kumar; Saini, Jogender; Sakaguchi, Hiroaki; Sakai, Shingo; Sakata, Dosatsu; Salgado, Carlos Albert; Salzwedel, Jai; Sambyal, Sanjeev Singh; Samsonov, Vladimir; Sanchez Castro, Xitzel; Sandor, Ladislav; Sandoval, Andres; Sano, Masato; Sano, Satoshi; Santo, Rainer; Santoro, Romualdo; Sarkamo, Juho Jaako; Scapparone, Eugenio; Scarlassara, Fernando; Scharenberg, Rolf Paul; Schiaua, Claudiu Cornel; Schicker, Rainer Martin; Schmidt, Hans Rudolf; Schmidt, Christian Joachim; Schreiner, Steffen; Schuchmann, Simone; Schukraft, Jurgen; Schutz, Yves Roland; Schwarz, Kilian Eberhard; Schweda, Kai Oliver; Scioli, Gilda; Scomparin, Enrico; Scott, Rebecca; Segato, Gianfranco; Selioujenkov, Ilya; Senyukov, Serhiy; Seo, Jeewon; Serci, Sergio; Serradilla, Eulogio; Sevcenco, Adrian; Shabetai, Alexandre; Shabratova, Galina; Shahoyan, Ruben; Sharma, Satish; Sharma, Natasha; Sharma, Rohini; Shigaki, Kenta; Shimomura, Maya; Shtejer, Katherin; Sibiriak, Yury; Siciliano, Melinda; Sicking, Eva; Siddhanta, Sabyasachi; Siemiarczuk, Teodor; Silvermyr, David Olle Rickard; Silvestre, Catherine; Simatovic, Goran; Simonetti, Giuseppe; Singaraju, Rama Narayana; Singh, Ranbir; Singha, Subhash; Singhal, Vikas; Sinha, Bikash; Sinha, Tinku; Sitar, Branislav; Sitta, Mario; Skaali, Bernhard; Skjerdal, Kyrre; Smakal, Radek; Smirnov, Nikolai; Snellings, Raimond; Sogaard, Carsten; Soltz, Ron Ariel; Son, Hyungsuk; Song, Myunggeun; Song, Jihye; Soos, Csaba; Soramel, Francesca; Sputowska, Iwona; Spyropoulou-Stassinaki, Martha; Srivastava, Brijesh Kumar; Stachel, Johanna; Stan, Ionel; Stan, Ionel; Stefanek, Grzegorz; Steinpreis, Matthew; Stenlund, Evert Anders; Steyn, Gideon Francois; Stiller, Johannes Hendrik; Stocco, Diego; Stolpovskiy, Mikhail; Strmen, Peter; Suaide, Alexandre Alarcon do Passo; Subieta Vasquez, Martin Alfonso; Sugitate, Toru; Suire, Christophe Pierre; Sultanov, Rishat; Sumbera, Michal; Susa, Tatjana; Symons, Timothy; Szanto de Toledo, Alejandro; Szarka, Imrich; Szczepankiewicz, Adam; Szostak, Artur Krzysztof; Szymanski, Maciej; Takahashi, Jun; Tapia Takaki, Daniel Jesus; Tauro, Arturo; Tejeda Munoz, Guillermo; Telesca, Adriana; Terrevoli, Cristina; Thader, Jochen Mathias; Thomas, Deepa; Tieulent, Raphael Noel; Timmins, Anthony; Tlusty, David; Toia, Alberica; Torii, Hisayuki; Toscano, Luca; Trubnikov, Victor; Truesdale, David Christopher; Trzaska, Wladyslaw Henryk; Tsuji, Tomoya; Tumkin, Alexandr; Turrisi, Rosario; Tveter, Trine Spedstad; Ulery, Jason Glyndwr; Ullaland, Kjetil; Ulrich, Jochen; Uras, Antonio; Urban, Jozef; Urciuoli, Guido Marie; Usai, Gianluca; Vajzer, Michal; Vala, Martin; Valencia Palomo, Lizardo; Vallero, Sara; Vande Vyvre, Pierre; van Leeuwen, Marco; Vannucci, Luigi; Vargas, Aurora Diozcora; Varma, Raghava; Vasileiou, Maria; Vasiliev, Andrey; Vechernin, Vladimir; Veldhoen, Misha; Venaruzzo, Massimo; Vercellin, Ermanno; Vergara, Sergio; Vernet, Renaud; Verweij, Marta; Vickovic, Linda; Viesti, Giuseppe; Vilakazi, Zabulon; Villalobos Baillie, Orlando; Vinogradov, Yury; Vinogradov, Leonid; Vinogradov, Alexander; Virgili, Tiziano; Viyogi, Yogendra; Vodopianov, Alexander; Voloshin, Kirill; Voloshin, Sergey; Volpe, Giacomo; von Haller, Barthelemy; Vranic, Danilo; vrebekk, Gaute; Vrlakova, Janka; Vulpescu, Bogdan; Vyushin, Alexey; Wagner, Boris; Wagner, Vladimir; Wan, Renzhuo; Wang, Mengliang; Wang, Dong; Wang, Yifei; Wang, Yaping; Watanabe, Kengo; Weber, Michael; Wessels, Johannes; Westerhoff, Uwe; Wiechula, Jens; Wikne, Jon; Wilde, Martin Rudolf; Wilk, Alexander; Wilk, Grzegorz Andrzej; Williams, Crispin; Windelband, Bernd Stefan; Xaplanteris Karampatsos, Leonidas; Yaldo, Chris G; Yamaguchi, Yorito; Yang, Shiming; Yang, Hongyan; Yasnopolsky, Stanislav; Yi, JunGyu; Yin, Zhongbao; Yoo, In-Kwon; Yoon, Jongik; Yu, Weilin; Yuan, Xianbao; Yushmanov, Igor; Zaccolo, Valentina; Zach, Cenek; Zampolli, Chiara; Zaporozhets, Sergey; Zarochentsev, Andrey; Zavada, Petr; Zaviyalov, Nikolai; Zbroszczyk, Hanna Paulina; Zelnicek, Pierre; Zgura, Sorin Ion; Zhalov, Mikhail; Zhang, Xiaoming; Zhang, Haitao; Zhou, You; Zhou, Fengchu; Zhou, Daicui; Zhu, Jianlin; Zhu, Jianhui; Zhu, Xiangrong; Zichichi, Antonino; Zimmermann, Alice; Zinovjev, Gennady; Zoccarato, Yannick Denis; Zynovyev, Mykhaylo; Zyzak, Maksym

2013-01-01

Measurements of cross sections of inelastic and diffractive processes in proton--proton collisions at LHC energies were carried out with the ALICE detector. The fractions of diffractive processes in inelastic collisions were determined from a study of gaps in charged particle pseudorapidity distributions: for single diffraction (diffractive mass $M_X 3$) $\\sigma_{\\rm DD}/\\sigma_{\\rm INEL} = 0.11 \\pm 0.03, 0.12 \\pm 0.05$, and $0.12^{+0.05}_{-0.04}$, respectively at $\\sqrt{s} = 0.9, 2.76$, and 7 TeV. To measure the inelastic cross section, beam properties were determined with van der Meer scans, and, using a simulation of diffraction adjusted to data, the following values were obtained: $\\sigma_{\\rm INEL} = 62.8^{+2.4}_{-4.0} (model) \\pm 1.2 (lumi)$ mb at $\\sqrt{s} =$ 2.76 TeV and $73.2^{+2.0}_{-4.6} (model) \\pm 2.6 (lumi)$ mb at $\\sqrt{s}$ = 7 TeV. The single- and double-diffractive cross sections were calculated combining relative rates of diffraction with inelastic cross sections. The results are compared t...

Online Reconstruction and Calibration with Feedback Loop in the ALICE High Level Trigger

Directory of Open Access Journals (Sweden)

Rohr David

2016-01-01

at the Large Hadron Collider (LHC at CERN. The High Level Trigger (HLT is an online computing farm, which reconstructs events recorded by the ALICE detector in real-time. The most computing-intensive task is the reconstruction of the particle trajectories. The main tracking devices in ALICE are the Time Projection Chamber (TPC and the Inner Tracking System (ITS. The HLT uses a fast GPU-accelerated algorithm for the TPC tracking based on the Cellular Automaton principle and the Kalman filter. ALICE employs gaseous subdetectors which are sensitive to environmental conditions such as ambient pressure and temperature and the TPC is one of these. A precise reconstruction of particle trajectories requires the calibration of these detectors. As our first topic, we present some recent optimizations to our GPU-based TPC tracking using the new GPU models we employ for the ongoing and upcoming data taking period at LHC. We also show our new approach to fast ITS standalone tracking. As our second topic, we present improvements to the HLT for facilitating online reconstruction including a new flat data model and a new data flow chain. The calibration output is fed back to the reconstruction components of the HLT via a feedback loop. We conclude with an analysis of a first online calibration test under real conditions during the Pb-Pb run in November 2015, which was based on these new features.

31 Jannuary 2012 - Pakistan COMSATS Executive Director I. E. Qureshi visiting the LHC tunnel at Point 2 with ALICE Collaboration Spokesperson P. Giubellino and International Relations Adviser R. Voss; Exchange of gifts and signature of the guest book with CERN Director-General R. Heuer.

CERN Multimedia

Maximilien Brice

2012-01-01

31 Jannuary 2012 - Pakistan COMSATS Executive Director I. E. Qureshi visiting the LHC tunnel at Point 2 with ALICE Collaboration Spokesperson P. Giubellino and International Relations Adviser R. Voss; Exchange of gifts and signature of the guest book with CERN Director-General R. Heuer.

LHC Report: Ion Age

CERN Multimedia

John Jowett for the LHC team

2013-01-01

The LHC starts the New Year facing a new challenge: proton-lead collisions in the last month before the shutdown in mid-February.    Commissioning this new and almost unprecedented mode of collider operation is a major challenge both for the LHC and its injector chain. Moreover, it has to be done very quickly to achieve a whole series of physics goals, requiring modifications of the LHC configuration, in a very short time. These include a switch of the beam directions halfway through the run, polarity reversals of the ALICE spectrometer magnet and Van der Meer scans.    The Linac3 team kept the lead source running throughout the end-of-year technical stop, and recovery of the accelerator complex was very quick. New proton and lead beams were soon ready, with a bunch filling pattern that ensures they will eventually match up in the LHC. The LEIR machine has even attained a new ion beam intensity record.  On Friday 11 January the first single bunches o...

AliEn - EDG Interoperability in ALICE

CERN Document Server

Bagnasco, S; Buncic, P; Carminati, F; Cerello, P G; Saiz, P

2003-01-01

AliEn (ALICE Environment) is a GRID-like system for large scale job submission and distributed data management developed and used in the context of ALICE, the CERN LHC heavy-ion experiment. With the aim of exploiting upcoming Grid resources to run AliEn-managed jobs and store the produced data, the problem of AliEn-EDG interoperability was addressed and an in-terface was designed. One or more EDG (European Data Grid) User Interface machines run the AliEn software suite (Cluster Monitor, Storage Element and Computing Element), and act as interface nodes between the systems. An EDG Resource Broker is seen by the AliEn server as a single Computing Element, while the EDG storage is seen by AliEn as a single, large Storage Element; files produced in EDG sites are registered in both the EDG Replica Catalogue and in the AliEn Data Catalogue, thus ensuring accessibility from both worlds. In fact, both registrations are required: the AliEn one is used for the data management, the EDG one to guarantee the integrity and...

Particles are back in the LHC!

CERN Multimedia

2009-01-01

Last weekend (23-25 October) particles once again entered the LHC after the one-year interruption following the incident of September 2008. Particles travelled through one sector clockwise and one anticlockwise. ALICE and LHCb, the two experiments sitting along the portion of the beam lines in question, were able to observe the first effects of real beams in the machine.

Multi-strange production of baryons at the LHC in proton-proton collisions with the ALICE experiment

International Nuclear Information System (INIS)

Maire, A.

2011-01-01

Strange quarks define a valuable probe for the understanding of quantum chromodynamics. The present PhD work falls within this scope; it deals with the study of multi-strange baryons Ξ - (dss) and Ω - (sss) in the proton-proton collisions (pp) at the LHC. The analyses make use of the ALICE experiment and are performed at central rapidities (|y| ∼ 0) and low transverse momentum (p T 2 N/dp T dy = f(p T ). At √(s) = 0.9 TeV, the production of (Ξ - +Ξ-bar + ) in the inelastic pp interactions is derived from a small statistics of events. At √(s) = 7 TeV, the large quantity of available data allows the measurement of production rates for each of the four species: Ξ - , Ξ-bar + , Ω - , and Ω-bar + . At both energies, experimental data spectra are compared to spectra as produced by different benchmark phenomenological models (PYTHIA and PHOJET). The comparison shows an unequivocal underestimate of the spectra by the Monte Carlo generators in their current versions (up to a factor ∼ 4 for Ξ, ∼ 15 for Ω). Furthermore, an analysis of azimuthal correlations (Ξ ± - h ± ) is led at intermediate p T (2 ± rises, the emission of the latter is preferentially done in correlation with jets. (author)

Light vector meson production in pp collisions at root s=7 TeV ALICE Collaboration

Czech Academy of Sciences Publication Activity Database

Abelev, B.; Adamová, Dagmar; Bielčík, J.; Bielčíková, Jana; Čepila, J.; Krus, M.; Kushpil, Svetlana; Kushpil, Vasilij; Mareš, Jiří A.; Pachr, M.; Petráček, V.; Petráň, M.; Polák, Karel; Pospíšil, V.; Šmakal, R.; Šumbera, Michal; Tlustý, D.; Vajzer, Michal; Wagner, V.; Zach, Č.; Závada, Petr

2012-01-01

Roč. 710, 4-5 (2012), s. 557-568 ISSN 0370-2693 R&D Projects: GA MŠk LA08015 Institutional support: RVO:68378271 ; RVO:61389005 Keywords : heavy ion collisions * LHC * ALICE Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 4.569, year: 2012

Jet fragmentation properties in proton-proton and Pb-Pb collisions with ALICE at the LHC

International Nuclear Information System (INIS)

Leon Vargas, Hermes

2012-01-01

The subject of this thesis is the characterization of jets produced by hadron collisions with ALICE at the LHC. The thesis can be divided into three sections. The first section presents the analysis of two jet observables measured in proton-proton collisions at √(s) = 7 TeV. The two jet observables that are used through this work are NT90 and the Second Central Moment of the Jet Profile (SCMJP). NT90 was proposed by J. Pumplin as an observable that could be used to discriminate quark from gluon jets using segmented calorimeters. The second section of the thesis is dedicated as well to the study of the charged jet fragmentation from proton-proton collisions at √(s) = 7 TeV but with a different objective. The goal of this second analysis was to study the dependence of the jet properties on the multiplicity of the event. The last section of the thesis presents the first study of charged jets from Pb-Pb collisions using the NT90 observable. In the thesis it is discussed that in order to decrease the background contamination in the observable it is better to use a harder part of the charged jet that it is more separated in transverse momentum from the bulk of the event, thus it was decided to use NT80 instead of NT90.

Improvements of the ALICE HLT data transport framework for LHC Run 2

Science.gov (United States)

Rohr, David; Krzwicki, Mikolaj; Engel, Heiko; Lehrbach, Johannes; Lindenstruth, Volker; ALICE Collaboration

2017-10-01

The ALICE HLT uses a data transport framework based on the publisher- subscriber message principle, which transparently handles the communication between processing components over the network and between processing components on the same node via shared memory with a zero copy approach. We present an analysis of the performance in terms of maximum achievable data rates and event rates as well as processing capabilities during Run 1 and Run 2. Based on this analysis, we present new optimizations we have developed for ALICE in Run 2. These include support for asynchronous transport via Zero-MQ which enables loops in the reconstruction chain graph and which is used to ship QA histograms to DQM. We have added asynchronous processing capabilities in order to support long-running tasks besides the event-synchronous reconstruction tasks in normal HLT operation. These asynchronous components run in an isolated process such that the HLT as a whole is resilient even to fatal errors in these asynchronous components. In this way, we can ensure that new developments cannot break data taking. On top of that, we have tuned the processing chain to cope with the higher event and data rates expected from the new TPC readout electronics (RCU2) and we have improved the configuration procedure and the startup time in order to increase the time where ALICE can take physics data. We analyze the maximum achievable data processing rates taking into account processing capabilities of CPUs and GPUs, buffer sizes, network bandwidth, the incoming links from the detectors, and the outgoing links to data acquisition.

Du personnel au politique : construction d’une identité militante dans le journal d’Alice Stone Blackwell (1872-1874

Directory of Open Access Journals (Sweden)

Claire Sorin

2008-09-01

Full Text Available Le militantisme n’est pas seulement affaire de scène publique ; les coulisses, qui sont en interaction permanente avec cette scène, forment un espace crucial où les enjeux se tissent et les acteurs se fabriquent. Alice Stone Blackwell, la fille de la célèbre féministe américaine Lucy Stone, a laissé un certain nombre de journaux mais c’est dans celui qu’elle écrivit adolescente (1872-1874 que l’on voit clairement s’ébaucher et s’incarner la voix militante de l’auteur. L’étude d’un texte « privé » (dont le statut est en fait beaucoup plus complexe ne présente pas seulement l’intérêt d’un regard intime et particulier sur le mouvement féministe américain de la fin du dix-neuvième siècle. Elle permet aussi de comprendre comment l’écriture autorise le sujet à tester et à s’approprier un ensemble de discours sur la nature féminine qui rompent avec l’idéal de domesticité et le culte de la fragilité. Le journal permet à Alice Blackwell de construire son identité de militante et de l’articuler avec d’autres facettes de son existence. Loin d’être simplement le reflet conventionnel d’une pratique bourgeoise essentiellement réservée au sexe féminin, l’écriture du journal chez Blackwell participe d’un acte militant, dont le trait le plus saillant est sans doute de mettre en scène un corps vigoureux et triomphant, apte à investir la sphère publique.El militantismo no sólo es un asunto de la escena pública ; los arcanos, en continua interacción con esa escena, forman un espacio donde se trama lo que está en juego y donde se fabrican los actores. Alice Stone Blackwell, hija de la famosa feminista americana Lucy Stone, ha dejado varios diarios, pero es en él que escribió de joven (1872-1874 donde claramente se esboza y se encarna la voz militante de la autora. El estudiar un texto « privado » no sólo presenta el interés de una mirada intima sobre el movimiento

LHC Results on Charmonium in Heavy Ions

CERN Document Server

Hong, Byungsik

2012-01-01

In heavy-ion collisions at high energies, the quantum chromodynamics (QCD) predicts the production of the deconfined quark-gluon plasma (QGP) state. Quarkonia ($c\\bar{c}$ or $b\\bar{b}$ bound states) are a useful means to probe QGP and to investigate the behavior of QCD under the high parton-density environment. Up to now, the large hadron collider (LHC) at CERN provided two runs for PbPb collisions at $\\sqrt{s_{NN}}$ = 2.76 TeV in the years 2010 and 2011. The ALICE, ATLAS, and CMS experiments at LHC have analyzed the yields and spectra of the $J/\\psi$ and $\\Upsilon$ families. In this article, we review particularly the recent charmonium results in PbPb collisions at LHC from the 2010 run.

Multivariate Analysis Techniques for charm reconstruction with ALICE

CERN Multimedia

CERN. Geneva

2018-01-01

ALICE is the experiment at the LHC dedicated to heavy-ion collisions. One of the key tools to investigate the strongly-interacting medium (Quark-Gluon Plasma, QGP) formed in heavy-ion collisions is the measurement of open-charm particle production. In particular, charmed baryons, such as ΛC, provide essential information for the understanding of charm thermalisation and hadronisation in the QGP. Data from proton-proton and proton-Pb collisions are needed as a reference for interpreting the results in Pb-Pb collisions, as well as to study charm hadronisation into baryons "in-vacuum". The relatively short lifetime of the ΛC baryon, cτ~60μm, makes the reconstruction of its decay a challenging task that profits from the excellent performance of ALICE in terms of secondary vertex reconstruction and particle identification. The application of multivariateanalysis (MVA) techniques through Boosted Decision Trees can facilitate the separation of the ΛC signal from the background, and as such be a complementary ap...

Upgrade of the Inner Tracking System of ALICE

CERN Document Server

Kofarago, Monika

2015-01-01

The upgrade of the Inner Tracking System (ITS) of ALICE is planned for the second long shutdown of the LHC in 2019-2020. The ALICE physics program after the shutdown requires the ITS to have improved tracking capabilities and improved impact parameter resolution at very low transverse momentum, as well as a substantial increase in the readout rate. To fulfill these requirements the current ITS will be replaced by seven layers of Monolithic Active Pixel Sensors. The new detector will be moved as close as 23 mm to the interaction point and will have a significantly reduced material budget. Several prototypes of the sensor have been developed to test different aspects of the sensor design including prototypes with analog and digital readout, as well as small and final-size sensors. These prototypes have been thoroughly characterized both in laboratory tests and at test beam facilities including studies on the radiation hardness of the sensors. This contribution gives an overview of the current status of the rese...

The ALICE Dimuon Trigger Overview and Electronics Prototypes

CERN Document Server

Arnaldi, R; Barret, V; Bastid, N; Blanchard, G; Chiavassa, E; Cortese, P; Crochet, Philippe; Dellacasa, G; De Marco, N; Drancourt, C; Dupieux, P; Espagnon, B; Fargeix, J; Ferretti, A; Gallio, M; Genoux-Lubain, A; Lamoine, L; Lefèvre, F; Luquin, Lionel; Manso, F; Métivier, V; Musso, A; Oppedisano, C; Piccotti, A; Royer, L; Roig, O; Rosnet, P; Scalas, E; Scomparin, E; Vercellin, Ermanno

2000-01-01

Presentation made at RPC99 and submitted to NIM ALICE is the LHC experiment (2005) dedicated to the study of heavy ion collisions. Amongst the ALICE sub-detectors, the muon spectrometer will investigate the dimuon production from heavy resonance (J/psi, Gamma) decays, which is believed to be a promising signature of the QGP (Quark Gluon Plasma) formation.For maximum efficiency of the spectrometer, a dedicated dimuon trigger is presently built. The detector partis itself based on RPCs operated in streamer mode and is the topic of another contribution to this conference. This paper gives the principle and the simulated performances of the trigger and is also focussed on the description of the electronics prototypes and future developments. The RPCs are read-out by X and Y orthogonal strips: the front-end chips are presently developed. The signals are sent to the trigger electronics which basically performs a pt cut on the tracks to reduce the background. A prototype of fast (decision time 200 ns) programmable e...

Performance optimisations for distributed analysis in ALICE

International Nuclear Information System (INIS)

Betev, L; Gheata, A; Grigoras, C; Hristov, P; Gheata, M

2014-01-01

Performance is a critical issue in a production system accommodating hundreds of analysis users. Compared to a local session, distributed analysis is exposed to services and network latencies, remote data access and heterogeneous computing infrastructure, creating a more complex performance and efficiency optimization matrix. During the last 2 years, ALICE analysis shifted from a fast development phase to the more mature and stable code. At the same time, the frameworks and tools for deployment, monitoring and management of large productions have evolved considerably too. The ALICE Grid production system is currently used by a fair share of organized and individual user analysis, consuming up to 30% or the available resources and ranging from fully I/O-bound analysis code to CPU intensive correlations or resonances studies. While the intrinsic analysis performance is unlikely to improve by a large factor during the LHC long shutdown (LS1), the overall efficiency of the system has still to be improved by an important factor to satisfy the analysis needs. We have instrumented all analysis jobs with ''sensors'' collecting comprehensive monitoring information on the job running conditions and performance in order to identify bottlenecks in the data processing flow. This data are collected by the MonALISa-based ALICE Grid monitoring system and are used to steer and improve the job submission and management policy, to identify operational problems in real time and to perform automatic corrective actions. In parallel with an upgrade of our production system we are aiming for low level improvements related to data format, data management and merging of results to allow for a better performing ALICE analysis

La Physique des gamma-jets avec le calorimètre EMCal de l'expérience ALICE au LHC

CERN Document Server

Bourdaud, Guénolé

Heavy ion collisions at LHC will produce a new state of matter : the quark-gluon plasma (QGP). Photons are not sensible to the strong interaction which dominates the nuclear medium, and hence are a valuable tool to explore QGP. Gamma-jets are rare hard processes : a photon and a parton are emitted back-to-back. The parton hadronises and produces a jet of particles. These jets are quenched due to the strong interaction of the parton with the QGP. This quenching, or more precisely the re-distribution of the energy in the jet, can be measured by the modification of the distribution of the particle energy in the jet, comparing p-p and Pb-Pb collisions (fragmentation functions or hump-backed plateau distributions). For this porpose, jet energy is needed, and can be provided precisely by gamma-jet measurement. Our goal is to use EMCal to detect a photon correlated with a jet reconstructed in ALICE tracking system. Then, the jet energy distribution are compared for p-p an Pb-Pb collisions. Gamma-jet physics is first...

Recent ALICE measurements on open heavy-flavour production in pp, p-Pb, and Pb-Pb collisions at the LHC

CERN Multimedia

CERN. Geneva

2016-01-01

According to QCD calculations on the lattice, as well as to several measurements performed at the SPS, RHIC, and LHC facilities, a state of matter composed of strongly-interacting deconfined quarks and gluons (the Quark-Gluon Plasma, QGP) is formed in heavy-ion collisions at ultra-relativistic energies. Produced in hard-scattering processes in the initial stage of the collision, heavy quarks are a powerful tool to probe the partonic interactions ongoing in the medium. The analysis of the pT-differential spectra and of the azimuthal anisotropy of heavy-flavour signals in nucleus-nucleus collisions provides a crucial piece of information to achieve a microscopic picture of the system. The ALICE experiment at CERN is equipped to measure electrons and muons from charm and beauty hadron decays and to reconstruct D mesons in hadronic decay channels. The results obtained in Pb-Pb collisions at 2.76 and 5.02 TeV will be discussed. Measurements of open heavy-flavour signals in proton-proton and proton-Pb collisions...

Analysis of D{sup 0} and D{sup *+}-meson production in pp and p-Pb collisions with ALICE at the LHC

Energy Technology Data Exchange (ETDEWEB)

Wilkinson, Jeremy John

2016-07-28

This thesis presents measurements of D-meson production in the central barrel of the ALICE detector in pp and p-Pb collisions. The reconstruction of D{sup 0} mesons in the hadronic channel D{sup 0}→K{sup -}π{sup +} was studied in pp collisions at √(s)=7 TeV using a Bayesian particle identification (PID) method, in order to test the validity of this new approach. Comparisons were made between these results and those obtained with established PID methods. Consistency was found between the different approaches, as well as an increase of the signal-to-background ratio and a similar or greater statistical significance for most of the implementations of the Bayesian approach. Further measurements of D{sup *+}→D{sup 0}π{sup +} were made as a function of charged-particle multiplicity in p-Pb collisions at √(s{sub NN})=5.02 TeV. The aim was to test the role of multi-parton interactions (MPI) and possible collective phenomena in small systems at LHC energies. The results for D{sup *+} mesons were consistent with the other D-meson species studied by ALICE (D{sup 0} and D{sup +}). The measurements against mid-rapidity multiplicity showed consistency with previous results from pp collisions; however, a slower increase of the relative D-meson yield was found as a function of multiplicity at large rapidity for p-Pb collisions than pp collisions. The results for both multiplicity estimators were reproduced by phenomenological models, both with and without viscous hydrodynamics.

Feasibility Study for a Muon Forward Tracker in the ALICE Experiment

CERN Document Server

Uras, Antonio

2012-01-01

ALICE is the experiment dedicated to the study of the quark gluon plasma in heavy-ion collisions at the CERN LHC. Improvements of ALICE sub-detectors are envisaged for the upgrade plans of year 2017. The Muon Forward Tracker (MFT) is a proposal in view of this upgrade, motivated both by the possibility to overcome the intrinsic limitations of the Muon Spectrometer, and by the possibility to perform new measurements of general interest for the whole ALICE physics. The measurement of the offset of single muons and dimuons will permit to disentangle open charm ($c\\tau \\sim 150 \\mu$m) and beauty ($c\\tau \\sim 500 \\mu$m) production. The MFT, thanks to its tracking capabilities, will allow to improve the mass resolution of the resonances for a better separation between $\\rho/\\omega$ and $\\phi$, $J/\\psi$ and $\\psi'$, and $-$ to a lesser extent $-$ $\\Upsilon$ family resonances. In addition, it will help to reject a large fraction of muons coming from pion and kaon decays, improving the signal over background ratio. In...

Track reconstruction principle in ALICE for LHC run I and run II

CERN Multimedia

Maire, Antonin

2011-01-01

Principles of tracking for an ALICE event, showing the three successive paths allowing to build a track and refine its parameters. Numbers ranging from 1 to 10 mention the bits that are activated in case of success during the propgation of the Kalman filter at the considered stage.

Multi-strange particle measurements in 7 TeV proton-proton and 2.76 TeV PbPb collisions with the ALICE experiment at the LHC

CERN Document Server

Chinellato, D D

2011-01-01

The production of charged multi-strange particles is studied with the ALICE experiment at the CERN LHC. Measurements of the central rapidity yields of $\\Xi^-$ and $\\Omega^-$ baryons, as well as their antiparticles, are presented as a function of transverse momentum ($p_\\mathrm{t}$) for inelastic pp collisions at $\\sqrt{s}=7$ TeV and compared to existing measurements performed at the same and/or at lower energies. The results are also compared to predictions from two different tunes of the PYTHIA event generator. We find that data significantly exceed the production rates from those models. Finally, we present the status of the multi-strange particle production studies in Pb-Pb at $\\sqrt{s_{NN}}=2.76$ TeV performed as a function of collision centrality.

Studies of isolated photons in proton-proton collisions with the EMCAL calorimeter of the ALICE experiment

International Nuclear Information System (INIS)

Ichou, R.

2010-10-01

Prompt photons produced in the hard initial parton-parton scatterings in high-energy proton-proton collisions - such as those at the CERN Large Hadron Collider (LHC) - are an excellent tool to study perturbative Quantum Chromodynamics. In particular, high transverse-momentum (p T ) photons provide crucial information on the parton distribution functions (PDFs) of the proton. Experimentally, in order to measure prompt photons, one needs first to get rid of various other photon sources, especially those from the large background due to π 0 decays. The electromagnetic calorimeter (EMCAL) of the ALICE (A Large Ion Collider Experiment) experiment at the LHC covers the central rapidities and provides improved capabilities to measure high-p T photons in ALICE. We present here studies of photon production in high-energy proton-proton collisions, as well as a complete analysis of their measurement with the EMCAL detector, giving details in particular on the methods developed to separate them from the π 0 decay photons with the help of isolation cuts. (author)

Analysis of Υ production in pp collisions at 7 TeV with the ALICE muon spectrometer

International Nuclear Information System (INIS)

Ahn, S.U.

2011-12-01

The ALICE experiment is a general-purpose detector designed to study the Quark-Gluon Plasma (QGP) in heavy-ion collisions at CERN LHC. One of powerful probe to the QGP is the heavy quarkonium production in heavy-ion collisions compared to the pp collisions. The interests of the heavy quarkonium production is not limited in heavy-ion physics since its production mechanism in pp collisions is still ambiguous. The aim of this thesis work is to estimate the production cross section of Υ(nS) in pp collisions at √(s)= 7 TeV in their muon decay channel with the ALICE muon spectrometer. The ALICE muon spectrometer is located at the forward rapidity region -4 + μ - ] = [0.62±0.38(stat.)+0.12-0.21(syst.)] nb per rapidity unit. (author)

Design specifications and test of the HMPID's control system in the ALICE experiment

CERN Document Server

Carrone, E

2001-01-01

The HMPID (High Momentum Particle Identification Detector) is one of the ALICE subdetectors planned to take data at LHC, starting in 2006. Since ALICE will be located underground, the HMPID will be remotely controlled by a Detector Control System (DCS). In this paper we will present the DCS design, accomplished via GRAFCET (GRAphe Fonctionnel de Commande Etape/Transition), the algorithm to translate into code readable by the PLC (the control device) and the first results of a prototype of the Low Voltage Control System. The results achieved so far prove that this way of proceeding is effective and time saving, since every step of the work is autonomous, making the debugging and updating phases simpler.

Implementation of the Control and supervision of ALICE ZDC positioning Systems- TWEEP-08

CERN Document Server

Swoboda, Detlef

2008-01-01

The ALICE Zero Degree Calorimeters (ZDC) have been installed to either side of the LHC IP2 in the machine tunnel next to the dipole magnet D2. The calorimeter modules are mounted on a special table equipped with a mechanism to lower the modules away from the beam orbit during injection and acceleration. During stable operation the modules can be raised individually to be aligned with the beam orbit. The horizontal clearance between ZDC modules and beam pipe will be only about 3 mm. Anti-collision switches are therefore installed to protect the beam pipes against accidental damage. The movement of the calorimeter modules and the protection switches are remote controlled by the ALICE ZDC positioning system.

Development of CMOS pixel sensors for the upgrade of the ALICE Inner Tracking System

International Nuclear Information System (INIS)

Molnar, L.

2014-01-01

The ALICE Collaboration is preparing a major upgrade of the current detector, planned for installation during the second long LHC shutdown in the years 2018-19, in order to enhance its low-momentum vertexing and tracking capability, and exploit the planned increase of the LHC luminosity with Pb beams. One of the cornerstones of the ALICE upgrade strategy is to replace the current Inner Tracking System in its entirety with a new, high resolution, low-material ITS detector. The new ITS will consist of seven concentric layers equipped with Monolithic Active Pixel Sensors (MAPS) implemented using the 0.18 μm CMOS technology of TowerJazz. In this contribution, the main key features of the ITS upgrade will be illustrated with emphasis on the functionality of the pixel chip. The ongoing developments on the readout architectures, which have been implemented in several fabricated prototypes, will be discussed. The operational features of these prototypes as well as the results of the characterisation tests before and after irradiation will also be presented

Development of CMOS pixel sensors for the upgrade of the ALICE Inner Tracking System

Science.gov (United States)

Molnar, L.

2014-12-01

The ALICE Collaboration is preparing a major upgrade of the current detector, planned for installation during the second long LHC shutdown in the years 2018-19, in order to enhance its low-momentum vertexing and tracking capability, and exploit the planned increase of the LHC luminosity with Pb beams. One of the cornerstones of the ALICE upgrade strategy is to replace the current Inner Tracking System in its entirety with a new, high resolution, low-material ITS detector. The new ITS will consist of seven concentric layers equipped with Monolithic Active Pixel Sensors (MAPS) implemented using the 0.18 μm CMOS technology of TowerJazz. In this contribution, the main key features of the ITS upgrade will be illustrated with emphasis on the functionality of the pixel chip. The ongoing developments on the readout architectures, which have been implemented in several fabricated prototypes, will be discussed. The operational features of these prototypes as well as the results of the characterisation tests before and after irradiation will also be presented.

MAPS development for the ALICE ITS upgrade

International Nuclear Information System (INIS)

Yang, P.; Gao, C.; Huang, G.; Aglieri, G.; Cavicchioli, C.; Hillemanns, H.; Junique, A.; Kofarago, M.; Keil, M.; Kugathasan, T.; Tobon, C.A. Marin; Mager, M.; Martinengo, P.; Chalmet, P.L.; Chanlek, N.; Collu, A.; Marras, D.; Kim, D.; Kim, J.; Lattuca, A.

2015-01-01

Monolithic Active Pixel Sensors (MAPS) offer the possibility to build pixel detectors and tracking layers with high spatial resolution and low material budget in commercial CMOS processes. Significant progress has been made in the field of MAPS in recent years, and they are now considered for the upgrades of the LHC experiments. This contribution will focus on MAPS detectors developed for the ALICE Inner Tracking System (ITS) upgrade and manufactured in the TowerJazz 180 nm CMOS imaging sensor process on wafers with a high resistivity epitaxial layer. Several sensor chip prototypes have been developed and produced to optimise both charge collection and readout circuitry. The chips have been characterised using electrical measurements, radioactive sources and particle beams. The tests indicate that the sensors satisfy the ALICE requirements and first prototypes with the final size of 1.5 × 3 cm 2 have been produced in the first half of 2014. This contribution summarises the characterisation measurements and presents first results from the full-scale chips

Inelastic and diffraction dissociation cross-sections in proton-proton collisions with ALICE

CERN Multimedia

CERN. Geneva

2012-01-01

ALICE results on proton-proton inelastic and diffractive cross-section measurements performed at $\\sqrt{s}$ = 0.9 TeV, 2.76 TeV and 7 TeV are presented. The relative rates of single- and double- diffractive processes are measured by studying properties of gaps in the pseudorapidity distribution of charged particles. ALICE trigger efficiencies are determined for various classes of events, using a detector simulation validated with experimental data. The results are presented together with earlier measurements at proton-antiproton and proton-proton colliders at lower energies and with the measurements by other LHC experiments. Predictions by different theoretical models are compared to the data. We will also discuss the main theoretical problems in the field and present some of the recent developments.

Proceedings of the second workshop of LHC Computing Grid, LCG-France

International Nuclear Information System (INIS)

Chollet, Frederique; Hernandez, Fabio; Malek, Fairouz; Gaelle, Shifrin

2007-03-01

The second LCG-France Workshop was held in Clermont-Ferrand on 14-15 March 2007. These sessions organized by IN2P3 and DAPNIA were attended by around 70 participants working with the Computing Grid of LHC in France. The workshop was a opportunity of exchanges of information between the French and foreign site representatives on one side and delegates of experiments on the other side. The event allowed enlightening the place of LHC Computing Task within the frame of W-LCG world project, the undergoing actions and the prospects in 2007 and beyond. The following communications were presented: 1. The current status of the LHC computation in France; 2.The LHC Grid infrastructure in France and associated resources; 3.Commissioning of Tier 1; 4.The sites of Tier-2s and Tier-3s; 5.Computing in ALICE experiment; 6.Computing in ATLAS experiment; 7.Computing in the CMS experiments; 8.Computing in the LHCb experiments; 9.Management and operation of computing grids; 10.'The VOs talk to sites'; 11.Peculiarities of ATLAS; 12.Peculiarities of CMS and ALICE; 13.Peculiarities of LHCb; 14.'The sites talk to VOs'; 15. Worldwide operation of Grid; 16.Following-up the Grid jobs; 17.Surveillance and managing the failures; 18. Job scheduling and tuning; 19.Managing the site infrastructure; 20.LCG-France communications; 21.Managing the Grid data; 22.Pointing the net infrastructure and site storage. 23.ALICE bulk transfers; 24.ATLAS bulk transfers; 25.CMS bulk transfers; 26. LHCb bulk transfers; 27.Access to LHCb data; 28.Access to CMS data; 29.Access to ATLAS data; 30.Access to ALICE data; 31.Data analysis centers; 32.D0 Analysis Farm; 33.Some CMS grid analyses; 34.PROOF; 35.Distributed analysis using GANGA; 36.T2 set-up for end-users. In their concluding remarks Fairouz Malek and Dominique Pallin stressed that the current workshop was more close to users while the tasks for tightening the links between the sites and the experiments were definitely achieved. The IN2P3 leadership expressed

Measurements of $\\Lambda^{+}_{c}$ production in $pp$ collisions at $\\sqrt{s}=7$ TeV with ALICE

CERN Document Server

Meninno, E

2015-01-01

A Large Ion Collider Experiment (ALICE) has been designed to study the strongly interacting medium created in heavy-ion collisions at LHC energies, the Quark Gluon Plasma (QGP). Heavy quarks (charm and beauty), produced in the early stages of the collisions, are among the most powerful probes to study this state of matter. We report about the charmed baryon Λ+ c measurement in pp collisions at √ s = 7TeV with the ALICE experiment, through the reconstruction of the decay channels Λ+ c → pK − π+ and Λ+ c → p ¯K 0 (and charge conjugates).

Open Access to the LHC takes on a new meaning

CERN Multimedia

2008-01-01

Complete scientific documentation on the LHC machine and detectors is now freely available on the Web. The ATLAS collaboration, shown here, contributed to the 1,600-page scientific documentation of the LHC, along with staff from the other five detectors and the LHC machine.Now that the LHC tunnel and the experimental caverns are shut down for public visits, "Open Access to the LHC" has taken on an entirely new meaning. Last Thursday, 14 August, seven major articles were published electronically in a special issue of the Journal of Instrumentation (JINST). Together they form the complete scientific documentation on the design and construction of the LHC machine and the six detectors (ALICE, ATLAS, CMS, LHCb, LHCf and TOTEM), and thus on the entire LHC project, well before start-up on 10 September. For many years to come, these papers will serve as key references for the stream of scientific results that will begin to emerge from the ...

Heavy­flavour measurements in Pb­Pb collisions with ALICE at the LHC

Directory of Open Access Journals (Sweden)

Bianchin Chiara

2013-11-01

Full Text Available The ALICE experiment studies the properties of the strongly-interacting matter created in high energy heavy-ion collisions, called Quark-Gluon Plasma (QGP. Heavy quarks are a powerful probe for investigating such a state of matter, since they are predominantly produced in the first hard scattering processes and they bring to the final state information on the deconfined phase. Heavy-flavour particles are reconstructed via hadronic and semi-leptonic decays in the ALICE detector. The measurements of the modification of the heavyflavour hadrons transverse momentum distribution in Pb–Pb collisions with respect to pp and of their azimuthal anisotropy show that heavy quarks have a sizeable interaction with the medium constituents.

Front end electronics and first results of the ALICE V0 detector

Energy Technology Data Exchange (ETDEWEB)

Zoccarato, Y., E-mail: y.zoccarato@ipnl.in2p3.f [Universite de Lyon, Universite Lyon 1, CNRS/IN2P3, Institut de Physique Nucleaire de Lyon (IPNL), 69622 Villeurbanne (France); Tromeur, W. [Universite de Lyon, Universite Lyon 1, CNRS/IN2P3, Institut de Physique Nucleaire de Lyon (IPNL), 69622 Villeurbanne (France); Aguilar, S.; Alfaro, R.; Almaraz Avina, E.; Anzo, A.; Belmont, E. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Circuito de la Investigacion Cientifica Ciudad Universitaria, C.P. 04510, Mexico, D.F. (Mexico); Cheshkov, C.; Cheynis, B.; Combaret, C. [Universite de Lyon, Universite Lyon 1, CNRS/IN2P3, Institut de Physique Nucleaire de Lyon (IPNL), 69622 Villeurbanne (France); Contreras, G. [Centro de Investigacion y de Estudios Avanzados (CINVESTAV), Av. Instituto Politecnico Nacional 2508 Col. San Pedro Zacatenco, C.P. 07360, Mexico, D.F. (Mexico); Cuautle, E. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior s/n, Ciudad Universitaria. Delg. Coyoacan, C.P. 04510, Mexico, D.F. (Mexico); Ducroux, L. [Universite de Lyon, Universite Lyon 1, CNRS/IN2P3, Institut de Physique Nucleaire de Lyon (IPNL), 69622 Villeurbanne (France); Gonzalez Trueba, L.; Grabski, V. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Circuito de la Investigacion Cientifica Ciudad Universitaria, C.P. 04510, Mexico, D.F. (Mexico); Grossiord, J.-Y. [Universite de Lyon, Universite Lyon 1, CNRS/IN2P3, Institut de Physique Nucleaire de Lyon (IPNL), 69622 Villeurbanne (France); Herrera Corral, G. [Centro de Investigacion y de Estudios Avanzados (CINVESTAV), Av. Instituto Politecnico Nacional 2508 Col. San Pedro Zacatenco, C.P. 07360, Mexico, D.F. (Mexico); Martinez, A. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Circuito de la Investigacion Cientifica Ciudad Universitaria, C.P. 04510, Mexico, D.F. (Mexico)

2011-01-21

This paper gives a detailed description of the acquisition and trigger electronics especially designed for the V0 detector of ALICE at LHC. A short presentation of the detector itself is given before the description of the Front End Electronics (FEE) system, which is completely embedded within the LHC environment as far as acquisition (DAQ), trigger (CTP), and detector control (DCS) are concerned. It is able to detect on-line coincident events and to achieve charge (with a precision of 0.6 pC) and time measurements (with a precision of 100 ps). It deploys quite a simple architecture. It is however totally programmable and fully non-standard in discriminating events coming from Beam-Beam interaction and Beam-Gas background. Finally, raw data collected from the first LHC colliding beams illustrate the performance of the system.

Conception et réalisation de l'unité de décision du système de déclenchement de premier niveau du détecteur LHCb au LHC

CERN Document Server

Laubser, Julien

2007-01-01

Le detecteur LHCb est l'une des quatre experiences de physique des particules installees sur la nouvelle chaine d'acceleration LHC (Large Hadron Collider) du CERN a Geneve. Afin de reduire la quantite de donnees destinees au stockage pour les analyses hors ligne, un dispositif de selection en ligne des collisions interessantes selon la physique a etudier est mis en place en parallele de la chaine d'acquisition des donnees. Ce dispositif est compose d'un premier niveau(niveau 0) realise par un systeme electronique complexe et d'un second niveau de selection realise par informatique HLT (High Level Trigger). L'unite de decision de niveau 0 (L0DU) est le systeme central du niveau 0 de declenchement. L0DU prend la decision d'accepter ou de rejeter la collision pour ce premier niveau a partir d'une fraction d'informations issues des sous-detecteurs les plus rapides (432 bits a 80 MHz). L'unite de decision est un circuit imprime 16 couches integrant des composants de haute technologie de type FPGA (Field Programmab...

The ALICE Data Quality Monitoring: qualitative and quantitative review of three years of operations

International Nuclear Information System (INIS)

Haller, Barthélémy von; Telesca, Adriana; Bellini, Francesca; Foka, Yiota

2014-01-01

ALICE (A Large Ion Collider Experiment) is a detector designed to study the physics of strongly interacting matter produced in heavy-ion collisions at the CERN Large Hadron Collider (LHC). Due to the complexity of ALICE in terms of number of detectors and performance requirements, Data Quality Monitoring (DQM) plays an essential role in providing online feedback on the data being recorded. It intends to provide shifters with precise and complete information to quickly identify problems, and as a consequence to ensure acquisition of high quality data. This paper presents a review of the ALICE DQM system during the first three years of LHC operations from a quantitative and qualitative point of view. We start by presenting the DQM software and tools before moving on to the various analyses carried out. An overview of the produced monitoring quantities is given, presenting the diversity of usage and flexibility of the DQM. Well-prepared shifters and experts, in addition to a precise organisation, were required to ensure smooth and successful operations. The description of the measures taken to ensure both aspects and an account of the DQM shifters' job are followed by a summary of the evolution of the system. We then give a quantitative review of the final setup of the system used during the whole year 2012. We conclude the paper with use cases where the DQM proved to be very valuable, scalable and efficient and with the plans for the coming years.

Half way round the LHC

CERN Multimedia

CERN Bulletin

The LHC operations teams are preparing the machine for circulating beams and things are going very smoothly. ALICE and LHCb are getting used to observing particle tracks coming from the LHC beams. During the weekend of 7-8 November, CMS also  saw its first signals from beams dumped just upstream of  the experiment cavern.   Operators in the CMS control room observe the good performance of their detector. Particles are smoothly making their way around the 27 km circumference of the LHC. Last weekend (7-8 November), the first bunches of injection energy protons completed their journey (anti-clockwise) through three octants of the LHC’s circumference and were dumped in a collimator just before entering the CMS cavern. The particles produced by the impact of the protons on the tertiary collimators (used to stop the beam) left their tracks in the calorimeters and the muon chambers of the experiment. The more delicate inner detectors were switched off for protection reasons....

Full kinematic reconstruction of charged B mesons with the upgraded Inner Tracking System of the ALICE Experiment

CERN Document Server

AUTHOR|(CDS)2074762

In this thesis, the performance of the full kinematic reconstruction of $\\mathrm{{B}}^{+}$ mesons in the decay channel $\\mathrm{{B}}^{+}\\rightarrow\\mathrm{\\overline{D}^{0}}\\pi^{+}$ ($\\mbox{$\\mathrm{\\overline{D}^{0}}\\rightarrow \\mathrm{K}^{+}\\pi^{-}$}$) and charge conjugates for the 0-10 % most central Pb-Pb collisions at $\\sqrt{s_{_{\\mathrm{NN}}}}$ = 5.5 TeV is demonstrated for the upgraded ALICE Experiment, which is planned before Run 3 of the Large Hadron Collider (LHC), beginning in 2020. Within the scope of the foreseen detector and readout upgrades to inspect all Pb-Pb collisions at their interaction rate of 50 kHz, in particular through the installation of a new high-granularity pixel inner tracker, for the first time these rare signals will become accessible using full kinematic reconstruction in central Pb-Pb collisions in ALICE at mid-rapidity at the LHC. Topological and kinematic criteria are used to select the beauty signal against the large combinatorial and correlated background. In addition to a...

The ALICE TPC, a large 3-dimensional tracking device with fast readout for ultra-high multiplicity events

CERN Document Server

INSPIRE-00249819; Appelshauser, H.; Bablok, S.; Bialas, N.; Bolgen, R.; Bonnes, U.; Bramm, R.; Braun-Munzinger, P.; Campagnolo, R.; Christiansen, P.; Dobrin, A.; Engster, C.; Fehlker, D.; Foka, Y.; Frankenfeld, U.; Gaardhoje, J.J.; Garabatos, C.; Glassel, P.; Gonzalez Gutierrez, C.; Gros, P.; Gustafsson, H.A.; Helstrup, H.; Hoch, M.; Ivanov, M.; Janik, R.; Junique, A.; Kalweit, A.; Keidel, R.; Kniege, S.; Kowalski, M.; Larsen, D.T.; Lesenechal, Y.; Lenoir, P.; Lindegaard, N.; Lippmann, C.; Mager, M.; Mast, M.; Matyja, A.; Munkejord, M.; Musa, L.; Nielsen, B.S.; Nikolic, V.; Oeschler, H.; Olsen, E.K.; Oskarsson, A.; Osterman, L.; Pikna, M.; Rehman, A.; Renault, G.; Renfordt, R.; Rossegger, S.; Rohrich, D.; Roed, K.; Richter, M.; Rueshmann, G.; Rybicki, A.; Sann, H.; Schmidt, H.R.; Siska, M.; Sitar, B.; Soegaard, C.; Soltveit, H.K.; Soyk, D.; Stachel, J.; Stelzer, H.; Stenlund, E.; Stock, R.; Strmen, P.; Szarka, I.; Ullaland, K.; Vranic, D.; Veenhof, R.; Westergaard, J.; Wiechula, J.; Windelband, B.

2010-01-01

The design, construction, and commissioning of the ALICE Time-Projection Chamber (TPC) is described. It is the main device for pattern recognition, tracking, and identification of charged particles in the ALICE experiment at the CERN LHC. The TPC is cylindrical in shape with a volume close to 90 m^3 and is operated in a 0.5 T solenoidal magnetic field parallel to its axis. In this paper we describe in detail the design considerations for this detector for operation in the extreme multiplicity environment of central Pb--Pb collisions at LHC energy. The implementation of the resulting requirements into hardware (field cage, read-out chambers, electronics), infrastructure (gas and cooling system, laser-calibration system), and software led to many technical innovations which are described along with a presentation of all the major components of the detector, as currently realized. We also report on the performance achieved after completion of the first round of stand-alone calibration runs and demonstrate result...

Hierarchical trigger of the ALICE calorimeters

CERN Document Server

Muller, Hans; Novitzky, Norbert; Kral, Jiri; Rak, Jan; Schambach, Joachim; Wang, Ya-Ping; Wang, Dong; Zhou, Daicui

2010-01-01

The trigger of the ALICE electromagnetic calorimeters is implemented in 2 hierarchically connected layers of electronics. In the lower layer, level-0 algorithms search shower energy above threshold in locally confined Trigger Region Units (TRU). The top layer is implemented as a single, global trigger unit that receives the trigger data from all TRUs as input to the level-1 algorithm. This architecture was first developed for the PHOS high pT photon trigger before it was adopted by EMCal also for the jet trigger. TRU units digitize up to 112 analogue input signals from the Front End Electronics (FEE) and concentrate their digital stream in a single FPGA. A charge and time summing algorithm is combined with a peakfinder that suppresses spurious noise and is precise to single LHC bunches. With a peak-to-peak noise level of 150 MeV the linear dynamic range above threshold spans from MIP energies at 215 up to 50 GeV. Local level-0 decisions take less than 600 ns after LHC collisions, upon which all TRUs transfer ...

Technical Design Report for the Upgrade of the ALICE Inner Tracking System

CERN Document Server

Abelev, B; Adamová, D; Aggarwal, M M; Aglieri Rinella, G; Agnello, M; Agostinelli, A; Agrawal, N; Ahammed, Z; Ahmad, N; Ahmad Masoodi, A; Ahmed, I; Ahn, S U; Ahn, S A; Aimo, I; Aiola, S; Ajaz, M; Akindinov, A; Aleksandrov, D; Alessandro, B; Alexandre, D; Alici, A; Alkin, A; Alme, J; Alt, T; Altini, V; Altinpinar, S; Altsybeev, I; Alves Garcia Prado, C; Anderssen, E C; Andrei, C; Andronic, A; Anguelov, V; Anielski, J; Anticic, T; Antinori, F; Antonioli, P; Aphecetche, L; Appelshäuser, H; Arbor, N; Arcelli, S; Armesto, N; Arnaldi, R; Aronsson, T; Arsene, I C; Arslandok, M; Augustinus, A; Averbeck, R; Awes, T C; Azmi, M D; Bach, M; Badalà, A; Baek, Y W; Bagnasco, S; Bailhache, R; Bairathi, V; Bala, R; Baldisseri, A; Baltasar Dos Santos Pedrosa, F; Bán, J; Baral, R C; Barbera, R; Barile, F; Barnaföldi, G G; Barnby, L S; Barret, V; Bartke, J; Basile, M; Bastian Van Beelen, J; Bastid, N; Basu, S; Bathen, B; Batigne, G; Battistin, M; Batyunya, B; Batzing, P C; Baudot, J; Baumann, C; Bearden, I G; Beck, H; Bedda, C; Behera, N K; Belikov, I; Bellini, F; Bellwied, R; Belmont-Moreno, E; Bencedi, G; Benettoni, M; Benotto, F; Beole, S; Berceanu, I; Bercuci, A; Berdnikov, Y; Berenyi, D; Berger, M E; Bertens, R A; Berzano, D; Besson, A; Betev, L; Bhasin, A; Bhati, A K; Bhatti, A; Bhattacharjee, B; Bhom, J; Bianchi, L; Bianchi, N; Bianchin, C; Bielcík, J; Bielcíková, J; Bilandzic, A; Bjelogrlic, S; Blanco, F; Blau, D; Blume, C; Bock, F; Boehmer, F V; Bogdanov, A; Boggild, H; Bogolyubsky, M; Boldizsár, L; Bombara, M; Book, J; Borel, H; Borissov, A; Bornschein, J; Borshchov, V N; Bortolin, C; Bossú, F; Botje, M; Botta, E; Böttger, S; Braun-Munzinger, P; Breitner, T; Broker, T A; Browning, T A; Broz, M; Bruna, E; Bruno, G E; Budnikov, D; Buesching, H; Bufalino, S; Buncic, P; Busch, O; Buthelezi, Z; Caffarri, D; Cai, X; Caines, H; Caliva, A; Calvo Villar, E; Camerini, P; Canoa Roman, V; Carena, F; Carena, W; Cariola, P; Carminati, F; Casanova Díaz, A; Castillo Castellanos, J; Casula, E A R; Catanescu, V; Caudron, T; Cavicchioli, C; Ceballos Sanchez, C; Cepila, J; Cerello, P; Chang, B; Chapeland, S; Charvet, J L; Chattopadhyay, S; Chattopadhyay, S; Cherney, M; Cheshkov, C; Cheynis, B; Chibante Barroso, V; Chinellato, D D; Chochula, P; Chojnacki, M; Choudhury, S; Christakoglou, P; Christensen, C H; Christiansen, P; Chujo, T; Chung, S U; Cicalo, C; Cifarelli, L; Cindolo, F; Claus, G; Cleymans, J; Colamaria, F; Colella, D; Coli, S; Colledani, C; Collu, A; Colocci, M; Conesa Balbastre, G; Conesa del Valle, Z; Connors, M E; Contin, G; Contreras, J G; Cormier, T M; Corrales Morales, Y; Cortese, P; Cortés Maldonado, I; Cosentino, M R; Costa, F; Crochet, P; Cruz Albino, R; Cuautle, E; Cunqueiro, L; Dainese, A; Dang, R; Danu, A; Da Riva, E; Das, D; Das, I; Das, K; Das, S; Dash, A; Dash, S; De, S; Decosse, C; Delagrange, H; Deloff, A; Dénes, E; D'Erasmo, G; de Barros, G O V; De Caro, A; de Cataldo, G; de Cuveland, J; De Falco, A; De Gruttola, D; De Marco, N; De Pasquale, S; De Robertis, G; De Roo, K; de Rooij, R; Diaz Corchero, M A; Dietel, T; Divià, R; Di Bari, D; Di Liberto, S; Di Mauro, A; Di Nezza, P; Djuvsland, o; Dobrin, A; Dobrowolski, T; Domenicis Gimenez, D; Dönigus, B; Dordic, O; Dorheim, S; Dorokhov, A; Doziere, G; Dubey, A K; Dubla, A; Ducroux, L; Dulinski, W; Dupieux, P; Dutta Majumdar, A K; Ehlers III, R J; Elia, D; Engel, H; Erazmus, B; Erdal, H A; Eschweiler, D; Espagnon, B; Estienne, M; Esumi, S; Evans, D; Evdokimov, S; Eyyubova, G; Fabris, D; Faivre, J; Falchieri, D; Fantoni, A; Fasel, M; Fehlker, D; Feldkamp, L; Felea, D; Feliciello, A; Feofilov, G; Ferencei, J; Fernández Téllez, A; Ferreiro, E G; Ferretti, A; Festanti, A; Figiel, J; Figueredo, M A S; Filchagin, S; Finogeev, D; Fionda, F M; Fiore, E M; Fiorenza, G; Floratos, E; Floris, M; Foertsch, S; Foka, P; Fokin, S; Fragiacomo, E; Francescon, A; Franco, M; Frankenfeld, U; Fuchs, U; Furget, C; Fusco Girard, M; Gaardhoje, J J; Gagliardi, M; Gajanana, D; Gallio, M; Gangadharan, D R; Ganoti, P; Garabatos, C; Garcia-Solis, E; Gargiulo, C; Garishvili, I; Gerhard, J; Germain, M; Gheata, A; Gheata, M; Ghidini, B; Ghosh, P; Ghosh, S K; Gianotti, P; Giubilato, P; Giubellino, P; Gladysz-Dziadus, E; Glässel, P; Gomez, R; Gomez Marzoa, M; González-Zamora, P; Gorbunov, S; Görlich, L; Gotovac, S; Graczykowski, L K; Grajcarek, R; Greiner, L C; Grelli, A; Grigoras, A; Grigoras, C; Grigoriev, V; Grigoryan, A; Grigoryan, S; Grinyov, B; Grion, N; Grondin, D; Grosse-Oetringhaus, J F; Grossiord, J -Y; Grosso, R; Guber, F; Guernane, R; Guerzoni, B; Guilbaud, M; Gulbrandsen, K; Gulkanyan, H; Gunji, T; Gupta, A; Gupta, R; H Khan, K; Haake, R; Haaland, o; Hadjidakis, C; Haiduc, M; Hamagaki, H; Hamar, G; Hanratty, L D; Hansen, A; Harris, J W; Hartmann, H; Harton, A; Hatzifotiadou, D; Hayashi, S; Heckel, S T; Heide, M; Helstrup, H; Hennes, E; Herghelegiu, A; Herrera Corral, G; Hess, B A; Hetland, K F; Hicks, B; Hillemanns, H; Himmi, A; Hippolyte, B; Hladky, J; Hristov, P; Huang, M; Hu-Guo, C; Humanic, T J; Hutter, D; Hwang, D S; Igolkin, S; Ijzermans, P; Ilkaev, R; Ilkiv, I; Inaba, M; Incani, E; Innocenti, G M; Ionita, C; Ippolitov, M; Irfan, M; Ivanov, M; Ivanov, V; Ivanytskyi, O; Jacholkowski, A; Jadlovsky, J; Jahnke, C; Jang, H J; Janik, M A; Jayarathna, P H S Y; Jena, S; Jimenez Bustamante, R T; Jones, P G; Jung, H; Junique, A; Jusko, A; Kalcher, S; Kalinak, P; Kalweit, A; Kamin, J; Kang, J H; Kaplin, V; Kar, S; Karasu Uysal, A; Karavichev, O; Karavicheva, T; Karpechev, E; Kebschull, U; Keidel, R; Keil, M; Ketzer, B; Khan, M Mohisin; Khan, P; Khan, S A; Khanzadeev, A; Kharlov, Y; Kileng, B; Kim, B; Kim, D; Kim, D W; Kim, D J; Kim, J S; Kim, M; Kim, M; Kim, S; Kim, T; Kirsch, S; Kisel, I; Kiselev, S; Kisiel, A; Kiss, G; Klay, J L; Klein, J; Klein-Bösing, C; Kluge, A; Knichel, M L; Knospe, A G; Kobdaj, C; Kofarago, M; Köhler, M K; Kollegger, T; Kolojvari, A; Kondratiev, V; Kondratyeva, N; Konevskikh, A; Kovalenko, V; Kowalski, M; Kox, S; Koyithatta Meethaleveedu, G; Kral, J; Králik, I; Kramer, F; Kravcáková, A; Krelina, M; Kretz, M; Krivda, M; Krizek, F; Krus, M; Krymov, E B; Kryshen, E; Krzewicki, M; Kucera, V; Kucheriaev, Y; Kugathasan, T; Kuhn, C; Kuijer, P G; Kulakov, I; Kumar, J; Kurashvili, P; Kurepin, A; Kurepin, A B; Kuryakin, A; Kushpil, S; Kushpil, V; Kweon, M J; Kwon, Y; Ladron de Guevara, P; Lagana Fernandes, C; Lakomov, I; Langoy, R; Lara, C; Lardeux, A; Lattuca, A; La Pointe, S L; La Rocca, P; Lea, R; Lee, G R; Legrand, I; Lehnert, J; Lemmon, R C; Lenhardt, M; Lenti, V; Leogrande, E; Leoncino, M; León Monzón, I; Lesenechal, Y; Lévai, P; Li, S; Lien, J; Lietava, R; Lindal, S; Lindenstruth, V; Lippmann, C; Lisa, M A; Listratenko, O M; Ljunggren, H M; Lodato, D F; Loddo, F; Loenne, P I; Loggins, V R; Loginov, V; Lohner, D; Loizides, C; Lopez, X; López Torres, E; Lu, X -G; Luettig, P; Lunardon, M; Luo, J; Luparello, G; Luzzi, C; M Gago, A; M Jacobs, P; Ma, R; Maevskaya, A; Mager, M; Mahapatra, D P; Maire, A; Malaev, M; Maldonado Cervantes, I; Malinina, L; Mal'Kevich, D; Maltsev, N A; Malzacher, P; Mamonov, A; Manceau, L; Manko, V; Manso, F; Manzari, V; Mapelli, A; Marchisone, M; Mares, J; Margagliotti, G V; Margotti, A; Marín, A; Marin Tobon, C A; Markert, C; Marquard, M; Marras, D; Martashvili, I; Martin, N A; Martinengo, P; Martínez, M I; Martínez García, G; Martin Blanco, J; Martynov, Y; Mas, A; Masciocchi, S; Masera, M; Maslov, M; Masoni, A; Massacrier, L; Mastroserio, A; Mattiazzo, S; Matyja, A; Mayer, C; Mazer, J; Mazumder, R; Mazza, G; Mazzoni, M A; Meddi, F; Menchaca-Rocha, A; Mercado Pérez, J; Meres, M; Miake, Y; Mikhaylov, K; Milano, L; Milosevic, J; Mischke, A; Mishra, A N; Miskowiec, D; Mitu, C M; Mlynarz, J; Mohanty, B; Molnar, L; Mongelli, M; Montaño Zetina, L; Montes, E; Morando, M; Moreira De Godoy, D A; Morel, F; Moretto, S; Morreale, A; Morsch, A; Muccifora, V; Mudnic, E; Muhammad Bhopal, F; Muhuri, S; Mukherjee, M; Müller, H; Munhoz, M G; Murray, S; Musa, L; Musinsky, J; Nandi, B K; Nania, R; Nappi, E; Nattrass, C; Nayak, T K; Nazarenko, S; Nedosekin, A; Nicassio, M; Niculescu, M; Nielsen, B S; Nikolaev, S; Nikulin, S; Nikulin, V; Nilsen, B S; Noferini, F; Nomokonov, P; Nooren, G; Nyanin, A; Nystrand, J; Oeschler, H; Oh, S; Oh, S K; Okatan, A; Olah, L; Oleniacz, J; Oliveira Da Silva, A C; Onderwaater, J; Oppedisano, C; Ortiz Velasquez, A; Oskarsson, A; Otwinowski, J; Oyama, K; Pachmayer, Y; Pachr, M; Pagano, P; Paic, G; Painke, F; Pajares, C; Pal, S K; Palmeri, A; Panati, S; Pant, D; Pantano, D; Papikyan, V; Pappalardo, G S; Park, W J; Passfeld, A; Pastore, C; Patalakha, D I; Paticchio, V; Paul, B; Pawlak, T; Peitzmann, T; Pereira Da Costa, H; Pereira De Oliveira Filho, E; Peresunko, D; Pérez Lara, C E; Peryt, W; Pesci, A; Pestov, Y; Petagna, P; Petrácek, V; Petran, M; Petris, M; Petrovici, M; Petta, C; Pham, H; Piano, S; Pikna, M; Pillot, P; Pinazza, O; Pinsky, L; Piyarathna, D B; Ploskon, M; Planinic, M; Pluta, J; Pochybova, S; Podesta-Lerma, P L M; Poghosyan, M G; Pohjoisaho, E H O; Polichtchouk, B; Poljak, N; Pop, A; Porteboeuf-Houssais, S; Porter, J; Pospisil, V; Potukuchi, B; Prasad, S K; Preghenella, R; Prino, F; Protsenko, M A; Pruneau, C A; Pshenichnov, I; Puddu, G; Puggioni, C; Punin, V; Putschke, J; Qvigstad, H; Rachevski, A; Raha, S; Rak, J; Rakotozafindrabe, A; Ramello, L; Raniwala, R; Raniwala, S; Räsänen, S S; Rascanu, B T; Rasson, J E; Rathee, D; Rauf, A W; Razazi, V; Read, K F; Real, J S; Redlich, K; Reed, R J; Rehman, A; Reichelt, P; Reicher, M; Reidt, F; Renfordt, R; Reolon, A R; Reshetin, A; Rettig, F; Revol, J -P; Reygers, K; Riabov, V; Ricci, R A; Richert, T; Richter, M; Riedler, P; Riegler, W; Riggi, F; Rivetti, A; Rocco, E; Rodríguez Cahuantzi, M; Rodriguez Manso, A; Roed, K; Rogochaya, E; Rohni, S; Rohr, D; Röhrich, D; Romita, R; Ronchetti, F; Ronflette, L; Rosnet, P; Rossegger, S; Rossewij, M J; Rossi, A; Roudier, S; Rousset, J; Roy, A; Roy, C; Roy, P; Rubio Montero, A J; Rui, R; Russo, R; Ryabinkin, E; Ryabov, Y; Rybicki, A; Sacchetti, M; Sadovsky, S; Safarík, K; Sahlmuller, B; Sahoo, R; Sahu, P K; Saini, J; Salgado, C A; Salzwedel, J; Sambyal, S; Samsonov, V; Sanchez Castro, X; Sánchez Rodríguez, F J; sándor, L; Sandoval, A; Sano, M; Santagati, G; Santoro, R; Sarkar, D; Scapparone, E; Scarlassara, F; Scharenberg, R P; Schiaua, C; Schicker, R; Schipper, J D; Schmidt, C; Schmidt, H R; Schuchmann, S; Schukraft, J; Schulc, M; Schuster, T; Schutz, Y; Schwarz, K; Schweda, K; Scioli, G; Scomparin, E; Scott, P A; Scott, R; Segato, G; Seger, J E; Selyuzhenkov, I; Senyukhov, S; Seo, J; Serradilla, E; Sevcenco, A; Sgura, I; Shabetai, A; Shabratova, G; Shahoyan, R; Shangaraev, A; Sharma, N; Sharma, S; Shigaki, K; Shtejer, K; Sibiriak, Y; Siddhanta, S; Siemiarczuk, T; Silvermyr, D; Silvestre, C; Simatovic, G; Singaraju, R; Singh, R; Singha, S; Singhal, V; Sinha, B C; Sinha, T; Sitar, B; Sitta, M; Skaali, T B; Skjerdal, K; Smakal, R; Smirnov, N; Snellings, R J M; Snoeys, W; Sogaard, C; Soltz, R; Song, J; Song, M; Sooden, V; Soramel, F; Sorensen, S; Spacek, M; spalek, J; Spiriti, E; Sputowska, I; Spyropoulou-Stassinaki, M; Srivastava, B K; Stachel, J; Stan, I; Stefanek, G; Steinpreis, M; Stenlund, E; Steyn, G; Stiller, J H; Stocco, D; Stolpovskiy, M; Strmen, P; Suaide, A A P; Subieta Vasquez, M A; Sugitate, T; Suire, C; Suleymanov, M; suljic, M; Sultanov, R; sumbera, M; Sun, X; Susa, T; Symons, T J M; Szanto de Toledo, A; Szarka, I; Szczepankiewicz, A; Szymanski, M; Takahashi, J; Tangaro, M A; Tapia Takaki, J D; Tarantola Peloni, A; Tarazona Martinez, A; Tauro, A; Tejeda Muñoz, G; Telesca, A; Terrevoli, C; Ter Minasyan, A; Thäder, J; Thomas, D; Tieulent, R; Timmins, A R; Toia, A; Torii, H; Trubnikov, V; Trzaska, W H; Tsuji, T; Tumkin, A; Turchetta, R; Turrisi, R; Tveter, T S; Tymchuk, I T; Ulery, J; Ullaland, K; Uras, A; Usai, G L; Vajzer, M; Vala, M; Valencia Palomo, L; Valentino, V; Valin, I; Vallero, S; Vande Vyvre, P; Vannucci, L; Van Der Maarel, J; Van Hoorne, J W; van Leeuwen, M; Vargas, A; Varma, R; Vasileiou, M; Vasiliev, A; Vasta, P; Vechernin, V; Veldhoen, M; Velure, A; Venaruzzo, M; Vercellin, E; Vergara Limón, S; Verlaat, B; Vernet, R; Verweij, M; Vickovic, L; Viesti, G; Viinikainen, J; Vilakazi, Z; Villalobos Baillie, O; Vinogradov, A; Vinogradov, L; Vinogradov, Y; Virgili, T; Viyogi, Y P; Vodopyanov, A; Völkl, M A; Voloshin, K; Voloshin, S A; Volpe, G; von Haller, B; Vorobyev, I; Vranic, D; Vrláková, J; Vulpescu, B; Vyushin, A; Wagner, B; Wagner, J; Wagner, V; Wang, M; Wang, Y; Watanabe, D; Weber, M; Wessels, J P; Westerhoff, U; Wiechula, J; Wikne, J; Wilde, M; Wilk, G; Wilkinson, J; Williams, M C S; Windelband, B; Winn, M; Winter, M; Xiang, C; Yaldo, C G; Yamaguchi, Y; Yang, H; Yang, P; Yang, S; Yano, S; Yasnopolskiy, S; Yi, J; Yin, Z; Yoo, I -K; Yushmanov, I; Zaccolo, V; Zach, C; Zaman, A; Zampolli, C; Zaporozhets, S; Zarochentsev, A; Závada, P; Zaviyalov, N; Zbroszczyk, H; Zgura, I S; Zhalov, M; Zhang, F; Zhang, H; Zhang, X; Zhang, Y; Zhao, C; Zherebchevsky, V I; Zhou, D; Zhou, F; Zhou, Y; Zhu, H; Zhu, J; Zhu, X; Zichichi, A; Zimmermann, A; Zimmermann, M B; Zinovjev, G; Zoccarato, Y; Zynovyev, M; Zyzak, M; CERN. Geneva. The LHC experiments Committee; LHCC

2014-01-01

ALICE (A Large Ion Collider Experiment) is preparing a major upgrade of its experimental apparatus, planned for installation in the second long LHC shutdown (LS2) in the years 2018-2019. These plans are presented in the ALICE Upgrade Letter of Intent submitted to the LHCC in September 2012. A key element of the upgrade is the construction of a new, ultra-light, high-resolution Inner Tracking System based on monolithic pixel detectors. This Technical Design Report is an update of the Conceptual Design Report for the Upgrade of the ALICE Inner Tracking System, which was presented to the LHCC in September 2012. The primary focus of the ITS upgrade is on the improved performance for detection of heavy-flavour hadrons, and of thermal photons and low-mass di-electrons emitted by the QGP. The Conceptual Design Report demonstrated that it is possible to build a new silicon tracker with greatly improved features in terms of determination of the distance of closest approach to the primary vertex, tracking efficiency a...

Multi-strange baryon production in pp collisions at root s=7 TeV with ALICE

Czech Academy of Sciences Publication Activity Database

Abelev, B.; Adam, J.; Adamová, Dagmar; Bielčík, J.; Bielčíková, Jana; Čepila, J.; Křelina, M.; Krus, M.; Kushpil, Svetlana; Kushpil, Vasilij; Mareš, Jiří A.; Petráček, V.; Petráň, M.; Polák, Karel; Pospíšil, V.; Šmakal, R.; Šumbera, Michal; Tlustý, D.; Vajzer, Michal; Wagner, V.; Zach, Č.; Závada, Petr

2012-01-01

Roč. 712, 4-5 (2012), s. 309-318 ISSN 0370-2693 R&D Projects: GA MŠk LA08015 Institutional support: RVO:68378271 ; RVO:61389005 Keywords : multi-strange baryons * P-T spectra * mid-rapidity * proton-proton * LHC * ALICE Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 4.569, year: 2012

Study of Monolithic Active Pixel Sensors for the Upgrade of the ALICE Inner Tracking System

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00531401

The upgrade of the ALICE vertex detector, the Inner Tracking System (ITS), is scheduled to be installed during the next long shutdown period (LS2 in 2019-2020) of the CERN Large Hadron Collider (LHC). The current ITS will be replaced by seven concentric layers of Monolithic Active Pixel Sensors (MAPS) with total active surface of $\\sim$10 m$^2$, thus making ALICE the first LHC experiment implementing MAPS detector technology on a large scale. The scope of this thesis is twofold; to report on the activity on the development and the characterisation of a MAPS for the ITS upgrade and to study the charge collection process using a first-principles Monte Carlo simulation. The performance of a MAPS depends on a large number of design and operational parameters, such as collection diode geometry, reverse bias voltage, and epitaxial layer thickness. I have studied this dependence by measuring the INVESTIGATOR chip response to X-rays emitted by an $^{55}$Fe source and to minimum ionising particles. In particular, I ha...

The ALICE data acquisition system

Energy Technology Data Exchange (ETDEWEB)

Carena, F.; Carena, W.; Chapeland, S.; Chibante Barroso, V.; Costa, F. [European Organization for Nuclear Research (CERN), Geneva 23 (Switzerland); Dénes, E. [Research Institute for Particle and Nuclear Physics, Wigner Research Center, Budapest (Hungary); Divià, R.; Fuchs, U. [European Organization for Nuclear Research (CERN), Geneva 23 (Switzerland); Grigore, A. [European Organization for Nuclear Research (CERN), Geneva 23 (Switzerland); Politehnica Univesity of Bucharest, Bucharest (Romania); Kiss, T. [Cerntech Ltd., Budapest (Hungary); Simonetti, G. [Dipartimento Interateneo di Fisica ‘M. Merlin’, Bari (Italy); Soós, C.; Telesca, A.; Vande Vyvre, P. [European Organization for Nuclear Research (CERN), Geneva 23 (Switzerland); Haller, B. von, E-mail: bvonhall@cern.ch [European Organization for Nuclear Research (CERN), Geneva 23 (Switzerland)

2014-03-21

In this paper we describe the design, the construction, the commissioning and the operation of the Data Acquisition (DAQ) and Experiment Control Systems (ECS) of the ALICE experiment at the CERN Large Hadron Collider (LHC). The DAQ and the ECS are the systems used respectively for the acquisition of all physics data and for the overall control of the experiment. They are two computing systems made of hundreds of PCs and data storage units interconnected via two networks. The collection of experimental data from the detectors is performed by several hundreds of high-speed optical links. We describe in detail the design considerations for these systems handling the extreme data throughput resulting from central lead ions collisions at LHC energy. The implementation of the resulting requirements into hardware (custom optical links and commercial computing equipment), infrastructure (racks, cooling, power distribution, control room), and software led to many innovative solutions which are described together with a presentation of all the major components of the systems, as currently realized. We also report on the performance achieved during the first period of data taking (from 2009 to 2013) often exceeding those specified in the DAQ Technical Design Report.

LHC related projects and studies - Part (I)

International Nuclear Information System (INIS)

Garoby, R.; Ponce, L.

2012-01-01

This session was the first of the two sessions dealing with future projects and the associated studies. Starting with descriptions of the plans and needs of the LHCb and ALICE experiments which are less extensively documented than those of ATLAS and CMS, it addressed the plans for the High Luminosity LHC and for the upgrade of the injectors, both for protons and other ions. (authors)

Jet-hadron correlations relative to the event plane at the LHC with ALICE

Science.gov (United States)

Mazer, Joel; Alice Collaboration

2017-11-01

In ultra relativistic heavy-ion collisions at the Large Hadron Collider (LHC), conditions are met to produce a hot, dense and strongly interacting medium known as the Quark Gluon Plasma (QGP). Quarks and gluons from incoming nuclei collide to produce partons at high momenta early in the collisions. By fragmenting into collimated sprays of hadrons, these partons form 'jets'. The outgoing partons scatter and interact with the medium, leading to a manifestation of medium modifications of jets in the final state, known as jet quenching. Within the framework of perturbative QCD, jet production is well understood in pp collisions. We use jets measured in pp interactions as a baseline reference for comparing to heavy-ion collision systems to detect and study jet quenching. The jet quenching mechanism can be studied through the angular correlations of jets with charged hadrons and is examined in transverse momentum (pT) bins of the jets, pT bins of the associated hadrons, and as a function of collision centrality. A robust and precise background subtraction method is used in this analysis to remove the complex, flow dominated, heavy-ion background. The analysis of angular correlations for different orientations of the jet relative to the event plane allows for the study of the path-length dependence of medium modifications to jets. The event plane dependence of azimuthal angular correlations of charged hadrons with respect to the axis of an R = 0.2 reconstructed full (charged + neutral) jet in Pb-Pb collisions at √{sNN} = 2.76 TeV in ALICE is presented. Results are compared for three angular bins of the jet relative to the event plane in mid-peripheral events. The yields relative to the event plane are presented and then quantified through yield ratio calculations. The results show no significant path-length dependence on the medium modifications.

Charged-Particle Multiplicity Distributions over Wide Pseudorapidity Range in Proton-Proton and Proton-Lead Collisions with ALICE

DEFF Research Database (Denmark)

Zaccolo, Valentina

distributionis sensitive to the number of collisions between quarks and gluonscontained in the colliding systems.In this thesis, data using the Forward Multiplicity Detector and the SiliconPixel Detector of ALICE at CERN’s Large Hadron Collider (LHC) arepresented, for pp and pPb collisions. For the first time...

ϒ production measurements in pp, p–Pb and Pb–Pb collisions with ALICE

Energy Technology Data Exchange (ETDEWEB)

Das, Indranil [Science and Engineering Research Board, Vasant Square, New Delhi-110070 (India); Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India)

2016-12-15

The ϒ production measurement provide an important tool to study the color dissociation properties of matter at extreme energy densities, which is measured using the nuclear modification factor in heavy-ion collisions. In the present paper, the measurement of the nuclear modification factor of ϒ is discussed using the data collected in pp, p-Pb and Pb-Pb collisions with ALICE at LHC energies.

Studies for the ALICE inner tracking system upgrade

International Nuclear Information System (INIS)

Reidt, Felix

2016-01-01

The ALICE experiment at the CERN LHC identifies D"0 mesons via secondary-vertex reconstruction and topological cuts to reduce the corresponding combinatorial background in heavy-ion collisions. The D"0 meson is produced promptly in initial, hard scatterings via the strong interaction or as feed-down from weakly decaying B hadrons. Within this thesis, a novel method for the separation of prompt and feed-down D"0 mesons using cut variations was implemented and applied to data from p-Pb collisions at √(s_N_N)=5.02 TeV. The effectiveness of the secondary-vertex reconstruction strongly depends on the performance and in particular the pointing resolution of the Inner Tracking System. The upgrade of the ALICE Inner Tracking System for the Long Shutdown 2 of the LHC in 2019/2020 will significantly improve its vertex-reconstruction and tracking capabilities. It will be equipped with Monolithic Active Pixel Sensors manufactured using the TowerJazz 180 nm CMOS process on wafers with a high-resistivity epitaxial layer. In another part of this thesis, several pixel-chip prototypes of the ALPIDE architecture with in-pixel amplification and discrimination as well as in-matrix data reduction were characterised. The pALPIDE-2 prototype was measured to fulfil the requirements in terms of detection efficiency, fake-hit rate, position resolution and tolerance to irradiation with non-ionising energy loss. Based on simulations modelling the tracking and vertex-reconstruction performance of the upgraded Inner Tracking System, the perspective of the feed-down separation using cut variations after the upgrade was assessed within this thesis.

D* Mesons in Jets Analysis in proton-proton collisions at √s 10 TeV using the ALICE detector at CERN-LHC

International Nuclear Information System (INIS)

Grelli, A.; Mische, A.

2009-01-01

Charm and bottom quarks have been proposed as probes to study partonic matter produced in high-energy heavy-ion collisions. The detailed understanding of the production mechanisms in such collisions is of considerable interest. Measurements of the D * yield in jets probe the production processes in which the observed D * mesons are formed primarily from gluon splitting into c-c(bar) or b-b(bar) pairs. The charm content in jets is calculable in perturbative QCD, and the leading non-perturbative correction is expected to be significant at LHC energies. In this contribution we present latest results on performance studies of the reconstruction of charged D * mesons in jets in proton-proton collisions at √s = 10 TeV using the ALICE central detector. D *+ mesons are reconstructed through the decay sequence D *+ → D 0 + π + and D 0 → K - + π + (and its charge conjugate channel). The results are compared for different jet transverse momenta, and topological cut effects are discussed. (authors)

Physics Goals and Experimental Challenges of the Proton-Proton High-Luminosity Operation of the LHC

Science.gov (United States)

Campana, P.; Klute, M.; Wells, P. S.

2016-10-01

The completion of Run 1 of the Large Hadron Collider (LHC) at CERN has seen the discovery of the Higgs boson and an unprecedented number of precise measurements of the Standard Model, and Run 2 has begun to provide the first data at higher energy. The high-luminosity upgrade of the LHC (HL-LHC) and the four experiments (ATLAS, CMS, ALICE, and LHCb) will exploit the full potential of the collider to discover and explore new physics beyond the Standard Model. We review the experimental challenges and the physics opportunities in proton-proton collisions at the HL-LHC.

Measurements of quarkonia with the central detectors of ALICE

International Nuclear Information System (INIS)

Sommer, Wolfgang

2008-01-01

The production of quarkonia, the bound state of an heavy quark with its anti-particle, has for a long time been seen as a key process to understand the properties of nuclear matter in a relativistic heavy-ion collision. This thesis presents studies on the production of quarkonia in heavy-ion collisions at the new Large Hadron collider (LHC). The focus is set on the decay of J/Psi and Upsilon-states into their di-electronic decay channel, measured within the central detectors of the ALICE detector. (orig.)

Measurements of quarkonia with the central detectors of ALICE

Energy Technology Data Exchange (ETDEWEB)

Sommer, Wolfgang

2008-03-26

The production of quarkonia, the bound state of an heavy quark with its anti-particle, has for a long time been seen as a key process to understand the properties of nuclear matter in a relativistic heavy-ion collision. This thesis presents studies on the production of quarkonia in heavy-ion collisions at the new Large Hadron collider (LHC). The focus is set on the decay of J/Psi and Upsilon-states into their di-electronic decay channel, measured within the central detectors of the ALICE detector. (orig.)

"Big Science: the LHC in Pictures" in the Globe

CERN Multimedia

2008-01-01

An exhibition of spectacular photographs of the LHC and its experiments is about to open in the Globe. The LHC and its four experiments are not only huge in size but also uniquely beautiful, as the exhibition "Big Science: the LHC in Pictures" in the Globe of Science and Innovation will show. The exhibition features around thirty spectacular photographs measuring 4.5 metres high and 2.5 metres wide. These giant pictures reflecting the immense scale of the LHC and the mysteries of the Universe it is designed to uncover fill the Globe with shape and colour. The exhibition, which will open on 4 March, is divided into six different themes: CERN, the LHC and the four experiments ATLAS, LHCb, CMS and ALICE. Facts about all these subjects will be available at information points and in an explanatory booklet accompanying the exhibition (which visitors will be able to buy if they wish to take it home with them). Globe of Science and Innovatio...

ALICE Masterclass on strangeness

Directory of Open Access Journals (Sweden)

Foka Panagiota

2014-04-01

Full Text Available An educational activity, the International Particle Physics Masterclasses, was developed by the International Particle Physics Outreach Group with the aim to bring the excitement of cutting-edge particle-physics research into the classroom. Thousands of pupils, every year since 2005, in many countries all over the world, are hosted in research centers or universities close to their schools and become “scientists for a day” as they are introduced to the mysteries of particle physics. The program of a typical day includes lectures that give insight to topics and methods of fundamental research followed by a “hands-on” session where the high-school students perform themselves measurements on real data from particle-physics experiments. The last three years data from the ALICE experiment at LHC were used. The performed measurement “strangeness enhancement” and the employed methodology are presented.

Strange particle production in proton-proton collisions at $\\sqrt{s}$ = 0.9 TeV with ALICE at the LHC

CERN Document Server

INSPIRE-00247373; Abrahantes Quintana, A.; Adamova, D.; Adare, A.M.; Aggarwal, M.M.; Aglieri Rinella, G.; Agocs, A.G.; Aguilar Salazar, S.; Ahammed, Z.; Ahmad, N.; Ahmad Masoodi, A.; Ahn, S.U.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Almaraz Avina, E.; Alt, T.; Altini, V.; Altinpinar, S.; Altsybeev, I.; Andrei, C.; Andronic, A.; Anguelov, V.; Anson, C.; Anticic, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshauser, H.; Arbor, N.; Arcelli, S.; Arend, A.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I.C.; Asryan, A.; Augustinus, A.; Averbeck, R.; Awes, T.C.; Aysto, J.; Azmi, M.D.; Bach, M.; Badala, A.; Baek, Y.W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldini Ferroli, R.; Baldisseri, A.; Baldit, A.; Ban, J.; Barbera, R.; Barile, F.; Barnafoldi, G.G.; Barnby, L.S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Bathen, B.; Batigne, G.; Batyunya, B.; Baumann, C.; Bearden, I.G.; Beck, H.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdermann, E.; Berdnikov, Y.; Betev, L.; Bhasin, A.; Bhati, A.K.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielcik, J.; Bielcikova, J.; Bilandzic, A.; Biolcati, E.; Blanc, A.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Boccioli, M.; Bock, N.; Bogdanov, A.; Boggild, H.; Bogolyubsky, M.; Boldizsar, L.; Bombara, M.; Bombonati, C.; Book, J.; Borel, H.; Bortolin, C.; Bose, S.; Bossu, F.; Botje, M.; Bottger, S.; Boyer, B.; Braun-Munzinger, P.; Bravina, L.; Bregant, M.; Breitner, T.; Broz, M.; Brun, R.; Bruna, E.; Bruno, G.E.; Budnikov, D.; Buesching, H.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Calvo Villar, E.; Camerini, P.; Canoa Roman, V.; Cara Romeo, G.; Carena, F.; Carena, W.; Carminati, F.; Casanova Diaz, A.; Caselle, M.; Castillo Castellanos, J.; Catanescu, V.; Cavicchioli, C.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J.L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chiavassa, E.; Chibante Barroso, V.; Chinellato, D.D.; Chochula, P.; Chojnacki, M.; Christakoglou, P.; Christensen, C.H.; Christiansen, P.; Chujo, T.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Coccetti, F.; Coffin, J.P.; Coli, S.; Conesa Balbastre, G.; Conesa del Valle, Z.; Constantin, P.; Contin, G.; Contreras, J.G.; Cormier, T.M.; Corrales Morales, Y.; Cortes Maldonado, I.; Cortese, P.; Cosentino, M.R.; Costa, F.; Cotallo, M.E.; Crescio, E.; Crochet, P.; Cuautle, E.; Cunqueiro, L.; D'Erasmo, G.; Dainese, A.; Dalsgaard, H.H.; Danu, A.; Das, D.; Das, I.; Dash, A.; Dash, S.; De, S.; De Azevedo Moregula, A.; de Barros, G.O.V.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; De Remigis, R.; de Rooij, R.; Delagrange, H.; Delgado Mercado, Y.; Dellacasa, G.; Deloff, A.; Demanov, V.; Denes, E.; Deppman, A.; Di Bari, D.; Di Giglio, C.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Dietel, T.; Divia, R.; Djuvsland, O.; Dobrin, A.; Dobrowolski, T.; Dominguez, I.; Donigus, B.; Dordic, O.; Driga, O.; Dubey, A.K.; Dubuisson, J.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A.K.; Dutta Majumdar, M.R.; Elia, D.; Emschermann, D.; Engel, H.; Erdal, H.A.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evrard, S.; Eyyubova, G.; Fabjan, C.W.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fearick, R.; Fedunov, A.; Fehlker, D.; Fekete, V.; Felea, D.; Feofilov, G.; Fernandez Tellez, A.; Ferretti, A.; Ferretti, R.; Figueredo, M.A.S.; Filchagin, S.; Fini, R.; Finogeev, D.; Fionda, F.M.; Fiore, E.M.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Fragkiadakis, M.; Frankenfeld, U.; Fuchs, U.; Furano, F.; Furget, C.; Fusco Girard, M.; Gaardhoje, J.J.; Gadrat, S.; Gagliardi, M.; Gago, A.; Gallio, M.; Ganoti, P.; Garabatos, C.; Gemme, R.; Gerhard, J.; Germain, M.; Geuna, C.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Girard, M.R.; Giraudo, G.; Giubellino, P.; Gladysz-Dziadus, E.; Glassel, P.; Gomez, R.; Gonzalez-Trueba, L.H.; Gonzalez-Zamora, P.; Gonzalez Santos, H.; Gorbunov, S.; Gotovac, S.; Grabski, V.; Grajcarek, R.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gros, P.; Grosse-Oetringhaus, J.F.; Grossiord, J.Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerra Gutierrez, C.; Guerzoni, B.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, R.; Gutbrod, H.; Haaland, O.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Harris, J.W.; Hartig, M.; Hasch, D.; Hasegan, D.; Hatzifotiadou, D.; Hayrapetyan, A.; Heide, M.; Heinz, M.; Helstrup, H.; Herghelegiu, A.; Hernandez, C.; Herrera Corral, G.; Herrmann, N.; Hetland, K.F.; Hicks, B.; Hille, P.T.; Hippolyte, B.; Horaguchi, T.; Hori, Y.; Hristov, P.; Hrivnacova, I.; Huang, M.; Huber, S.; Humanic, T.J.; Hwang, D.S.; Ichou, R.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Incani, E.; Innocenti, G.M.; Innocenti, P.G.; Ippolitov, M.; Irfan, M.; Ivan, C.; Ivanov, A.; Ivanov, M.; Ivanov, V.; Jacholkowski, A.; Jacobs, P.M.; Jancurova, L.; Jangal, S.; Janik, R.; Jayarathna, S.P.; Jena, S.; Jirden, L.; Jones, G.T.; Jones, P.G.; Jovanovic, P.; Jung, H.; Jung, W.; Jusko, A.; Kalcher, S.; Kalinak, P.; Kalisky, M.; Kalliokoski, T.; Kalweit, A.; Kamermans, R.; Kanaki, K.; Kang, E.; Kang, J.H.; Kaplin, V.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kazantsev, A.; Kebschull, U.; Keidel, R.; Khan, M.M.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, D.J.; Kim, D.S.; Kim, D.W.; Kim, H.N.; Kim, J.H.; Kim, J.S.; Kim, M.; Kim, M.; Kim, S.; Kim, S.H.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Klay, J.L.; Klein, J.; Klein-Bosing, C.; Kliemant, M.; Klovning, A.; Kluge, A.; Knichel, M.L.; Koch, K.; Kohler, M.K.; Kolevatov, R.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Konevskih, A.; Kornas, E.; Kottachchi Kankanamge Don, C.; Kour, R.; Kowalski, M.; Kox, S.; Kozlov, K.; Kral, J.; Kralik, I.; Kramer, F.; Kraus, I.; Krawutschke, T.; Kretz, M.; Krivda, M.; Krumbhorn, D.; Krus, M.; Kryshen, E.; Krzewicki, M.; Kucheriaev, Y.; Kuhn, C.; Kuijer, P.G.; Kurashvili, P.; Kurepin, A.; Kurepin, A.B.; Kuryakin, A.; Kushpil, S.; Kushpil, V.; Kweon, M.J.; Kwon, Y.; La Rocca, P.; Ladron de Guevara, P.; Lafage, V.; Lara, C.; Larsen, D.T.; Lazzeroni, C.; Le Bornec, Y.; Lea, R.; Lee, K.S.; Lee, S.C.; Lefevre, F.; Lehnert, J.; Leistam, L.; Lenhardt, M.; Lenti, V.; Leon Monzon, I.; Leon Vargas, H.; Levai, P.; Li, X.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M.A.; Liu, L.; Loggins, V.R.; Loginov, V.; Lohn, S.; Lohner, D.; Lopez, X.; Lopez Noriega, M.; Lopez Torres, E.; Lovhoiden, G.; Lu, X.G.; Luettig, P.; Lunardon, M.; Luparello, G.; Luquin, L.; Luzzi, C.; Ma, K.; Ma, R.; Madagodahettige-Don, D.M.; Maevskaya, A.; Mager, M.; Mahapatra, D.P.; Maire, A.; Malaev, M.; Maldonado Cervantes, I.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manceau, L.; Mangotra, L.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Mares, J.; Margagliotti, G.V.; Margotti, A.; Marin, A.; Martashvili, I.; Martinengo, P.; Martinez, M.I.; Martinez Davalos, A.; Martinez Garcia, G.; Martynov, Y.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Massacrier, L.; Mastromarco, M.; Mastroserio, A.; Matthews, Z.L.; Matyja, A.; Mayani, D.; Mazza, G.; Mazzoni, M.A.; Meddi, F.; Menchaca-Rocha, A.; Mendez Lorenzo, P.; Mercado Perez, J.; Mereu, P.; Miake, Y.; Midori, J.; Milano, L.; Milosevic, J.; Mischke, A.; Miskowiec, D.; Mitu, C.; Mlynarz, J.; Mohanty, B.; Molnar, L.; Montano Zetina, L.; Monteno, M.; Montes, E.; Morando, M.; Moreira De Godoy, D.A.; Moretto, S.; Morsch, A.; Muccifora, V.; Mudnic, E.; Muller, H.; Muhuri, S.; Munhoz, M.G.; Munoz, J.; Musa, L.; Musso, A.; Nandi, B.K.; Nania, R.; Nappi, E.; Nattrass, C.; Navach, F.; Navin, S.; Nayak, T.K.; Nazarenko, S.; Nazarov, G.; Nedosekin, A.; Nendaz, F.; Newby, J.; Nicassio, M.; Nielsen, B.S.; Nikolaev, S.; Nikolic, V.; Nikulin, S.; Nikulin, V.; Nilsen, B.S.; Nilsson, M.S.; Noferini, F.; Nooren, G.; Novitzky, N.; Nyanin, A.; Nyatha, A.; Nygaard, C.; Nystrand, J.; Obayashi, H.; Ochirov, A.; Oeschler, H.; Oh, S.K.; Oleniacz, J.; Oppedisano, C.; Ortiz Velasquez, A.; Ortona, G.; Oskarsson, A.; Ostrowski, P.; Otterlund, I.; Otwinowski, J.; Ovrebekk, G.; Oyama, K.; Ozawa, K.; Pachmayer, Y.; Pachr, M.; Padilla, F.; Pagano, P.; Paic, G.; Painke, F.; Pajares, C.; Pal, S.; Pal, S.K.; Palaha, A.; Palmeri, A.; Pappalardo, G.S.; Park, W.J.; Paticchio, V.; Pavlinov, A.; Pawlak, T.; Peitzmann, T.; Peresunko, D.; Perez Lara, C.E.; Perini, D.; Perrino, D.; Peryt, W.; Pesci, A.; Peskov, V.; Pestov, Y.; Peters, A.J.; Petracek, V.; Petris, M.; Petrov, P.; Petrovici, M.; Petta, C.; Piano, S.; Piccotti, A.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Pitz, N.; Piuz, F.; Piyarathna, D.B.; Platt, R.; Ploskon, M.; Pluta, J.; Pocheptsov, T.; Pochybova, S.; Podesta-Lerma, P.L.M.; Poghosyan, M.G.; Polak, K.; Polichtchouk, B.; Pop, A.; Pospisil, V.; Potukuchi, B.; Prasad, S.K.; Preghenella, R.; Prino, F.; Pruneau, C.A.; Pshenichnov, I.; Puddu, G.; Pulvirenti, A.; Punin, V.; Putis, M.; Putschke, J.; Quercigh, E.; Qvigstad, H.; Rachevski, A.; Rademakers, A.; Rademakers, O.; Radomski, S.; Raiha, T.S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Ramirez Reyes, A.; Rammler, M.; Raniwala, R.; Raniwala, S.; Rasanen, S.S.; Read, K.F.; Real, J.S.; Redlich, K.; Renfordt, R.; Reolon, A.R.; Reshetin, A.; Rettig, F.; Revol, J.P.; Reygers, K.; Ricaud, H.; Riccati, L.; Ricci, R.A.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Rivetti, A.; Rodriguez Cahuantzi, M.; Rohr, D.; Rohrich, D.; Romita, R.; Ronchetti, F.; Rosinsky, P.; Rosnet, P.; Rossegger, S.; Rossi, A.; Roukoutakis, F.; Rousseau, S.; Roy, C.; Roy, P.; Rubio Montero, A.J.; Rui, R.; Rusanov, I.; Ryabinkin, E.; Rybicki, A.; Sadovsky, S.; Safarik, K.; Sahoo, R.; Sahu, P.K.; Saiz, P.; Sakai, S.; Sakata, D.; Salgado, C.A.; Samanta, T.; Sambyal, S.; Samsonov, V.; Sandor, L.; Sandoval, A.; Sano, M.; Sano, S.; Santo, R.; Santoro, R.; Sarkamo, J.; Saturnini, P.; Scapparone, E.; Scarlassara, F.; Scharenberg, R.P.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H.R.; Schreiner, S.; Schuchmann, S.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, P.A.; Scott, R.; Segato, G.; Senyukov, S.; Seo, J.; Serci, S.; Serradilla, E.; Sevcenco, A.; Shabratova, G.; Shahoyan, R.; Sharma, N.; Sharma, S.; Shigaki, K.; Shimomura, M.; Shtejer, K.; Sibiriak, Y.; Siciliano, M.; Sicking, E.; Siemiarczuk, T.; Silenzi, A.; Silvermyr, D.; Simonetti, G.; Singaraju, R.; Singh, R.; Sinha, B.C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T.B.; Skjerdal, K.; Smakal, R.; Smirnov, N.; Snellings, R.; Sogaard, C.; Soloviev, A.; Soltz, R.; Son, H.; Song, M.; Soos, C.; Soramel, F.; Spyropoulou-Stassinaki, M.; Srivastava, B.K.; Stachel, J.; Stan, I.; Stefanek, G.; Stefanini, G.; Steinbeck, T.; Stenlund, E.; Steyn, G.; Stocco, D.; Stock, R.; Stolpovskiy, M.; Strmen, P.; Suaide, A.A.P.; Subieta Vasquez, M.A.; Sugitate, T.; Suire, C.; Sumbera, M.; Susa, T.; Swoboda, D.; Symons, T.J.M.; Szanto de Toledo, A.; Szarka, I.; Szostak, A.; Tagridis, C.; Takahashi, J.; Tapia Takaki, J.D.; Tauro, A.; Tavlet, M.; Tejeda Munoz, G.; Telesca, A.; Terrevoli, C.; Thader, J.; Thomas, D.; Thomas, J.H.; Tieulent, R.; Timmins, A.R.; Tlusty, D.; Toia, A.; Torii, H.; Toscano, L.; Tosello, F.; Traczyk, T.; Truesdale, D.; Trzaska, W.H.; Tumkin, A.; Turrisi, R.; Turvey, A.J.; Tveter, T.S.; Ulery, J.; Ullaland, K.; Uras, A.; Urban, J.; Urciuoli, G.M.; Usai, G.L.; Vacchi, A.; Vala, M.; Valencia Palomo, L.; Vallero, S.; van der Kolk, N.; van Leeuwen, M.; Vande Vyvre, P.; Vannucci, L.; Vargas, A.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vechernin, V.; Venaruzzo, M.; Vercellin, E.; Vergara, S.; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Vikhlyantsev, O.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Viyogi, Y.P.; Vodopyanov, A.; Voloshin, K.; Voloshin, S.; Volpe, G.; von Haller, B.; Vranic, D.; Vrlakova, J.; Vulpescu, B.; Wagner, B.; Wagner, V.; Wan, R.; Wang, D.; Wang, Y.; Wang, Y.; Watanabe, K.; Wessels, J.P.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilde, M.; Wilk, A.; Wilk, G.; Williams, M.C.S.; Windelband, B.; Yang, H.; Yasnopolskiy, S.; Yi, J.; Yin, Z.; Yokoyama, H.; Yoo, I.K.; Yuan, X.; Yushmanov, I.; Zabrodin, E.; Zampolli, C.; Zaporozhets, S.; Zarochentsev, A.; Zavada, P.; Zbroszczyk, H.; Zelnicek, P.; Zenin, A.; Zgura, I.; Zhalov, M.; Zhang, X.; Zhou, D.; Zhu, X; Zichichi, A.; Zinovjev, G.; Zoccarato, Y.; Zynovyev, M.

2011-01-01

The production of mesons containing strange quarks (K0 S, f ) and both singly and doubly strange baryons (L, L, and X−+X+) are measured at central rapidity in pp collisions at √s = 0.9 TeV with the ALICE experiment at the LHC. The results are obtained from the analysis of about 250 k minimum bias events recorded in 2009. Measurements of yields (dN/dy) and transverse momentum spectra at central rapidities for inelastic pp collisions are presented. For mesons, we report yields (hdN/dyi) of 0.184 ± 0.002 (stat.) ± 0.006 (syst.) for K0S and 0.021 ± 0.004 (stat.) ± 0.003 (syst.) for phi. For baryons, we find dN/dy = 0.048±0.001 (stat.) ±0.004 (syst.) for Lambda, 0.047±0.002 (stat.) ±0.005 (syst.) for Lambda and 0.0094±0.0020 (stat.) ±0.0007 (syst.) for Xi−+Xi+. The results are also compared with predictions for identified particle spectra from QCD inspired models and provide a baseline for comparisons with both future pp measurements at higher energies and heavy-ion collisions

First p-Pb results from the ALICE experiment

CERN Multimedia

CERN. Geneva

2012-01-01

We present the first results from proton-lead collisions at sqrt(s_NN)=5.02 TeV obtained by the ALICE experiment at the CERN LHC. They are based on the data obtained during the pilot p-Pb run in September 2012. The measurements include the pseudorapidity density, transverse momentum distribution and the nuclear modification factor of unidentified charged particles. Our results will be compared to previous p-p, A-A and d-A experimental results and to the available theoretical model predictions. Prospects for the long p-Pb run at the beginning of 2013 will be given.

ALICE Particle Identification

CERN Document Server

Hussein Ezzelarab, Nada

2014-01-01

During my stay at CERN, I have attended lectures mornings and worked on my research project under orienting guidance of my supervisors afternoons. The lectures were informative and pedagog- ically well-prepared and presented. Their contents was an excellent combination of theoretical and experimental topics in high-energy physics. Furthermore, I was privileged to visit the ALICE, CMS and LHCb detectors and the LINIAC accelerator. I have participated in workshop on ”MadGraph software”. I was furnished with excellent experiences and cultural exchanges with good colleagues from different countries. I got opportunities to know what the other students have done, in which projects they were involved and how they performed their scientific researches, especially regarding LHC data analysis. For my own project, I have to prove excellent experience with C++ and of course LINUX, ROOT and AliROOT. Tools such as Histograms, Graphs, Fitting, trees and many others were very essential. Furthermore, I am very proud getti...

The LHC at the AAAS

CERN Multimedia

CERN Bulletin

2011-01-01

The American Association for the Advancement of Science held its annual meeting in the Walter E. Washington Convention Center in Washington D.C. last week.   Veteran science writer Tim Radford introduces LHC scientists during a media briefing at the AAAS annual meeting. Left to right: Felicitas Pauss, Tom LeCompte, Yves Schutz and Nick Hadley. As the world’s largest popular science meeting, the AAAS meeting is a major event in the calendar of science journalists.  At this year’s LHC session, CERN’s coordinator for international relations, Felicitas Pauss, opened the discussion, paving the way for Tom LeCompte of ATLAS, Joe Incandela of CMS, Yves Schutz of ALICE and Monica Pepe-Altarelli of LHCb to report on the status of the first year’s analysis from their experiments.    

Production of $\\pi^{0}$, $K^{\\pm}$ and $\\eta$ mesons in Pb-Pb and pp collisions at $\\sqrt{s_{\\rm NN}}=$2.76 TeV measured with the ALICE detector at the LHC

CERN Document Server

Morreale, Astrid

2017-01-01

One of the key signatures of the Quark-Gluon Plasma (QGP) is the modification of hadron transverse momentum differential cross-sections in heavy-ion collisions (HIC) as compared to proton-proton (pp) collisions. Suppression of hadron production at high transverse momenta ($p_{\\rm T}$) in HIC has been explained by the energy loss of the partons produced in the hard scattering processes which traverse the deconfined quantum chromodynamic (QCD) matter. The dependence of the observed suppression on the $p_{\\rm T}$ of the measured hadron towards higher $p_{\\rm T}$ is an important input for the theoretical understanding of jet quenching effects in the QGP and the nature of the energy loss, while suppression towards lower $p_{\\rm T}$ gives information about collective behaviour. The ALICE experiment at the Large Hadron Collider (LHC) performs a variety of measurements including the spectra of neutral mesons and kaons at mid-rapidity in a wide $p_{\\rm T}$ range in pp, p-Pb and Pb-Pb collisions. An overview of ALICE r...

Detection of atmospheric muons with ALICE detectors

International Nuclear Information System (INIS)

Alessandro, B.; Cortes Maldonado, I.; Cuautle, E.; Fernandez Tellez, A.; Gomez Jimenez, R.; Gonzalez Santos, H.; Herrera Corral, G.; Leon, I.; Martinez, M.I.; Munoz Mata, J.L.; Podesta, P.; Ramirez Reyes, A.; Rodriguez Cahuantzi, M.; Sitta, M.; Subieta, M.; Tejeda Munoz, G.; Vargas, A.; Vergara, S.

2010-01-01

The calibration, alignment and commissioning of most of the ALICE (A Large Ion Collider Experiment at the CERN LHC) detectors have required a large amount of cosmic events during 2008. In particular two types of cosmic triggers have been implemented to record the atmospheric muons passing through ALICE. The first trigger, called ACORDE trigger, is performed by 60 scintillators located on the top of three sides of the large L3 magnet surrounding the central detectors, and selects atmospheric muons. The Silicon Pixel Detector (SPD) installed on the first two layers of the Inner Tracking System (ITS) gives the second trigger, called SPD trigger. This trigger selects mainly events with a single atmospheric muon crossing the SPD. Some particular events, in which the atmospheric muon interacts with the iron of the L3 magnet and creates a shower of particles crossing the SPD, are also selected. In this work the reconstruction of events with these two triggers will be presented. In particular, the performance of the ACORDE detector will be discussed by the analysis of multi-muon events. Some physical distributions are also shown.

The ALICE online-offline framework for the extraction of conditions data

Energy Technology Data Exchange (ETDEWEB)

Grosse-Oetringhaus, Jan Fiete; Zampolli, Chiara; Carminati, Federico [CERN, 1211 Geneva 23 (Switzerland); Colla, Alberto, E-mail: Jan.Fiete.Grosse-Oetringhaus@cern.c, E-mail: Chiara.Zampolli@cern.c, E-mail: Alberto.Colla@roma1.infn.i, E-mail: Federico.Carminati@cern.c [Universita ' La Sapienza' and INFN, Roma (Italy)

2010-04-01

A Large Ion Collider Experiment (ALICE) is the dedicated heavy-ion experiment at the CERN LHC and will take data with a bandwidth of up to 1.25 GB/s. It consists of 18 subdetectors that interact with five online systems (CTP, DAQ, DCS, ECS, and HLT). Data recorded is read out by DAQ in a raw data stream produced by the subdetectors. In addition the subdetectors produce conditions data derived from the raw data, i.e. calibration and alignment information, which have to be available from the beginning of the reconstruction and therefore cannot be included in the raw data. The extraction of the conditions data is steered by a system called Shuttle. It provides the link between data produced by the subdetectors in the online systems and a dedicated procedure per subdetector, called preprocessor, that runs in the Shuttle system. The preprocessor performs merging, consolidation, and reformatting of the data. Finally, it stores the data in the Grid Offline Conditions DataBase (OCDB) so that they are available for the Offline reconstruction. The reconstruction of a given run is initiated automatically once the raw data is successfully exported to the Grid storage and the run has been processed in the Shuttle framework. These proceedings introduce the Shuttle system. The performance of the system during the ALICE cosmics commissioning and LHC startup is described.

The ALICE online-offline framework for the extraction of conditions data

International Nuclear Information System (INIS)

Grosse-Oetringhaus, Jan Fiete; Zampolli, Chiara; Carminati, Federico; Colla, Alberto

2010-01-01

A Large Ion Collider Experiment (ALICE) is the dedicated heavy-ion experiment at the CERN LHC and will take data with a bandwidth of up to 1.25 GB/s. It consists of 18 subdetectors that interact with five online systems (CTP, DAQ, DCS, ECS, and HLT). Data recorded is read out by DAQ in a raw data stream produced by the subdetectors. In addition the subdetectors produce conditions data derived from the raw data, i.e. calibration and alignment information, which have to be available from the beginning of the reconstruction and therefore cannot be included in the raw data. The extraction of the conditions data is steered by a system called Shuttle. It provides the link between data produced by the subdetectors in the online systems and a dedicated procedure per subdetector, called preprocessor, that runs in the Shuttle system. The preprocessor performs merging, consolidation, and reformatting of the data. Finally, it stores the data in the Grid Offline Conditions DataBase (OCDB) so that they are available for the Offline reconstruction. The reconstruction of a given run is initiated automatically once the raw data is successfully exported to the Grid storage and the run has been processed in the Shuttle framework. These proceedings introduce the Shuttle system. The performance of the system during the ALICE cosmics commissioning and LHC startup is described.

The High Momentum Particle IDentification (HMPID) detector PID performance and its contribution to the ALICE physics program

Science.gov (United States)

Volpe, Giacomo; ALICE Collaboration

2017-12-01

The ALICE apparatus is dedicated to study the properties of strongly interacting matter under extremely high temperature and energy density conditions. For this, enhanced particle identification (PID) capabilities are required. Among the PID ALICE detectors, the ALICE-HMPID (High Momentum Particle IDentification) detector is devoted to the identification of charged hadrons, exploiting the Cherenkov effect. It consists of seven identical RICH modules, with liquid C6F14 as Cherenkov radiator (n ≈1.298 at λ=175 nm). Photon and charged particle detection is performed by a MWPC, coupled with a pad segmented CsI coated photo-cathode. The total CsI active area is 10.3 m2. The HMPID provides 3 sigma separation for pions and kaons up to pT = 3 GeV / c and for kaons and (anti-)protons up to pT = 5 GeV / c . A review of the HMPID PID performance, in particular in the challenging central Pb-Pb collisions, and its contribution to the ALICE physics program, using the LHC RUN1 (2010-2013) and RUN2 (2015) data, are presented.

Beam test performance and simulation of prototypes for the ALICE silicon pixel detector

International Nuclear Information System (INIS)

Conrad, J.; Anelli, G.; Antinori, F.

2007-01-01

The silicon pixel detector (SPD) of the ALICE experiment in preparation at the Large Hadron Collider (LHC) at CERN is designed to provide the precise vertex reconstruction needed for measuring heavy flavor production in heavy ion collisions at very high energies and high multiplicity. The SPD forms the innermost part of the Inner Tracking System (ITS) which also includes silicon drift and silicon strip detectors. Single assembly prototypes of the ALICE SPD have been tested at the CERN SPS using high energy proton/pion beams in 2002 and 2003. We report on the experimental determination of the spatial precision. We also report on the first combined beam test with prototypes of the other ITS silicon detector technologies at the CERN SPS in November 2004. The issue of SPD simulation is briefly discussed

Optimisation of the muon spectrometer from the detector ALICE used for the study of the quark and gluon plasma at LHC

International Nuclear Information System (INIS)

Guernane, R.

2001-01-01

The ALICE experiment performed at the LHC will establish and study the phase transition from hadronic matter to a matter to a state of deconfined partons called Quark Gluon Plasma (QGP). The suppression of heavy flavour resonances (Jφ,γ) is the most promising probe for diagnosing the formation and early stages of the QGP in ultrarelativistic heavy ion collisions. The complete spectrum of heavy quarkonia resonances, i.e. J/φ, φ', γ, γ' and φ' will be measured via their muonic decay in a forward spectrometer with a mass resolution sufficient to separate all states. It is composed of five tracking stations, each consisting of two Cathode Pad Chambers (CPC). In this work, we developed a prototype of CPC having the original feature of parallel charge read out from one segmented cathode. The geometry and operating parameters have been optimized for station 3. The expected multi-hit rate and multi-hit deconvolution have been evaluated with a complete detailed simulation and an efficient method to disentangle close hits has been proposed. The magnetic field effect on the intrinsic spatial resolution of the chambers has also been estimated. The simulated performance of the CPC's is confirmed by beam-test results obtained at CERN with prototypes. The measurement of dimuons is expected to be contaminated by beam-related background. The rate of beam-gas interactions is several orders of magnitude larger than the signal rate for p-p collisions which is the reference for further studies of p-A and A-A collisions. The ALICE Collaboration decided to equip the muon spectrometer with a level 0 trigger counter (V0) in order to validate the dimuon trigger signal in p-p mode. The various steps involved in designing the V0 scintillator hodoscope are presented in this thesis. (author)

Study of the neutral mesons in Pb-Pb collisions at $\\sqrt{s_{NN}}$ = 2.76 TeV in the ALICE experiment at LHC

CERN Document Server

Leardini, Lucia

2015-01-01

The $\\pi^{0}$ and $\\eta$ meson production in Pb-Pb collisions at $\\sqrt{s_{NN}}$ = 2.76 TeV is studied with the ALICE experiment at the LHC. The $\\pi^{0}$ invariant yields and nuclear modification factor $R_{\\mbox{AA}}$ are presented here in six centrality classes. The results are a combined measurement using the Photon Conversion Method (PCM) and the PHOS detector, in the transverse momentum range 0.4 $< p_{\\mbox{T}} <$ 12 GeV/$c$. The $\\pi^{0}$ $R_{\\mbox{AA}}$ is studied in different centrality classes and compared with results from experiments at lower energies, both as a function of transverse momentum. The $\\eta$ meson production is studied using the PCM and the EMCal detector. The combination of the individual results will make possible the measurement of the $\\eta$ differential invariant cross section as a function of transverse momentum from 1 to 22 GeV/$c$ in different centrality classes.

High $p_T$ particle correlations in pp collisions at LHC/ALICE

CERN Document Server

Mao, Yaxian

2011-01-01

Two-particle correlation triggered by high-\\pt{} particles allows us to study hard scattering phenomena when full jet reconstruction is challenging. An analysis of the first ALICE pp data where charged and neutral particles isolated or not are used as trigger particles is presented. The two-particle correlation between the trigger ($t$) and the associate ($a$) particles is studied as a function of the imbalance parameter \\xe=-$\\vec{p}_{T_{a}} \\cdot \\vec{p}_{T_{t}}/\\mid \\vec{p}_{T_{t}}\\mid ^{2}$ and interpreted in terms of jet fragmentation function.

10 February 2012 - Permanent Representative of the Republic of India to the Conference on Disarmament, United Nations Office at Geneva Ambassador Mehta signing the guest book with International Relations Adviser R. Voss;in the LHC tunnel at Point 2 and ALICE underground experimental area with Collaboration Deputy Spokesperson Y. Schutz.

CERN Document Server

Maximilien Brice

2012-01-01

10 February 2012 - Permanent Representative of the Republic of India to the Conference on Disarmament, United Nations Office at Geneva Ambassador Mehta signing the guest book with International Relations Adviser R. Voss;in the LHC tunnel at Point 2 and ALICE underground experimental area with Collaboration Deputy Spokesperson Y. Schutz.

LHC Inner Triplet Powering Strategy

CERN Document Server

Bordry, Frederick

2001-01-01

In order to achieve a luminosity in excess of 10**34 cm**-2s**-1 at the Large Hadron Collider (LHC), special high gradient quadrupoles are required for the final focusing triplets. These low-b triplets, located in the four experimental insertions (ATLAS, CMS, ALICE, LHC-B), consist of four wide-aperture superconducting magnets: two outer quadrupoles, Q1 and Q3, with a maximum current of 7 kA and a central one divided into two identical magnets, Q2a and Q2b, with a maximum current of 11.5 kA. To optimise the powering of these mixed quadrupoles, it was decided to use two nested high-current power converters : [8kA, 8V] and [6kA, 8V]. This paper presents the consequence of the interaction between the two galvanically coupled circuits. A control strategy, using two independent, standard, LHC digital controllers, to decouple the two systems is proposed and described. The converter protection during the discharge of the magnet energy due to quenches or interlocks of the magnets are discussed. Simulation and experim...

Studies for the ALICE inner tracking system upgrade

Energy Technology Data Exchange (ETDEWEB)

Reidt, Felix

2016-04-28

The ALICE experiment at the CERN LHC identifies D{sup 0} mesons via secondary-vertex reconstruction and topological cuts to reduce the corresponding combinatorial background in heavy-ion collisions. The D{sup 0} meson is produced promptly in initial, hard scatterings via the strong interaction or as feed-down from weakly decaying B hadrons. Within this thesis, a novel method for the separation of prompt and feed-down D{sup 0} mesons using cut variations was implemented and applied to data from p-Pb collisions at √(s{sub NN})=5.02 TeV. The effectiveness of the secondary-vertex reconstruction strongly depends on the performance and in particular the pointing resolution of the Inner Tracking System. The upgrade of the ALICE Inner Tracking System for the Long Shutdown 2 of the LHC in 2019/2020 will significantly improve its vertex-reconstruction and tracking capabilities. It will be equipped with Monolithic Active Pixel Sensors manufactured using the TowerJazz 180 nm CMOS process on wafers with a high-resistivity epitaxial layer. In another part of this thesis, several pixel-chip prototypes of the ALPIDE architecture with in-pixel amplification and discrimination as well as in-matrix data reduction were characterised. The pALPIDE-2 prototype was measured to fulfil the requirements in terms of detection efficiency, fake-hit rate, position resolution and tolerance to irradiation with non-ionising energy loss. Based on simulations modelling the tracking and vertex-reconstruction performance of the upgraded Inner Tracking System, the perspective of the feed-down separation using cut variations after the upgrade was assessed within this thesis.

Measurement of neutral pions with the ALICE PHOS in pp-collisions at √(s) = 8 TeV

Energy Technology Data Exchange (ETDEWEB)

Pflitsch, Svenja [Institut fuer Kernphysik, Goethe-Universitaet Frankfurt (Germany)

2015-07-01

The ALICE-experiment at the LHC is dedicated to study the properties of the Quark-Gluon-Plasma by means of heavy-ion-collisions. Hadronic spectra in pp-collisions at the same energy establish a vital baseline for the understanding of hadron-production. In this context the measurement of neutral pions via the two-photon decay channel provides a complementary analysis to the measurement of charged pions. The PHOS is one of the two electromagnetic calorimeters of ALICE, consisting of PbWO{sub 4} crystals. The reconstruction method of the decay-photons and the large signal-to-background ratio in pp collisions lead to a high statistics measurement across a large p{sub T} range. We present the status of the analysis of neutral pions based on LHC Run 1 data at √(s)=8 TeV. Details of the analysis such as peak extraction and the resulting spectra are discussed. This includes acceptance and reconstruction efficiencies derived from Monte-Carlo simulations as well as a comparison with an independent parallel analysis.

Application of diamond based beam loss monitors at LHC

International Nuclear Information System (INIS)

Hempel, Maria

2013-04-01

The Large Hadron Collider (LHC) was conceived in the 1980s and started the operation in 2008. It needed more than 20 years to plan and construct this accelerator and its experiments. Four main experiments are located around the ring, Compact Muon Solenoid (CMS), A Toroidal LHC Apparatus(ATLAS), A Large Ion Collider Experiment (ALICE) and LHC beauty (LHCb). Two beams that traveling in opposite direction in the LHC tunnel, collide in each of the experiments to study the questions: ''What is mass?'', ''What is the universe made of?'' and ''Why is there no antimatter?''. The four experiments take data of the collision products and try to answer the fundamental questions of physics. The two larger detectors, CMS and ATLAS, are looking for the Higgs boson to study the electroweak symmetry breaking. Both detectors were built with contrasting concepts to exclude potential error sources and to rea rm the results. The smaller experiment LHCb studies the matter-antimatter asymmetry with a focus of the beauty quark. Another smaller experiment is ALICE that studies the conditions right after the Big Bang by colliding heavy ions. The navigation of the beams is done by over 10000 magnets and each beam has a stored energy of 362MJ which correspond to the kinetic energy of a train like the TGV travelling of 150 km/h. Only a small percentage of that energy can damage the material in the LHC ring or the magnets. This would mean a repair time of months or years, without taking any data. To avoid such a scenario, it is important to monitor the beam condition and measure the amount of losses of the beam. Such losses can for example happen due to dust particles in the vacuum chambers or due to deviations of the beam parameters. Several systems called beam loss monitors (BLMs) can measure beam losses. This thesis concentrates on two of them, ionization chambers and diamond detectors. Over 3600 ionization chambers are installed in the LHC, especially near each quadrupole and next to

Recent ALICE results on hadronic resonance production

CERN Document Server

Badalà, Angela

2015-01-01

Hadronic resonances are a valuable tool to study the properties of the medium formed in heavy-ion collisions. In particular, they can provide information on particle-formation mechanisms and on the properties of the medium at chemical freeze-out. Furthermore they contribute to the systematic study of parton energy loss and quark recombination. Measurements of resonances in pp and in p-Pb collisions provide a necessary baseline for heavy-ion data and help to disentangle initial-state effects from medium-induced effects. In this paper the latest ALICE results on mid-rapidity K*(892)^0 and {\\phi}(1020) production in pp, p-Pb and Pb-Pb collisions at LHC energies are presented

The new Inner Tracking System of the ALICE experiment

Science.gov (United States)

Martinengo, P.; Alice Collaboration

2017-11-01

The ALICE experiment will undergo a major upgrade during the next LHC Long Shutdown scheduled in 2019-20 that will enable a detailed study of the properties of the QGP, exploiting the increased Pb-Pb luminosity expected during Run 3 and Run 4. The replacement of the existing Inner Tracking System with a completely new ultra-light, high-resolution detector is one of the cornerstones within this upgrade program. The main motivation of the ITS upgrade is to provide ALICE with an improved tracking capability and impact parameter resolution at very low transverse momentum, as well as to enable a substantial increase of the readout rate. The new ITS will consist of seven layers of innovative Monolithic Active Pixel Sensors with the innermost layer sitting at only 23 mm from the interaction point. This talk will focus on the design and the physics performance of the new ITS, as well as the technology choices adopted. The status of the project and the results from the prototypes characterization will also be presented.

Studies on the upgrade of the ALICE central tracker

CERN Document Server

Mager, Magnus; Musa, Luciano

2012-11-14

When two high-energy lead ions collide, as they currently do inside the “Large Hadron Collider” (LHC) of the “European Organization for Nuclear Research” (CERN), energy densities similar to those shortly (some 1ps to 10μs) after the Big Bang are created. At these energies quarks are loosing their confinement into hadrons and may move around freely, the “quark-gluon plasma” (QGP) is created. Such a picture deserves of course a thorough check and a precise measurement. There are however intrinsic difficulties to overcome: the macroscopic free energy (about 1 mJ) of these collision allow for an infinite number of processes to happen and finally—-due to mass-energy equivalence--a significant number (order of 10,000) of particles is created. The ALICE experiment was designed to be able to cope with this large number of particles, it can measure the properties (species and momentum) of the big majority. This requires a very fine segmentation of the detector. The central part of ALICE is made of a 90 ...

High level trigger system for the ALICE experiment

International Nuclear Information System (INIS)

Frankenfeld, U.; Roehrich, D.; Ullaland, K.; Vestabo, A.; Helstrup, H.; Lien, J.; Lindenstruth, V.; Schulz, M.; Steinbeck, T.; Wiebalck, A.; Skaali, B.

2001-01-01

The ALICE experiment at the Large Hadron Collider (LHC) at CERN will detect up to 20,000 particles in a single Pb-Pb event resulting in a data rate of ∼75 MByte/event. The event rate is limited by the bandwidth of the data storage system. Higher rates are possible by selecting interesting events and subevents (High Level trigger) or compressing the data efficiently with modeling techniques. Both require a fast parallel pattern recognition. One possible solution to process the detector data at such rates is a farm of clustered SMP nodes, based on off-the-shelf PCs, and connected by a high bandwidth, low latency network

A study of Double Pomeron Exchange in ALICE

CERN Document Server

Kirk, A.

1998-01-01

The non-Abelian nature of QCD suggests that particles that have a gluon constituent, such as glueballs or hybrids, should exist. Experiments WA76, WA91 and WA102 have performed a dedicated search for these states in central production using the CERN Omega Spectrometer. New results from central production show that there is a kinematical filter which can select out glueball candidates from known qqbar states. A further study of this at high energies is essential in order to get information on the M(X0) > 2 GeV region. This paper describes how this could be done using the the ALICE detector at the LHC.

Results on ultra-peripheral interactions in Pb-Pb and p-Pb collisions in ALICE

CERN Document Server

Scapparone, E

2013-01-01

Ultra-relativistic heavy ions generate strong electromagnetic fields which offer the possibility to study $\\gamma$-nucleus and $\\gamma$-proton interactions at the LHC in the so called ultra-peripheral collisions (UPC). Here we report ALICE results on J/psi photoproduction measured in Pb-Pb collisions at $\\sqrt{s_{\\rm NN}}$ = 2.76 TeV and in p-Pb collisions at $\\sqrt{s_{\\rm NN}}$ = 5.02 TeV.

LHC Report: Ticking over

CERN Multimedia

Mike Lamont for the LHC Team

2012-01-01

The past two weeks have seen luminosity production rates vary somewhat but the overall upwards slope has remained steady. Over 17 fb-1 have been delivered to both ATLAS and CMS; LHCb is also doing well, with around 1.6 fb-1 delivered so far in 2012. The proton physics production also slotted in a five-day machine development period (Monday 8 to Saturday 13 October).   When producing the LHC beam in the PS, some parasitic low-intensity satellite bunches are formed 25 ns from the main bunches, which are spaced by 50 ns. ALICE, whose detector is designed to work with relatively low collision rates, has been taking data from satellite-main collisions. The population of these satellites has recently been increased thanks to gentle tweaks by the PS radio frequency experts. This has increased the peak luminosity in ALICE and will help them to reach their proton-proton integrated luminosity goal for the year. The October machine development programme was a mixed bag. While some studies were aimed at sho...

Production des baryons multi-étranges au LHC dans les collisions proton-proton avec l'expérience ALICE

CERN Document Server

Maire, Antonin

     Strange quarks define a valuable probe for the understanding of quantum chromodynamics. The present PhD work falls within this scope; it deals with the study of multi-strange baryons Ξ– (dss) and Ω– (sss) in proton-proton (pp) collisions at the LHC. The analyses make use of the ALICE experiment and are performed at central rapidities (y ≈ 0) and low transverse momentum (pT < 8,5 GeV/c). The production rates per event of these baryons are drawn from the measurement of differential spectra as a function of the hyperon momentum, d²N / dpTdy = f(pT). At √s = 0.9 TeV, the production for ( Ξ– + Ξ+ ) in the inelastic pp interactions is derived from a small statistics of events. At √s = 7 TeV, the large quantity of available data allows the measurement of production rates for each of the four species : Ξ–, Ξ+, Ω– and Ω+. At both energies, experimental data spectra are compared to spectra as produced by different benchmark phenomenological models (Pythia...

ALICE high-level trigger readout and FPGA processing in Run 2

Energy Technology Data Exchange (ETDEWEB)

Engel, Heiko; Kebschull, Udo [IRI, Goethe-Universitaet Frankfurt (Germany); Collaboration: ALICE-Collaboration

2016-07-01

The ALICE experiment uses the optical Detector Data Link (DDL) protocol to connect the detectors to the computing clusters of Data Acquisition (DAQ) and High-Level Trigger (HLT). The interfaces between the clusters and the optical links are realized with FPGA boards. HLT has replaced all of its interface boards with the Common Read-Out Receiver Card (C-RORC) for Run 2. This enables the read-out of detectors at higher link rates and allows to extend the data pre-processing capabilities, like online cluster finding, already in the FPGA. The C-RORC is integrated transparently into the existing HLT data transport framework and the cluster monitoring and management infrastructure. The board is in use since the start of LHC Run 2 and all ALICE data from and to HLT as well as all data from the TPC and the TRD is handled by C-RORCs. This contribution gives an overview on the firmware and software status of the C-RORC in the HLT.

A study of parton fragmentation using photon-hadron correlation with the ALICE experiment at LHC

International Nuclear Information System (INIS)

Arbor, N.

2013-01-01

The strong interaction theory, Quantum Chromodynamic (QCD), predicts a new phase of nuclear matter at very high temperature and/or very high density. This state is composed of deconfined quarks and gluons known as the quark-gluon plasma (QGP). The measurement of its composition and properties is a challenge for the nuclear physics of the 21. century and should lead to a better understanding of the fundamental symmetries and mechanisms related to the quarks confinement inside hadrons and the strong interaction generally.The Large Hadron Collider (LHC) accelerator at CERN (European Organization for Nuclear Research) allows to reach the thermodynamic conditions required to create the quark-gluon plasma using ultra-relativistic heavy ion collisions (Pb). The ALICE experiment (A Large Ion Collider Experiment) allows to access several probes to characterize the QGP through particles reconstruction and. Among these probes, high energy parton energy loss is used to access medium characteristics such as density or temperature. Parton energy loss is estimated from the modification of the energy distribution of hadrons produced by fragmentation.This thesis is dedicated to the photon-hadron correlations analysis in order to study the modification of the parton fragmentation due to the quark-gluon plasma. First part of this thesis is devoted to the characterization of the electromagnetic calorimeter (EMCal), the central detector for energy measurement and photon identification. The second part is dedicated to the photon-hadron correlation measurement, for the 7 TeV proton-proton collisions and 2.76 TeV Lead-Lead collisions. An important work has been done to improve the prompt photon identification, one of the key point of this analysis. (author) [fr

A study of parton fragmentation using photon-hadron correlation with the ALICE experiment at LHC

International Nuclear Information System (INIS)

Arbor, Nicolas

2013-01-01

The strong interaction theory, Quantum Chromodynamic (QCD), predicts a new phase of nuclear matter at very high temperature and/or very high density. This state is composed of deconfined quarks and gluons known as the quark-gluon plasma (QGP). The measurement of its composition and properties is a challenge for the nuclear physics of the 21. century and should lead to a better understanding of the fundamental symmetries and mechanisms related to the quarks confinement inside hadrons and the strong interaction generally. The Large Hadron Collider (LHC) accelerator at CERN (European Organization for Nuclear Research) allows to reach the thermodynamic conditions required to create the quark-gluon plasma using ultra-relativistic heavy ion collisions (Pb). The ALICE experiment (A Large Ion Collider Experiment) allows to access several probes to characterize the QGP through particles reconstruction and. Among these probes, high energy parton energy loss is used to access medium characteristics such as density or temperature. Parton energy loss is estimated from the modification of the energy distribution of hadrons produced by fragmentation. This thesis is dedicated to the photon-hadron correlations analysis in order to study the modification of the parton fragmentation due to the quark-gluon plasma. First part of this thesis is devoted to the characterization of the electromagnetic calorimeter (EMCal), the central detector for energy measurement and photon identification. The second part is dedicated to the photon-hadron correlation measurement, for the 7 TeV proton-proton collisions and 2.76 TeV Lead-Lead collisions. An important work has been done to improve the prompt photon identification, one of the key point of this analysis. (author) [fr

ALICE makes a clean sweep at Point 2

CERN Document Server

2001-01-01

Since the middle of June the ALICE collaboration has taken up residence at Point 2, previously occupied by L3, and is now preparing the cavern for the arrival of its detector. The last muon chambers of the L3 experiment were removed at the beginning of July. Anyone who knew L3 when it was in operation will be in for a shock if they go down to the cavern at Point 2, which looks as if it's been emptied of all its contents. The members of the ALICE collaboration would not quite share that point of view, however, as some components still have to be dismantled before the cavern can receive its new detector. The collaboration, which has inherited L3's huge red magnet, took over at Point 2 in the middle of June and is now getting down to work. This is the first major stage in the installation of the future detector, which has to be ready to observe its first LHC collisions on 1 April 2006. The first difficulty is to remove the support tube running through the magnet. This huge 32-metre long, 4.5-m diameter, 300-t...

LHC preparations change gear

International Nuclear Information System (INIS)

Anon.

1995-01-01

After the formal approval by CERN Council in December (January, page 1) of the LHC protonproton collider for CERN's 27- kilometre LEP tunnel, preparations for the new machine change gear. Lyndon Evans becomes LHC Project Leader, and CERN's internal structure will soon be reorganized to take account of the project becoming a definite commitment. On the experimental side, the full Technical Proposals for the big general purpose ATLAS and CMS detectors were aired at a major meeting of the LHC Committee at CERN in January. These Technical Proposals are impressive documents each of some several hundred pages. (Summaries of the detector designs will appear in forthcoming issues of the CERN Courier.) The ALICE heavy ion experiment is not far behind, and plans for other LHC experiments are being developed. Playing an important role in this groundwork has been the Detector Research and Development Committee (DRDC), founded in 1990 to foster detector development for the LHC experimental programme and structured along the lines of a traditional CERN Experiments Committee. Established under the Director Generalship of Carlo Rubbia and initially steered by Research Director Walter Hoogland, the DRDC has done sterling work in blazing a trail for LHC experiments. Acknowledging that the challenge of LHC experimentation needs technological breakthroughs as well as specific detector subsystems, DRDC proposals have covered a wide front, covering readout electronics and computing as well as detector technology. Its first Chairman was Enzo larocci, succeeded in 1993 by Michal Turala. DRDC's role was to evaluate proposals, and make recommendations to CERN's Research Board for approval and resource allocation, not an easy task when the LHC project itself had yet to be formally approved. Over the years, a comprehensive portfolio of detector development has been built up, much of which has either led to specific LHC detector subsystems for traditional detector tasks

LHC-GCS a model-driven approach for automatic PLC and SCADA code generation

CERN Document Server

Thomas, Geraldine; Barillère, Renaud; Cabaret, Sebastien; Kulman, Nikolay; Pons, Xavier; Rochez, Jacques

2005-01-01

The LHC experiments’ Gas Control System (LHC GCS) project [1] aims to provide the four LHC experiments (ALICE, ATLAS, CMS and LHCb) with control for their 23 gas systems. To ease the production and maintenance of 23 control systems, a model-driven approach has been adopted to generate automatically the code for the Programmable Logic Controllers (PLCs) and for the Supervision Control And Data Acquisition (SCADA) systems. The first milestones of the project have been achieved. The LHC GCS framework [4] and the generation tools have been produced. A first control application has actually been generated and is in production, and a second is in preparation. This paper describes the principle and the architecture of the model-driven solution. It will in particular detail how the model-driven solution fits with the LHC GCS framework and with the UNICOS [5] data-driven tools.

Study and Development of a novel Silicon Pixel Detector for the Upgrade of the ALICE Inner Tracking System

CERN Document Server

van Hoorn, Jacobus Willem; Riedler, Petra

ALICE (A Large Ion Collider Experiment) is the heavy-ion experiment at the CERN Large Hadron Collider (LHC). As an important part of its upgrade plans, the ALICE experiment schedules the installation of a new Inner Tracking System (ITS) during the Long Shutdown 2 (LS2) of the LHC in 2019/20. The new ITS will consist of seven concentric layers, covering about 10m2 with Monolithic Active Pixel Sensors (MAPS). This choice of technology has been guided by the tight requirements on the material budget of 0.3 % x/X0 per layer for the three innermost layers and backed by the significant progress in the field of MAPS in recent years. The pixel chips are manufactured in the TowerJazz 180 nm CMOS process on wafers with a high-resistivity epitaxial layer on top of the substrate. During the R&D phase several chip architectures have been investigated, which take full advantage of a particular process feature, the deep p-well, that allows for full CMOS circuitry within the pixel matrix while retaining full charge colle...

Physics Goals and Experimental Challenges of the Proton-Proton High-Luminosity Operation of the LHC

CERN Document Server

Campana, Pierluigi; Wells, Pippa

2016-01-01

The completion of Run 1 of the CERN Large Hadron Collider has seen the discovery of the Higgs boson and an unprecedented number of precise measurements of the Standard Model, while Run 2 operation has just started to provide first data at higher energy. Upgrades of the LHC to high luminosity (HL-LHC) and the experiments (ATLAS, CMS, ALICE and LHCb) will exploit the full potential of the collider to discover and explore new physics beyond the Standard Model. In this article, the experimental challenges and the physics opportunities in proton-proton collisions at the HL-LHC are reviewed.

Design of the interfaces for monitoring the Cooling Systems of Point 8 in the LHC

OpenAIRE

Caldés Llull, Maria Antonia

2009-01-01

El Cern es el Centro Europeo para la Investigación Nuclear donde se ha llevado a cabo la construcción y puesta en funcionamiento, en Septiembre de 2008, del LHC el mayor acelerador de partículas en el mundo. El LHC es un acelerador con forma anular de 27 km de perímetro situado a 100 metros bajo tierra en la frontera Franco-Suiza. A lo largo de él se localizan 4 grandes detectores de partículas: ATLAS, CMS, LHC-b y ALICE. Teóricamente se espera que, una vez en pleno funciona...

Cryogénie hélium et efficacité énergétique: L'expérience du LHC au CERN

CERN Document Server

Claudet, S; Tavian, L

2012-01-01

Résumé La supraconductivité et la cryogénie hélium associée sont devenues des technologies clés des grands équipements de recherche en physique, et en particulier des accélérateurs de particules. Le coût thermodynamique du fonctionnement à basse température impose à leurs systèmes cryogéniques une haute efficacité énergétique dans la gestion des charges thermiques, la distribution des fluides et la production de froid, obtenue par une approche intégrée couvrant toutes les phases du projet, de la conception préliminaire jusqu'à l'exploitation. L'expérience du LHC au CERN vient illustrer le propos, tandis que quelques pistes de développements futurs sont évoquées. Abstract Superconductivity and associated helium cryogenics have become key technologies for large research infrastructures in physics, and particularly particle accelerators. The thermodynamic penalty for operating at low temperature requires their cryogenic systems to be highly energy efficient in managing heat loads, dis...

Multiplicity dependence of 2-particle correlations in proton-proton collisions measured with ALICE at the LHC

International Nuclear Information System (INIS)

Sicking, E.

2014-01-01

We investigate properties of jets in proton-proton collisions using 2-particle angular correlations. By choosing an analysis approach based on 2-particle angular correlations, also the properties of low-energetic jets can be accessed. Observing the strength of the correlation as a function of the charged particle multiplicity reveals jet fragmentation properties as well as the contribution of jets to the overall charged particle multiplicity. Furthermore, the analysis discloses information on the underlying multiple parton interactions. We present results from proton-proton collisions at the center-of-mass energies √(s) = 0.9, 2.76 and 7 TeV recorded by the ALICE experiment. The ALICE data are compared to Pythia6, Pythia8 and Phojet simulations. (author)

Multiplicity Dependence of Two-Particle Correlations in Proton-Proton Collisions Measured with ALICE at the LHC

CERN Document Server

Sicking, Eva

2012-01-01

We investigate properties of jets in proton-proton collisions using two-particle angular correlations. By choosing an analysis approach based on two-particle angular correlations, also the properties of low-energetic jets can be accessed. Observing the strength of the correlation as a function of the charged particle multiplicity reveals jet fragmentation properties as well as the contribution of jets to the overall charged particle multiplicity. Furthermore, the analysis discloses information on the underlying multiple parton interactions. We present results from proton-proton collisions at the center-of-mass energies $\\sqrt{s}$ = 0.9, 2.76, and 7.0 TeV recorded by the ALICE experiment. The ALICE data are compared to Pythia6, Pythia8, and Phojet simulations.

The ALICE time machine

Directory of Open Access Journals (Sweden)

Ferretti Alessandro

2013-09-01

Full Text Available According to the Big Bang theory, the Universe was once in an extremely hot and dense state which expanded rapidly. In such a state the normal nuclear matter could not exist: it is believed that a few microsecond after big-bang the matter underwent a phase transition, from a state called Quark-Gluon Plasma (QGP to a hadron gas. Some of the unexplained features of the Universe could be explained by the QGP properties. One of the aims of the CERN LHC is to recreate (on a smaller scale a QGP state, compressing and heating ordinary nuclear matter by means of ultrarelativistic heavy-ion collisions. The ALICE experiment at CERN is dedicated to the study of the medium produced in these collisions : in particular, the study of the heavy quarkonia suppression pattern can give a measure of the temperature reached in these collisions, helping us to understand how close we are getting to the conditions of the starting point of the Universe.

Innovative low-mass cooling systems for the ALICE ITS Upgrade detector at CERN

OpenAIRE

Gomez Marzoa, Manuel; Thome, John

2016-01-01

The Phase-1 upgrade of the LHC to full design luminosity, planned for 2019 at CERN, requires the modernisation of the experiments around the accelerator. The Inner Tracking System (ITS), the innermost detector at the ALICE experiment, will be upgraded by replacing the current apparatus by new silicon pixels arranged in 7 cylindrical layers. Each layer is composed by multiple independent modules, named staves, which provide mechanical support and cooling to the chips. This thesis aims to devel...

Open-charm production as a function of charged particle multiplicity in pp collisions at $\\sqrt{s}$=7 TeV with ALICE

CERN Document Server

Bala, Renu

2014-01-01

Heavy quarks (charm and beauty) are an effective tool to investigate the properties of the Quark-Gluon Plasma created in heavy-ion collisions as they are produced in initial hard scattering processes and as they experience all the stages of the medium evolution. The measurement of heavy-flavour production cross sections in pp collisions at the LHC, besides providing a reference for heavy-ion studies, allows one to test perturbative QCD calculations. A brief review of ALICE results on the production of heavy-flavoured hadrons measured from fully reconstructed hadronic decay topologies in pp collisions at \\sqrt{s} = 7 TeV is presented. Furthermore, heavy-flavour production was also studied as a function of the particle multiplicity in pp collisions. This could provide insight into multi-parton scatterings. A measurement of the inclusive J/{\\psi} yield as a function of the charged-particle pseudorapidity density was performed by the ALICE Collaboration at the LHC in pp collisions at \\sqrt{s} = 7 TeV. An increase...

Readout of the upgraded ALICE-ITS

Science.gov (United States)

Szczepankiewicz, A.; ALICE Collaboration

2016-07-01

The ALICE experiment will undergo a major upgrade during the second long shutdown of the CERN LHC. As part of this program, the present Inner Tracking System (ITS), which employs different layers of hybrid pixels, silicon drift and strip detectors, will be replaced by a completely new tracker composed of seven layers of monolithic active pixel sensors. The upgraded ITS will have more than twelve billion pixels in total, producing 300 Gbit/s of data when tracking 50 kHz Pb-Pb events. Two families of pixel chips realized with the TowerJazz CMOS imaging process have been developed as candidate sensors: the ALPIDE, which uses a proprietary readout and sparsification mechanism and the MISTRAL-O, based on a proven rolling shutter architecture. Both chips can operate in continuous mode, with the ALPIDE also supporting triggered operations. As the communication IP blocks are shared among the two chip families, it has been possible to develop a common Readout Electronics. All the sensor components (analog stages, state machines, buffers, FIFOs, etc.) have been modelled in a system level simulation, which has been extensively used to optimize both the sensor and the whole readout chain design in an iterative process. This contribution covers the progress of the R&D efforts and the overall expected performance of the ALICE-ITS readout system.

Readout of the upgraded ALICE-ITS

International Nuclear Information System (INIS)

Szczepankiewicz, A.

2016-01-01

The ALICE experiment will undergo a major upgrade during the second long shutdown of the CERN LHC. As part of this program, the present Inner Tracking System (ITS), which employs different layers of hybrid pixels, silicon drift and strip detectors, will be replaced by a completely new tracker composed of seven layers of monolithic active pixel sensors. The upgraded ITS will have more than twelve billion pixels in total, producing 300 Gbit/s of data when tracking 50 kHz Pb–Pb events. Two families of pixel chips realized with the TowerJazz CMOS imaging process have been developed as candidate sensors: the ALPIDE, which uses a proprietary readout and sparsification mechanism and the MISTRAL-O, based on a proven rolling shutter architecture. Both chips can operate in continuous mode, with the ALPIDE also supporting triggered operations. As the communication IP blocks are shared among the two chip families, it has been possible to develop a common Readout Electronics. All the sensor components (analog stages, state machines, buffers, FIFOs, etc.) have been modelled in a system level simulation, which has been extensively used to optimize both the sensor and the whole readout chain design in an iterative process. This contribution covers the progress of the R&D efforts and the overall expected performance of the ALICE-ITS readout system.

Readout of the upgraded ALICE-ITS

Energy Technology Data Exchange (ETDEWEB)

Szczepankiewicz, A., E-mail: Adam.Szczepankiewicz@cern.ch [CERN, Geneva (Switzerland); Institute of Computer Science, Warsaw University of Technology, Warsaw (Poland)

2016-07-11

The ALICE experiment will undergo a major upgrade during the second long shutdown of the CERN LHC. As part of this program, the present Inner Tracking System (ITS), which employs different layers of hybrid pixels, silicon drift and strip detectors, will be replaced by a completely new tracker composed of seven layers of monolithic active pixel sensors. The upgraded ITS will have more than twelve billion pixels in total, producing 300 Gbit/s of data when tracking 50 kHz Pb–Pb events. Two families of pixel chips realized with the TowerJazz CMOS imaging process have been developed as candidate sensors: the ALPIDE, which uses a proprietary readout and sparsification mechanism and the MISTRAL-O, based on a proven rolling shutter architecture. Both chips can operate in continuous mode, with the ALPIDE also supporting triggered operations. As the communication IP blocks are shared among the two chip families, it has been possible to develop a common Readout Electronics. All the sensor components (analog stages, state machines, buffers, FIFOs, etc.) have been modelled in a system level simulation, which has been extensively used to optimize both the sensor and the whole readout chain design in an iterative process. This contribution covers the progress of the R&D efforts and the overall expected performance of the ALICE-ITS readout system.

21 May 2013 - Slovakian State Secretary, Ministry of Health V. Čislák signing the Guest Book with CERN Director-General R. Heuer; in the LHC tunnel at Point 2 with V. Senaj (Technology Department); in the ALICE experimental cavern with P. Chochula (Physics Department). M. Cirilli (Knowledge Transfer Group) present.

CERN Multimedia

Jean-Claude Gadmer

2013-01-01

21 May 2013 - Slovakian State Secretary, Ministry of Health V. Čislák signing the Guest Book with CERN Director-General R. Heuer; in the LHC tunnel at Point 2 with V. Senaj (Technology Department); in the ALICE experimental cavern with P. Chochula (Physics Department). M. Cirilli (Knowledge Transfer Group) present.

Simulation of the job processing performance at an ALICE Tier-2 site with MONARC

International Nuclear Information System (INIS)

Zach, C; Adamová, D; Betev, L

2011-01-01

The MONARC (MOdels of Networked Analysis at Regional Centers) framework has been developed and designed with the aim to provide a tool for realistic simulations of large scale distributed computing systems, with a special focus on the Grid systems of the experiments at the CERN LHC. In this paper, we describe a usage of the MONARC framework and tools for a simulation of the job processing performance at an ALICE Tier-2 site.

The ALICE data challenges

International Nuclear Information System (INIS)

Baud, J.P.; Collignon, M.; Collin, F.; Durand, J.; Jarp, S.; Jouanigot, J.M.; Panzer, B.; Carena, W.; Carminati, F.; Divia, R.; Rademakers, F.; Saiz, P.; Schossmaier, K.; Vande Vyvre, P.; Vascotto, A.

2001-01-01

Since 1998, the ALICE experiment and the CERN/IT division have jointly executed several large-scale high throughput distributed computing exercises: the ALICE data challenges. The goals of these regular exercises are to test hardware and software components of the data acquisition and computing systems in realistic conditions and to execute an early integration of the overall ALICE computing infrastructure. The authors report on the third ALICE Data Challenge (ADC III) that has been performed at CERN from January to March 2001. The data used during the ADC III are simulated physics raw data of the ALICE TPC, produced with the ALICE simulation program AliRoot. The data acquisition was based on the ALICE online framework called the ALICE Data Acquisition Test Environment (DATE) system. The data, after event building, were then formatted with the ROOT I/O package and a data catalogue based on MySQL was established. The Mass Storage System used during ADC III is CASTOR. Different software tools have been used to monitor the performances. DATE has demonstrated performances of more than 500 MByte/s. An aggregate data throughput of 85 MByte/s was sustained in CASTOR over several days. The total collected data amounts to 100 TBytes in 100.000 files

Inclusive lepton production from heavy-hadron decay in pp collisions at the LHC

Energy Technology Data Exchange (ETDEWEB)

Bolzoni, Paolo; Kramer, Gustav [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

2012-12-15

We present predictions for the inclusive production of leptons (e{sup {+-}}, {mu}{sup {+-}}) originating from charm and bottom-hadrons at the CERN LHC in the general-mass variable-flavor-number scheme at next-to-leading order. Detailed numerical results are compared to data of the CMS, ATLAS and ALICE collaborations.

Radiography of the connection between a LHC magnet and its diode in sector 3-4

CERN Multimedia

Brice, Maximilien

2015-01-01

Fin mars 2015, les équipes du LHC ont réalisé différents tests pour identifier la cause d'un court-circuit vers la terre entre un aimant et sa diode de protection qui retardait le redémarrage du LHC. Le 25 mars, ils ont effectué des radiographies de la connexion. End of March 2015, LHC teams have performed different tests to identify the cause of a short-circuit to ground between a magnet and its protection diode. On 25 March they took an X-ray of the affected diode.

ALICE doffs hat to two companies

CERN Multimedia

2007-01-01

During the fifth annual ALICE Industrial Awards ceremony, the ALICE Collaboration honoured two companies for their outstanding contributions to the construction of the experiment.For the past five years, the ALICE collaboration has been presenting its industrial partners with awards for meeting demanding or unusual requirements, for excellence in design or execution, for delivery on-time and on-budget and for outstanding cooperation. This year, on 9 March, ALICE presented awards to two companies for their exceptional performance. From left to right: Kees Oskamp (ALICE SSD), Arie de Haas (ALICE SSD), Gert-Jan Nooren (ALICE SSD), Shon Shmuel (FIBERNET), Yehuda Mor-Yosef (FIBERNET), Hans Boggild (ALICE), Jurgen Schukraft (ALICE Spokesperson), Catherine Decosse (ALICE) and Jean-Robert Lutz (ALICE SSD). FIBERNET Ltd., based in Yokneam, Israel, was rewarded for the excellent and timely assembly of the Silicon Strip Detector boards (SSD) of the Inner Tracking System with cable connections. Special low-mass cables, ...

Prompt D*+ production in proton-proton and lead-lead collisions, measured with the ALICE experiment at the CERN Large Hadron Collider

NARCIS (Netherlands)

de Rooij, R. S.

2013-01-01

In this thesis the results are presented of the first measurements of the D*+ meson nuclear modification factor RAA in heavy ion collisions at the Large Hadron Collider (LHC) using the ALICE (A Large Ion Collider Experiment) detector at CERN. These open charmed mesons are a useful tool to

Intrusion Prevention and Detection in Grid Computing - The ALICE Case

Science.gov (United States)

Gomez, Andres; Lara, Camilo; Kebschull, Udo

2015-12-01

Grids allow users flexible on-demand usage of computing resources through remote communication networks. A remarkable example of a Grid in High Energy Physics (HEP) research is used in the ALICE experiment at European Organization for Nuclear Research CERN. Physicists can submit jobs used to process the huge amount of particle collision data produced by the Large Hadron Collider (LHC). Grids face complex security challenges. They are interesting targets for attackers seeking for huge computational resources. Since users can execute arbitrary code in the worker nodes on the Grid sites, special care should be put in this environment. Automatic tools to harden and monitor this scenario are required. Currently, there is no integrated solution for such requirement. This paper describes a new security framework to allow execution of job payloads in a sandboxed context. It also allows process behavior monitoring to detect intrusions, even when new attack methods or zero day vulnerabilities are exploited, by a Machine Learning approach. We plan to implement the proposed framework as a software prototype that will be tested as a component of the ALICE Grid middleware.

TAB Bonded SSD Module for the STAR and ALICE Trackers

CERN Document Server

Lutz, Jean Robert; Baudot, J; Bonnet, D; Coffin, J P; Germain, M; Gojak, C; Jundt, F; Kühn, C E; Suire, C; Tarchini, A; Berst, D; Clauss, G; Colledani, C; Dulinski, W; Boucham, A; Bouvier, S; Castillo, J; Drancourt, C; Erazmus, B; Guilloux, G; Martin, L; Roy, C

1999-01-01

Presentation made at LEB99, 20-24 September 1999A novel compact detector module has been produced by the "IReS"-"Subatech"-"Thomson-CSF-Detexis" collaboration. It includes a Double-Sided (DS) Silicon Strip Detector (SSD) and the related Front End Electronics (FEE) located on two hybrids, one for the N side and one for the P side. Bumpless Tape Automated Bonding (TAB) is used to connect the detector to the hybrids by means of microcables with neither wirebonding nor pitch adapter. Each of the six dedicated ALICE128C FE chip [1], located on the hybrid, is TABed on identical single layer microcables, which connect its inputs to the DS SSD and its outputs to the hybrid [2]. These microcables are bent in order to fold over the two hybrids on the DS SSD. This module meets the specifications of two experiments, ALICE (A Large Ion Collider Experiment) on the LHC accelerator at CERN [3] and STAR (Solenoid Tracker At Rhic) on the RHIC accelerator at BNL (Brookhaven National Laboratory)[4]. It can be used with air cooli...

Intrusion Prevention and Detection in Grid Computing - The ALICE Case

International Nuclear Information System (INIS)

Gomez, Andres; Lara, Camilo; Kebschull, Udo

2015-01-01

Grids allow users flexible on-demand usage of computing resources through remote communication networks. A remarkable example of a Grid in High Energy Physics (HEP) research is used in the ALICE experiment at European Organization for Nuclear Research CERN. Physicists can submit jobs used to process the huge amount of particle collision data produced by the Large Hadron Collider (LHC). Grids face complex security challenges. They are interesting targets for attackers seeking for huge computational resources. Since users can execute arbitrary code in the worker nodes on the Grid sites, special care should be put in this environment. Automatic tools to harden and monitor this scenario are required. Currently, there is no integrated solution for such requirement. This paper describes a new security framework to allow execution of job payloads in a sandboxed context. It also allows process behavior monitoring to detect intrusions, even when new attack methods or zero day vulnerabilities are exploited, by a Machine Learning approach. We plan to implement the proposed framework as a software prototype that will be tested as a component of the ALICE Grid middleware. (paper)

Application of diamond based beam loss monitors at LHC

Energy Technology Data Exchange (ETDEWEB)

Hempel, Maria

2013-04-15

The Large Hadron Collider (LHC) was conceived in the 1980s and started the operation in 2008. It needed more than 20 years to plan and construct this accelerator and its experiments. Four main experiments are located around the ring, Compact Muon Solenoid (CMS), A Toroidal LHC Apparatus(ATLAS), A Large Ion Collider Experiment (ALICE) and LHC beauty (LHCb). Two beams that traveling in opposite direction in the LHC tunnel, collide in each of the experiments to study the questions: ''What is mass?'', ''What is the universe made of?'' and ''Why is there no antimatter?''. The four experiments take data of the collision products and try to answer the fundamental questions of physics. The two larger detectors, CMS and ATLAS, are looking for the Higgs boson to study the electroweak symmetry breaking. Both detectors were built with contrasting concepts to exclude potential error sources and to rea rm the results. The smaller experiment LHCb studies the matter-antimatter asymmetry with a focus of the beauty quark. Another smaller experiment is ALICE that studies the conditions right after the Big Bang by colliding heavy ions. The navigation of the beams is done by over 10000 magnets and each beam has a stored energy of 362MJ which correspond to the kinetic energy of a train like the TGV travelling of 150 km/h. Only a small percentage of that energy can damage the material in the LHC ring or the magnets. This would mean a repair time of months or years, without taking any data. To avoid such a scenario, it is important to monitor the beam condition and measure the amount of losses of the beam. Such losses can for example happen due to dust particles in the vacuum chambers or due to deviations of the beam parameters. Several systems called beam loss monitors (BLMs) can measure beam losses. This thesis concentrates on two of them, ionization chambers and diamond detectors. Over 3600 ionization chambers are installed in

Results from the first heavy ion run at the LHC

CERN Document Server

Schukraft, J

2012-01-01

Early November 2010, the LHC collided for the first time heavy ions, Pb on Pb, at a centre-of-mass energy of 2.76 TeV/nucleon. This date marked both the end of almost 20 years of preparing for nuclear collisions at the LHC, as well as the start of a new era in ultra-relativistic heavy ion physics at energies exceeding previous machines by more than an order of magnitude. This contribution summarizes some of the early results from all three experiments participating in the LHC heavy ion program (ALICE, ATLAS, and CMS), which show that the high density matter created at the LHC, while much hotter and larger, still behaves like the very strongly interacting, almost perfect liquid discovered at RHIC. Some surprising and even puzzling results are seen in particle ratios, jet-quenching, and Quarkonia suppression observables. The overall experimental conditions at the LHC, together with its set of powerful and state-of-the-art detectors, should allow for precision measurements of quark-gluon-plasma parameters like v...

LHC experiments present new results at Quark Matter 2011 Conference

CERN Multimedia

CERN Press Office

2011-01-01

The three LHC experiments that study lead ion collisions all presented their latest results today at the annual Quark Matter conference, held this year in Annecy, France. The results are based on analysis of data collected during the last two weeks of the 2010 LHC run, when the LHC switched from protons to lead-ions. All experiments report highly subtle measurements, bringing heavy-ion physics into a new era of high precision studies.   Events recorded by the ALICE experiment from the first lead ion collisions (Nov-Dec 2010). “These results from the LHC lead ion programme are already starting bring new understanding of the primordial universe,” said CERN Director General Rolf Heuer. “The subtleties they are already seeing are very impressive.” In its infancy, just microseconds after the Big Bang, the universe consisted of a plasma of quarks and gluons (QGP), the fundamental building blocks of matter. By colliding heavy ions, physicists can turn back time an...

Important step towards the LHC

CERN Document Server

2001-01-01

The TI2 tunnel, one of the two tunnels that will transfer protons from the SPS to the LHC, broke through into the LEP/LHC ring on 15 May. TI2 will carry clockwise-moving protons from under the Laboratory's West Area to Point 2, future home of the ALICE experiment. It is coming up to 16:00 on 15 May and a group of some 50 people, fully kitted out in boots, helmets, and masks is intently watching a point on the wall in front of them. They are down in the LEP/LHC tunnel waiting for civil engineers to excavate the last few centimetres separating them from the TI2 transfer tunnel. The noise of machines begins, and just five minutes later the wall comes tumbling down. The excavator breaks through right on target, bringing a two-year project to a happy conclusion. Later, the survey team published the outstanding result that the tunnel junction was made within 6 millimetres of target. TI2 measures 2648 metres in length and three metres in diameter. Around 32,000 cubic metres of rock have been excavated to make it, so...

The Strongly Interacting Quark Gluon Plasma at RHIC and LHC

Directory of Open Access Journals (Sweden)

Tserruya Itzhak

2014-04-01

Full Text Available The study of heavy-ion collisions has currently unprecedented opportunities with two first class facilities, the Relativistic Heavy Ion Collider (RHIC at BNL and the Large Hadron Collider (LHC at CERN, and five large experiments ALICE, ATLAS, CMS, PHENIX and STAR producing a wealth of high quality data. Selected results recently obtained are presented on the study of flow, energy loss and direct photons.

Summary of Session 8 'LHC-related Projects and Studies (I)'

Energy Technology Data Exchange (ETDEWEB)

Garoby, R; Ponce, Laurette [European Organization for Nuclear Research, Geneva (Switzerland)

2012-07-01

This session was the first of the two sessions dealing with future projects and the associated studies. Starting with descriptions of the plans and needs of the LHCb and ALICE experiments which are less extensively documented than those of ATLAS and CMS, it addressed the plans for the High Luminosity LHC and for the upgrade of the injectors, both for protons and other ions. (author)

Physics at 13 TeV: ALICE - scratching under the surface

CERN Multimedia

Antonella Del Rosso

2014-01-01

ALICE’s wonderland materialises where the lead-lead ultrarelativistic collisions happen in the LHC. With a jump of over one order of magnitude in collision energy from the Relativistic Heavy Ion Collider (RHIC) and using state-of-the-art detectors, the experiment studies the quark-gluon plasma, a state of matter that existed during the Universe’s infancy.   The hugely hot medium was observed to behave almost like an ideal fluid, which, although absorbing their energy, leaves single propagating quarks and gluons almost undeflected, enhances the production of strange quarks, suppresses the production of particles made of quarks and antiquarks, and seems to be emitting light in the early stages of its expansion. “The data from the first LHC run have already challenged some of the notions that had emerged from the previous RHIC programme,” says Federico Antinori, ALICE Physics Coordinator. “The abundance of hard probes, that is, high-energy partic...

DYNAMIC CONFIGURATION OF THE COMPUTING NODES OF THE ALICE O2 SYSTEM

CERN Document Server

Pugdeethosapol, Krittaphat

2015-01-01

The ALICE (A Large Ion Collider Experiment) Collaboration is preparing major upgrades for the detectors in 2020 in order to take advantage of the increase of collision rate at up to 50 KHz in the LHC for Pb-Pb beams. Together with these upgrades, the ALICE Online and Offline computing systems are being redesigned and upgraded to a new common system called O2. The O2 system is made of a software framework and a computing facility. The concept of the framework consists of implementing an online reconstruction and archiving of the data of all reconstructed collisions to permanent data storage. The main objective is to achieve a high-throughput system on heterogeneous computing platforms. Our KMUTT team has taken the responsibility of designing of accomplishing the design of the Control, Configuration, and Monitoring (CCM) of the computing infrastructure. This thesis is focusing on Configuration. The configuration module should allow dynamic configuration of processes and environment parameters during runtime. ...

Isolated photon production measurement in p-p collisions at √s = 7 TeV with the ALICE detector

International Nuclear Information System (INIS)

Mas, A.

2013-01-01

The high transverse momentum photon production in proton-proton collisions (p-p) is described by perturbative quantum chromodynamics (pQCD). Among these photons, those produced directly by an energetic partonic interaction (called direct photons) are of great interest since their measurement allows to test pQCD predictions and it allows also the constraint of proton structure functions. The work of this thesis aims at studying and measuring direct photons produced in p-p collisions at 7 TeV with the ALICE detector. The ALICE electromagnetic calorimeter (EMCal) is used to achieve this measurement which is based on an isolation procedure that allows to reduce background coming from other photon production modes (fragmentation, decay). Multiple aspects like EMCal data quality, photon identification as well as spectrum correction and its normalization are highlighted. Finally, the first isolated prompt photon cross-section measured with ALICE detector is presented, compared to theoretical predictions and to the last results from other LHC experiments. (author)

Intriguing results from p-Pb collisions at the LHC

CERN Multimedia

CERN. Geneva

2013-01-01

Analysis of data of the short p-Pb pilot run in fall 2012, led to some intriguing observations by ALICE, ATLAS and CMS of ridge structures in two-particle correlations. In particular, the observed patterns are reminiscent of collective effects measured in Pb-Pb collisions. This triggered a lively discussion in the theoretical and experimental community. Various mechanisms ranging from saturation effects to hydrodynamical modeling have been confronted with the data. At the same time, the experimental collaborations at the LHC have continued the data analysis with the 2013 p-Pb run with interesting results. The talk will give an overview of the findings in p-Pb collisions and their theoretical implications. Further, recent results of the ALICE collaboration exploiting particle identification will be presented which further assess the question: does it flow or not?

Muon production from heavy-flavour hadron decays in p-Pb and pp collisions with ALICE at the CERN-LHC

International Nuclear Information System (INIS)

Shuang, Li

2015-01-01

The LHC heavy-ion physics program aims at investigating the properties of strongly-interacting matter in extreme conditions of temperature and energy density where the Quark-Gluon Plasma (QGP) is formed. In high-energy heavy-ion collisions, heavy quarks (charm and beauty) are regarded as efficient probes of the properties of the QGP. The heavy-ion physics program requires also the study of proton-proton (pp) and proton-nucleus (p-Pb) collisions. The study of p-Pb collisions is used to investigate cold nuclear matter effects and to validate and quantify hot nuclear matter effects which are observed in nucleus-nucleus (Pb-Pb) collisions. This thesis work is devoted to the study of open heavy-flavour production at forward and backward rapidity via single muons in p-Pb collisions at √(s_N_N) = 5.02 TeV with the ALICE experiment at the LHC. The pp reference using available measurements at 2.76 and 7 TeV and a pQCD-driven method for the scaling to 5.02 TeV is estimated. The measurements of the nuclear modification factor (R_p_P_b) at forward and backward rapidity and forward-to-backward ratio in p-Pb collisions, indicate that cold nuclear matter effects are small over the whole transverse momentum (p_T) region at forward rapidity (R_p_P_b compatible with unity within uncertainties). In the backward rapidity, the nuclear modification factor deviates from unity in the intermediate p_T region (2 < pT < 4 GeV/c). These results confirm that the strong suppression measured at high p_T in central Pb-Pb collisions is due to final-state effects induced by the hot and dense nuclear medium. The results of the nuclear modification factor and forward-to-backward ratio as a function of centrality in p-Pb collisions are discussed. Even in central collisions, the nuclear modification factor is compatible with unity at high p_T. (author)

LHC 2008 lectures
The LHC: an accelerator of science

CERN Multimedia

2008-01-01

In 2008, CERN will be switching on the greatest physics experiment ever undertaken. The Large Hadron Collider, or LHC, is a particle accelerator that will provide many answers to our questions about the Universe - What is the reason for mass? Where is the invisible matter in the Universe hiding? What is the relationship between matter and antimatter? Will we have to use a theory claiming more than four dimensions? … and what about "time" ? To understand better the raison d’être of the LHC, this gigantic, peerless scientific instrument and all the knowledge it can bring to us, members of the general public are invited to a series of lectures at the Globe of Science and Innovation. Thursday 8 May 2008 at 8.00 p.m. « Comment fonctionne l’Univers ? Ce que le LHC peut nous apprendre » Alvaro de Rujula, CERN physicist Thursday 15 May 2008 at 8.00 p.m. – « Une nouvelle vision du monde » Jean-Pierre Luminet, Director of...

Exploring virtualisation tools with a new virtualisation provisioning method to test dynamic grid environments for ALICE grid jobs over ARC grid middleware

International Nuclear Information System (INIS)

Wagner, B; Kileng, B

2014-01-01

The Nordic Tier-1 centre for LHC is distributed over several computing centres. It uses ARC as the internal computing grid middleware. ALICE uses its own grid middleware AliEn to distribute jobs and the necessary software application stack. To make use of most of the AliEn infrastructure and software deployment methods for running ALICE grid jobs on ARC, we are investigating different possible virtualisation technologies. For this a testbed and possible framework for bridging different middleware systems is under development. It allows us to test a variety of virtualisation methods and software deployment technologies in the form of different virtual machines.

Measurement of the production cross-section of heavy hadrons with the muon spectrometer of the ALICE detector at LHC

International Nuclear Information System (INIS)

Manceau, L.

2010-10-01

Lattice quantum chromodynamics calculations predict a transition from the phase of hadronic matter to quark and gluon plasma for a temperature T ∼ 173 MeV and a vanishing baryonic potential. Ultra-relativistic heavy ion collisions allow to highlight this phase transition. Heavy flavours can be used to probe the first instants of the collisions where the temperature is the highest. The LHC will provide proton-proton and lead-lead collisions at unprecedented large energy (√(s) = 14 TeV and √(s NN ) 5.5 TeV respectively). The ALICE detector is dedicated to heavy ion collisions but it can also measure proton-proton collisions. The detector includes a muon spectrometer. The spectrometer has been designed to measure heavy flavours. This work presents the performance of the spectrometer to measure beauty hadrons (B) and charmed hadrons (D) inclusive production cross-section in proton-proton collisions. The first step of the measurement consists in extracting heavy hadron decayed muon distributions. The next step consists in extrapolating these distributions to heavy hadrons inclusive production cross-section. This work also presents a preliminary study of the performance of the spectrometer for the measurement of the nuclear modification factor and the associated observable named R B/D in 0-10% central heavy ions collisions. Uncertainties and transverse impulsion range of extraction of the observables have been investigated. (author)

Proceedings of the second workshop of LHC Computing Grid, LCG-France; ACTES, 2e colloque LCG-France

Energy Technology Data Exchange (ETDEWEB)

Chollet, Frederique; Hernandez, Fabio; Malek, Fairouz; Gaelle, Shifrin (eds.) [Laboratoire de Physique Corpusculaire Clermont-Ferrand, Campus des Cezeaux, 24, avenue des Landais, Clermont-Ferrand (France)

2007-03-15

The second LCG-France Workshop was held in Clermont-Ferrand on 14-15 March 2007. These sessions organized by IN2P3 and DAPNIA were attended by around 70 participants working with the Computing Grid of LHC in France. The workshop was a opportunity of exchanges of information between the French and foreign site representatives on one side and delegates of experiments on the other side. The event allowed enlightening the place of LHC Computing Task within the frame of W-LCG world project, the undergoing actions and the prospects in 2007 and beyond. The following communications were presented: 1. The current status of the LHC computation in France; 2.The LHC Grid infrastructure in France and associated resources; 3.Commissioning of Tier 1; 4.The sites of Tier-2s and Tier-3s; 5.Computing in ALICE experiment; 6.Computing in ATLAS experiment; 7.Computing in the CMS experiments; 8.Computing in the LHCb experiments; 9.Management and operation of computing grids; 10.'The VOs talk to sites'; 11.Peculiarities of ATLAS; 12.Peculiarities of CMS and ALICE; 13.Peculiarities of LHCb; 14.'The sites talk to VOs'; 15. Worldwide operation of Grid; 16.Following-up the Grid jobs; 17.Surveillance and managing the failures; 18. Job scheduling and tuning; 19.Managing the site infrastructure; 20.LCG-France communications; 21.Managing the Grid data; 22.Pointing the net infrastructure and site storage. 23.ALICE bulk transfers; 24.ATLAS bulk transfers; 25.CMS bulk transfers; 26. LHCb bulk transfers; 27.Access to LHCb data; 28.Access to CMS data; 29.Access to ATLAS data; 30.Access to ALICE data; 31.Data analysis centers; 32.D0 Analysis Farm; 33.Some CMS grid analyses; 34.PROOF; 35.Distributed analysis using GANGA; 36.T2 set-up for end-users. In their concluding remarks Fairouz Malek and Dominique Pallin stressed that the current workshop was more close to users while the tasks for tightening the links between the sites and the experiments were definitely achieved. The IN2P3

That’s a matter for ALICE!

CERN Multimedia

Katarina Anthony

2010-01-01

ALICE has launched a new online newsletter to report on developments at the detector: ALICE Matters. The fortnightly newsletter will keep members of the collaboration – and a wider readership – up-to-date with the latest news from the detector.   Screenshot of the ALICE Matters website. The new ALICE Matters newsletter highlights the work of ALICE collaborators through news, interviews and feature articles. Published online every fortnight, it will report the latest developments from the experiment, providing information about operation and data taking, installation work during technical stops, and news from ALICE members. The newsletter is aimed at members of the collaboration, but as an online publication it is also open to the general public. “We often receive questions from people who follow our progress and are interested in what's happening at ALICE,” explains Despina Hatzifotiadou, ALICE Outreach Coordinator. “With ALICE Matters, we can n...

The ALICE DAQ infoLogger

Science.gov (United States)

Chapeland, S.; Carena, F.; Carena, W.; Chibante Barroso, V.; Costa, F.; Dénes, E.; Divià, R.; Fuchs, U.; Grigore, A.; Ionita, C.; Delort, C.; Simonetti, G.; Soós, C.; Telesca, A.; Vande Vyvre, P.; Von Haller, B.; Alice Collaboration

2014-04-01

ALICE (A Large Ion Collider Experiment) is a heavy-ion experiment studying the physics of strongly interacting matter and the quark-gluon plasma at the CERN LHC (Large Hadron Collider). The ALICE DAQ (Data Acquisition System) is based on a large farm of commodity hardware consisting of more than 600 devices (Linux PCs, storage, network switches). The DAQ reads the data transferred from the detectors through 500 dedicated optical links at an aggregated and sustained rate of up to 10 Gigabytes per second and stores at up to 2.5 Gigabytes per second. The infoLogger is the log system which collects centrally the messages issued by the thousands of processes running on the DAQ machines. It allows to report errors on the fly, and to keep a trace of runtime execution for later investigation. More than 500000 messages are stored every day in a MySQL database, in a structured table keeping track for each message of 16 indexing fields (e.g. time, host, user, ...). The total amount of logs for 2012 exceeds 75GB of data and 150 million rows. We present in this paper the architecture and implementation of this distributed logging system, consisting of a client programming API, local data collector processes, a central server, and interactive human interfaces. We review the operational experience during the 2012 run, in particular the actions taken to ensure shifters receive manageable and relevant content from the main log stream. Finally, we present the performance of this log system, and future evolutions.

LHC Report: protons to the right, ions to the left please!

CERN Multimedia

Mike Lamont for the LHC Team

2011-01-01

The LHC finished proton physics for the year on Sunday 30 October at 17:00 after delivering around 5.6 fb-1 to both ATLAS and CMS, 1.2 fb-1 to LHCb, and 5 pb-1 to ALICE.   A number of factors have contributed to these impressive totals, including: the increase in the total number of bunches to 1380 during the first part of the year, the high bunch intensity and small beam sizes delivered by the LHC injectors, and the very good aperture in the regions around ATLAS and CMS which have allowed a squeeze to beta* = 1 m. Despite some persistent issues, overall availability has been acceptable. About 25% of the programmed physics time was spent with stable beams - not bad at this stage in the LHC’s career given its complexity and the operation with high intensity beams. Over the last two weeks, the luminosity delivery has been a bit fractured, with timeouts for tests with 25 ns beam, and with a high number of events per bunch crossing. The squeeze to 1 m in ALICE was also commissioned in prep...

More Than ALICE: Development of an augmented reality mobile application for the ALICE detector

CERN Document Server

Ouellette, Jeff

2016-01-01

More Than ALICE is a mobile application for iOS and Android built in the Unity Engine. This project concerns the development of the second edition of the application, which is meant to completely succeed the original version built in 2014. The purpose of the application is to describe the various components of the ALICE detector and to overlay live collisions to increase public awareness for the research goals of the ALICE collaboration. The application provides an augmented reality (AR) interface via the Vuforia SDK to track images of the ALICE detector or components of the paper model of ALICE that can be purchased at the ALICE secretariat office. For those without access to either images of the detector or the detector model, the app provides a virtual detector model (VR) that contains the same functionality as the augmented reality.

The Alice dimuon trigger: overview and electronics prototypes

International Nuclear Information System (INIS)

Arnaldi, R.; Baldit, A.; Barret, V.; Bastid, N.

2000-01-01

ALICE is the LHC experiment (2005) dedicated to the study of heavy ion collisions. Amongst the ALICE sub-detectors, the muon spectrometer will investigate the dimuon production from heavy resonance (J/ψ,γ) decays, which is believed to be a promising signature of the QGP (quark Gluon Plasma) formation. For maximum efficiency of the spectrometer, a dedicated dimuon trigger is presently built. The detector part itself is based on RPCs operated in streamer mode and is the topic of another contribution to this conference. This paper gives the principle and the simulated performances of the trigger and is also focussed on the description of the electronics prototypes and future developments. The RPCs are read-out by X and Y orthogonal strips: the front-end chips are presently developed. The signals are sent to the trigger electronics which basically performs a pt cut on the tracks to reduce the background. A prototype of fast (decision time 200 ns) programmable electronics working in a pipelined mode at 40 MHz has been built and tested. This prototype handles simultaneously 160 digital information from the strips. The tests of the trigger card have required the construction of a pattern generator (160 bits at 40 MHz). (author)

Computing in ALICE

International Nuclear Information System (INIS)

Brun, R.; Buncic, P.; Carminati, F.; Morsch, A.; Rademakers, F.; Safarik, K.

2003-01-01

The objective of the offline framework is to reconstruct and analyse the data coming from real interactions. The ALICE Offline framework, AliRoot, has already been used during the production of the Technical Design Reports of each detector to optimise their design and it is currently used to evaluate the physics performance of the full ALICE detector. This paper describes the AliRoot software environment. We wish to put into perspective the main decisions and the organisation of the offline project. First a general description of the ALICE offline framework (AliRoot) is given, starting with a short historical background followed by a description of the simulation, reconstruction and analysis architecture and the organisation of the ALICE offline project. Finally we briefly indicate the main conclusions of our work on AliRoot

Computing in ALICE

CERN Document Server

Brun, R; Carminati, F; Morsch, Andreas; Rademakers, F; Safarík, K

2003-01-01

The objective of the offline framework is to reconstruct and analyse the data coming from real interactions. The ALICE Offline framework, AliRoot, has already been used during the production of the Technical Design Reports of each detector to optimise their design and it is currently used to evaluate the physics performance of the full ALICE detector. This paper describes the AliRoot software environment. We wish to put into perspective the main decisions and the organisation of the offline project. First a general description of the ALICE offline framework (AliRoot) is given, starting with a short historical background followed by a description of the simulation, reconstruction and analysis architecture and the organisation of the ALICE offline project. Finally we briefly indicate the main conclusions of our work on AliRoot.

ALICE HMPID Radiator Vessel

CERN Document Server

2003-01-01

View of the radiator vessels of the ALICE/HMPID mounted on the support frame. Each HMPID module is equipped with 3 indipendent radiator vessels made out of neoceram and fused silica (quartz) windows glued together. The spacers inside the vessel are needed to stand the hydrostatic pressure. http://alice-hmpid.web.cern.ch/alice-hmpid

20 fevrier 2012 - Le Vice-Président du Gouvernement Wallon et Ministre du Développement durable et de la Fonction Publique en charge de l’Energie du Logement et de la Recherche J.-M. Nollet, Royaume de Belgique, visite la salle de contrôle de CMS au Point 5, la caverne expérimentale CMS et le hall de tests des aimants supraconducteurs du LHC. Les chefs de département T. Lagrange et F. Hemmer accompagnent la délégation. L. Walckiers guide la visite SM18.

CERN Multimedia

Maximilien Brice

2012-01-01

20 fevrier 2012 - Le Vice-Président du Gouvernement Wallon et Ministre du Développement durable et de la Fonction Publique en charge de l’Energie du Logement et de la Recherche J.-M. Nollet, Royaume de Belgique, visite la salle de contrôle de CMS au Point 5, la caverne expérimentale CMS et le hall de tests des aimants supraconducteurs du LHC. Les chefs de département T. Lagrange et F. Hemmer accompagnent la délégation. L. Walckiers guide la visite SM18.

ALICE presents its first award to Industry

CERN Multimedia

On 19 June, a French company received the first ALICE award to industry. ST Technologies has provided ALICE with a key device for the design of a very sophisticated chip for the readout of the ALICE Time Projection Chamber. Behind from left to right (Derrière de gauche à droite): Bernardo Mota, member of the ALTRO design team, Jurgen Schukraft, ALICE Spokesperson, Luciano Musa, leader of the ALTRO Design Team and Coordinator of the ALICE TPC FEE, Roberto Camapagnolo, member of the ALICE TPC FEE team, Jean-Pierre Coffin, Deputy of the ALICE Collaboration Board Chairman, Hans de Groot ALICE Resource Coordinator, Laurent Degoujon, ST - Data Converter Design Manager, Claude Engster, member of the ALICE TPC FEE team, Alain Delpi, ST - Data Converter Business Unit Manager, Carmen Gonzalez, member of the ALICE TPC FEE team, Yiota Foka, ALICE Outreach Coordinator; Front: Fabio Formenti , EP-ED Group Leader, Juan Antonio Rubio, ETT Division Leader The ALICE experiment is setting new demands on readout electronics i...

Charged-particle multiplicity measurement in proton-proton collisions at $\\sqrt{s}$ = 0.9 and 2.36 TeV with ALICE at LHC

CERN Document Server

Aamodt, K.; Abeysekara, U.; Abrahantes Quintana, A.; Abramyan, A.; Adamova, D.; Aggarwal, M.M.; Aglieri Rinella, G.; Agocs, A.G.; Aguilar Salazar, S.; Ahammed, Z.; Ahmad, A.; Ahmad, N.; Ahn, S.U.; Akimoto, R.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alfaro Molina, R.; Alici, A.; Avina, E.Almaraz; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Andrei, C.; Andronic, A.; Anelli, G.; Angelov, V.; Anson, C.; Anticic, T.; Antinori, F.; Antinori, S.; Antipin, K.; Antonczyk, D.; Antonioli, P.; Anzo, A.; Aphecetche, L.; Appelshauser, H.; Arcelli, S.; Arceo, R.; Arend, A.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I.C.; Asryan, A.; Augustinus, A.; Averbeck, R.; Awes, T.C.; Aysto, J.; Azmi, M.D.; Bablok, S.; Bach, M.; Badala, A.; Baek, Y.W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baldit, A.; Ban, J.; Barbera, R.; Barnafoldi, G.G.; Barnby, L.; Barret, V.; Bartke, J.; Barile, F.; Basile, M.; Basmanov, V.; Bastid, N.; Bathen, B.; Batigne, G.; Batyunya, B.; Baumann, C.; Bearden, I.G.; Becker, B.; Belikov, I.; Bellwied, R.; Belmont-Moreno, E.; Belogianni, A.; Benhabib, L.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdermann, E.; Berdnikov, Y.; Betev, L.; Bhasin, A.; Bhati, A.K.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielcik, J.; Bielcikova, J.; Bilandzic, A.; Bimbot, L.; Biolcati, E.; Blanc, A.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Boccioli, M.; Bock, N.; Bogdanov, A.; Boggild, H.; Bogolyubsky, M.; Bohm, J.; Boldizsar, L.; Bombara, M.; Bombonati, C.; Bondila, M.; Borel, H.; Borshchov, V.; Borisov, A.; Bortolin, C.; Bose, S.; Bosisio, L.; Bossu, F.; Botje, M.; Bottger, S.; Bourdaud, G.; Boyer, B.; Braun, M.; Braun-Munzinger, P.; Bravina, L.; Bregant, M.; Breitner, T.; Bruckner, G.; Brun, R.; Bruna, E.; Bruno, G.E.; Budnikov, D.; Buesching, H.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Camacho, E.; Camerini, P.; Campbell, M.; Canoa Roman, V.; Capitani, G.P.; Cara Romeo, G.; Carena, F.; Carena, W.; Carminati, F.; Casanova Diaz, A.; Caselle, M.; Castellanos, J.Castillo; Castillo Hernandez, J.F.; Catanescu, V.; Cattaruzza, E.; Cavicchioli, C.; Cerello, P.; Chambert, V.; Chang, B.; Chapeland, S.; Charpy, A.; Charvet, J.L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chiavassa, E.; Chibante Barroso, V.; Chinellato, D.D.; Chochula, P.; Choi, K.; Chojnacki, M.; Christakoglou, P.; Christensen, C.H.; Christiansen, P.; Chujo, T.; Chuman, F.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Cobanoglu, O.; Coffin, J.P.; Coli, S.; Colla, A.; Conesa Balbastre, G.; Conesa del Valle, Z.; Conner, E.S.; Constantin, P.; Contin, G.; Contreras, J.G.; Corrales Morales, Y.; Cormier, T.M.; Cortese, P.; Cortes Maldonado, I.; Cosentino, M.R.; Costa, F.; Cotallo, M.E.; Crescio, E.; Crochet, P.; Cuautle, E.; Cunqueiro, L.; Cussonneau, J.; Dainese, A.; Dalsgaard, H.H.; Danu, A.; Das, I.; Das, S.; Dash, A.; Dash, S.; de Barros, G.O.V.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gaspari, M.; de Groot, J.; De Gruttola, D.; de Haas, A.P.; De Marco, N.; De Pasquale, S.; De Remigis, R.; de Rooij, R.; de Vaux, G.; Delagrange, H.; Dellacasa, G.; Deloff, A.; Demanov, V.; Denes, E.; Deppman, A.; D'Erasmo, G.; Derkach, D.; Devaux, A.; Di Bari, D.; Di Giglio, C.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Dialinas, M.; Diaz, L.; Diaz, R.; Dietel, T.; Divia, R.; Djuvsland, O.; Dobretsov, V.; Dobrin, A.; Dobrowolski, T.; Donigus, B.; Dominguez, I.; Dordic, O.; Dubey, A.K.; Dubuisson, J.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A.K.; Dutta Majumdar, M.R.; Elia, D.; Emschermann, D.; Enokizono, A.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evrard, S.; Eyyubova, G.; Fabjan, C.W.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fateev, O.; Fearick, R.; Fedunov, A.; Fehlker, D.; Fekete, V.; Felea, D.; Fenton-Olsen, B.; Feofilov, G.; Fernandez Tellez, A.; Ferreiro, E.G.; Ferretti, A.; Ferretti, R.; Figueredo, M.A.S.; Filchagin, S.; Fini, R.; Fionda, F.M.; Fiore, E.M.; Floris, M.; Fodor, Z.; Foertsch, S.; Foka, P.; Fokin, S.; Formenti, F.; Fragiacomo, E.; Fragkiadakis, M.; Frankenfeld, U.; Frolov, A.; Fuchs, U.; Furano, F.; Furget, C.; Fusco Girard, M.; Gaardhoje, J.J.; Gadrat, S.; Gagliardi, M.; Gago, A.; Gallio, M.; Ganoti, P.; Ganti, M.S.; Garabatos, C.; Garcia Trapaga, C.; Gebelein, J.; Gemme, R.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Giraudo, G.; Giubellino, P.; Gladysz-Dziadus, E.; Glasow, R.; Glassel, P.; Glenn, A.; Gomez Jimenez, R.; Gonzalez Santos, H.; Gonzalez-Trueba, L.H.; Gonzalez-Zamora, P.; Gorbunov, S.; Gorbunov, Y.; Gotovac, S.; Gottschlag, H.; Grabski, V.; Grajcarek, R.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gros, P.; Grosse-Oetringhaus, J.F.; Grossiord, J.Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Gustafsson, H.A.; Gutbrod, H.; Haaland, O.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hamblen, J.; Han, B.H.; Harris, J.W.; Hartig, M.; Harutyunyan, A.; Hasch, D.; Hasegan, D.; Hatzifotiadou, D.; Hayrapetyan, A.; Heide, M.; Heinz, M.; Helstrup, H.; Herghelegiu, A.; Hernandez, C.; Herrera Corral, G.; Herrmann, N.; Hetland, K.F.; Hicks, B.; Hiei, A.; Hille, P.T.; Hippolyte, B.; Horaguchi, T.; Hori, Y.; Hristov, P.; Hrivnacova, I.; Hu, S.; Huang, M.; Huber, S.; Humanic, T.J.; Hutter, D.; Hwang, D.S.; Ichou, R.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Innocenti, P.G.; Ippolitov, M.; Irfan, M.; Ivan, C.; Ivanov, A.; Ivanov, M.; Ivanov, V.; Iwasaki, T.; Jacholkowski, A.; Jacobs, P.; Jancurova, L.; Jangal, S.; Janik, R.; Jena, C.; Jena, S.; Jirden, L.; Jones, G.T.; Jones, P.G.; Jovanovic, P.; Jung, H.; Jung, W.; Jusko, A.; Kaidalov, A.B.; Kalcher, S.; Kalinak, P.; Kalisky, M.; Kalliokoski, T.; Kalweit, A.; Kamal, A.; Kamermans, R.; Kanaki, K.; Kang, E.; Kang, J.H.; Kapitan, J.; Kaplin, V.; Kapusta, S.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kazantsev, A.; Kebschull, U.; Keidel, R.; Khan, M.M.; Khan, S.A.; Khanzadeev, A.; Kharlov, Y.; Kikola, D.; Kileng, B.; Kim, D.J.; Kim, D.S.; Kim, D.W.; Kim, H.N.; Kim, J.; Kim, J.H.; Kim, J.S.; Kim, M.; Kim, M.; Kim, S.H.; Kim, S.; Kim, Y.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Klay, J.L.; Klein, J.; Klein-Bosing, C.; Kliemant, M.; Klovning, A.; Kluge, A.; Kniege, S.; Koch, K.; Kolevatov, R.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Konevskih, A.; Kornas, E.; Kour, R.; Kowalski, M.; Kox, S.; Kozlov, K.; Kral, J.; Kralik, I.; Kramer, F.; Kraus, I.; Kravcakova, A.; Krawutschke, T.; Krivda, M.; Krumbhorn, D.; Krus, M.; Kryshen, E.; Krzewicki, M.; Kucheriaev, Y.; Kuhn, C.; Kuijer, P.G.; Kumar, L.; Kumar, N.; Kupczak, R.; Kurashvili, P.; Kurepin, A.; Kurepin, A.N.; Kuryakin, A.; Kushpil, S.; Kushpil, V.; Kutouski, M.; Kvaerno, H.; Kweon, M.J.; Kwon, Y.; La Rocca, P.; Lackner, F.; Ladron de Guevara, P.; Lafage, V.; Lal, C.; Lara, C.; Larsen, D.T.; Laurenti, G.; Lazzeroni, C.; Le Bornec, Y.; Le Bris, N.; Lee, H.; Lee, K.S.; Lee, S.C.; Lefevre, F.; Lenhardt, M.; Leistam, L.; Lehnert, J.; Lenti, V.; Leon, H.; Leon Monzon, I.; Leon Vargas, H.; Levai, P.; Li, X.; Li, Y.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M.A.; Listratenko, O.; Liu, L.; Loginov, V.; Lohn, S.; Lopez, X.; Lopez Noriega, M.; Lopez-Ramirez, R.; Lopez Torres, E.; Lovhoiden, G.; Lozea Feijo Soares, A.; Lu, S.; Lunardon, M.; Luparello, G.; Luquin, L.; Lutz, J.R.; Ma, K.; Ma, R.; Madagodahettige-Don, D.M.; Maevskaya, A.; Mager, M.; Mahapatra, D.P.; Maire, A.; Makhlyueva, I.; Mal'Kevich, D.; Malaev, M.; Malagalage, K.J.; Maldonado Cervantes, I.; Malek, M.; Malkiewicz, T.; Malzacher, P.; Mamonov, A.; Manceau, L.; Mangotra, L.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Mares, J.; Margagliotti, G.V.; Margotti, A.; Marin, A.; Martashvili, I.; Martinengo, P.; Martinez Hernandez, M.I.; Martinez Davalos, A.; Martinez Garcia, G.; Maruyama, Y.; Marzari Chiesa, A.; Masciocchi, S.; Masera, M.; Masetti, M.; Masoni, A.; Massacrier, L.; Mastromarco, M.; Mastroserio, A.; Matthews, Z.L.; Matyja, A.; Mayani, D.; Mazza, G.; Mazzoni, M.A.; Meddi, F.; Menchaca-Rocha, A.; Mendez Lorenzo, P.; Meoni, M.; Mercado Perez, J.; Mereu, P.; Miake, Y.; Michalon, A.; Miftakhov, N.; Milosevic, J.; Minafra, F.; Mischke, A.; Miskowiec, D.; Mitu, C.; Mizoguchi, K.; Mlynarz, J.; Mohanty, B.; Molnar, L.; Mondal, M.M.; Montano Zetina, L.; Monteno, M.; Montes, E.; Morando, M.; Moretto, S.; Morsch, A.; Moukhanova, T.; Muccifora, V.; Mudnic, E.; Muhuri, S.; Muller, H.; Munhoz, M.G.; Munoz, J.; Musa, L.; Musso, A.; Nandi, B.K.; Nania, R.; Nappi, E.; Navach, F.; Navin, S.; Nayak, T.K.; Nazarenko, S.; Nazarov, G.; Nedosekin, A.; Nendaz, F.; Newby, J.; Nianine, A.; Nicassio, M.; Nielsen, B.S.; Nikolaev, S.; Nikolic, V.; Nikulin, S.; Nikulin, V.; Nilsen, B.S.; Nilsson, M.S.; Noferini, F.; Nomokonov, P.; Nooren, G.; Novitzky, N.; Nyatha, A.; Nygaard, C.; Nyiri, A.; Nystrand, J.; Ochirov, A.; Odyniec, G.; Oeschler, H.; Oinonen, M.; Okada, K.; Okada, Y.; Oldenburg, M.; Oleniacz, J.; Oppedisano, C.; Orsini, F.; Ortiz Velasquez, A.; Ortona, G.; Oskamp, C.J.; Oskarsson, A.; Osmic, F.; Osterman, L.; Ostrowski, P.; Otterlund, I.; Otwinowski, J.; Ovrebekk, G.; Oyama, K.; Ozawa, K.; Pachmayer, Y.; Pachr, M.; Padilla, F.; Pagano, P.; Paic, G.; Painke, F.; Pajares, C.; Pal, S.; Pal, S.K.; Palaha, A.; Palmeri, A.; Panse, R.; Papikyan, V.; Pappalardo, G.S.; Park, W.J.; Pastircak, B.; Pastore, C.; Paticchio, V.; Pavlinov, A.; Pawlak, T.; Peitzmann, T.; Pepato, A.; Pereira, H.; Peressounko, D.; Perez, C.; Perini, D.; Perrino, D.; Peryt, W.; Peschek, J.; Pesci, A.; Peskov, V.; Pestov, Y.; Peters, A.J.; Petracek, V.; Petridis, A.; Petris, M.; Petrov, P.; Petrovici, M.; Petta, C.; Peyre, J.; Piano, S.; Piccotti, A.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Pitz, N.; Piuz, F.; Platt, R.; Ploskon, M.; Pluta, J.; Pocheptsov, T.; Pochybova, S.; Podesta Lerma, P.L.M.; Poggio, F.; Poghosyan, M.G.; Polak, K.; Polichtchouk, B.; Polozov, P.; Polyakov, V.; Pommeresch, B.; Pop, A.; Posa, F.; Pospisil, V.; Potukuchi, B.; Pouthas, J.; Prasad, S.K.; Preghenella, R.; Prino, F.; Pruneau, C.A.; Pshenichnov, I.; Puddu, G.; Pujahari, P.; Pulvirenti, A.; Punin, A.; Punin, V.; Putis, M.; Putschke, J.; Quercigh, E.; Rachevski, A.; Rademakers, A.; Radomski, S.; Raiha, T.S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Ramirez Reyes, A.; Rammler, M.; Raniwala, R.; Raniwala, S.; Rasanen, S.S.; Rashevskaya, I.; Rath, S.; Read, K.F.; Real, J.S.; Redlich, K.; Renfordt, R.; Reolon, A.R.; Reshetin, A.; Rettig, F.; Revol, J.P.; Reygers, K.; Ricaud, H.; Riccati, L.; Ricci, R.A.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Rivetti, A.; Rodriguez Cahuantzi, M.; Roed, K.; Rohrich, D.; Roman Lopez, S.; Romita, R.; Ronchetti, F.; Rosinsky, P.; Rosnet, P.; Rossegger, S.; Rossi, A.; Roukoutakis, F.; Rousseau, S.; Roy, C.; Roy, P.; Rubio-Montero, A.J.; Rui, R.; Rusanov, I.; Russo, G.; Ryabinkin, E.; Rybicki, A.; Sadovsky, S.; Safarik, K.; Sahoo, R.; Saini, J.; Saiz, P.; Sakata, D.; Salgado, C.A.; Salgueiro Domingues da Silva, R.; Salur, S.; Samanta, T.; Sambyal, S.; Samsonov, V.; Sandor, L.; Sandoval, A.; Sano, M.; Sano, S.; Santo, R.; Santoro, R.; Sarkamo, J.; Saturnini, P.; Scapparone, E.; Scarlassara, F.; Scharenberg, R.P.; Schiaua, C.; Schicker, R.; Schindler, H.; Schmidt, C.; Schmidt, H.R.; Schossmaier, K.; Schreiner, S.; Schuchmann, S.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Segato, G.; Semenov, D.; Senyukov, S.; Seo, J.; Serci, S.; Serkin, L.; Serradilla, E.; Sevcenco, A.; Sgura, I.; Shabratova, G.; Shahoyan, R.; Sharkov, G.; Sharma, N.; Sharma, S.; Shigaki, K.; Shimomura, M.; Shtejer, K.; Sibiriak, Y.; Siciliano, M.; Sicking, E.; Siddi, E.; Siemiarczuk, T.; Silenzi, A.; Silvermyr, D.; Simili, E.; Simonetti, G.; Singaraju, R.; Singh, R.; Singhal, V.; Sinha, B.C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T.B.; Skjerdal, K.; Smakal, R.; Smirnov, N.; Snellings, R.; Snow, H.; Sogaard, C.; Soloviev, A.; Soltveit, H.K.; Soltz, R.; Sommer, W.; Son, C.W.; Son, H.; Song, M.; Soos, C.; Soramel, F.; Soyk, D.; Spyropoulou-Stassinaki, M.; Srivastava, B.K.; Stachel, J.; Staley, F.; Stan, E.; Stefanek, G.; Stefanini, G.; Steinbeck, T.; Stenlund, E.; Steyn, G.; Stocco, D.; Stock, R.; Stolpovsky, P.; Strmen, P.; Suaide, A.A.P.; Subieta Vasquez, M.A.; Sugitate, T.; Suire, C.; Sumbera, M.; Susa, T.; Swoboda, D.; Symons, J.; Szanto de Toledo, A.; Szarka, I.; Szostak, A.; Szuba, M.; Tadel, M.; Tagridis, C.; Takahara, A.; Takahashi, J.; Tanabe, R.; Takaki, D.J.Tapia; Taureg, H.; Tauro, A.; Tavlet, M.; Tejeda Munoz, G.; Telesca, A.; Terrevoli, C.; Thader, J.; Tieulent, R.; Tlusty, D.; Toia, A.; Tolyhy, T.; Torcato de Matos, C.; Torii, H.; Torralba, G.; Toscano, L.; Tosello, F.; Tournaire, A.; Traczyk, T.; Tribedy, P.; Troger, G.; Truesdale, D.; Trzaska, W.H.; Tsiledakis, G.; Tsilis, E.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Turvey, A.; Tveter, T.S.; Tydesjo, H.; Tywoniuk, K.; Ulery, J.; Ullaland, K.; Uras, A.; Urban, J.; Urciuoli, G.M.; Usai, G.L.; Vacchi, A.; Vala, M.; Valencia Palomo, L.; Vallero, S.; van den Brink, A.; van der Kolk, N.; Vyvre, P.Vande; van Leeuwen, M.; Vannucci, L.; Vargas, A.; Varma, R.; Vasiliev, A.; Vassiliev, I.; Vasileiou, M.; Vechernin, V.; Venaruzzo, M.; Vercellin, E.; Vergara, S.; Vernet, R.; Verweij, M.; Vetlitskiy, I.; Vickovic, L.; Viesti, G.; Vikhlyantsev, O.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Viyogi, Y.P.; Vodopianov, A.; Voloshin, K.; Voloshin, S.; Volpe, G.; von Haller, B.; Vranic, D.; Vrlakova, J.; Vulpescu, B.; Wagner, B.; Wagner, V.; Wallet, L.; Wan, R.; Wang, D.; Wang, Y.; Watanabe, K.; Wen, Q.; Wessels, J.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilk, A.; Wilk, G.; Williams, M.C.S.; Willis, N.; Windelband, B.; Xu, C.; Yang, C.; Yang, H.; Yasnopolskiy, S.; Yermia, F.; Yi, J.; Yin, Z.; Yokoyama, H.; Yoo, I-K.; Yuan, X.; Yurevich, V.; Yushmanov, I.; Zabrodin, E.; Zagreev, B.; Zalite, A.; Zampolli, C.; Zanevsky, Yu.; Zaporozhets, S.; Zarochentsev, A.; Zavada, P.; Zbroszczyk, H.; Zelnicek, P.; Zenin, A.; Zepeda, A.; Zgura, I.; Zhalov, M.; Zhang, X.; Zhou, D.; Zhou, S.; Zhu, J.; Zichichi, A.; Zinchenko, A.; Zinovjev, G.; Zoccarato, Y.; Zychacek, V.; Zynovyev, M.

2010-01-01

Charged-particle production was studied in proton-proton collisions collected at the LHC with the ALICE detector at centre-of-mass energies 0.9 TeV and 2.36 TeV in the pseudorapidity range |eta| < 1.4. In the central region (|eta| < 0.5), at 0.9 TeV, we measure charged-particle pseudorapidity density dNch/deta = 3.02 +- 0.01 (stat.) +0.08 -0.05 (syst.) for inelastic interactions, and dNch/deta = 3.58 +- 0.01 (stat.) +0.12 -0.12 (syst.) for non-single-diffractive interactions. At 2.36 TeV, we find dNch/deta = 3.77 +- 0.01 (stat.) +0.25 -0.12 (syst.) for inelastic, and dNch/deta = 4.43 +- 0.01 (stat.) +0.17 -0.12 (syst.) for non-single-diffractive collisions. The relative increase in charged-particle multiplicity from the lower to higher energy is 24.7% +- 0.5% (stat.) +5.7% -2.8% (syst.) for inelastic and 23.7% +- 0.5% (stat.) +4.6% -1.1% (syst.) for non-single-diffractive interactions. This increase is consistent with that reported by the CMS collaboration for non-single-diffractive events and larger th...

Fast TPC Online Tracking on GPUs and Asynchronous Data Processing in the ALICE HLT to facilitate Online Calibration

International Nuclear Information System (INIS)

Rohr, David; Gorbunov, Sergey; Krzewicki, Mikolaj; Breitner, Timo; Kretz, Matthias; Lindenstruth, Volker

2015-01-01

ALICE (A Large Heavy Ion Experiment) is one of the four major experiments at the Large Hadron Collider (LHC) at CERN, which is today the most powerful particle accelerator worldwide. The High Level Trigger (HLT) is an online compute farm of about 200 nodes, which reconstructs events measured by the ALICE detector in real-time. The HLT uses a custom online data-transport framework to distribute data and workload among the compute nodes.ALICE employs several calibration-sensitive subdetectors, e.g. the TPC (Time Projection Chamber). For a precise reconstruction, the HLT has to perform the calibration online. Online- calibration can make certain Offline calibration steps obsolete and can thus speed up Offline analysis. Looking forward to ALICE Run III starting in 2020, online calibration becomes a necessity.The main detector used for track reconstruction is the TPC. Reconstructing the trajectories in the TPC is the most compute-intense step during event reconstruction. Therefore, a fast tracking implementation is of great importance. Reconstructed TPC tracks build the basis for the calibration making a fast online-tracking mandatory.We present several components developed for the ALICE High Level Trigger to perform fast event reconstruction and to provide features required for online calibration.As first topic, we present our TPC tracker, which employs GPUs to speed up the processing, and which bases on a Cellular Automaton and on the Kalman filter. Our TPC tracking algorithm has been successfully used in 2011 and 2012 in the lead-lead and the proton-lead runs. We have improved it to leverage features of newer GPUs and we have ported it to support OpenCL, CUDA, and CPUs with a single common source code. This makes us vendor independent.As second topic, we present framework extensions required for online calibration. The extensions, however, are generic and can be used for other purposes as well. We have extended the framework to support asynchronous compute chains

Exclusive ϒ photoproduction in hadronic collisions at CERN LHC energies

Energy Technology Data Exchange (ETDEWEB)

Gonçalves, V.P., E-mail: barros@ufpel.edu.br [High and Medium Energy Group, Instituto de Física e Matemática, Universidade Federal de Pelotas, Caixa Postal 354, CEP 96010-900, Pelotas, RS (Brazil); Moreira, B.D.; Navarra, F.S. [Instituto de Física, Universidade de São Paulo, C.P. 66318, 05315-970 São Paulo, SP (Brazil)

2015-03-06

The exclusive ϒ photoproduction in proton–proton and proton–nucleus collisions at LHC energies is investigated using the color dipole formalism and considering different models for the ϒ wave function and forward dipole–target scattering amplitude. Our goal is to update the color dipole predictions and estimate the theoretical uncertainty present in these predictions. We present predictions for the kinematical ranges probed by the ALICE, CMS and LHCb Collaborations.

The upgrade of the RPC-based ALICE Muon Trigger arXiv

CERN Document Server

INSPIRE-00033003

The ALICE Muon Trigger is currently yielded by a detector currently composed of 72 Bakelite single-gap Resistive Plate Chambers operated in maxi-avalanche mode, arranged in four 5.5x6.5 m2 detection planes. In order to meet the requirements posed by the forthcoming LHC high luminosity runs starting from 2021 onwards, in which ALICE will be read out in continuous mode, the Muon Trigger will become a Muon Identifier and will undergo a major upgrade. In the current setup, signals from about 21k strips are discriminated by 2400 non-amplified Front End (FEE) cards, whose thresholds are provided by external analog voltages (one for each chamber side). All these cards will be replaced with discriminators equipped with a pre-amplification stage which will allow a reduction in the operating high voltage of the detectors, thus prolonging their lifetime. Furthermore, their reference thresholds will be passed via wireless (and I2C chained per chamber side) allowing the tuning of the values at the single card level. Moreo...

Open charm reconstruction in ALICE: ${\\rm D^+\\to K^-\\pi^+\\pi^+}$

CERN Document Server

Bruna, E

2007-01-01

Open charm mesons produced in high energy A-A interactions are expected to be powerful probes to investigate the medium produced in the collision. In this context it is important to measure the production of as many charmed hadrons as possible, such as D$^0$, D$^+$, D$^+_s$ and $\\Lambda_c$, because the measurement of their relative yield can provide information on the hadronization mechanism and is necessary to reduce the systematic error on the absolute cross section. The ALICE experiment at the LHC is designed to perform such measurements at midrapidity down to $p_T$ below 1 GeV/c, mainly by means of the silicon vertex and tracker detector, the time projection chamber and the time of flight detector. One of the main channels for the detection of charm production in ALICE is the exclusive reconstruction of the D$^+$ meson through its three charged body decay $K^-\\pi^+\\pi^+$ in Pb-Pb ($\\sqrt s=5.5$ TeV) and pp ($\\sqrt s=14$ TeV) collisions. The selection strategies for this analysis and the results of a feasi...

9 décembre 2016 - Visite du hall d'assemblage des aimants supraconducteurs du LHC par le Prof. D. Le Bihan, Directeur, NeuroSpin; membre de l’Académie des Sciences, République française avec le Directeur des accélérateurs et de la technologie F. Bordry et le chef de groupe L. Bottura.

CERN Multimedia

Bennett, Sophia Elizabeth

2016-01-01

9 décembre 2016 - Visite du hall d'assemblage des aimants supraconducteurs du LHC par le Prof. D. Le Bihan, Directeur, NeuroSpin; membre de l’Académie des Sciences, République française avec le Directeur des accélérateurs et de la technologie F. Bordry et le chef de groupe L. Bottura.

ALICE rewards one of its suppliers

CERN Multimedia

2007-01-01

On 6 October 2007 the ALICE Collaboration Board awarded one of its prestigious Industrial Awards to Hewlett-Packard for its instrumental role in enabling ALICE physicists to collect and process experimental data on the Grid. From left to right: Jurgen Schukraft, ALICE Spokesperson; Michel Bénard, Hewlett Packard, Director, Technology Programs and University Relations; Federico Carminati, ALICE Computing Project Leader; Lodovico Riccati, ALICE Collaboration Board Chairperson; Arnaud Pierson, Hewlett Packard, E.M.E.A Program Manager, University Relations and HP Labs; Latchezar Betev, ALICE Distributed Computing Coordinator.The ALICE DAQ and Offline groups have been collaborating with HP since 1993 in the yearly Computing and GRID physics data challenges programme. These are high-level exercises of readiness of hardware and software frameworks for data acquisition and processing. HP hosted ALICE experts in their "centre de compétences"...

Etude de la fragmentation des partons par la mesure de corrélations photon-hadron auprès de l'expérience ALICE au LHC

CERN Document Server

ARBOR, Nicolas

The strong interaction theory, Quantum Chromodynamic (QCD), predicts a new phase of nuclear matter at very high temperature and/or very high density. This state, which should have been the state of the Univers some microseconds after the Big Bang, is composed of deconfined quarks and gluons known as the quark-gluon plasma (QGP). The measurement of its composition and properties is a challenge for the nuclear physics of the 21st century and should lead to a better understanding of the fundamental symetries and mechanisms related to the quarks confinement inside hadrons and the strong interaction generally. The Large Hadron Collider (LHC) accelerator at CERN (European Organization for Nuclear Research) allows to reach the thermodynamic conditions required to create the quark-gluon plasma using ultra-relativistic heavy ion collisions (Pb). The ALICE experiment (A Large Ion Collider Experiment) allows to access several probes to characterize the QGP through particles reconstruction and. Among these probes, hi...

An optimization of the ALICE XRootD storage cluster at the Tier-2 site in Czech Republic

International Nuclear Information System (INIS)

Adamova, D; Horky, J

2012-01-01

ALICE, as well as the other experiments at the CERN LHC, has been building a distributed data management infrastructure since 2002. Experience gained during years of operations with different types of storage managers deployed over this infrastructure has shown, that the most adequate storage solution for ALICE is the native XRootD manager developed within a CERN - SLAC collaboration. The XRootD storage clusters exhibit higher stability and availability in comparison with other storage solutions and demonstrate a number of other advantages, like support of high speed WAN data access or no need for maintaining complex databases. Two of the operational characteristics of XRootD data servers are a relatively high number of open sockets and a high Unix load. In this article, we would like to describe our experience with the tuning/optimization of machines hosting the XRootD servers, which are part of the ALICE storage cluster at the Tier-2 WLCG site in Prague, Czech Republic. The optimization procedure, in addition to boosting the read/write performance of the servers, also resulted in a reduction of the Unix load.

The Laser of the ALICE Time Projection Chamber

CERN Document Server

Renault, G; Westergaard, J; GaardhOJe, J J

2007-01-01

The large TPC ($95 \\mathrm{m}^3$) of the ALICE detector at the CERN LHC was commissioned in summer 2006. The first tracks were observed both from the cosmic ray muons and from the laser rays injected into the TPC. In this article the basic principles of operating the $266 \\mathrm{nm}$ lasers are presented, showing the installation and adjustment of the optical system and describing the control system. To generate the laser tracks, a wide laser beam is split into several hundred narrow beams by fixed micro-mirrors at stable and known positions throughout the TPC. In the drift volume, these narrow beams generate straight tracks at many angles. Here we describe the generation of the first tracks and compare them with simulations.

Triggering with the ALICE TRD. Results and prospects

Energy Technology Data Exchange (ETDEWEB)

Klein, Jochen; Pachmayer, Yvonne [Physikalisches Institut, University of Heidelberg (Germany); Westerhoff, Uwe [Institut fuer Kernphysik, Universitaet Muenster (Germany); Collaboration: ALICE-Collaboration

2015-07-01

The ALICE Transition Radiation Detector provides multiple level-1 trigger contributions. The signatures are based on tracks which are reconstructed in an FPGA array from chamber-wise track segments. The latter are calculated on the detector-mounted frontend electronics. The massive parallelization allows for the low latency trigger 8 us after the interaction. We show the performance of the triggers on electrons and jets during LHC Run 1. Further, we discuss improvements and prospects for Run 2. In particular, an online calculation of the distance of closest approach to the primary vertex shall be used to reject the dominant background from the conversion of photons at large radii. The combination of tracks over stack and sector boundaries will help to improve the efficiency of the jet trigger.

Production of light (anti-)nuclei and (anti-)hypernuclei with ALICE at the LHC

CERN Multimedia

CERN. Geneva

2017-01-01

The measurements in smaller collision systems may also provide an input to cosmological searches for segregated primordial anti-matter and dark matter, since anti-nuclei produced in pp and p--A collisions in interstellar space represent a background source in these measurements. Thanks to its excellent particle identification and tracking capabilities, the ALICE detector allows for the measurement of deuterons, tritons, 3He, 4He and their corresponding anti-nuclei. Moreover, the secondary vertices from the mesonic decays of (anti-)hypernuclei can ...

Development of Microstrip Silicon Detectors for Star and ALICE

CERN Document Server

Arnold, L; Coffin, J P; Guillaume, G; Guthneck, L; Higueret, S; Hundt, F; Kühn, C E; Lutz, Jean Robert; Pozdniakov, S; Rami, F; Tarchini, A; Boucham, A; Bouvier, S; Erazmus, B; Germain, M; Giliberto, S; Martin, L; Le Moal, C; Roy, C; Colledani, C; Dulinski, W; Turchetta, R

1998-01-01

The physics program of STAR and ALICE at ultra-relativistic heavy ion colliders, RHIC and LHC respectively, requires very good tracking capabilities. Some specific quark gluon plasma signatures, based on strange matter measurements implies quite a good secondary vertex reconstruction.For this purpose, the inner trackers of both experiments are composed of high-granularity silicon detectors. The current status of the development of double-sided silicon microstrip detectors is presented in this work.The global performance for tracking purpose adn particle identification are first reviewed. Then tests of the detectors and of the associated readout electronics are described. In-beam measurements of noise, spatial resolution, efficiency and charge matching capability, as well as radiation hardness, are examined.

Flow of strange and charm particles in Pb--Pb collisions at sqrt{s_{NN}} = 2.76 TeV measured with ALICE

CERN Document Server

INSPIRE-00014860

2013-01-01

The ALICE experiment studies Pb-Pb collisions at the LHC in order to investigate the properties of the hot and dense QCD matter at extreme energy densities. Recent results from ALICE in identified particle flow allow for the exploration of the collective properties of the medium created in heavy-ion collisions. In this paper, I give special attention to strange and charm particles which probe the medium differently and thus provide new constraints for the study of its properties. The paper covers results on elliptic flow for pion, kaon, kzero, antiproton, phi, lambda, xi, omega, dplus, dzero and dstar measured at midrapidity by ALICE in Pb-Pb collisions at sqrt{s_{NN}} = 2.76 TeV. I present also the comparison with available models that predict the hydrodynamical evolution of the medium and the energy loss of light and heavy quarks as they travel through.

"Alice imedemaal" Vanemuises

Index Scriptorium Estoniae

2004-01-01

7. veebr. esietendub Vanemuises tantsulavastus "Alice imedemaal". Etendus põhineb briti kirjaniku L. Carrolli samanimelisel lasteraamatul, koreograaf M. Murdmaa, kunstnik K. Jancis ja muusika on kirjutanud ungari helilooja S. Kall̤s, Alice'i osa tantsib korealanna Hye Min Kim

Event-by-Event Identified Particle Ratio Fluctuations in Pb–Pb Collisions with ALICE

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00245664

ALICE is the dedicated heavy-ion experiment among the experiments at the LHC at CERN. It is, in particular, designed to exploit the physics of strongly interacting matter. The theory of strong interactions, Quantum Chromodynamics (QCD), predicts that at sufficiently high energy densities nuclear matter transforms into a deconfined state of quarks and gluons. One of the possible signatures of a transition between hadronic and partonic phases is the enhancement of fluctuations of the number of particles in the hadronic final state of relativistic heavy-ion collisions. \\\\ \\\\ The observable $\

ALICE presents its first award to Industry

CERN Multimedia

Maximilien Brice

2003-01-01

Behind from left to right (Derrière de gauche à droite): Bernardo Mota, member of the ALTRO design team, Jurgen Schukraft, ALICE Spokesperson, Luciano Musa, leader of the ALTRO Design Team and Coordinator of the ALICE TPC FEE, Roberto Camapagnolo, member of the ALICE TPC FEE team, Jean-Pierre Coffin, Deputy of the ALICE Collaboration Board Chairman, Hans de Groot ALICE Resource Coordinator, Laurent Degoujon, ST - Data Converter Design Manager, Claude Engster, member of the ALICE TPC FEE team, Alain Delpi, ST - Data Converter Business Unit Manager, Carmen Gonzalez, member of the ALICE TPC FEE team, Yiota Foka, ALICE Outreach Coordinator; Front: Fabio Formenti , EP-ED Group Leader, Juan Antonio Rubio, ETT Division Leader.

ALICE honours industries

CERN Document Server

2006-01-01

The third annual ALICE Awards ceremony recognizes three companies for their contribution to the experiment's detector. The ALICE Awards winners pictured with CERN Secretary-General, Maximilian Metzger, during the ceremony. Three industries were honoured at the ALICE Awards ceremony on 17 March for their exceptional work on the collaboration's detector. Representatives from the companies accepted their awards at the ceremony, which was also attended by CERN Secretary-General Maximilian Metzger and members of the ALICE Collaboration Board. VTT Microelectronics of Finland received an award for the production of the thin bump bonded ladders (detector arrays, each consisting of 40 960 active cells) for the silicon pixel detector (SPD) in the inner tracking system. A number of technical hurdles had to be overcome: complex and expensive equipment was procured or upgraded, and processes underwent a detailed study and careful tuning. The ladders have a high and stable yield and the production will soon be completed...

Investigation of a Huffman-based compression algorithm for the ALICE TPC read-out in LHC Run 3

Energy Technology Data Exchange (ETDEWEB)

Klewin, Sebastian [Physikalisches Institut, University of Heidelberg (Germany); Collaboration: ALICE-Collaboration

2016-07-01

Within the scope of the ALICE upgrade towards the Run 3 of the Large Hadron Collider at CERN, starting in 2020, the ALICE Time Projection Chamber (TPC) will be reworked in order to allow for a continuous read-out. This rework includes not only a replacement of the current read-out chambers with Gas Electron Multiplier (GEM) technology, but also new front-end electronics. To be able to read out the whole data stream without loosing information, in particular without zero-suppression, a lossless compression algorithm, the Huffman encoding, was investigated and adapted to the needs of the TPC. In this talk, an algorithm, adapted for an FPGA implementation, is presented. We show its capability to reduce the data volume to less than 40% of its original size.

Chasseurs de Higgs au LHC - A la Recherche des l'Origines

CERN Multimedia

Yves Sirois

To increase understanding of the LHC, why scientists collaborate on this experiment and what they hope to achieve with the LHC. A 51 slide presentation in French for a general audience. Delivered at the "Cité des Sciences" in Paris, "Rencontres du Ciel et de l'Espace," November, 2010 This presentation covers the following topics: - The LHC --what it is --what it looks like --where it is located --the international nature of CERN & experiment collaborations --the experiments - Accelerators --a brief history on accelerators --what accelerators can do - The scientific goals of the LHC - Particle Physics in General --history & the basics - Impact on Technology and Society - First LHC Results - Concluding remarks

LHC Report: a very productive hiatus

CERN Document Server

Mike Lamont for the LHC team

2015-01-01

On Monday, 24 August, the LHC transitioned from nascent 25 ns operation to a two-week hiatus devoted to luminosity calibration (two days), machine development (five days) and a technical stop (five days).   No stopping for Sunday at the CERN Control Centre. (Image: Rogelio Tomás García) Accurate calibration of the luminosity is vital input for many of an experiment’s measurements. The luminosity is calibrated using separation scans pioneered in 1968 by Simon van der Meer at the ISR. In these scans, carefully prepared beams are stepped across each other, horizontally and vertically, one plane at a time. Accurate measurements of the interaction rates, beam intensity, beam movement during the scan and other factors allow determination of the absolute luminosity. ATLAS, ALICE, CMS and LHCb all had dedicated time for Van der Meer scans. TOTEM and ALFA also took advantage of the special conditions to take data. The LHC machine development (MD) period that followed consis...

Multi-strange baryon production in pp collisions at $\\sqrt{s}$ = 7 TeV with ALICE

CERN Document Server

Abelev, Betty; Adamova, Dagmar; Adare, Andrew Marshall; Aggarwal, Madan; Aglieri Rinella, Gianluca; Agocs, Andras Gabor; Agostinelli, Andrea; Aguilar Salazar, Saul; Ahammed, Zubayer; Ahmad, Arshad; Ahmad, Nazeer; Ahn, Sang Un; Akindinov, Alexander; Aleksandrov, Dmitry; Alessandro, Bruno; Alfaro Molina, Jose Ruben; Alici, Andrea; Alkin, Anton; Almaraz Avina, Erick Jonathan; Alme, Johan; Alt, Torsten; Altini, Valerio; Altinpinar, Sedat; Altsybeev, Igor; Andrei, Cristian; Andronic, Anton; Anguelov, Venelin; Anielski, Jonas; Anson, Christopher Daniel; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Aphecetche, Laurent Bernard; Appelshauser, Harald; Arbor, Nicolas; Arcelli, Silvia; Arend, Andreas; Armesto, Nestor; Arnaldi, Roberta; Aronsson, Tomas Robert; Arsene, Ionut Cristian; Arslandok, Mesut; Asryan, Andzhey; Augustinus, Andre; Averbeck, Ralf Peter; Awes, Terry; Aysto, Juha Heikki; Azmi, Mohd Danish; Bach, Matthias Jakob; Badala, Angela; Baek, Yong Wook; Bailhache, Raphaelle Marie; Bala, Renu; Baldini Ferroli, Rinaldo; Baldisseri, Alberto; Baldit, Alain; Baltasar Dos Santos Pedrosa, Fernando; Ban, Jaroslav; Baral, Rama Chandra; Barbera, Roberto; Barile, Francesco; Barnafoldi, Gergely Gabor; Barnby, Lee Stuart; Barret, Valerie; Bartke, Jerzy Gustaw; Basile, Maurizio; Bastid, Nicole; Basu, Sumit; Bathen, Bastian; Batigne, Guillaume; Batyunya, Boris; Baumann, Christoph Heinrich; Bearden, Ian Gardner; Beck, Hans; Behera, Nirbhay Kumar; Belikov, Iouri; Bellini, Francesca; Bellwied, Rene; Belmont-Moreno, Ernesto; Bencedi, Gyula; Beole, Stefania; Berceanu, Ionela; Bercuci, Alexandru; Berdnikov, Yaroslav; Berenyi, Daniel; Berzano, Dario; Betev, Latchezar; Bhasin, Anju; Bhati, Ashok Kumar; Bhom, Jihyun; Bianchi, Livio; Bianchi, Nicola; Bianchin, Chiara; Bielcik, Jaroslav; Bielcikova, Jana; Bilandzic, Ante; Bjelogrlic, Sandro; Blanco, Francesco; Blanco, F; Blau, Dmitry; Blume, Christoph; Boccioli, Marco; Bock, Nicolas; Boettger, Stefan; Bogdanov, Alexey; Boggild, Hans; Bogolyubsky, Mikhail; Boldizsar, Laszlo; Bombara, Marek; Book, Julian; Borel, Herve; Borissov, Alexander; Bose, Suvendu Nath; Bossu, Francesco; Botje, Michiel; Boyer, Bruno Alexandre; Braidot, Ermes; Braun-Munzinger, Peter; Bregant, Marco; Breitner, Timo Gunther; Browning, Tyler Allen; Broz, Michal; Brun, Rene; Bruna, Elena; Bruno, Giuseppe Eugenio; Budnikov, Dmitry; Buesching, Henner; Bufalino, Stefania; Bugaiev, Kyrylo; Busch, Oliver; Buthelezi, Edith Zinhle; Caballero Orduna, Diego; Caffarri, Davide; Cai, Xu; Caines, Helen Louise; Calvo Villar, Ernesto; Camerini, Paolo; Canoa Roman, Veronica; Cara Romeo, Giovanni; Carena, Francesco; Carena, Wisla; Carlin Filho, Nelson; Carminati, Federico; Carrillo Montoya, Camilo Andres; Casanova Diaz, Amaya Ofelia; Castillo Castellanos, Javier Ernesto; Castillo Hernandez, Juan Francisco; Casula, Ester Anna Rita; Catanescu, Vasile; Cavicchioli, Costanza; Ceballos Sanchez, Cesar; Cepila, Jan; Cerello, Piergiorgio; Chang, Beomsu; Chapeland, Sylvain; Charvet, Jean-Luc Fernand; Chattopadhyay, Sukalyan; Chattopadhyay, Subhasis; Chawla, Isha; Cherney, Michael Gerard; Cheshkov, Cvetan; Cheynis, Brigitte; Chibante Barroso, Vasco Miguel; Chinellato, David; Chochula, Peter; Chojnacki, Marek; Choudhury, Subikash; Christakoglou, Panagiotis; Christensen, Christian Holm; Christiansen, Peter; Chujo, Tatsuya; Chung, Suh-Urk; Cicalo, Corrado; Cifarelli, Luisa; Cindolo, Federico; Cleymans, Jean Willy Andre; Coccetti, Fabrizio; Colamaria, Fabio; Colella, Domenico; Conesa Balbastre, Gustavo; Conesa del Valle, Zaida; Constantin, Paul; Contin, Giacomo; Contreras, Jesus Guillermo; Cormier, Thomas Michael; Corrales Morales, Yasser; Cortese, Pietro; Cortes Maldonado, Ismael; Cosentino, Mauro Rogerio; Costa, Filippo; Cotallo, Manuel Enrique; Crescio, Elisabetta; Crochet, Philippe; Cruz Alaniz, Emilia; Cuautle, Eleazar; Cunqueiro, Leticia; Dainese, Andrea; Dalsgaard, Hans Hjersing; Danu, Andrea; Das, Debasish; Das, Kushal; Das, Indranil; Dash, Sadhana; Dash, Ajay Kumar; De, Sudipan; de Barros, Gabriel; De Caro, Annalisa; de Cataldo, Giacinto; de Cuveland, Jan; De Falco, Alessandro; De Gruttola, Daniele; Delagrange, Hugues; Del Castillo Sanchez, Eduardo; Deloff, Andrzej; Demanov, Vyacheslav; De Marco, Nora; Denes, Ervin; De Pasquale, Salvatore; Deppman, Airton; D'Erasmo, Ginevra; de Rooij, Raoul Stefan; Diaz Corchero, Miguel Angel; Di Bari, Domenico; Dietel, Thomas; Di Giglio, Carmelo; Di Liberto, Sergio; Di Mauro, Antonio; Di Nezza, Pasquale; Divia, Roberto; Djuvsland, Oeystein; Dobrin, Alexandru Florin; Dobrowolski, Tadeusz Antoni; Dominguez, Isabel; Donigus, Benjamin; Dordic, Olja; Driga, Olga; Dubey, Anand Kumar; Ducroux, Laurent; Dupieux, Pascal; Dutta Majumdar, AK; Dutta Majumdar, Mihir Ranjan; Elia, Domenico; Emschermann, David Philip; Engel, Heiko; Erdal, Hege Austrheim; Espagnon, Bruno; Estienne, Magali Danielle; Esumi, Shinichi; Evans, David; Eyyubova, Gyulnara; Fabris, Daniela; Faivre, Julien; Falchieri, Davide; Fantoni, Alessandra; Fasel, Markus; Fearick, Roger Worsley; Fedunov, Anatoly; Fehlker, Dominik; Feldkamp, Linus; Felea, Daniel; Fenton-Olsen, Bo; Feofilov, Grigory; Fernandez Tellez, Arturo; Ferretti, Roberta; Ferretti, Alessandro; Figiel, Jan; Figueredo, Marcel; Filchagin, Sergey; Finogeev, Dmitry; Fionda, Fiorella; Fiore, Enrichetta Maria; Floris, Michele; Foertsch, Siegfried Valentin; Foka, Panagiota; Fokin, Sergey; Fragiacomo, Enrico; Frankenfeld, Ulrich Michael; Fuchs, Ulrich; Furget, Christophe; Fusco Girard, Mario; Gaardhoje, Jens Joergen; Gagliardi, Martino; Gago, Alberto; Gallio, Mauro; Gangadharan, Dhevan Raja; Ganoti, Paraskevi; Garabatos, Jose; Garcia-Solis, Edmundo; Garishvili, Irakli; Gerhard, Jochen; Germain, Marie; Geuna, Claudio; Gheata, Andrei George; Gheata, Mihaela; Ghidini, Bruno; Ghosh, Premomoy; Gianotti, Paola; Girard, Martin Robert; Giubellino, Paolo; Gladysz-Dziadus, Ewa; Glassel, Peter; Gomez, Ramon; Gonzalez Ferreiro, Elena; Gonzalez-Trueba, Laura Helena; Gonzalez-Zamora, Pedro; Gorbunov, Sergey; Goswami, Ankita; Gotovac, Sven; Grabski, Varlen; Graczykowski, Lukasz Kamil; Grajcarek, Robert; Grelli, Alessandro; Grigoras, Costin; Grigoras, Alina Gabriela; Grigoriev, Vladislav; Grigoryan, Ara; Grigoryan, Smbat; Grinyov, Boris; Grion, Nevio; Gros, Philippe; Grosse-Oetringhaus, Jan Fiete; Grossiord, Jean-Yves; Grosso, Raffaele; Guber, Fedor; Guernane, Rachid; Guerra Gutierrez, Cesar; Guerzoni, Barbara; Guilbaud, Maxime Rene Joseph; Gulbrandsen, Kristjan Herlache; Gunji, Taku; Gupta, Anik; Gupta, Ramni; Gutbrod, Hans; Haaland, Oystein Senneset; Hadjidakis, Cynthia Marie; Haiduc, Maria; Hamagaki, Hideki; Hamar, Gergoe; Han, Byounghee; Hanratty, Luke David; Hansen, Alexander; Harmanova, Zuzana; Harris, John William; Hartig, Matthias; Hasegan, Dumitru; Hatzifotiadou, Despoina; Hayrapetyan, Arsen; Heckel, Stefan Thomas; Heide, Markus Ansgar; Helstrup, Haavard; Herghelegiu, Andrei Ionut; Herrera Corral, Gerardo Antonio; Herrmann, Norbert; Hetland, Kristin Fanebust; Hicks, Bernard; Hille, Per Thomas; Hippolyte, Boris; Horaguchi, Takuma; Hori, Yasuto; Hristov, Peter Zahariev; Hrivnacova, Ivana; Huang, Meidana; Humanic, Thomas; Hwang, Dae Sung; Ichou, Raphaelle; Ilkaev, Radiy; Ilkiv, Iryna; Inaba, Motoi; Incani, Elisa; Innocenti, Pier Giorgio; Innocenti, Gian Michele; Ippolitov, Mikhail; Irfan, Muhammad; Ivan, Cristian George; Ivanov, Andrey; Ivanov, Vladimir; Ivanov, Marian; Ivanytskyi, Oleksii; Jacholkowski, Adam Wlodzimierz; Jacobs, Peter; Jancurova, Lucia; Jang, Haeng Jin; Jangal, Swensy Gwladys; Janik, Rudolf; Janik, Malgorzata Anna; Jayarathna, Sandun; Jena, Satyajit; Jha, Deeptanshu Manu; Jimenez Bustamante, Raul Tonatiuh; Jirden, Lennart; Jones, Peter Graham; Jung, Hyung Taik; Jusko, Anton; Kaidalov, Alexei; Kakoyan, Vanik; Kalcher, Sebastian; Kalinak, Peter; Kalisky, Matus; Kalliokoski, Tuomo Esa Aukusti; Kalweit, Alexander Philipp; Kanaki, Kalliopi; Kang, Ju Hwan; Kaplin, Vladimir; Karasu Uysal, Ayben; Karavichev, Oleg; Karavicheva, Tatiana; Karpechev, Evgeny; Kazantsev, Andrey; Kebschull, Udo Wolfgang; Keidel, Ralf; Khan, Palash; Khan, Shuaib Ahmad; Khan, Mohisin Mohammed; Khanzadeev, Alexei; Kharlov, Yury; Kileng, Bjarte; Kim, Taesoo; Kim, Beomkyu; Kim, Dong Jo; Kim, Se Yong; Kim, Do Won; Kim, Jonghyun; Kim, Jin Sook; Kim, Mimae; Kim, Minwoo; Kim, Seon Hee; Kirsch, Stefan; Kisel, Ivan; Kiselev, Sergey; Kisiel, Adam Ryszard; Klay, Jennifer Lynn; Klein, Jochen; Klein-Bosing, Christian; Kliemant, Michael; Kluge, Alexander; Knichel, Michael Linus; Knospe, Anders Garritt; Koch, Kathrin; Kohler, Markus; Kolojvari, Anatoly; Kondratiev, Valery; Kondratyeva, Natalia; Konevskih, Artem; Korneev, Andrey; Kour, Ravjeet; Kowalski, Marek; Kox, Serge; Koyithatta Meethaleveedu, Greeshma; Kral, Jiri; Kralik, Ivan; Kramer, Frederick; Kraus, Ingrid Christine; Krawutschke, Tobias; Krelina, Michal; Kretz, Matthias; Krivda, Marian; Krizek, Filip; Krus, Miroslav; Kryshen, Evgeny; Krzewicki, Mikolaj; Kucheriaev, Yury; Kuhn, Christian Claude; Kuijer, Paul; Kurashvili, Podist; Kurepin, A; Kurepin, AB; Kuryakin, Alexey; Kushpil, Vasily; Kushpil, Svetlana; Kvaerno, Henning; Kweon, Min Jung; Kwon, Youngil; Ladron de Guevara, Pedro; Lakomov, Igor; Langoy, Rune; La Pointe, Sarah Louise; Lara, Camilo Ernesto; Lardeux, Antoine Xavier; La Rocca, Paola; Lazzeroni, Cristina; Lea, Ramona; Le Bornec, Yves; Lechman, Mateusz; Lee, Sung Chul; Lee, Ki Sang; Lefevre, Frederic; Lehnert, Joerg Walter; Leistam, Lars; Lenhardt, Matthieu Laurent; Lenti, Vito; Leon, Hermes; Leon Monzon, Ildefonso; Leon Vargas, Hermes; Levai, Peter; Lien, Jorgen; Lietava, Roman; Lindal, Svein; Lindenstruth, Volker; Lippmann, Christian; Lisa, Michael Annan; Liu, Lijiao; Loenne, Per-Ivar; Loggins, Vera; Loginov, Vitaly; Lohn, Stefan Bernhard; Lohner, Daniel; Loizides, Constantinos; Loo, Kai Krister; Lopez, Xavier Bernard; Lopez Torres, Ernesto; Lovhoiden, Gunnar; Lu, Xianguo; Luettig, Philipp; Lunardon, Marcello; Luo, Jiebin; Luparello, Grazia; Luquin, Lionel; Luzzi, Cinzia; Ma, Rongrong; Ma, Ke; Madagodahettige-Don, Dilan Minthaka; Maevskaya, Alla; Mager, Magnus; Mahapatra, Durga Prasad; Maire, Antonin; Malaev, Mikhail; Maldonado Cervantes, Ivonne Alicia; Malinina, Ludmila; Mal'Kevich, Dmitry; Malzacher, Peter; Mamonov, Alexander; Manceau, Loic Henri Antoine; Mangotra, Lalit Kumar; Manko, Vladislav; Manso, Franck; Manzari, Vito; Mao, Yaxian; Marchisone, Massimiliano; Mares, Jiri; Margagliotti, Giacomo Vito; Margotti, Anselmo; Marin, Ana Maria; Marin Tobon, Cesar Augusto; Markert, Christina; Martashvili, Irakli; Martinengo, Paolo; Martinez, Mario Ivan; Martinez Davalos, Arnulfo; Martinez Garcia, Gines; Martynov, Yevgen; Mas, Alexis Jean-Michel; Masciocchi, Silvia; Masera, Massimo; Masoni, Alberto; Massacrier, Laure Marie; Mastromarco, Mario; Mastroserio, Annalisa; Matthews, Zoe Louise; Matyja, Adam Tomasz; Mayani, Daniel; Mayer, Christoph; Mazer, Joel; Mazzoni, Alessandra Maria; Meddi, Franco; Menchaca-Rocha, Arturo Alejandro; Mercado Perez, Jorge; Meres, Michal; Miake, Yasuo; Milano, Leonardo; Milosevic, Jovan; Mischke, Andre; Mishra, Aditya Nath; Miskowiec, Dariusz; Mitu, Ciprian Mihai; Mlynarz, Jocelyn; Mohanty, Bedangadas; Mohanty, Ajit Kumar; Molnar, Levente; Montano Zetina, Luis Manuel; Monteno, Marco; Montes, Esther; Moon, Taebong; Morando, Maurizio; Moreira De Godoy, Denise Aparecida; Moretto, Sandra; Morsch, Andreas; Muccifora, Valeria; Mudnic, Eugen; Muhuri, Sanjib; Mukherjee, Maitreyee; Muller, Hans; Munhoz, Marcelo; Musa, Luciano; Musso, Alfredo; Nandi, Basanta Kumar; Nania, Rosario; Nappi, Eugenio; Nattrass, Christine; Naumov, Nikolay; Navin, Sparsh; Nayak, Tapan Kumar; Nazarenko, Sergey; Nazarov, Gleb; Nedosekin, Alexander; Nicassio, Maria; Nielsen, Borge Svane; Niida, Takafumi; Nikolaev, Sergey; Nikolic, Vedran; Nikulin, Vladimir; Nikulin, Sergey; Nilsen, Bjorn Steven; Nilsson, Mads Stormo; Noferini, Francesco; Nomokonov, Petr; Nooren, Gerardus; Novitzky, Norbert; Nyanin, Alexandre; Nyatha, Anitha; Nygaard, Casper; Nystrand, Joakim Ingemar; Ochirov, Alexander; Oeschler, Helmut Oskar; Oh, Saehanseul; Oh, Sun Kun; Oleniacz, Janusz; Oppedisano, Chiara; Ortiz Velasquez, Antonio; Ortona, Giacomo; Oskarsson, Anders Nils Erik; Ostrowski, Piotr Krystian; Otwinowski, Jacek Tomasz; Oyama, Ken; Ozawa, Kyoichiro; Pachmayer, Yvonne Chiara; Pachr, Milos; Padilla, Fatima; Pagano, Paola; Paic, Guy; Painke, Florian; Pajares, Carlos; Pal, Susanta Kumar; Pal, S; Palaha, Arvinder Singh; Palmeri, Armando; Papikyan, Vardanush; Pappalardo, Giuseppe; Park, Woo Jin; Passfeld, Annika; Pastircak, Blahoslav; Patalakha, Dmitri Ivanovich; Paticchio, Vincenzo; Pavlinov, Alexei; Pawlak, Tomasz Jan; Peitzmann, Thomas; Pereira Da Costa, Hugo Denis Antonio; Pereira De Oliveira Filho, Elienos; Peresunko, Dmitri; Perez Lara, Carlos Eugenio; Perez Lezama, Edgar; Perini, Diego; Perrino, Davide; Peryt, Wiktor Stanislaw; Pesci, Alessandro; Peskov, Vladimir; Pestov, Yury; Petracek, Vojtech; Petran, Michal; Petris, Mariana; Petrov, Plamen Rumenov; Petrovici, Mihai; Petta, Catia; Piano, Stefano; Piccotti, Anna; Pikna, Miroslav; Pillot, Philippe; Pinazza, Ombretta; Pinsky, Lawrence; Pitz, Nora; Piyarathna, Danthasinghe; Ploskon, Mateusz Andrzej; Pluta, Jan Marian; Pocheptsov, Timur; Pochybova, Sona; Podesta Lerma, Pedro Luis Manuel; Poghosyan, Martin; Polak, Karel; Polichtchouk, Boris; Pop, Amalia; Porteboeuf-Houssais, Sarah; Pospisil, Vladimir; Potukuchi, Baba; Prasad, Sidharth Kumar; Preghenella, Roberto; Prino, Francesco; Pruneau, Claude Andre; Pshenichnov, Igor; Puchagin, Sergey; Puddu, Giovanna; Pujol Teixido, Jordi; Pulvirenti, Alberto; Punin, Valery; Putis, Marian; Putschke, Jorn Henning; Quercigh, Emanuele; Qvigstad, Henrik; Rachevski, Alexandre; Rademakers, Alphonse; Radomski, Sylwester; Raiha, Tomi Samuli; Rak, Jan; Rakotozafindrabe, Andry Malala; Ramello, Luciano; Ramirez Reyes, Abdiel; Raniwala, Sudhir; Raniwala, Rashmi; Rasanen, Sami Sakari; Rascanu, Bogdan Theodor; Rathee, Deepika; Read, Kenneth Francis; Real, Jean-Sebastien; Redlich, Krzysztof; Reichelt, Patrick; Reicher, Martijn; Renfordt, Rainer Arno Ernst; Reolon, Anna Rita; Reshetin, Andrey; 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Wang, Mengliang; Watanabe, Kengo; Wessels, Johannes; Westerhoff, Uwe; Wiechula, Jens; Wikne, Jon; Wilde, Martin Rudolf; Wilk, Grzegorz Andrzej; Wilk, Alexander; Williams, Crispin; Windelband, Bernd Stefan; Xaplanteris Karampatsos, Leonidas; Yaldo, Chris G; Yang, Shiming; Yang, Hongyan; Yasnopolsky, Stanislav; Yi, JunGyu; Yin, Zhongbao; Yoo, In-Kwon; Yoon, Jongik; Yu, Weilin; Yuan, Xianbao; Yushmanov, Igor; Zach, Cenek; Zampolli, Chiara; Zaporozhets, Sergey; Zarochentsev, Andrey; Zavada, Petr; Zaviyalov, Nikolai; Zbroszczyk, Hanna Paulina; Zelnicek, Pierre; Zgura, Sorin Ion; Zhalov, Mikhail; Zhang, Xiaoming; Zhang, Haitao; Zhou, You; Zhou, Daicui; Zhou, Fengchu; Zhu, Jianhui; Zhu, Xiangrong; Zhu, Jianlin; Zichichi, Antonino; Zimmermann, Alice; Zinovjev, Gennady; Zoccarato, Yannick Denis; Zynovyev, Mykhaylo

2013-07-16

A measurement of the multi-strange Xi- and Omega- baryons and their antiparticles by the ALICE experiment at the CERN Large Hadron Collider (LHC) is presented for proton-proton collisions at centre of mass energy of 7 TeV. The transverse momentum (pt) distributions were studied at mid-rapidity (|y| 6.0 GeV/c. We also illustrate the difference between the experimental data and model by comparing the corresponding ratios of (Omega-+Omega+)/(Xi-+Xi+) as a function of transverse mass.

Integration of XRootD into the cloud infrastructure for ALICE data analysis

CERN Document Server

Kompaniets, Mikhail; Svirin, Pavlo; Yurchenko, Volodymyr; Zarochentsev, Andrey

2015-01-01

Cloud technologies allow easy load balancing between different tasks and projects. From the viewpoint of the data analysis in the ALICE experiment, cloud allows to deploy software using Cern Virtual Machine (CernVM) and CernVM File System (CVMFS), to run different (including outdated) versions of software for long term data preservation and to dynamically allocate resources for different computing activities, e.g. grid site, ALICE Analysis Facility (AAF) and possible usage for local projects or other LHC experiments.We present a cloud solution for Tier-3 sites based on OpenStack and Ceph distributed storage with an integrated XRootD based storage element (SE). One of the key features of the solution is based on idea that Ceph has been used as a backend for Cinder Block Storage service for OpenStack, and in the same time as a storage backend for XRootD, with redundancy and availability of data preserved by Ceph settings. For faster and easier OpenStack deployment was applied the Packstack solution, which is ba...

A radiation tolerance study of the ALICE TPC Readout Control Unit 2

CERN Document Server

Zhao, Chengxin; Balk, Helge; Alme, Johan

2017-11-17

ALICE is a general-purpose detector that is designed to study the physics of quark-gluon plasma. The Time Projection Chamber (TPC) is one of the major detectors of ALICE. The TPC electronics consists of 4356 Front-end cards (FECs), which are controlled by 216 Readout Control Units (RCU). Each RCU connects to between 18 and 25 FECs using a multi-drop bus. In LHC Run1, the Readout Control Unit 1 (RCU1) performed even better than specification. However, in Run2 the energy of colliding beams is increased from 8 TeV to 14 TeV (maximum value) and higher luminosity, which leads to larger event size and higher radiation load on the electronics. As a solution, the Readout Control Unit 2 (RCU2) is designed to provide faster readout speed and improved radiation tolerance with respect to the RCU1. The RCU2 is conceptually similar to the RCU1 and it reuses the existing infrastructure and readout architecture of the TPC electronics. However, the multi-drop bus is split into four branches from the two branches and the bandw...

Recent ALICE results on Pb-Pb and p-Pb Ultra Peripheral Collisions

CERN Multimedia

CERN. Geneva

2013-01-01

The strong electromagnetic fields surrounding the Pb-ions acceleratedat the LHC allow two-photon, photon-proton and photon-lead interactions to be studied in a new kinematic regime. These interactions can be studied in ultra-peripheral collisions,where the impact parameters are larger than the sum of the nuclear radii and hadronic interactions are suppressed. During the lead-lead runs at the LHC in 2010 and 2011, and during the proton-lead run in 2013, the ALICE experiment implemented dedicated triggers to select ultra-peripheral collisions. Based on signals from the Muon spectrometer, the Time-of-Flight detector, the Silicon Pixel detector, and the VZERO scintillator array. The cross section for photoproduction of J/Psi mesons at mid- and forward-rapidities in Pb-Pb collisions will be presented. The results will be compared to model calculations and their implications for the study of nuclear gluon shadowing will be discussed. First results on J/Psi photoproduction in p-Pb collisions will also be discussed ...

Online Calibration of the TPC Drift Time in the ALICE High Level Trigger

Science.gov (United States)

Rohr, David; Krzewicki, Mikolaj; Zampolli, Chiara; Wiechula, Jens; Gorbunov, Sergey; Chauvin, Alex; Vorobyev, Ivan; Weber, Steffen; Schweda, Kai; Lindenstruth, Volker

2017-06-01

A Large Ion Collider Experiment (ALICE) is one of the four major experiments at the Large Hadron Collider (LHC) at CERN. The high level trigger (HLT) is a compute cluster, which reconstructs collisions as recorded by the ALICE detector in real-time. It employs a custom online data-transport framework to distribute data and workload among the compute nodes. ALICE employs subdetectors that are sensitive to environmental conditions such as pressure and temperature, e.g., the time projection chamber (TPC). A precise reconstruction of particle trajectories requires calibration of these detectors. Performing calibration in real time in the HLT improves the online reconstructions and renders certain offline calibration steps obsolete speeding up offline physics analysis. For LHC Run 3, starting in 2020 when data reduction will rely on reconstructed data, online calibration becomes a necessity. Reconstructed particle trajectories build the basis for the calibration making a fast online-tracking mandatory. The main detectors used for this purpose are the TPC and Inner Tracking System. Reconstructing the trajectories in the TPC is the most compute-intense step. We present several improvements to the ALICE HLT developed to facilitate online calibration. The main new development for online calibration is a wrapper that can run ALICE offline analysis and calibration tasks inside the HLT. In addition, we have added asynchronous processing capabilities to support long-running calibration tasks in the HLT framework, which runs event-synchronously otherwise. In order to improve the resiliency, an isolated process performs the asynchronous operations such that even a fatal error does not disturb data taking. We have complemented the original loop-free HLT chain with ZeroMQ data-transfer components. The ZeroMQ components facilitate a feedback loop that inserts the calibration result created at the end of the chain back into tracking components at the beginning of the chain, after a

A tool for optimization of the production and user analysis on the Grid, C. Grigoras for the ALICE Collaboration

Science.gov (United States)

Grigoras, Costin; Carminati, Federico; Vladimirovna Datskova, Olga; Schreiner, Steffen; Lee, Sehoon; Zhu, Jianlin; Gheata, Mihaela; Gheata, Andrei; Saiz, Pablo; Betev, Latchezar; Furano, Fabrizio; Mendez Lorenzo, Patricia; Grigoras, Alina Gabriela; Bagnasco, Stefano; Peters, Andreas Joachim; Saiz Santos, Maria Dolores

2011-12-01

With the LHC and ALICE entering a full operation and production modes, the amount of Simulation and RAW data processing and end user analysis computational tasks are increasing. The efficient management of all these tasks, all of which have large differences in lifecycle, amounts of processed data and methods to analyze the end result, required the development and deployment of new tools in addition to the already existing Grid infrastructure. To facilitate the management of the large scale simulation and raw data reconstruction tasks, ALICE has developed a production framework called a Lightweight Production Manager (LPM). The LPM is automatically submitting jobs to the Grid based on triggers and conditions, for example after a physics run completion. It follows the evolution of the job and publishes the results on the web for worldwide access by the ALICE physicists. This framework is tightly integrated with the ALICE Grid framework AliEn. In addition to the publication of the job status, LPM is also allowing a fully authenticated interface to the AliEn Grid catalogue, to browse and download files, and in the near future will provide simple types of data analysis through ROOT plugins. The framework is also being extended to allow management of end user jobs.

A tool for optimization of the production and user analysis on the Grid, C. Grigoras for the ALICE Collaboration

International Nuclear Information System (INIS)

Grigoras, Costin; Carminati, Federico; Vladimirovna Datskova, Olga; Schreiner, Steffen; Gheata, Mihaela; Gheata, Andrei; Saiz, Pablo; Betev, Latchezar; Furano, Fabrizio; Lorenzo, Patricia Mendez; Grigoras, Alina Gabriela; Peters, Andreas Joachim; Saiz Santos, Maria Dolores; Lee, Sehoon; Zhu Jianlin; Bagnasco, Stefano

2011-01-01

With the LHC and ALICE entering a full operation and production modes, the amount of Simulation and RAW data processing and end user analysis computational tasks are increasing. The efficient management of all these tasks, all of which have large differences in lifecycle, amounts of processed data and methods to analyze the end result, required the development and deployment of new tools in addition to the already existing Grid infrastructure. To facilitate the management of the large scale simulation and raw data reconstruction tasks, ALICE has developed a production framework called a Lightweight Production Manager (LPM). The LPM is automatically submitting jobs to the Grid based on triggers and conditions, for example after a physics run completion. It follows the evolution of the job and publishes the results on the web for worldwide access by the ALICE physicists. This framework is tightly integrated with the ALICE Grid framework AliEn. In addition to the publication of the job status, LPM is also allowing a fully authenticated interface to the AliEn Grid catalogue, to browse and download files, and in the near future will provide simple types of data analysis through ROOT plugins. The framework is also being extended to allow management of end user jobs.

Azimuthally sensitive Hanbury Brown-Twiss interferometry measured with the ALICE experiment

Energy Technology Data Exchange (ETDEWEB)

Gramling, Johanna Lena

2011-07-01

Bose-Einstein correlations of identical pions emitted in high-energy particle collisions provide information about the size of the source region in space-time. If analyzed via HBT Interferometry in several directions with respect to the reaction plane, the shape of the source can be extracted. Hence, HBT Interferometry provides an excellent tool to probe the characteristics of the quark-gluon plasma possibly created in high-energy heavy-ion collisions. This thesis introduces the main theoretical concepts of particle physics, the quark gluon plasma and the technique of HBT interferometry. The ALICE experiment at the CERN Large Hadron Collider (LHC) is explained and the first azimuthallyintegrated results measured in Pb-Pb collisions at √(s{sub NN})=2.76 TeV with ALICE are presented. A detailed two-track resolution study leading to a global pair cut for HBT analyses has been performed, and a framework for the event plane determination has been developed. The results from azimuthally sensitive HBT interferometry are compared to theoretical models and previous measurements at lower energies. Oscillations of the transverse radii in dependence on the pair emission angle are observed, consistent with a source that is extended out-of-plane.

Very high momentum particle identification in ALICE at the LHC

CERN Document Server

Agocs, A; Barnafoldi, G G; Boldizsar, L; Cuautle, E; De Cataldo, G; Di Bari, D; Di Mauro, A; Dominguez, I; Fodor, Z; Futo, E; Garcia, E; Hamar, G; Harris, J W; Levai, P; Martinengo, P; Mayani, D; Molnar, L; Nappi, E; Ortiz, A; Paic, G; Perini, D; Perrino, D; Peskov, V; Piuz, F; Smirnov, N; Varga, D; Volpe, G

2010-01-01

We propose to construct and install a limited acceptance detector to identify hadrons (pions, K, p) up to 30 GeV/c on a track-by-track basis in space available in ALICE. Details and PID performance simulation results will be presented for two possible options, including a high transverse momentum (pT) trigger for this detector. The first option is a RICH design with a C4F10 gas UV-photon radiator, UV-mirror, quartz window and pad-readout. This design requires additional tracking detectors to enable high pT triggering. A second option is a combination of three detectors: a RICH with CF4 gas both as a UV-photon radiator and as a gas amplification medium (a windowless approach); and a threshold Cherenkov detector (C4F10) with a quartz window and pad readout. The response for minimum ionizing particles (MIP) and UV-photons in these detectors can be well separated. With an additional tracking detector this design will also provide high pT triggering. The simulation includes UV-photon production due to CF4 scintill...

Exclusive photoproduction of quarkonium at the LHC energies within the color dipole approach

Energy Technology Data Exchange (ETDEWEB)

Ducati, M. B. Gay; Griep, M. T.; Machado, M. V. T. [High Energy Physics Phenomenology Group, GFPAE IF-UFRGS, Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS (Brazil)

2015-04-10

The exclusive photoproduction of ψ(2S) meson was investigated and the coherent and the incoherent contributions were evaluated. The light-cone dipole formalism was considered in this analysis and predictions are done for PbPb collisions at the CERN-LHC energy of 2.76 TeV. A comparison is done to the recent ALICE Collaboration data for the ψ(1S) state photoproduction with good agreement.

ALICE & LHCb: refinements for the restart

CERN Multimedia

2009-01-01

Following the previous issue, the Bulletin continues its series to find out what the six LHC experiments have been up to since last September, and how they are preparing for the restart. Previously we looked at CMS and ATLAS; this issue we will round up the past 10 months of activity at ALICE and LHCb. LHCb The cavern of the LHCb experiment. This year has given LHCb the chance to install the 5th and final plane of muon chambers, which will improve the triggering at nominal luminosity. This is the final piece of the experiment to be installed. "Now the detector looks exactly as it does in the technical design report," confirms Andrei Golutvin, LHCb Spokesperson. "We also took advantage of this shutdown to make several improvements. For example, we modified the high voltage system of the electromagnetic calorimeter to reduce noise further to a negligible level. We also took some measures to improve ...

Integration of XRootD into the cloud infrastructure for ALICE data analysis

Science.gov (United States)

Kompaniets, Mikhail; Shadura, Oksana; Svirin, Pavlo; Yurchenko, Volodymyr; Zarochentsev, Andrey

2015-12-01

Cloud technologies allow easy load balancing between different tasks and projects. From the viewpoint of the data analysis in the ALICE experiment, cloud allows to deploy software using Cern Virtual Machine (CernVM) and CernVM File System (CVMFS), to run different (including outdated) versions of software for long term data preservation and to dynamically allocate resources for different computing activities, e.g. grid site, ALICE Analysis Facility (AAF) and possible usage for local projects or other LHC experiments. We present a cloud solution for Tier-3 sites based on OpenStack and Ceph distributed storage with an integrated XRootD based storage element (SE). One of the key features of the solution is based on idea that Ceph has been used as a backend for Cinder Block Storage service for OpenStack, and in the same time as a storage backend for XRootD, with redundancy and availability of data preserved by Ceph settings. For faster and easier OpenStack deployment was applied the Packstack solution, which is based on the Puppet configuration management system. Ceph installation and configuration operations are structured and converted to Puppet manifests describing node configurations and integrated into Packstack. This solution can be easily deployed, maintained and used even in small groups with limited computing resources and small organizations, which usually have lack of IT support. The proposed infrastructure has been tested on two different clouds (SPbSU & BITP) and integrates successfully with the ALICE data analysis model.

Multiplicity and Underlying Event in ALICE: as measurements and as tools to probe QCD arXiv

CERN Document Server

INSPIRE-00361691

With the high collision energies at the LHC, the contributions to particle production from hard-QCD processes increase, but it remains dominated by soft-QCD processes. Such processes challenge the theoretical models, since they are described by non-perturbative phenomenology. A selection of the most recent ALICE measurements of charged-particle multiplicities and the Underlying Event will be presented, focusing on model comparisons. A summary of the current understanding of soft-QCD processes will be discussed, evaluating possible ways to further constrain theory.

Latin American collaboration to the CERN-LHC accelerator assembly and its projects

Energy Technology Data Exchange (ETDEWEB)

Sajo B, L. [Universidad Simon Bolivar, Nuclear Physics Laboratory, Caracas 1080-A (Venezuela, Bolivarian Republic of)

2016-10-15

Summary of Latin American (LA) scientists main contributions to the construction of a heavy ion detector assembly currently operating at the Large Hadron Collider (LHC) at CERN, Geneva,Switzerland is given with description of the provided support for posterior data analysis. This joint effort highlights the much needed recognition of LA as a technologically emerging region. It has also shown a net benefit in development of science for our region. Details are given on the LHC-Alice experiment where several LA countries have contributed with innovative technological solutions. These include the ability to build part of the numerous detectors, including the central barrel as well as acquired knowledge on aspects concerning high energy dosimetry and radiation damage. (Author)

Latin American collaboration to the CERN-LHC accelerator assembly and its projects

International Nuclear Information System (INIS)

Sajo B, L.

2016-10-01

Summary of Latin American (LA) scientists main contributions to the construction of a heavy ion detector assembly currently operating at the Large Hadron Collider (LHC) at CERN, Geneva,Switzerland is given with description of the provided support for posterior data analysis. This joint effort highlights the much needed recognition of LA as a technologically emerging region. It has also shown a net benefit in development of science for our region. Details are given on the LHC-Alice experiment where several LA countries have contributed with innovative technological solutions. These include the ability to build part of the numerous detectors, including the central barrel as well as acquired knowledge on aspects concerning high energy dosimetry and radiation damage. (Author)

Prospects for forward photon measurements at LHC

Directory of Open Access Journals (Sweden)

van Leeuwen Marco

2016-01-01

Full Text Available We present the opportunities to experimentally probe the gluon density at small x in nuclei to explore non-linear gluon evolution, saturation and the physics of the Color Glass Condensate by measuring photon production at forward rapidity in proton-nucleus collisions at the LHC. Performance studies for π0 and direct photon measurements based on simulations of a Forward Calorimeter (FoCal, which is under consideration as an upgrade for the ALICE detector, are presented. Other aspects of the FoCal physics program for pp, p+Pb and Pb+Pb collisions are briefly discussed as well.

Measurement of neutral mesons in pp and Pb-Pb collisions at mid-rapidity with ALICE

CERN Document Server

Morreale, Astrid

2016-01-01

One of the key signatures of the Quark-Gluon Plasma (QGP), is the modification of hadron transverse momentum differential cross-sections in heavy-ion collisions (HIC) as compared to proton-proton (pp) collisions. Suppression of hadron production at high transverse momenta (\\pt)~in HIC has been explained by the energy loss of the partons produced in the hard scattering processes which traverse the deconfined quantum chromodynamic (QCD) matter. The dependence of the observed suppression on the \\pt~ of the measured hadron towards higher \\pt~ is an important input for the theoretical understanding of jet quenching effects in the QGP and the nature of the energy loss. The ALICE experiment at the Large Hadron Collider (LHC) performs measurements of neutral meson inclusive spectra at mid-rapidity in a wide \\pt~ range in $pp$, $p$-Pb and Pb-Pb collisions. Neutral mesons ($\\pi^{0}$, $\\eta$, $\\omega$) are reconstructed via complementary methods, using the ALICE electromagnetic calorimeters, PHOS and EMCal, and by the c...

Development of Large Area CsI Photocathodes for the ALICE/HMPID RICH Detector

CERN Document Server

Hoedlmoser, H; Schyns, E

2005-01-01

The work carried out within the framework of this PhD deals with the measurement of the photoelectric properties of large area thin film Cesium Iodide (CsI) photocathodes (PCs) which are to be used as a photon converter in a proximity focusing RICH detector for High Momentum Particle Identification (HMPID) in the ALICE experiment at the LHC. The objective was to commission a VUV-scanner setup for in-situ measurements of the photoelectric response of the CsI PCs immediately after the thin film coating process and the use of this system to investigate the properties of these photon detectors. Prior to this work and prior to the finalization of the ALICE/HMPID detector design, R&D work investigating the properties of CsI PCs had been performed at CERN and at other laboratories in order to determine possible substrates and optimized thin film coating procedures. These R&D studies were usually carried out with small samples on different substrates and with various procedures with sometimes ambiguous result...

Particle Identification in Jets and High-Multiplicity pp Events with the ALICE TPC

CERN Document Server

AUTHOR|(SzGeCERN)683272; Vogelsang, Werner

The spectra of identified particles in a collision experiment comprise crucial information about the underlying physical processes. The ALICE experiment has powerful Particle IDentification (PID) capabilities, which are unique at the Large Hadron Collider (LHC). In this thesis, a statistical PID method based on the specific energy loss d$E$/d$x$ in the ALICE Time Projection Chamber (TPC) is developed: the TPC Multi-Template Fit (MTF). The MTF allows for the extraction of identified charged particle spectra in a wide momentum range, which extends from about 150 MeV/$c$ to above 20 GeV/$c$. The TPC PID requires a detailed modelling of the TPC d$E$/d$x$ response for momenta above 2-3 GeV/$c$. A framework is developed that allows for the determination of the model parameters and for evaluating the PID information of charged particles. With the MTF, the transverse momentum $p_{\\mathrm{T}}$ spectra of charged pions, kaons and protons at mid-rapidity ($|\\eta| < 0.9$) are measured for pp collisions at $\\sqrt{s}$ ...

Fitting ALICE

CERN Multimedia

2004-01-01

The support structures for the detectors inside the ALICE solenoid magnet (the L3 magnet) were finished in December 2003. After commissioning and testing, over the next year, the structures will be lowered into the cavern and installed in the magnet by spring 2005. At first sight you might mistake them for scaffolding. But a closer look reveals unusual features: Two are made of austenitic (non-magnetic) stainless steel with a cross section that looks like an "H". Another is made of 8 centimetre aluminium square tubes. "Them" are the support structures for the detectors and services inside the ALICE solenoid magnet (the L3 magnet) which were finished in December 2003. «The physicists don't want to have a lot of material close to their detectors; it has to be as few as possible,» says Diego Perini, who is responsible for the common support structures of ALICE. «We therefore had the very difficult task to design something relatively light that i...

ALICE Cosmic Ray Detector

CERN Multimedia

Fernandez Tellez, A; Martinez Hernandez, M; Rodriguez Cahuantzi, M

2013-01-01

The ALICE underground cavern provides an ideal place for the detection of high energy atmospheric muons coming from cosmic ray showers. ACORDE detects cosmic ray showers by triggering the arrival of muons to the top of the ALICE magnet.

ALICE honours two Italian suppliers

CERN Multimedia

2006-01-01

During the ALICE week held in Bologna from 19 to 23 June, the Collaboration recognized two of its top suppliers. From left to right: Robert Terpin (MIPOT), Pier Luigi Bellutti (ITC), Andrea Zanotti, President of ITC, Luciano Bosisio (Trieste University), Gennady Zinovjev (Kiev), Catherine Decosse (CERN), Lodovico Riccati, ALICE Collaboration Board Chair (INFN Torino), Paolo Giubellino (INFN Torino), Mario Zen, Director of ITC, Maurizio Boscardin (ITC), Paolo Tonella (ITC), Jurgen Schukraft, ALICE Spokesperson (CERN), Giacomo Vito Margagliotti (Trieste University), Nevio Grion (INFN Trieste), Marco Bregant (INFN Trieste). Front row from left to right: Paolo Traverso (ITC), Federico Carminati, ALICE Computing Project Leader (CERN), and Jean-Robert Lutz, ITS-SSD Project leader (IPHC Strasbourg). It is in the picturesque city of Bologna that the ALICE Collaboration has rewarded two Italian suppliers, Istituto Trentino di Cultura ITC-irst (Trento) and MIPOT (Cormons), both involved in the construction of the Sili...

First results from ALICE on anisotropic flow at Run 2 at LHC

CERN Multimedia

CERN. Geneva

2016-01-01

The goal of studies with relativistic heavy-ion collisions is to investigate the Quark-Gluon Plasma (QGP), a state of matter where quarks and gluons move freely over distances large in comparison to the typical size of a hadron. The exploration of QGP properties has broken new ground with the recent heavy-ion collisions from Run 2 operations at Large Hadron Collider, at the highest energies to date. The ALICE Collaboration has made the first observation of anisotropic flow of charged particles in lead-lead collisions at the record breaking energy of 5.02 TeV per nucleon pair. The talk presents these new results and discusses how they further enlighten the properties of matter produced in ultrarelativistic nuclear collisions.

Measurement of azimuthal correlations of D$^{+}$ mesons with charged particles in pp collisions at $\\sqrt{s}$ = 7 TeV and p-Pb collisions at $\\sqrt{s_{\\mathrm{NN}}}$ = 5.02 TeV with ALICE at the LHC

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00361265

ALICE (A Large Ion Collider Experiment) was designed for the study of heavy-ion collisions at the LHC. It is now established that in these collisions a state of matter consisting of deconfined quarks and gluons, Quark-Gluon Plasma (QGP), is formed. The QGP appears as the hottest and almost lowest-viscosity liquid ever observed. While the experiments at LHC and at RHIC have unravelled a lot of its properties, one still does not have a complete picture. One of the ways of exploring the properties of the QGP would be to perform Rutherford scattering experiments with well-defined probes. One can use hard scattering processes as sources of strongly-interacting probes. Then by comparing particle production rates in ion-ion collisions to that in proton-proton collisions, one can gain insight into the properties of the medium. There are several ways by which one can learn about medium properties, for example, measurement of two particle correlations distribution and their properties such as, yield $I_{\\rm{AA}}$, defi...

ALICE chip processor

CERN Multimedia

Maximilien Brice

2003-01-01

This tiny chip provides data processing for the time projection chamber on ALICE. Known as the ALICE TPC Read Out (ALTRO), this device was designed to minimize the size and power consumption of the TPC front end electronics. This single chip contains 16 low-power analogue-to-digital converters with six million transistors of digital processing and 8 kbits of data storage.

Event-by-event mean pT fluctuations in pp and Pb–Pb collisions at the LHC

NARCIS (Netherlands)

ALICE Collaboration, Collaboration; Abelev, B.; Adam, J.; Adamová, D.; Aggarwal, M. M.; Rinella, G. Aglieri; Agnello, M.; Agostinelli, A.; Agrawal, N.; Ahammed, Z.; Ahmad, N.; Ahmed, I.; Ahn, S. U.; Ahn, S. A.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baltasar Dos Santos Pedrosa, F.; Baral, R. C.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Baumann, C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Belmont, R.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Berger, M. E.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bjelogrlic, S.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Böhmer, F. V.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Bossú, F.; Botje, M.; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Calero Diaz, L.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Castillo Castellanos, J.; Casula, E. A R; Catanescu, V.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Dang, R.; Danu, A.; Das, D.; Das, I.; Das, K.; Das, S.; Dash, A.; Dash, S.; De, S.; Delagrange, H.; Deloff, A.; Dénes, E.; D’Erasmo, G.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; de Rooij, R.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Di Bari, D.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Djuvsland, O.; Dobrin, A.; Dobrowolski, T.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Dørheim, S.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A. K.; Hilden, T. E.; Ehlers, R. J.; Elia, D.; Engel, H.; Erazmus, B.; Erdal, H. A.; Eschweiler, D.; Espagnon, B.; Esposito, M.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fehlker, D.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A S; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floratos, E.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Garishvili, I.; Gerhard, J.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez Ramirez, A.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Graczykowski, L. K.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grosse-Oetringhaus, J. F.; Grossiord, J. Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Guilbaud, M.; Gulbrandsen, K.; Gulkanyan, H.; Gumbo, M.; Gunji, T.; Gupta, A.; Gupta, R.; Khan, K. H.; Haake, R.; Haaland, I.M.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hanratty, L. D.; Hansen, A.; Harris, J. W.; Hartmann, H.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Heide, M.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Hess, B. A.; Hetland, K. F.; Hippolyte, B.; Hladky, J.; Hristov, P.; Huang, M.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Innocenti, G. M.; Ionita, C.; Ippolitov, M.; Irfan, M.; Ivanov, M.; Ivanov, V.; Jachołkowski, A.; Jacobs, P. M.; Jahnke, C.; Jang, H. J.; Janik, M. A.; Jayarathna, P. H S Y; Jena, C.; Jena, S.; Jimenez Bustamante, R. T.; Jones, P. G.; Jung, H.; Jusko, A.; Kadyshevskiy, V.; Kalinak, P.; Kalweit, A.; Kamin, J.; Kang, J. H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L D; SVN, M. Keil; Khan, M. M.; Khan, P.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, B.; Kim, D. W.; Kim, D. J.; Kim, J. S.; Kim, M.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, J.; Klein-Bösing, C.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobdaj, C.; Kofarago, M.; Köhler, M. K.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Konevskikh, A.; Kovalenko, V.; Kowalski, M.; Kox, S.; Koyithatta Meethaleveedu, G.; Kral, J.; Králik, I.; Kravčáková, A.; Krelina, M.; Kretz, M.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kučera, V.; Kucheriaev, Y.; Kugathasan, T.; Kuhn, C.; Kuijer, P. G.; Kulakov, I.; Kumar, J.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kweon, M. J.; Kwon, Y.; Ladron de Guevara, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; Lara, C.; Lardeux, A.; Lattuca, A.; La Pointe, S. L.; La Rocca, P.; Lea, R.; Leardini, L.; Lee, G. R.; Legrand, I.; Lehnert, J.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; Leoncino, M.; León Monzón, I.; Lévai, P.; Li, S.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Lodato, D. F.; Loenne, P. I.; Loggins, V. R.; Loginov, V.; Lohner, D.; Loizides, C.; Lopez, X.; López Torres, E.; Lu, X. G.; Luettig, P.; Lunardon, M.; Luparello, G.; Ma, R.; Maevskaya, A.; Mager, M.; Mahapatra, D. P.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal’Kevich, D.; Malzacher, P.; Mamonov, A.; Manceau, L.; Manko, V.; Manso, F.; Manzari, V.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Marín, A.; Markert, C.; Marquard, M.; Martashvili, I.; Martin, N. A.; Martinengo, P.; Martínez, M. I.; Martínez García, G.; Martin Blanco, J.; Martynov, Y.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Massacrier, L.; Mastroserio, A.; Matyja, A.; Mayer, C.; Mazer, J.; Mazzoni, M. A.; McDonald, D.; Meddi, F.; Menchaca-Rocha, A.; Meninno, E.; Mercado Pérez, J.; Meres, M.; Miake, Y.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A. N.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mlynarz, J.; Mohammadi, N.; Mohanty, B.; Molnar, L.; Montaño Zetina, L.; Montes, E.; Morando, M.; Moreira De Godoy, D. A.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Müller, H.; Munhoz, M. G.; Murray, S.; Musa, L.; Musinsky, J.; Nandi, B. K.; Nania, R.; Nappi, E.; Nattrass, C.; Nayak, K.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Nilsen, B. S.; Noferini, F.; Nomokonov, P.; Nooren, G.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Oh, S. K.; Okatan, A.; Olah, L.; Oleniacz, J.; Oliveira Da Silva, A. C.; Onderwaater, J.; Oppedisano, C.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Ozdemir, M.; Sahoo, P.; Pachmayer, Y.; Pachr, M.; Pagano, P.; Paić, G.; Pajares, C.; Pal, S. K.; Palmeri, A.; Pant, D.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, W. J.; Parmar, S.; Passfeld, A.; Patalakha, D. I.; Paticchio, V.; Paul, B.; Pawlak, T.; Peitzmann, T.; Pereira Da Costa, H.; Pereira De Oliveira Filho, E.; Peresunko, D.; Pérez Lara, C. E.; Pesci, A.; Peskov, V.; Pestov, Y.; Petráček, V.; Petran, M.; Petris, M.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L M; Poghosyan, M. G.; Pohjoisaho, E. H O; Polichtchouk, B.; Poljak, N.; Pop, A.; Porteboeuf-Houssais, S.; Porter, J.; Potukuchi, B.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Rauf, A. W.; Razazi, V.; Read, K. F.; Real, J. S.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reicher, M.; Reidt, F.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J. P.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Rivetti, A.; Rocco, E.; Rodríguez Cahuantzi, M.; Rodriguez Manso, A.; Røed, K.; Rogochaya, E.; Rohni, S.; Rohr, D.; Röhrich, D.; Romita, R.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahlmuller, B.; Sahoo, R.; Sahu, P. K.; Saini, J.; Sakai, S.; Salgado, C. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sanchez Castro, X.; Sánchez Rodríguez, F. J.; Šándor, L.; Sandoval, A.; Sano, M.; Santagati, G.; Sarkar, D.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schuchmann, S.; Schukraft, J.; Schulc, M.; Schuster, T.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Segato, G.; Seger, J. E.; Sekiguchi, Y.; Selyuzhenkov, I.; Senosi, K.; Seo, J.; Serradilla, E.; Sevcenco, A.; Shabetai, A.; Shabratova, G.; Shahoyan, R.; Shangaraev, A.; Sharma, A.; Sharma, N.; Sharma, S.; Shigaki, K.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Skjerdal, K.; Slupecki, M.; Smirnov, N.; Snellings, R. J M; Søgaard, C.; Soltz, R.; Song, J.; Song, M.; Soramel, F.; Sorensen, S.; Spacek, M.; Spiriti, E.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stefanek, G.; Steinpreis, M.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Stolpovskiy, M.; Strmen, P.; Suaide, A. A P; Sugitate, T.; Suire, C.; Suleymanov, M.; Sultanov, R.; Šumbera, M.; Symons, T. J M; Szabo, A.; Szanto de Toledo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Takahashi, J.; Tangaro, M. A.; Tapia Takaki, J. D.; Tarantola Peloni, A.; Tarazona Martinez, A.; Tariq, M.; Tarzila, M. G.; Tauro, A.; Tejeda Muñoz, G.; Telesca, A.; Terasaki, K.; Terrevoli, C.; Thäder, J.; Thomas, D.; Tieulent, R.; Timmins, A. R.; Toia, A.; Trubnikov, V.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ullaland, K.; Uras, A.; Usai, G. L.; Vajzer, M.; Vala, M.; Valencia Palomo, L.; Vallero, S.; Vande Vyvre, P.; Van Der Maarel, J.; Van Hoorne, J. W.; van Leeuwen, M.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vechernin, V.; Veldhoen, M.; Velure, A.; Venaruzzo, M.; Vercellin, E.; Vergara Limón, S.; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Vislavicius, V.; Viyogi, Y. P.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; von Haller, B.; Vorobyev, I.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Vyushin, A.; Wagner, B.; Wagner, J.; Wagner, V.; Wang, M.; Wang, Y.; Watanabe, D.; Weber, M.; Weber, S. G.; Wessels, J. P.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilde, M.; Wilk, G.; Wilkinson, J.; Williams, M. C S; Windelband, B.; Winn, M.; Yaldo, C. G.; Yamaguchi, Y.; Yang, H.; Yang, P.; Yang, S.; Yano, S.; Yasnopolskiy, S.; Yi, J.; Yin, Z.; Yoo, I. K.; Yushmanov, I.; Zaccolo, V.; Zach, C.; Zaman, A.; Zampolli, C.; Zaporozhets, S.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zgura, I. S.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, F.; Zhou, Y.; Zhuo, Zhou; Zhu, H.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zoccarato, Y.; Zyzak, M.

2014-01-01

Event-by-event fluctuations of the mean transverse momentum of charged particles produced in pp collisions at 0.9, 2.76 and 7 TeV, and Pb–Pb collisions at 2.76 TeV are studied as a function of the charged-particle multiplicity using the ALICE detector at the LHC. Dynamical fluctuations indicative of

Open Charm Reconstruction in Alice:. D+ → K-π+π+

Science.gov (United States)

Bruna, Elena

Open charm mesons produced in high energy A-A interactions are expected to be powerful probes to investigate the medium produced in the collision. In this context it is important to measure the production of as many charmed hadrons as possible, such as D0, D+, D_{s}^{+} and Λc, because the measurement of their relative yield can provide information on the hadronization mechanism and is necessary to reduce the systematic error on the absolute cross section. The ALICE experiment at the LHC is designed to perform such measurements at midrapidity down to pT below 1 GeV/c, mainly by means of the silicon vertex and tracker detector, the time projection chamber and the time of flight detector. One of the main channels for the detection of charm production in ALICE is the exclusive reconstruction of the D+ meson through its three charged body decay K-π+π+ in Pb-Pb (\\sqrt{s} = 5.5 TeV) and pp (\\sqrt{s} = 14 TeV)$ collisions. The selection strategies for this analysis and the results of a feasibility study on Monte Carlo events will be presented together with the perspectives for the study of D+ quenching and azimuthal anisotropy measurements.

LHC Detector Vacuum System Consolidation for Long Shutdown 1 (LS1) in 2013-2014

CERN Document Server

Gallilee, M; Cruikshank, P; Gallagher, J; Garion, C; Jimenez, J M; Kersevan, R; Kos, H; Leduc, L; Lepeule, P; Provot, N; Rambeau, H; Veness, R

2012-01-01

The LHC has ventured into unchartered territory for Particle Physics accelerators. A dedicated consolidation program is required between 2013 and 2014 to ensure optimal physics performance. The experiments, ALICE, ATLAS, CMS, and LHCb, will utilise this shutdown, along with the gained experience of three years of physics running, to make optimisations to their detectors. New vacuum technologies have been developed for the experimental areas, to be integrated during this first phase shutdown. These technologies include bellows, vacuum chambers and ion pumps in aluminium, new beryllium vacuum chambers, and composite mechanical supports. An overview of this first phase consolidation program for the LHC experiments is presented.

Fast polycrystalline CdTe detectors for bunch-by-bunch luminosity monitoring in the LHC

CERN Document Server

Brambilla, A; Jolliot, M; Bravin, E

2008-01-01

The luminosity at the four interaction points of the Large Hadron Collider (LHC) must be continuously monitored in order to provide an adequate tool for the control and optimisation of beam parameters. Polycrystalline cadmium telluride (CdTe) detectors have previously been tested, showing their high potential to fulfil the requirements of luminosity measurement in the severe environment of the LHC interaction regions. Further, the large signal yield and the fast response time should allow bunch-by-bunch measurement of the luminosity at 40 MHz with high accuracy. Four luminosity monitors with two rows of five polycrystalline CdTe detectors each have been fabricated and will be installed at both sides of the low-luminosity interaction points ALICE and LHC-b. A detector housing was specially designed to meet the mechanical constraints in the LHC. A series of elementary CdTe detectors were fabricated and tested, of which 40 were selected for the luminosity monitors. A sensitivity of 104 electrons per minimum ioni...

An experimental research program on chirality at the LHC

International Nuclear Information System (INIS)

Markert, Christina

2016-01-01

Heavy-ion collisions provide a unique opportunity to investigate the fundamental laws of physics of the strong force. The extreme conditions created by the collisions within a finite volume are akin to the properties of the deconfined partonic state which existed very shortly after the Big Bang and just prior to visible matter formation in the Universe. In this state massless quarks and gluons (partons) are ''quasi free'' particles, the so-called Quark Gluon Plasma (QGP). By following the expansion and cooling of this state, we will map out the process of nucleonic matter formation, which occurs during the phase transition. The fundamental properties of this early partonic phase of matter are not well understood, but they are essential for confirming QCD (Quantum Chromo-Dynamics) and the Standard Model. The specific topic, chiral symmetry restoration, has been called ''the remaining puzzle of QCD.'' This puzzle can only be studied in the dense partonic medium generated in heavy-ion collisions. The research objectives of this proposal are the development and application of new analysis strategies to study chirality and the properties of the medium above the QGP phase transition using hadronic resonances detected with the ALICE experiment at the Large Hadron Collider (LHC) at the CERN research laboratory in Switzerland. This grant funded a new effort at the University of Texas at Austin (UT Austin) to investigate the Quark Gluon Plasma (QGP) at the highest possible energy of 2.76 TeV per nucleon at the Large Hadron Collider (LHC) at CERN via the ALICE experiment. The findings added to our knowledge of the dynamical evolution and the properties of the hot, dense matter produced in heavy-ion collisions, and provided a deeper understanding of multi-hadron interactions in these extreme nuclear matter systems. Our group contributed as well to the hardware and software for the ALICE USA-funded Calorimeter Detector (EMCal). The LHC research program and its connection to

First Results of the LHC Collision Rate Monitors

CERN Document Server

Burger, S; Bart Pedersen, S; Boccardi, A; Dutriat, C; Miyamoto, R; Doolittle, L; Matis, H S; Placidi, M; Ratti, A; Stezelberger, T; Yaver, H

2011-01-01

The aim of CERN large hadron collider (LHC) is to collide protons and heavy ions with centre of mass energies up to 14 zTeV. In order to monitor and optimize the collision rates special detectors have been developed and installed around the four luminous interaction regions. Due to the different conditions at the high luminosity experiments (ATLAS and CMS) and the low luminosity experiments (ALICE and LHC-b) two very different types of monitors are used: a fast ionisation chamber (BRAN-A) and a Cd-Te solid state detector (BRAN-B respectively. Moreover, in order to cope with the low collision rates foreseen for the initial run, a third type of monitor, based on a simple scintillating pad, was installed in parallel with the BRAN-A (BRAN-P). This contribution illustrates the results obtained during the 2010 run with an outlook for 2011 and beyond.

Exploring heavy-quark energy loss via b-tagging in heavy-ion collisions at the LHC

International Nuclear Information System (INIS)

Klay, Jennifer L

2005-01-01

A strategy to study flavour-dependent parton energy loss by tagging heavy quark jets in p+p, p+Pb and Pb+Pb collisions at the LHC is discussed. Estimates for production cross-sections and experimental techniques employed at collider detectors to search QQ-bar jets are presented and a brief evaluation of the capabilities of CMS, ALICE and ATLAS detectors are given

ALICE bags data storage accolades

CERN Multimedia

2007-01-01

ComputerWorld has recognized CERN with an award for the 'Best Practices in Storage' for ALICE's data acquisition system, in the category of 'Systems Implementation'. The award was presented to the ALICE DAQ team on 18 April at a ceremony in San Diego, CA. (Top) ALICE physicist Ulrich Fuchs. (Bottom) Three of the five storage racks for the ALICE Data Acquisition system (Photo Antonio Saba). Between 16 and19 April, one thousand people from data storage networks around the world gathered to attend the biannual Storage Networking World Conference. Twenty-five companies and organizations were celebrated as finalists, and five of those were given honorary awards-among them CERN, which tied for first place in the category of Systems Implementation for the success of the ALICE Data Acquisition System. CERN was one of five finalists in this category, which recognizes the winning facility for 'the successful design, implementation and management of an interoperable environment'. 'Successful' could include documentati...

Design, development and deployment of the ALICE experiment data processing for simulation, reconstruction and analysis

International Nuclear Information System (INIS)

Carminati, Federico

2013-01-01

The ALICE (A Large Ion Collider Experiment) at the CERN (Conseil Europeen pour la Recherche Nucleaire) LHC (Large Hadron Collider) facility uses an integrated software framework for the design of the experimental apparatus, the evaluation of its performance and the processing of the experimental data. The author has designed this framework. It includes the event generators and the algorithms for particle transport describing the details of the interaction particles - matter (designed and implemented by the author), the reconstruction of the particle trajectories and the final physics analysis. (author) [fr

Front end optimization for the monolithic active pixel sensor of the ALICE Inner Tracking System upgrade

OpenAIRE

Kim, D; Rinella, G Aglieri; Cavicchioli, C; Chanlek, N; Collu, A; Degerli, Y; Dorokhov, A; Flouzat, C; Gajanana, D; Gao, C; Guilloux, F; Hillemanns, H; Hristozkov, S; Junique, A; Keil, M

2016-01-01

ALICE plans to replace its Inner Tracking System during the second long shut down of the LHC in 2019 with a new 10 m(2) tracker constructed entirely with monolithic active pixel sensors. The TowerJazz 180 nm CMOS imaging Sensor process has been selected to produce the sensor as it offers a deep pwell allowing full CMOS in-pixel circuitry and different starting materials. First full-scale prototypes have been fabricated and tested. Radiation tolerance has also been verified. In this paper the ...

Performance of the ALICE secondary vertex b-tagging algorithm

CERN Document Server

INSPIRE-00262232

2016-11-04

The identification of jets originating from beauty quarks in heavy-ion collisions is important to study the properties of the hot and dense matter produced in such collisions. A variety of algorithms for b-jet tagging was elaborated at the LHC experiments. They rely on the properties of B hadrons, i.e. their long lifetime, large mass and large multiplicity of decay products. In this work, the b-tagging algorithm based on displaced secondary-vertex topologies is described. We present Monte Carlo based performance studies of the algorithm for charged jets reconstructed with the ALICE tracking system in p-Pb collisions at $\\sqrt{s_\\text{NN}}$ = 5.02 TeV. The tagging efficiency, rejection rate and the correction of the smearing effects of non-ideal detector response are presented.

Characterisation of pixel sensor prototypes for the ALICE ITS upgrade

Energy Technology Data Exchange (ETDEWEB)

Reidt, Felix [CERN (Switzerland); Physikalisches Institut, Universitaet Heidelberg (Germany); Collaboration: ALICE-Collaboration

2014-07-01

ALICE is preparing a major upgrade of its experimental apparatus to be installed in the second long LHC shutdown (LS2) in the years 2018-2019. A key element of the upgrade is the replacement of the Inner Tracking System (ITS) deploying Monolithic Active Pixel Sensors (MAPS). The upgraded ITS will have a reduced material budget while increasing the pixel density and readout rate capabilities. The novel design leads to higher pointing and momentum resolution as well as a p{sub T} acceptance extended to lower values. The corresponding sensor prototypes were qualified in laboratory measurements and beam tests with respect to their radiation tolerance and detection efficiency. This talk summarises recent results on the characterisation of prototypes belonging to the ALPIDE family.

28th February 2012 - Slovak Prime Minister I. Radicova signing the guest book with CERN Director-General R. Heuer; visiting the ALICE surface exhibition and underground experimental area with Collaboration Spokesperson P. Giubellino and Senior Physicist K. Safarik; throughout accompanied by Adviser E. Tsesmelis.

CERN Multimedia

Maximilien.brice@cern.ch

2012-01-01

Iveta Radicova, the Slovak Republic’s prime minister, came to CERN on 28 February. During her visit she was welcomed by Rolf Heuer, CERN’s director-general, Emmanuel Tsesmelis, CERN international relations office, and Karel Safarik, of the ALICE collaboration, who all provided a brief introduction to CERN’s activities. She also toured the ALICE underground experimental area and the LHC superconducting magnet test hall.

Élaboration et gestion des plans d'installation de la machine LHC

CERN Document Server

Corso, Jean Pierre

2005-01-01

Remplir 27 km de l’étroit tunnel du LEP avec plusieurs milliers d’équipements est le défi posé par le LHC et à relever par les techniciens et ingénieurs du CERN. Le LEP avait initié ce concept avec un outil nommé LEGO ; Le LHC a encore franchi une étape avec DMU (Digital Mock-Up), en tirant profit de l’évolution significative des outils informatiques (langages de programmation et logiciels). Utilisé comme interface entre une base de données Oracle® regroupant toutes les informations sur chaque équipement et les modèles 3D standard correspondants issus d’Euclid®, DMU a étendu, depuis, son champ d’application en permettant dorénavant de générer automatiquement tous les plans d’installation des 514 demi cellules de la Machine. Les évolutions futures de la configuration du LHC nous conduiront à modifier ou déplacer les équipements en place et à en insérer de nouveaux. Ceux-ci seront introduits dans la base de données avant de pouvoir être restitués via DMU sous forme de pl...

Build your own tiny Lego LHC

CERN Multimedia

Abha Eli Phoboo

2015-01-01

A PhD student working on the ATLAS experiment has created a replica of the Large Hadron Collider using Lego building blocks. Nathan Readioff, from the University of Liverpool (see here), submitted his design to Lego Ideas (see here) this week and is now awaiting the 10,000 votes needed for it to qualify for the Lego Review, which decides if projects become new Lego products. You can help this project, vote online now!   A computer simulation of the miniature Lego LHC, complete with four detectors connected with blue dipole magnets. His Lego design is a stylised model of the LHC, showcasing the four main detectors ALICE, ATLAS, CMS and LHCb at the micro scale. Each detector is small enough to fit in the palm of your hand, yet the details of the internal systems are intricate, revealed by cutaway walls. Every major detector component is represented by a Lego piece. The models are not strictly to scale with one another, but the same size base is used for each one to maximise the detail that can...

The ALICE experiment: $\\rm D^{+}$-meson production in heavy-ion collisions and silicon low noise sensors characterization for the ITS Upgrade.

CERN Document Server

AUTHOR|(CDS)2084697; Bruna, Elena

This thesis collects my work on two aspects of the ALICE experiment at the Large Hadron Collider: the measurement of $\\rm D^{+}$-meson production in Pb-Pb collisions at $\\sqrt{s_{\\rm {NN}}}= 2.76$ TeV and the characterization of silicon low noise sensors for the Inner Tracking System Upgrade. I worked within the INFN group of Torino that it is involved in the ALICE experiment both in the physics program related to the study of heavy-flavour production and in the project of the ITS Upgrade. ALICE is one of the main experiment of the LHC and it is the only one optimized to study ultra-relativistic heavy-ion collisions. The main goal is to study the properties of the Quark Gluon Plasma (QGP), a phase of matter where quarks and gluons are deconned. Heavy quarks are a powerful tool to study such properties because they can be created only in hard scattering processes at the initial stage of the collision and, subsequently, they interact with the QGP. The measurement of charmed meson production in Pb-P...

O2: A novel combined online and offline computing system for the ALICE Experiment after 2018

International Nuclear Information System (INIS)

Ananya; Agrawal, N; Avasthi, A; Suaide, A Alarcon Do Passo; Prado, C Alves Garcia; Alt, T; Bach, M; Breitner, T; Aphecetche, L; Bala, R; Bhasin, A; Barnafoldi, G; Belikov, J; Bellini, F; Betev, L; Buncic, P; Carena, F; Carena, W; Chapeland, S; Barroso, V Chibante

2014-01-01

ALICE (A Large Ion Collider Experiment) is a detector dedicated to the studies with heavy ion collisions exploring the physics of strongly interacting nuclear matter and the quark-gluon plasma at the CERN LHC (Large Hadron Collider). After the second long shutdown of the LHC, the ALICE Experiment will be upgraded to make high precision measurements of rare probes at low pT, which cannot be selected with a trigger, and therefore require a very large sample of events recorded on tape. The online computing system will be completely redesigned to address the major challenge of sampling the full 50 kHz Pb-Pb interaction rate increasing the present limit by a factor of 100. This upgrade will also include the continuous un-triggered read-out of two detectors: ITS (Inner Tracking System) and TPC (Time Projection Chamber)) producing a sustained throughput of 1 TB/s. This unprecedented data rate will be reduced by adopting an entirely new strategy where calibration and reconstruction are performed online, and only the reconstruction results are stored while the raw data are discarded. This system, already demonstrated in production on the TPC data since 2011, will be optimized for the online usage of reconstruction algorithms. This implies much tighter coupling between online and offline computing systems. An R and D program has been set up to meet this huge challenge. The object of this paper is to present this program and its first results.

Small systems at the LHC

Science.gov (United States)

Preghenella, Roberto

2018-02-01

In these proceedings, I report on a selection of recent LHC results in small systems from ALICE [1], ATLAS [2] and CMS [3] experiments. Due to the fact that the investigation of QCD in small systems at high multiplicity is becoming an increasingly large subject, interesting the heavy-ion community and more in general the high-energy physics community, not all the related topics can be discussed in this paper. The focus will be given to some of the measurements addressing the physics of collective phenomena in small systems and to the recent results on strangeness enhancement in proton-proton collisions. The reader must be informed that a large number of interesting results did not find space in the discussion reported here.

ALPIDE, the Monolithic Active Pixel Sensor for the ALICE ITS upgrade

Science.gov (United States)

Mager, M.; ALICE Collaboration

2016-07-01

A new 10 m2 inner tracking system based on seven concentric layers of Monolithic Active Pixel Sensors will be installed in the ALICE experiment during the second long shutdown of LHC in 2019-2020. The monolithic pixel sensors will be fabricated in the 180 nm CMOS Imaging Sensor process of TowerJazz. The ALPIDE design takes full advantage of a particular process feature, the deep p-well, which allows for full CMOS circuitry within the pixel matrix, while at the same time retaining the full charge collection efficiency. Together with the small feature size and the availability of six metal layers, this allowed a continuously active low-power front-end to be placed into each pixel and an in-matrix sparsification circuit to be used that sends only the addresses of hit pixels to the periphery. This approach led to a power consumption of less than 40 mWcm-2, a spatial resolution of around 5 μm, a peaking time of around 2 μs, while being radiation hard to some 1013 1 MeVneq /cm2, fulfilling or exceeding the ALICE requirements. Over the last years of R & D, several prototype circuits have been used to verify radiation hardness, and to optimize pixel geometry and in-pixel front-end circuitry. The positive results led to a submission of full-scale (3 cm×1.5 cm) sensor prototypes in 2014. They are being characterized in a comprehensive campaign that also involves several irradiation and beam tests. A summary of the results obtained and prospects towards the final sensor to instrument the ALICE Inner Tracking System are given.

Quality assurance of GEM foils in the framework of the TPC upgrade in the ALICE experiment

CERN Document Server

Ozcelik, Melih Arslan

2016-01-01

In the framework of the TPC upgrade of the ALICE Experiment, new readout chambers will be installed during the LHC long shutdown 2, which is scheduled to start in July 2018. The current MWPCs (Multi Wire Proportional Chambers) will be replaced by readout chambers consisting of GEM (Gas Electron Multipliers) foils in order to meet the increasing readout rate requirements. QA (Quality Assurance) tests on the GEMs are performed to classify the foils. In this report we present the work done during the CERN Summer Student Programme 2016.

Use of fluorocarbons in the cooling of LHC experiments

CERN Document Server

Pimenta dos Santos, M

2003-01-01

Perfluorochemicals sold by 3M under the trade name 3M Fluorinert Electronic Liquids have been used for many years as heat transfer media in a variety of industries. The suitability of these liquids for the cooling of LHC experiment originates from their high dielectric strength as well as from their chemical stability under ionizing radiation. The Fluorinerts are clear, colorless, non-flammable with low toxicity and low corrosiveness. Additionally, they offer low global waming potential – GWP – and zero ozone-depletion potential – ODP. Some examples of fluorinert application in the cooling of LHC experiments will be presented : (a) the ATLAS Inner detector C3F8 evaporative cooling system (b) the ATLAS TRF C6F14 monophase cooling system and (c) the ALICE SPD “active heat pipe” C4F10 evaporative cooling system. A brief comparison of evaporative and monophase cooling systems will be outlined.

Le bureau d'études mécaniques du groupe TS-MME

CERN Document Server

Menot, C

2004-01-01

Le bureau d'études du groupe MME représente le principal support d'ingénierie mécanique pour le LHC et quelques projets autres. Il est constitué de trois sections au mandat distinct. Ses activités couvrent le design des divers équipements : des aimants supraconducteurs du LHC et leur alimentation électrique, le design pour le système vide et de l'instrumentation et calibration de faisceau. Le groupe a aussi en charge le design de tout système se rapportant aux complexes PS et SPS Les principaux sujets présentés dans ce rapport concernent la structure du bureau d'études et son effectif, les ressources à disposition, son domaine d'activité, son mode de fonctionnement, les outils et les méthodologies développés. La coordination entre sections du groupe, qui apportent chacune son expertise, sera mise en évidence. Une vision du futur avec les besoins en ressources liés aux activités vitales pour le CERN est abordée en conclusion.

Neutral meson production in pp and Pb-Pb collisions at the LHC with ALICE

International Nuclear Information System (INIS)

Borissov, Alexander

2013-01-01

The first measurements of the invariant differential cross sections of inclusive π 0 and η meson production with ALICE are presented for pp collisions at √(s) = 0.9 and 7 TeV. Next-to-Leading Order perturbative QCD calculations overestimate the data at √(s) = 7TeV, but are consistent with the π 0 spectrum at √(s) = 0.9TeV and with the measured π 0 /η cross section ratio at √(s) = 7TeV. The nuclear modification factors (R AA ) of π 0 production at different centralities show a strong suppression with respect to pp collisions.

ALICE installs its TPC

CERN Multimedia

2007-01-01

The ALICE time projection chamber has been transported to the experimental cavern. The handling of this extremely fragile detector was a long and delicate process. The lorry transporting the TPC took one hour to travel from the assembly hall to the access shaft...200 metres away.The TPC was lowered into the ALICE experimental cavern with extreme care. The gap between the structure and the shaft wall was only 10 centimetres! For ALICE the year started with a flurry of activity...but at a snail's pace. On 8 January, the day CERN reopened after the end-of-year break, teams from ALICE and the TS Department began the transportation of the experiment's time projection chamber (TPC), the largest ever built. This 5-metre long and 5-m diameter cylinder was transported from the clean room where it had been assembled to the experimental cavern. The 300-metre journey took no less than four days! Since the TPC is an extremely fragile object, the utmost precautions were exercised in its transportation. The TPC, which is d...

First ALICE detectors installed!

CERN Multimedia

2006-01-01

Detectors to track down penetrating muon particles are the first to be placed in their final position in the ALICE cavern. The Alice muon spectrometer: in the foreground the trigger chamber is positioned in front of the muon wall, with the dipole magnet in the background. After the impressive transport of its dipole magnet, ALICE has begun to fill the spectrometer with detectors. In mid-July, the ALICE muon spectrometer team achieved important milestones with the installation of the trigger and the tracking chambers of the muon spectrometer. They are the first detectors to be installed in their final position in the cavern. All of the eight half planes of the RPCs (resistive plate chambers) have been installed in their final position behind the muon filter. The role of the trigger detector is to select events containing a muon pair coming, for instance, from the decay of J/ or Y resonances. The selection is made on the transverse momentum of the two individual muons. The internal parts of the RPCs, made o...

J/psi production in pp collisions from ALICE

CERN Multimedia

CERN. Geneva

2012-01-01

The ALICE experiment studied J/psi production in the mu+mu- and e+e- decay channels. Inclusive cross sections were measured at both forward and central rapidity down to zero transverse momentum. The results are compared with NRQCD calculations and, for the pp sample collected at sqrt(s)=2.76 TeV, are used as a reference for the determination of nuclear effects on J/psi production in Pb-Pb. At central rapidity, the fraction of J/psi coming from B-decays has been evaluated down to p_T=1.3 GeV/c. In addition, the J/psi yield has been found to linearly increase as a function of the charged hadron multiplicity produced in the collision. Finally, the first LHC results on J/psi polarization, an essential observable for the understanding of the production mechanisms and for theory comparisons, will be presented.

L'energie du moustique

CERN Document Server

Augereau, J F

2002-01-01

ENSEMBLE DE QUATRE ARTICLES - LARGE HADRON COLLIDER: Le dernier accelerateur de particules du CERN, le LEP, produisait des faisceaux d'electrons de 100 GeV chacun. Le LHC, qui accelere des faisceaux de protons, leur communiquera une energie de 7 TeV chacun. Une energie a la fois colossale et derisoire. Un TeV represente a peu pres l'energie cinetique d'un moustique (1/2 page).

Inbetriebnahme und Kalibrierung der ALICE-TPC

CERN Document Server

Wiechula, Jens

2008-01-01

ALICE (A Large Ion Collider Experiment), is the dedicated heavy-ion experiment at the Large Hadron Collider (LHC) at CERN. It is optimised to reconstruct and identify the particles created in a lead-lead collision with a centre of mass energy of 5.5TeV. The main tracking detector is a large-volume time-projection chamber (TPC). With an active volume of about 88m^3 and a total readout area of 32.5m^2 it is the most challenging TPC ever build. A central electrode divides the 5m long detector into two drift regions. Each readout side is subdivided into 18 inner and 18 outer multi-wire proportional read-out chambers. The readout area is subdivide into 557568 pads, where each pad is read out by and electronics chanin. A complex calibration is needed in order to reach the design position-resolution of the reconstructed particle tracks of about 200um. One part of the calibration lies in understanding the electronic-response. The work at hand presents results of the pedestal and noise behaviour of the front-end elect...

ALICE gets its first ‘upgrade’

CERN Multimedia

2009-01-01

The ALICE experiment has reached another milestone with the successful installation of the first two modules of the electromagnetic calorimeter. Preparations for installing the EMCal in the ALICE cavern. On 17 and 19 March the first two sections of the electromagnetic calorimeter (EMCal) were fitted in the ALICE cavern. The full EMCal, a lead-scintillator sampling calorimeter, will be made up of 12 separate modules plus 2 half modules. Weighing 8 tons each, these modules required a whole new support structure to be built and a sophisticated ‘bridge’ device (pictured) to install them in situ. Project Leader, Tom Cormier from Wayne State University, notes that: "The EMCal is a late addition to ALICE, arriving in effect as a first upgrade. Indeed full approval with construction funds occurred only in early 2008." Although ALICE has excellent momentum measurement and identification capabilities for charged hadrons it previously lac...

ACORDE a cosmic ray detector for ALICE

International Nuclear Information System (INIS)

Fernandez, A.; Gamez, E.; Herrera, G.; Lopez, R.; Leon-Monzon, I.; Martinez, M.I.; Pagliarone, C.; Paic, G.; Roman, S.; Tejeda, G.; Vargas, M.A.; Vergara, S.; Villasenor, L.; Zepeda, A.

2007-01-01

ACORDE is one of the ALICE detectors, presently under construction at CERN. It consists of an array of plastic scintillator counters placed on the three upper faces of the ALICE magnet. It will act as a cosmic ray trigger, and, together with other ALICE sub-detectors, will provide precise information on cosmic rays with primary energies around 10 15 -10 17 eV. Here we describe the design of ACORDE along with the present status and integration into ALICE

La Physique au LHC - Partie I

CERN Multimedia

CERN. Geneva

2004-01-01

Le LHC devrait permettre l'observation du boson de Higgs et pouvoir lever le voile sur l'un des scénarios de nouvelle physique présentés dans la cours précédent. Ce cours détaillera les perspectives de physique au LHC (découvertes possibles et mesures de précision) ainsi que les méthodes et difficultés expérimentales. L'accent sera mis sur les problèmes liés à la brisure de la symétrie electrofaible. Les possibilités de développement futur à plus haute luminosité et/ou énergie seront également discutées.

Clock and trigger distribution for ALICE using the CRU FPGA card

CERN Document Server

Imrek, Jozsef

2017-01-01

ALICE is preparing a major upgrade for 2021. Subdetectors upgrading their DAQ electronics will use a common hardware to receive physics data: the Common Readout Unit (CRU). The same CRU will also distribute the LHC clock and trigger to many of the upgrading subdetectors (to 7800 front end cards). Requirements are strict: for the clock the allowed jitter (RMS) is typically <300ps, and <20ps for timing critical subdetectors; the allowed variation of skew is typically <1ns, and <100ps for timing critical subdetectors. A constant latency for distributing the trigger is essential. A novel approach to implement clock forwarding – using only the internal PLLs of the CRU’s onboard FPGA, without using an external jitter cleaner PLL – is presented.

ALICE honours two Italian suppliers

CERN Multimedia

2006-01-01

From left to right: Robert Terpin (MIPOT), Pier Luigi Bellutti (ITC), Andrea Zanotti, President of ITC, Luciano Bosisio (Trieste University), Gennady Zinovjev (Kiev), Catherine Decosse (CERN), Lodovico Riccati, ALICE Collaboration Board Chair (INFN Torino), Paolo Giubellino (INFN Torino), Mario Zen, Director of ITC, Maurizio Boscardin (ITC), Paolo Tonella (ITC), Jurgen Schukraft, ALICE Spokesperson (CERN), Giacomo Vito Margagliotti (Trieste University), Nevio Grion (INFN Trieste), Marco Bregant (INFN Trieste) Front row from left to right: Paolo Traverso (ITC), Federico Carminati, ALICE Computing Project Leader (CERN), and Jean-Robert Lutz, ITS-SSD Project leader (IPHC Strasbourg).

Modeling and simulation of critical parameters of the first chamber of the dimuon arm spectrometer of the Alice experiment

International Nuclear Information System (INIS)

Guez, D.

2003-10-01

The Alice experiment that is dedicated to the study of ultra-relativistic heavy ion collisions, will take place in the future large hadron collider (LHC) at CERN. The dimuon arm spectrometer of the Alice experiment is devoted to the search of a new signature of the existence of the quark gluon plasma (QGP). The first chapter is dedicated to the physics notions linked to the study of QGP, a few signatures are proposed for the detection of QGP, particularly the signature concerning the production rate of quarkonium. The second chapter deals with particle detection involved in Alice experiment, the dimuon arm spectrometer is a detector dedicated to the track reconstruction of muons issued from the decay of heavy mesons from J/Ψ and Υ families. The third and the fourth chapters present the studies made to integrate a reliable model of the dimuon arm in the global simulation code of Alice (Aliroot). The fifth chapter presents the software TB 2 that has been developed within the framework of this thesis in order to check and control the output data when the detector is tested with a real particle beam. The sixth chapter presents the results of the tests that have been performed with a 7 GeV/c pion beam. These tests have shown that the electronic noise is coherent with the specifications of Alice experiment. A factor 1,8 between the highest and the weakest values of the gain has been measured in the chamber. The detection efficiency of the chamber has been estimated to 99% in the different cases studied. (A.C.)

More than ALICE: Development of an augmented reality mobile application for the ALICE detector

CERN Document Server

Stamatouli, Anastasia

2017-01-01

More Than ALICE is a mobile application for iOS and Android devices. This project concerns the development of the v2.1 of the application which is meant to enhance the capacity of tracking quickly and reliably parts of the detector and its paper model. It recognises different parts of it and displays labels explaining its structure. Additionally, visualisation of the collisions can also be shown on the top of the camera image. More Than ALICE aims to increase the public awareness of the research goals of the ALICE collaboration. The application provides an Augmented Reality (AR) interface to track the detector during underground visits or its paper model which can be purchased at the ALICE secretariat. For those without access to either the detector or the paper model, the app provides the virtual model of the detector where the users can explore and understand the different parts of the detector and see real-time collisions.

Exclusive photoproduction of Upsilon in pPb collisions at LHC energies

International Nuclear Information System (INIS)

Dutta, Dipanwita; Chudasama, Ruchi; Mohanty, A.K.

2014-01-01

Recent results of exclusive photoproduction of heavy vector mesons at LHC energies by ALICE and LHCb in pp, pPb and PbPb Ultraperipheral collisions (UPC) confirmed the expectations that UPCs are a very promising probe to study the gluon distributions in nucleons and in nuclei at small x. In this work, we have estimated the photoproduction of γ in pPb collisions at √s NN = 5.02 TeV in the framework of perturbative two-gluon exchange formalism employing various parametrization of gluon distributions functions

ALICE opens its new nerve centre

CERN Multimedia

Antonella Del Rosso

2014-01-01

Twenty-nine fully equipped and ergonomic workstations, one meeting area and 11 large format screens in a completely refurbished room: the ALICE Run Control Centre (ARC) implements the best and newest solutions for its shift workers and expert operators, including access for persons with reduced mobility and very soon a magic window for Point 2 visitors.   The ALICE Run Control Centre. “Our initial intention was just to optimise the old layout,” says Federico Ronchetti from Laboratori Nazionali di Frascati (Italy), a CERN scientific associate currently appointed as ALICE Run Coordinator and person in charge of the ALICE Consolidation Task Force. “However, during the review process, we carried out a study of all the existing control rooms at CERN and became aware we needed a radical change. Hence we started planning a complete redesign of the workspace.” Designed and equipped over many years, the old ALICE control room did not have enough space to fit al...

Anisotropic flow and related phenomena in Pb-Pb collisions at $\\sqrt{{s}_{NN}} = 5.02$ TeV with ALICE

CERN Document Server

Margutti, Jacopo

2016-01-01

ALICE (A Large Ion Collider Experiment) is designed and optimised to study the properties of the Quark-Gluon Plasma (QGP), a new state of matter, which is expected to be created at the high energy densities reached at the LHC. One of the key observables used to characterize the proper- ties of the QGP is the azimuthal anisotropy in particle production. This so-called anisotropic flow is sensitive to the transport properties and equation of state of the QGP. In this presentation, we report the first measurements of anisotropic flow in Pb–Pb collisions at √ s NN = 5 . 02 TeV with ALICE and compare them with both theoretical predictions and experimental measurements at lower energies and other collision systems. This provides a unique opportunity to test the validity of the hydrodynamic paradigm and to further constraint the key transport parameters of the QGP.

Analysis of test beam data of ALPIDE, the Monolithic Active Pixel Sensor (MAPS) for the ALICE ITS upgrade

CERN Document Server

Lazareva, Tatiana

2017-01-01

The ALICE experiment has scheduled a major upgrade of its experimen- tal apparatus for the Long Shutdown 2 of LHC in 2019-2020. Within this enterprise, CERN is strongly involved in the development of a novel Inner Tracking System (ITS). The ITS will be based on Monolithic Active Pixel Sensors (MAPS), a cutting-edge technology that will allow to improve the detector performance signicantly. The nal sensor, called ALPIDE, is in production since December 2016. This project is focused on the characterization of irradiated ALPIDE sensors.

The upgrade of the ALICE Inner Tracking System - Status of the R&D; on monolithic silicon pixel sensors

OpenAIRE

Van Hoorne, Jacobus Willem

2014-01-01

s a major part of its upgrade plans, the ALICE experiment schedules the installation of a novel Inner Tracking System (ITS) during the Long Shutdown 2 (LS2) of the LHC in 2018/19. It will replace the present silicon tracker with seven layers of Monolithic Active Pixel Sensors (MAPS) and significantly improve the detector performance in terms of tracking and rate capabilities. The choice of technology has been guided by the tight requirements on the material budget of 0 : 3 % X = X 0 /layer fo...

LHC : sur la piste des mysteres de l`Univers par Michael Doser

CERN Multimedia

CERN. Geneva

2007-01-01

Le CERN, le plus grand centre en physique des particules au monde, va mettre en service le Grand collisionneur de hadrons (Large Hadron Collider), le LHC. Cette machine, le plus grand rouage du complexe d’accélérateurs du CERN, doit répondre aux énigmes qui subsistent sur les briques élémentaires de la matière et l’histoire de l’Univers.

Neutral meson production in pp and Pb-Pb collisions at the LHC with ALICE

Energy Technology Data Exchange (ETDEWEB)

Borissov, Alexander [Wayne State University, Detroit, MI, United States and European Organization for Nuclear Research (CERN), Geneva (Switzerland); Collaboration: ALICE Collaboration

2013-04-15

The first measurements of the invariant differential cross sections of inclusive {pi}{sup 0} and {eta} meson production with ALICE are presented for pp collisions at {radical}(s) = 0.9 and 7 TeV. Next-to-Leading Order perturbative QCD calculations overestimate the data at {radical}(s) = 7TeV, but are consistent with the {pi}{sup 0} spectrum at {radical}(s) = 0.9TeV and with the measured {pi}{sup 0}/{eta} cross section ratio at {radical}(s) = 7TeV. The nuclear modification factors (R{sub AA}) of {pi}{sup 0} production at different centralities show a strong suppression with respect to pp collisions.

Data Quality Monitoring : Automatic MOnitoRing Environment (AMORE ) Web Administration Tool in ALICE Experiment

CERN Document Server

Nagi, Imre

2013-01-01

ALICE (A Large Ion Collider Experiment) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). The quality of the acquired data evolves over time depending on the status of the detectors, its components and the operating environment. To get an excellent performance of detector, all detector configurations have to be set perfectly so that the data-taking can be done in an optimal way. This report describes a new implementation of the administration tools of the ALICE’s DQM framework called AMORE (Automatic MonitoRing Environment) with web technologies.

Monte Carlo studies on Cathode Strip/Pad Chambers for the ALICE Di-Muon Arm

Energy Technology Data Exchange (ETDEWEB)

Wurzinger, R.; Le Bornec, Y.; Willis, N.

1996-04-01

A general overview about the properties of Cathode Strip and Pad Chambers is given. Position finding methods are discussed and compared within Monte Carlo studies. Noise contributions and their minimization are discussed. Pad chambers allow a two-dimensional readout with spatial resolution of {sigma} < 100 {mu}m in direction parallel to the anode wire. The resolution normal to the anode wire depends mainly on the wire spacing. Special attention is paid on the double-hit resolution capability of the pad chamber. An outlook is given on the possible utilisation of Cathode Pad Chambers in the Di-Muon Arm of the ALICE detector at LHC. (author). 44 refs.

Energy resolution studies of an IROC GEM prototype for the ALICE TPC