WorldWideScience

Sample records for baryonic matter experiment

  1. The Compressed Baryonic Matter Experiment at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Heuser, Johann M.

    2013-05-02

    The Compressed Baryonic Matter (CBM) experiment will explore the phase diagram of strongly interacting matter in the region of high net baryon densities. The experiment is being laid out for nuclear collision rates from 0.1 to 10 MHz to access a unique wide spectrum of probes, including rarest particles like hadrons containing charm quarks, or multi-strange hyperons. The physics programme will be performed with ion beams of energies up to 45 GeV/nucleon. Those will be delivered by the SIS-300 synchrotron at the completed FAIR accelerator complex. Parts of the research programme can already be addressed with the SIS-100 synchrotron at the start of FAIR operation in 2018. The initial energy range of up to 11 GeV/nucleon for heavy nuclei, 14 GeV/nucleon for light nuclei, and 29 GeV for protons, allows addressing the equation of state of compressed nuclear matter, the properties of hadrons in a dense medium, the production and propagation of charm near the production threshold, and exploring the third, strange dimension of the nuclide chart. In this article we summarize the CBM physics programme, the preparation of the detector, and give an outline of the recently begun construction of the Facility for Antiproton and Ion Research.

  2. Baryonic matter and beyond

    CERN Document Server

    Fukushima, Kenji

    2014-01-01

    We summarize recent developments in identifying the ground state of dense baryonic matter and beyond. The topics include deconfinement from baryonic matter to quark matter, a diquark mixture, topological effect coupled with chirality and density, and inhomogeneous chiral condensates.

  3. Challenges in QCD matter physics -The scientific programme of the Compressed Baryonic Matter experiment at FAIR

    Science.gov (United States)

    Ablyazimov, T.; Abuhoza, A.; Adak, R. P.; Adamczyk, M.; Agarwal, K.; Aggarwal, M. M.; Ahammed, Z.; Ahmad, F.; Ahmad, N.; Ahmad, S.; Akindinov, A.; Akishin, P.; Akishina, E.; Akishina, T.; Akishina, V.; Akram, A.; Al-Turany, M.; Alekseev, I.; Alexandrov, E.; Alexandrov, I.; Amar-Youcef, S.; Anđelić, M.; Andreeva, O.; Andrei, C.; Andronic, A.; Anisimov, Yu.; Appelshäuser, H.; Argintaru, D.; Atkin, E.; Avdeev, S.; Averbeck, R.; Azmi, M. D.; Baban, V.; Bach, M.; Badura, E.; Bähr, S.; Balog, T.; Balzer, M.; Bao, E.; Baranova, N.; Barczyk, T.; Bartoş, D.; Bashir, S.; Baszczyk, M.; Batenkov, O.; Baublis, V.; Baznat, M.; Becker, J.; Becker, K.-H.; Belogurov, S.; Belyakov, D.; Bendarouach, J.; Berceanu, I.; Bercuci, A.; Berdnikov, A.; Berdnikov, Y.; Berendes, R.; Berezin, G.; Bergmann, C.; Bertini, D.; Bertini, O.; Beşliu, C.; Bezshyyko, O.; Bhaduri, P. P.; Bhasin, A.; Bhati, A. K.; Bhattacharjee, B.; Bhattacharyya, A.; Bhattacharyya, T. K.; Biswas, S.; Blank, T.; Blau, D.; Blinov, V.; Blume, C.; Bocharov, Yu.; Book, J.; Breitner, T.; Brüning, U.; Brzychczyk, J.; Bubak, A.; Büsching, H.; Bus, T.; Butuzov, V.; Bychkov, A.; Byszuk, A.; Cai, Xu; Cãlin, M.; Cao, Ping; Caragheorgheopol, G.; Carević, I.; Cătănescu, V.; Chakrabarti, A.; Chattopadhyay, S.; Chaus, A.; Chen, Hongfang; Chen, LuYao; Cheng, Jianping; Chepurnov, V.; Cherif, H.; Chernogorov, A.; Ciobanu, M. I.; Claus, G.; Constantin, F.; Csanád, M.; D'Ascenzo, N.; Das, Supriya; Das, Susovan; de Cuveland, J.; Debnath, B.; Dementiev, D.; Deng, Wendi; Deng, Zhi; Deppe, H.; Deppner, I.; Derenovskaya, O.; Deveaux, C. A.; Deveaux, M.; Dey, K.; Dey, M.; Dillenseger, P.; Dobyrn, V.; Doering, D.; Dong, Sheng; Dorokhov, A.; Dreschmann, M.; Drozd, A.; Dubey, A. K.; Dubnichka, S.; Dubnichkova, Z.; Dürr, M.; Dutka, L.; Dželalija, M.; Elsha, V. V.; Emschermann, D.; Engel, H.; Eremin, V.; Eşanu, T.; Eschke, J.; Eschweiler, D.; Fan, Huanhuan; Fan, Xingming; Farooq, M.; Fateev, O.; Feng, Shengqin; Figuli, S. P. D.; Filozova, I.; Finogeev, D.; Fischer, P.; Flemming, H.; Förtsch, J.; Frankenfeld, U.; Friese, V.; Friske, E.; Fröhlich, I.; Frühauf, J.; Gajda, J.; Galatyuk, T.; Gangopadhyay, G.; García Chávez, C.; Gebelein, J.; Ghosh, P.; Ghosh, S. K.; Gläßel, S.; Goffe, M.; Golinka-Bezshyyko, L.; Golovatyuk, V.; Golovnya, S.; Golovtsov, V.; Golubeva, M.; Golubkov, D.; Gómez Ramírez, A.; Gorbunov, S.; Gorokhov, S.; Gottschalk, D.; Gryboś, P.; Grzeszczuk, A.; Guber, F.; Gudima, K.; Gumiński, M.; Gupta, A.; Gusakov, Yu.; Han, Dong; Hartmann, H.; He, Shue; Hehner, J.; Heine, N.; Herghelegiu, A.; Herrmann, N.; Heß, B.; Heuser, J. M.; Himmi, A.; Höhne, C.; Holzmann, R.; Hu, Dongdong; Huang, Guangming; Huang, Xinjie; Hutter, D.; Ierusalimov, A.; Ilgenfritz, E.-M.; Irfan, M.; Ivanischev, D.; Ivanov, M.; Ivanov, P.; Ivanov, Valery; Ivanov, Victor; Ivanov, Vladimir; Ivashkin, A.; Jaaskelainen, K.; Jahan, H.; Jain, V.; Jakovlev, V.; Janson, T.; Jiang, Di; Jipa, A.; Kadenko, I.; Kähler, P.; Kämpfer, B.; Kalinin, V.; Kallunkathariyil, J.; Kampert, K.-H.; Kaptur, E.; Karabowicz, R.; Karavichev, O.; Karavicheva, T.; Karmanov, D.; Karnaukhov, V.; Karpechev, E.; Kasiński, K.; Kasprowicz, G.; Kaur, M.; Kazantsev, A.; Kebschull, U.; Kekelidze, G.; Khan, M. M.; Khan, S. A.; Khanzadeev, A.; Khasanov, F.; Khvorostukhin, A.; Kirakosyan, V.; Kirejczyk, M.; Kiryakov, A.; Kiš, M.; Kisel, I.; Kisel, P.; Kiselev, S.; Kiss, T.; Klaus, P.; Kłeczek, R.; Klein-Bösing, Ch.; Kleipa, V.; Klochkov, V.; Kmon, P.; Koch, K.; Kochenda, L.; Koczoń, P.; Koenig, W.; Kohn, M.; Kolb, B. W.; Kolosova, A.; Komkov, B.; Korolev, M.; Korolko, I.; Kotte, R.; Kovalchuk, A.; Kowalski, S.; Koziel, M.; Kozlov, G.; Kozlov, V.; Kramarenko, V.; Kravtsov, P.; Krebs, E.; Kreidl, C.; Kres, I.; Kresan, D.; Kretschmar, G.; Krieger, M.; Kryanev, A. V.; Kryshen, E.; Kuc, M.; Kucewicz, W.; Kucher, V.; Kudin, L.; Kugler, A.; Kumar, Ajit; Kumar, Ashwini; Kumar, L.; Kunkel, J.; Kurepin, A.; Kurepin, N.; Kurilkin, A.; Kurilkin, P.; Kushpil, V.; Kuznetsov, S.; Kyva, V.; Ladygin, V.; Lara, C.; Larionov, P.; Laso García, A.; Lavrik, E.; Lazanu, I.; Lebedev, A.; Lebedev, S.; Lebedeva, E.; Lehnert, J.; Lehrbach, J.; Leifels, Y.; Lemke, F.; Li, Cheng; Li, Qiyan; Li, Xin; Li, Yuanjing; Lindenstruth, V.; Linnik, B.; Liu, Feng; Lobanov, I.; Lobanova, E.; Löchner, S.; Loizeau, P.-A.; Lone, S. A.; Lucio Martínez, J. A.; Luo, Xiaofeng; Lymanets, A.; Lyu, Pengfei; Maevskaya, A.; Mahajan, S.; Mahapatra, D. P.; Mahmoud, T.; Maj, P.; Majka, Z.; Malakhov, A.; Malankin, E.; Malkevich, D.; Malyatina, O.; Malygina, H.; Mandal, M. M.; Mandal, S.; Manko, V.; Manz, S.; Marin Garcia, A. M.; Markert, J.; Masciocchi, S.; Matulewicz, T.; Meder, L.; Merkin, M.; Mialkovski, V.; Michel, J.; Miftakhov, N.; Mik, L.; Mikhailov, K.; Mikhaylov, V.; Milanović, B.; Militsija, V.; Miskowiec, D.; Momot, I.; Morhardt, T.; Morozov, S.; Müller, W. F. J.; Müntz, C.; Mukherjee, S.; Muñoz Castillo, C. E.; Murin, Yu.; Najman, R.; Nandi, C.; Nandy, E.; Naumann, L.; Nayak, T.; Nedosekin, A.; Negi, V. S.; Niebur, W.; Nikulin, V.; Normanov, D.; Oancea, A.; Oh, Kunsu; Onishchuk, Yu.; Ososkov, G.; Otfinowski, P.; Ovcharenko, E.; Pal, S.; Panasenko, I.; Panda, N. R.; Parzhitskiy, S.; Patel, V.; Pauly, C.; Penschuck, M.; Peshekhonov, D.; Peshekhonov, V.; Petráček, V.; Petri, M.; Petriş, M.; Petrovici, A.; Petrovici, M.; Petrovskiy, A.; Petukhov, O.; Pfeifer, D.; Piasecki, K.; Pieper, J.; Pietraszko, J.; Płaneta, R.; Plotnikov, V.; Plujko, V.; Pluta, J.; Pop, A.; Pospisil, V.; Poźniak, K.; Prakash, A.; Prasad, S. K.; Prokudin, M.; Pshenichnov, I.; Pugach, M.; Pugatch, V.; Querchfeld, S.; Rabtsun, S.; Radulescu, L.; Raha, S.; Rami, F.; Raniwala, R.; Raniwala, S.; Raportirenko, A.; Rautenberg, J.; Rauza, J.; Ray, R.; Razin, S.; Reichelt, P.; Reinecke, S.; Reinefeld, A.; Reshetin, A.; Ristea, C.; Ristea, O.; Rodriguez Rodriguez, A.; Roether, F.; Romaniuk, R.; Rost, A.; Rostchin, E.; Rostovtseva, I.; Roy, Amitava; Roy, Ankhi; Rożynek, J.; Ryabov, Yu.; Sadovsky, A.; Sahoo, R.; Sahu, P. K.; Sahu, S. K.; Saini, J.; Samanta, S.; Sambyal, S. S.; Samsonov, V.; Sánchez Rosado, J.; Sander, O.; Sarangi, S.; Satława, T.; Sau, S.; Saveliev, V.; Schatral, S.; Schiaua, C.; Schintke, F.; Schmidt, C. J.; Schmidt, H. R.; Schmidt, K.; Scholten, J.; Schweda, K.; Seck, F.; Seddiki, S.; Selyuzhenkov, I.; Semennikov, A.; Senger, A.; Senger, P.; Shabanov, A.; Shabunov, A.; Shao, Ming; Sheremetiev, A. D.; Shi, Shusu; Shumeiko, N.; Shumikhin, V.; Sibiryak, I.; Sikora, B.; Simakov, A.; Simon, C.; Simons, C.; Singaraju, R. N.; Singh, A. K.; Singh, B. K.; Singh, C. P.; Singhal, V.; Singla, M.; Sitzmann, P.; Siwek-Wilczyńska, K.; Škoda, L.; Skwira-Chalot, I.; Som, I.; Song, Guofeng; Song, Jihye; Sosin, Z.; Soyk, D.; Staszel, P.; Strikhanov, M.; Strohauer, S.; Stroth, J.; Sturm, C.; Sultanov, R.; Sun, Yongjie; Svirida, D.; Svoboda, O.; Szabó, A.; Szczygieł, R.; Talukdar, R.; Tang, Zebo; Tanha, M.; Tarasiuk, J.; Tarassenkova, O.; Târzilă, M.-G.; Teklishyn, M.; Tischler, T.; Tlustý, P.; Tölyhi, T.; Toia, A.; Topil'skaya, N.; Träger, M.; Tripathy, S.; Tsakov, I.; Tsyupa, Yu.; Turowiecki, A.; Tuturas, N. G.; Uhlig, F.; Usenko, E.; Valin, I.; Varga, D.; Vassiliev, I.; Vasylyev, O.; Verbitskaya, E.; Verhoeven, W.; Veshikov, A.; Visinka, R.; Viyogi, Y. P.; Volkov, S.; Volochniuk, A.; Vorobiev, A.; Voronin, Aleksey; Voronin, Alexander; Vovchenko, V.; Vznuzdaev, M.; Wang, Dong; Wang, Xi-Wei; Wang, Yaping; Wang, Yi; Weber, M.; Wendisch, C.; Wessels, J. P.; Wiebusch, M.; Wiechula, J.; Wielanek, D.; Wieloch, A.; Wilms, A.; Winckler, N.; Winter, M.; Wiśniewski, K.; Wolf, Gy.; Won, Sanguk; Wu, Ke-Jun; Wüstenfeld, J.; Xiang, Changzhou; Xu, Nu; Yang, Junfeng; Yang, Rongxing; Yin, Zhongbao; Yoo, In-Kwon; Yuldashev, B.; Yushmanov, I.; Zabołotny, W.; Zaitsev, Yu.; Zamiatin, N. I.; Zanevsky, Yu.; Zhalov, M.; Zhang, Yifei; Zhang, Yu; Zhao, Lei; Zheng, Jiajun; Zheng, Sheng; Zhou, Daicui; Zhou, Jing; Zhu, Xianglei; Zinchenko, A.; Zipper, W.; Żoładź, M.; Zrelov, P.; Zryuev, V.; Zumbruch, P.; Zyzak, M.

    2017-03-01

    Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (√{s_{NN}}= 2.7-4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials ( μ_B > 500 MeV), effects of chiral symmetry, and the equation of state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2024, in the context of the worldwide efforts to explore high-density QCD matter.

  4. Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

    CERN Document Server

    ,

    2016-01-01

    Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram ...

  5. Dark Matter is Baryons

    CERN Document Server

    Soberman, R K; Soberman, Robert K.; Dubin, Maurice

    2001-01-01

    A comet-like, but magnitudes smaller, extremely low albedo interstellar meteoroid population of fragile aggregates with solar type composition, measured in space and terrestrially, is most probably the universal dark matter. Although non-baryonic particles cannot be excluded, only "Big Bang" cosmology predicts an appreciable fraction of such alternate forms. As more counter-physics hypotheses are added to fit observation to the expanding universe assumption, a classical physics alternative proffers dark matter interactive red shifts normally correlated with distance. The cosmic microwave background results from size-independent thermal plateau radiation that emanates from dark matter gravitationally drawn into the Galaxy.

  6. Constraints on the Interactions between Dark Matter and Baryons from the X-ray Quantum Calorimetry Experiment

    CERN Document Server

    Erickcek, Adrienne L; McCammon, Dan; McGuire, Patrick C

    2007-01-01

    Although the rocket-based X-ray Quantum Calorimetry (XQC) experiment was designed for X-ray spectroscopy, the minimal shielding of its calorimeters, its low atmospheric overburden, and its low-threshold detectors make it among the most sensitive instruments for detecting or constraining strong interactions between dark matter particles and baryons. We use Monte Carlo simulations to obtain the precise limits the XQC experiment places on spin-independent interactions between dark matter and baryons, improving upon earlier analytical estimates. We find that the XQC experiment rules out a wide range of nucleon-scattering cross sections centered around one barn for dark matter particles with masses between 0.01 and 10^5 GeV. Our analysis also provides new constraints on cases where only a fraction of the dark matter strongly interacts with baryons.

  7. Dilatons in Dense Baryonic Matter

    CERN Document Server

    Lee, Hyun Kyu

    2013-01-01

    We discuss the role of dilaton, which is supposed to be representing a special feature of scale symmetry of QCD, trace anomaly, in dense baryonic matter. The idea that the scale symmetry breaking of QCD is responsible for the spontaneous breaking of chiral symmetry is presented along the similar spirit of Freund-Nambu model. The incorporation of dilaton field in the hidden local symmetric parity doublet model is briefly sketched with the possible role of dilaton at high density baryonic matter, the emergence of linear sigma model in dilaton limit.

  8. Optimization of a transition radiation detector for the compressed baryonic matter experiment

    Energy Technology Data Exchange (ETDEWEB)

    Arend, Andreas

    2014-07-01

    The Transition Radiation Detector (TRD) of the compressed baryonic matter (CBM) experiment at FAIR has to provide electron-pion separation as well as charged-particle tracking. Within this work, thin and symmetric Multi-Wire Proportional Chambers (MWPCs) without additional drift region were proposed. the proposed prototypes feature a foil-based entrance window to minimize the material budget and to reduce the absorption probability of the generated TR photon. Based on the conceptual design of thin and symmetric MWPCs without drift region, multiple prototypes were constructed and their performance presented within this thesis. With the constructed prototypes of generations II and III the geometries of the wire and cathode planes were determined to be 4+4 mm and 5+5 mm. Based on the results of a performed test beam campaign in 2011 with this prototypes new prototypes of generation IV were manufactured and tested in a subsequent test beam campaign in 2012. Prototypes of different radiators were developed together with the MWPC prototypes. Along with regular foil radiators, foam-based radiator types made of polyethylene foam were utilized. Also radiators constructed in a sandwich design, which used different fiber materials confined with solid foam sheets, were used. For the prototypes without drift region, simulations of the electrostatic and mechanical properties were performed. The GARFIELD software package was used to simulate the electric field and to determine the resulting drift lines of the generated electrons. The mean gas amplification depending on the utilized gas and the applied anode voltage was simulated and the gas-gain homogeneity was verified. Since the thin foil-based entrance window experiences a deformation due to pressure differences inside and outside the MWPC, the variation on the gas gain depending on the deformation was simulated. The mechanical properties focusing on the stability of the entrance window was determined with a finiteelement

  9. Diffuse baryonic matter beyond 2020

    CERN Document Server

    Markevitch, M; Nulsen, P; Rasia, E; Vikhlinin, A; Kravtsov, A; Forman, W; Brunetti, G; Sarazin, C; Elvis, M; Fabbiano, G; Hornschemeier, A; Brissenden, R

    2009-01-01

    The hot, diffuse gas that fills the largest overdense structures in the Universe -- clusters of galaxies and a web of giant filaments connecting them -- provides us with tools to address a wide array of fundamental astrophysical and cosmological questions via observations in the X-ray band. Clusters are sensitive cosmological probes. To utilize their full potential for precision cosmology in the following decades, we must precisely understand their physics -- from their cool cores stirred by jets produced by the central supermassive black hole (itself fed by inflow of intracluster gas), to their outskirts, where the infall of intergalactic medium (IGM) drives shocks and accelerates cosmic rays. Beyond the cluster confines lies the virtually unexplored warm IGM, believed to contain most of the baryonic matter in the present-day Universe. As a depository of all the matter ever ejected from galaxies, it carries unique information on the history of energy and metal production in the Universe. Currently planned ma...

  10. Baryons and baryonic matter in four-fermion interaction models

    Energy Technology Data Exchange (ETDEWEB)

    Urlichs, K.

    2007-02-23

    In this work we discuss baryons and baryonic matter in simple four-fermion interaction theories, the Gross-Neveu model and the Nambu-Jona-Lasinio model in 1+1 and 2+1 space-time dimensions. These models are designed as toy models for dynamical symmetry breaking in strong interaction physics. Pointlike interactions (''four-fermion'' interactions) between quarks replace the full gluon mediated interaction of quantum chromodynamics. We consider the limit of a large number of fermion flavors, where a mean field approach becomes exact. This method is formulated in the language of relativistic many particle theory and is equivalent to the Hartree-Fock approximation. In 1+1 dimensions, we generalize known results on the ground state to the case where chiral symmetry is broken explicitly by a bare mass term. For the Gross-Neveu model, we derive an exact self-consistent solution for the finite density ground state, consisting of a one-dimensional array of equally spaced potential wells, a baryon crystal. For the Nambu- Jona-Lasinio model we apply the derivative expansion technique to calculate the total energy in powers of derivatives of the mean field. In a picture akin to the Skyrme model of nuclear physics, the baryon emerges as a topological soliton. The solution for both the single baryon and dense baryonic matter is given in a systematic expansion in powers of the pion mass. The solution of the Hartree-Fock problem is more complicated in 2+1 dimensions. In the massless Gross-Neveu model we derive an exact self-consistent solution by extending the baryon crystal of the 1+1 dimensional model, maintaining translational invariance in one spatial direction. This one-dimensional configuration is energetically degenerate to the translationally invariant solution, a hint in favor of a possible translational symmetry breakdown by more general geometrical structures. In the Nambu-Jona-Lasinio model, topological soliton configurations induce a finite baryon

  11. The segregation of baryons and dark matter during halo assembly

    CERN Document Server

    Liao, Shihong; Frenk, Carlos S; Guo, Qi; Wang, Jie

    2016-01-01

    The standard galaxy formation theory assumes that baryons and dark matter are initially well-mixed before becoming segregated due to radiative cooling. We use non-radiative hydrodynamical simulations to explicitly examine this assumption and find that baryons and dark matter can also be segregated during the build-up of the halo. As a result, baryons in many haloes do not originate from the same Lagrangian region as the dark matter. When using the fraction of corresponding dark matter and gas particles in the initial conditions (the "paired fraction") as a proxy of the dark matter and gas segregation strength of a halo, on average about $25$ percent of the baryonic and dark matter of the final halo are segregated in the initial conditions. A consequence of this effect is that the baryons and dark matter of the same halo initially experience different tidal torques and thus their angular momentum vectors are often misaligned. This is at odds with the assumption of the standard galaxy formation model, and chall...

  12. Compressed Baryonic Matter: from Nuclei to Pulsars

    CERN Document Server

    Xu, Renxin

    2013-01-01

    Our world is wonderful because of the negligible baryonic part although unknown dark matter and dark energy dominate the Universe. Those nuclei in the daily life are forbidden to fuse by compression due to the Coulomb repulse, nevertheless, it is usually unexpected in extraterrestrial extreme-environments: the gravity in a core of massive evolved star is so strong that all the other forces (including the Coulomb one) could be neglected. Compressed baryonic matter is then produced after supernova, manifesting itself as pulsar-like stars observed. The study of this compressed baryonic matter can not only be meaningful in fundamental physics (e.g., the elementary color interaction at low-energy scale, testing gravity theories, detecting nano-Hertz background gravitational waves), but has also profound implications in engineering applications (including time standard and navigation), and additionally, is focused by Chinese advanced telescopes, either terrestrial or in space. Historically, in 1930s, L. Landau spec...

  13. Non-baryonic dark matter in cosmology

    Science.gov (United States)

    Del Popolo, A.

    2013-07-01

    This paper is based on lectures given at the IX Mexican School on Gravitation and Mathematical Physics. The lectures (as the paper) were a broad-band review of the current status of non-baryonic dark matter research. I start with a historical overview of the evidences of dark matter existence, then I discuss how dark matter is distributed from small scale to large scale, and I then verge the attention to dark matter nature: dark matter candidates and their detection. I finally discuss some of the limits of the ΛCDM model, with particular emphasis on the small scale problems of the paradigm.

  14. Non-Baryonic Dark Matter in Cosmology

    CERN Document Server

    Del Popolo, A

    2014-01-01

    This paper is a broad-band review of the current status of non-baryonic dark matter research. I start with a historical overview of the evidences of dark matter existence, then I discuss how dark matter is distributed from small scale to large scale, and I then verge the attention to dark matter nature: dark matter candidates and their detection. I finally discuss some of the limits of the $\\Lambda$CDM model, with particular emphasis on the small scale problems of the paradigm.

  15. Dark Matter and the Baryon Asymmetry

    CERN Document Server

    Farrar, G R; Farrar, Glennys R.; Zaharijas, Gabrijela

    2006-01-01

    We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the Big Bang. If dark matter particles carry baryon number $B_X$, and $\\sigma^{\\rm annih}_{\\bar{X}} < \\sigma^{\\rm annih}_{X} $, the $\\bar{X}$'s freeze out at a higher temperature and have a larger relic density than $X$'s. If $m_X \\lsi 4.5 B_X $GeV and the annihilation cross sections differ by $\\mathcal{O}$(10%) or more, this type of scenario naturally explains the observed $\\Omega_{DM} \\approx 5 \\Omega_b$. Two concrete examples are given, one of which can be excluded on observational grounds.

  16. Flavour Oscillations in Dense Baryonic Matter

    Science.gov (United States)

    Filip, Peter

    2017-01-01

    We suggest that fast neutral meson oscillations may occur in a dense baryonic matter, which can influence the balance of s/¯s quarks in the nucleus-nucleus and proton-nucleus interactions, if primordial multiplicities of neutral K 0, mesons are sufficiently asymmetrical. The phenomenon can occur even if CP symmetry is fully conserved, and it may be responsible for the enhanced sub-threshold production of multi-strange hyperons observed in the low-energy A+A and p+A interactions.

  17. Development of optical quality assurance procedures for the sensors of silicon tracking system (STS) detector of the compressed baryonic matter experiment (CBM) at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Lavrik, Evgeny [Eberhard-Karls Universitaet Tuebingen, Tuebingen (Germany); Collaboration: CBM-Collaboration

    2015-07-01

    The CBM experiment aims to study the properties of nuclear matter at high net-baryon densities. The STS is the key detector to reconstruct charged particle tracks created in heavy-ion interactions. In order to assure the quality of about 1300 silicon sensors, highly efficient and highly automated procedures need to be developed. In this contribution we report on a microscope camera based optical inspection system, used to scan along the individual sensors to recognize and classify sensor defects. Examples of these defects are: photo-resist residues, top metallization layer lithography defects, surface scratches. In order to separate and classify these defects various image-processing algorithms are used, including: pattern recognition, object classification, etc.

  18. Baryons and baryonic matter in the large Nc and heavy quark limits

    CERN Document Server

    Cohen, Thomas D; Ndousse, Kamal K

    2011-01-01

    This paper explores properties of baryons and finite density baryonic matter in an artificial world in which Nc, the number of colors, is large and the quarks of all species are degenerate and much larger than {\\Lambda}_QCD. It has long been known that in large Nc QCD, baryons composed entirely of heavy quarks are accurately described in the mean-field approximation. However, the detailed properties of baryons in the combined large Nc and heavy quark limits have not been fully explored. Here some basic properties of baryons are computed using a variational approach. At leading order in both the large Nc and heavy quark expansions the baryon mass is computed explicitly as is the baryon form factor. Baryonic matter, the analog of nuclear matter in this artificial world, should also be well described in the mean-field approximation. In the special case where all baryons have an identical spin flavor structure, it is shown that in the formal heavy quark and large Nc limit interactions between baryons are strictly...

  19. Dark Matter in Lepto-Baryonic Left-Right Theories

    CERN Document Server

    Patra, Sudhanwa

    2015-01-01

    A Lepto-Baryonic Left-Right symmetric theory is considered where leptons and baryons are local gauge symmetries. These theories are generally anomalous and the possible gauge anomaly free solutions for these theories are presented here. This paper also shows different ways in which Lepto-Baryonic Left-Right theories are broken down to Standard Model gauge group which further breaks down to low energy by SM Higgs boson. It is found that the neutral component of fermion triplets can be a viable dark matter candidate originally introduced for gauge anomaly cancellation. The other dark matter possibilities within this Lepto-Baryonic Left-Right symmetric theories are also presented.

  20. Direct searches for non-baryonic dark matter; Experiences de detection directe de la matiere sombre non baryonique

    Energy Technology Data Exchange (ETDEWEB)

    Di Stefano, Philippe E. [Max-Planck-Institut fuer Physik, Munich (Germany)]. E-mail: distefano@mppmu.mpg.de

    2001-10-01

    Since the mid-1980s, non-accelerator particle physics experiments have been searching for weakly interacting massive particles which could solve the dark matter enigma first pointed out some 70 years ago. The low event rate and energies expected pose a formidable experimental challenge. The first detectors were ionization devices, soon followed by scintillation detectors able to reject a small portion of the photon and electron radioactive backgrounds. The performance of these early generations of detectors has now been matched by new cryogenic detectors in which a simultaneous reading of phonons and charge allows a very efficient rejection of the background. These devices, along with recently developed simultaneous phonon and scintillation techniques could provide cryogenic devices with a decisive advantage. (author) [French] La question astrophysique de la matiere sombre, posee dans les annees trente, attire depuis une quinzaine d'annees des experiences de physique des particules hors accelerateur tentant d'y repondre par la mise en evidence de particules lourdes et interagissant faiblement. Le faible taux et la basse energie des evenements attendus rendent la tache ardue. Les premiers detecteurs employes furent a ionisation, puis a scintillation, ceux-ci disposant d'une methode rudimentaire pour rejeter le fond electromagnetique. Ces deux premieres generations d'experiences massives sont aujourd'hui rattrapees par des nouveaux detecteurs cryogeniques associant une mesure de l'ionisation a un signal phonons, qui permettent de rejeter le fond electromagnetique tres efficacement. Ces dispositifs, et de recents developpements de mesure simultanee de scintillation et de phonons, pourraient donner l'avantage aux detecteurs cryogeniques. (author)

  1. Finite Volume Effect of Baryons in Strange Hadronic Matter

    Institute of Scientific and Technical Information of China (English)

    SUN Bao-Xi; LI Lei; NING Ping-Zhi; ZHAO En-Guang

    2001-01-01

    The finite volume effect of baryons in strange hadronic matter (SHM) is studied within the framework of relativistic mean-field theory. As this effect is concerned, the saturation density of SHM turns lower, and the binding energy per baryon decreases. Its influence to the compression modulus of SHM is also discussed.

  2. Helioseismology with long-range dark matter-baryon interactions

    DEFF Research Database (Denmark)

    Lopes, I.; Panci, Paolo; Silk, J.

    2014-01-01

    Assuming the existence of a primordial asymmetry in the dark sector, we study how long-range dark matter (DM)-baryon interactions, induced by the kinetic mixing of a new U(1) gauge boson and a photon, affect the evolution of the Sun and, in turn, the sound speed the profile obtained from...... the agreement between the best solar model and the helioseismic data without being excluded by direct detection experiments. In particular, the LUX detector will soon be able to either constrain or confirm our best-fit solar model in the presence of a dark sector with long-range interactions that reconcile...

  3. Measurement of matter-antimatter differences in beauty baryon decays

    CERN Document Server

    Aaij, Roel; Adinolfi, Marco; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Andreassi, Guido; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Archilli, Flavio; d'Argent, Philippe; Arnau Romeu, Joan; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Babuschkin, Igor; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baker, Sophie; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Baszczyk, Mateusz; Batozskaya, Varvara; Batsukh, Baasansuren; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Bel, Lennaert; Bellee, Violaine; Belloli, Nicoletta; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Betti, Federico; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bezshyiko, Iaroslava; Bifani, Simone; Billoir, Pierre; Bird, Thomas; Birnkraut, Alex; Bitadze, Alexander; Bizzeti, Andrea; Blake, Thomas; Blanc, Frederic; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Boettcher, Thomas; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borgheresi, Alessio; Borghi, Silvia; Borisyak, Maxim; Borsato, Martino; Bossu, Francesco; Boubdir, Meriem; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Braun, Svende; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Buchanan, Emma; Burr, Christopher; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Camboni, Alessandro; Campana, Pierluigi; Campora Perez, Daniel; Campora Perez, Daniel Hugo; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cavallero, Giovanni; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chatzikonstantinidis, Georgios; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chobanova, Veronika; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Costa Sobral, Cayo Mar; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Da Cunha Marinho, Franciole; Dall'Occo, Elena; Dalseno, Jeremy; David, Pieter; Davis, Adam; De Aguiar Francisco, Oscar; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Serio, Marilisa; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Demmer, Moritz; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Dijkstra, Hans; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dovbnya, Anatoliy; Dreimanis, Karlis; Dufour, Laurent; Dujany, Giulio; Dungs, Kevin; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Déléage, Nicolas; Easo, Sajan; Ebert, Marcus; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Farley, Nathanael; Farry, Stephen; Fay, Robert; Fazzini, Davide; Ferguson, Dianne; Fernandez Albor, Victor; Fernandez Prieto, Antonio; Ferrari, Fabio; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fini, Rosa Anna; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fleuret, Frederic; Fohl, Klaus; Fontana, Marianna; Fontanelli, Flavio; Forshaw, Dean Charles; Forty, Roger; Franco Lima, Vinicius; Frank, Markus; Frei, Christoph; Fu, Jinlin; Furfaro, Emiliano; Färber, Christian; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; Garcia Martin, Luis Miguel; García Pardiñas, Julián; Garra Tico, Jordi; Garrido, Lluis; Garsed, Philip John; Gascon, David; Gaspar, Clara; Gavardi, Laura; Gazzoni, Giulio; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianì, Sebastiana; Gibson, Valerie; Girard, Olivier Göran; Giubega, Lavinia-Helena; Gizdov, Konstantin; Gligorov, V.V.; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gorelov, Igor Vladimirovich; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Griffith, Peter; Grillo, Lucia; Gruberg Cazon, Barak Raimond; Grünberg, Oliver; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Göbel, Carla; Hadavizadeh, Thomas; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; Hatch, Mark; He, Jibo; Head, Timothy; Heister, Arno; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hombach, Christoph; Hopchev, P H; Hulsbergen, Wouter; Humair, Thibaud; Hushchyn, Mikhail; Hussain, Nazim; Hutchcroft, David; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jiang, Feng; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Kariuki, James Mwangi; Karodia, Sarah; Kecke, Matthieu; Kelsey, Matthew; Kenyon, Ian; Kenzie, Matthew; Ketel, Tjeerd; Khairullin, Egor; Khanji, Basem; Khurewathanakul, Chitsanu; Kirn, Thomas; Klaver, Suzanne; Klimaszewski, Konrad; Koliiev, Serhii; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Kozachuk, Anastasiia; Kozeiha, Mohamad; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krokovny, Pavel; Kruse, Florian; Krzemien, Wojciech; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kuonen, Axel Kevin; Kurek, Krzysztof; Kvaratskheliya, Tengiz; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lanfranchi, Gaia; Langenbruch, Christoph; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Leflat, Alexander; Lefrançois, Jacques; Lefèvre, Regis; Lemaitre, Florian; Lemos Cid, Edgar; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Liu, Xuesong; Loh, David; Longstaff, Iain; Lopes, Jose; Lucchesi, Donatella; Lucio Martinez, Miriam; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Lusiani, Alberto; Lyu, Xiao-Rui; Machefert, Frederic; Maciuc, Florin; Maev, Oleg; Maguire, Kevin; Malde, Sneha; Malinin, Alexander; Maltsev, Timofei; Manca, Giulia; Mancinelli, Giampiero; Manning, Peter Michael; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Marks, Jörg; Martellotti, Giuseppe; Martin, Morgan; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massacrier, Laure Marie; Massafferri, André; Matev, Rosen; Mathad, Abhijit; Mathe, Zoltan; Matteuzzi, Clara; Mauri, Andrea; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; Meadows, Brian; Meier, Frank; Meissner, Marco; Melnychuk, Dmytro; Merk, Marcel; Merli, Andrea; Michielin, Emanuele; Milanes, Diego Alejandro; Minard, Marie-Noelle; Mitzel, Dominik Stefan; Mogini, Andrea; Molina Rodriguez, Josue; Monroy, Ignacio Alberto; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Mulder, Mick; Mussini, Manuel; Müller, Dominik; Müller, Janine; Müller, Katharina; Müller, Vanessa; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nandi, Anita; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen-Mau, Chung; Nieswand, Simon; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Oldeman, Rudolf; Onderwater, Gerco; Otalora Goicochea, Juan Martin; Otto, Adam; Owen, Patrick; Oyanguren, Maria Aranzazu; Pais, Preema Rennee; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parker, William; Parkes, Christopher; Passaleva, Giovanni; Pastore, Alessandra; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Pescatore, Luca; Petridis, Konstantinos; Petrolini, Alessandro; Petrov, Aleksandr; Petruzzo, Marco; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pikies, Malgorzata; Pinci, Davide; Pistone, Alessandro; Piucci, Alessio; Playfer, Stephen; Plo Casasus, Maximo; Poikela, Tuomas; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Pomery, Gabriela Johanna; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Poslavskii, Stanislav; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Quagliani, Renato; Rachwal, Bartolomiej; Rademacker, Jonas; Rama, Matteo; Ramos Pernas, Miguel; Rangel, Murilo; Raniuk, Iurii; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; dos Reis, Alberto; Remon Alepuz, Clara; Renaudin, Victor; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vicente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Lopez, Jairo Alexis; Rodriguez Perez, Pablo; Rogozhnikov, Alexey; Roiser, Stefan; Romanovskiy, Vladimir; Romero Vidal, Antonio; Ronayne, John William; Rotondo, Marcello; Rudolph, Matthew Scott; Ruf, Thomas; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sadykhov, Elnur; Sagidova, Naylya; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santimaria, Marco; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schael, Stefan; Schellenberg, Margarete; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmelzer, Timon; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schubert, Konstantin; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sergi, Antonino; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Siddi, Benedetto Gianluca; Silva Coutinho, Rafael; Silva de Oliveira, Luiz Gustavo; Simi, Gabriele; Simone, Saverio; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Eluned; Smith, Iwan Thomas; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Stefko, Pavol; Stefkova, Slavorima; Steinkamp, Olaf; Stemmle, Simon; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Syropoulos, Vasileios; Szczekowski, Marek; Szumlak, Tomasz; T'Jampens, Stephane; Tayduganov, Andrey; Tekampe, Tobias; Tellarini, Giulia; Teubert, Frederic; Thomas, Eric; van Tilburg, Jeroen; Tilley, Matthew James; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Toriello, Francis; Tournefier, Edwige; Tourneur, Stephane; Trabelsi, Karim; Traill, Murdo; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tully, Alison; Tuning, Niels; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valassi, Andrea; Valat, Sebastien; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vecchi, Stefania; van Veghel, Maarten; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Venkateswaran, Aravindhan; Vernet, Maxime; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Volkov, Vladimir; Vollhardt, Achim; Voneki, Balazs; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Vázquez Sierra, Carlos; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wang, Jianchun; Ward, David; Wark, Heather Mckenzie; Watson, Nigel; Websdale, David; Weiden, Andreas; Whitehead, Mark; Wicht, Jean; Wilkinson, Guy; Wilkinson, Michael; Williams, Mark Richard James; Williams, Matthew; Williams, Mike; Williams, Timothy; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wraight, Kenneth; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yin, Hang; Yu, Jiesheng; Yuan, Xuhao; Yushchenko, Oleg; Zarebski, Kristian Alexander; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Yanxi; Zhang, Yu; Zhelezov, Alexey; Zheng, Yangheng; Zhokhov, Anatoly; Zhu, Xianglei; Zhukov, Valery; Zucchelli, Stefano

    2017-01-01

    Differences in the behaviour of matter and antimatter have been observed in $K$ and $B$ meson decays, but not yet in any baryon decay. Such differences are associated with the non-invariance of fundamental interactions under the combined charge-conjugation and parity transformations, known as CP violation. Using data from the LHCb experiment at the Large Hadron Collider, a search is made for CP-violating asymmetries in the decay angle distributions of $\\Lambda_b^0$ baryons decaying to $p\\pi^-\\pi^+\\pi^-$ and $p \\pi^- K^+ K^-$ final states. These four-body hadronic decays are a promising place to search for sources of CP violation both within and beyond the Standard Model of particle physics. We find evidence for CP violation in $\\Lambda_b^0$ to $p\\pi^-\\pi^+\\pi^-$ decays with a statistical significance corresponding to 3.3 standard deviations including systematic uncertainties. This represents the first evidence for CP violation in the baryon sector.

  4. Accurate initial conditions in mixed Dark Matter--Baryon simulations

    CERN Document Server

    Valkenburg, Wessel

    2016-01-01

    We quantify the error in the results of mixed baryon--dark-matter hydrodynamic simulations, stemming from outdated approximations for the generation of initial conditions. The error at redshift 0 in contemporary large simulations, is of the order of few to ten percent in the power spectra of baryons and dark matter, and their combined total-matter power spectrum. After describing how to properly assign initial displacements and peculiar velocities to multiple species, we review several approximations: (1) {using the total-matter power spectrum to compute displacements and peculiar velocities of both fluids}, (2) scaling the linear redshift-zero power spectrum back to the initial power spectrum using the Newtonian growth factor ignoring homogeneous radiation, (3) using longitudinal-gauge velocities with synchronous-gauge densities, and (4) ignoring the phase-difference in the Fourier modes for the offset baryon grid, relative to the dark-matter grid. Three of these approximations do not take into account that ...

  5. Baryon formation and dissociation in dense hadronic and quark matter

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jincheng [Interdisciplinary Center for Theoretical Study and Department of Modern Physics, University of Science and Technology of China, Anhui 230026 (China); Institute for Theoretical Physics, Johann Wolfgang Goethe University, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany); Wang Qun, E-mail: qunwang@ustc.edu.cn [Interdisciplinary Center for Theoretical Study and Department of Modern Physics, University of Science and Technology of China, Anhui 230026 (China); Theoretical Physics Center for Science Facilities, Chinese Academy of Sciences, Beijing 100049 (China); Rischke, Dirk H. [Institute for Theoretical Physics, Johann Wolfgang Goethe University, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany); Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main (Germany)

    2011-10-19

    We study the formation of baryons as composed of quarks and diquarks in hot and dense hadronic matter in a Nambu-Jona-Lasinio (NJL)-type model. We first solve the Dyson-Schwinger equation for the diquark propagator and then use this to solve the Dyson-Schwinger equation for the baryon propagator. We find that stable baryon resonances exist only in the phase of broken chiral symmetry. In the chirally symmetric phase, we do not find a pole in the baryon propagator. In the color-superconducting phase, there is a pole, but it has a large decay width. The diquark does not need to be stable in order to form a stable baryon, a feature typical for so-called Borromean states. Varying the strength of the diquark coupling constant, we also find similarities to the properties of an Efimov state.

  6. Dark Matter and the Baryon Asymmetry of the Universe

    CERN Document Server

    Farrar, G R; Farrar, Glennys R.; Zaharijas, Gabrijela

    2004-01-01

    We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the Big Bang. If dark matter particles carry baryon number $B_X$, and $\\sigma^{\\rm annih}_{\\bar{X}} < \\sigma^{\\rm annih}_{X} $, the $\\bar{X}$'s freeze out at a higher temperature and have a larger relic density than $X$'s. If $m_X \\lsi 4.5 B_X $GeV and the annihilation cross sections differ by $\\gsi 10%$, this type of scenario naturally explains the observed $\\Omega_{DM} \\approx 5 \\Omega_b$.

  7. Medium modifications of baryon properties in nuclear matter and hypernuclei

    CERN Document Server

    Liang, J S

    2013-01-01

    We study the medium modifications of baryon properties in nuclear many-body systems, especially in $\\Lambda$ hypernuclei. The nucleon and the $\\Lambda$ hyperon are described in the Friedberg-Lee model as nontopological solitons which interact through the self-consistent exchange of scalar and vector mesons. The quark degrees of freedom are explicitly considered in the model, so that the medium effects on baryons could be investigated. It is found that the model can provide reasonable descriptions for nuclear matter, finite nuclei, and $\\Lambda$ hypernuclei. The present model predicts a significant increase of the baryon radius in nuclear medium.

  8. Exodus: Hidden origin of dark matter and baryons

    Science.gov (United States)

    Unwin, James

    2013-06-01

    We propose a new framework for explaining the proximity of the baryon and dark matter relic densities ΩDM ≈ 5Ω B . The scenario assumes that the number density of the observed dark matter states is generated due to decays from a second hidden sector which simultaneously generates the baryon asymmetry. In contrast to asymmetric dark matter models, the dark matter can be a real scalar or Majorana fermion and thus presents distinct phenomenology. We discuss aspects of model building and general constraints in this framework. Moreover, we argue that this scenario circumvents several of the experimental bounds which significantly constrain typical models of asymmetric dark matter. We present a simple supersymmetric implementation of this mechanism and show that it can be used to obtain the correct dark matter relic density for a bino LSP.

  9. Exodus: Hidden origin of dark matter and baryons

    CERN Document Server

    Unwin, James

    2012-01-01

    We propose a new framework for explaining the proximity of the baryon and dark matter relic densities \\Omega_{DM} \\approx 5\\Omega_B. The scenario assumes that the number density of the observed dark matter states is generated due to decays from a second hidden sector which simultaneously generates the baryon asymmetry. In contrast to asymmetric dark matter models, the dark matter can be a real scalar or Majorana fermion and thus presents distinct phenomenology. We discuss aspects of model building and general constraints in this framework. We present a simple supersymmetric implementation of this mechanism and show that it can be used to obtain the correct dark matter relic density for a bino LSP.

  10. Moduli induced cogenesis of baryon asymmetry and dark matter

    CERN Document Server

    Dhuria, Mansi; Sarkar, Utpal

    2015-01-01

    We study a cogenesis mechanism in which the observed baryon asymmetry of the universe and the dark matter abundance can be produced simultaneously at low reheating temperature without violating baryon number in the fundamental vertex. In particular, we consider a model which could be realized in the context of type IIB large volume string compactifications. The matter superfields in this model include additional pairs of color triplet and singlet superfields in addition to the Minimal Supersymmetric Standard Model (MSSM) superfields. Assuming that the mass of the additional singlet fermions is O(GeV) and color triplet fermions is O(TeV), we show that the modulus dominantly decays into the additional color triplet superfields. After soft supersymmetry (SUSY) breaking, the lightest eigenstate of scalar component of color triplet superfield further decays into fermionic component of singlet superfield and quarks without violating baryon number. Assuming R-parity conservation, it follows that the singlet superfie...

  11. Constraining Dark Matter-Baryon Scattering with Linear Cosmology

    CERN Document Server

    Dvorkin, Cora; Kamionkowski, Marc

    2013-01-01

    We derive constraints on elastic scattering between baryons and dark matter using the cosmic microwave background (CMB) data from the Planck satellite and the Lyman-alpha forest data from the Sloan Digital Sky Survey. Elastic scattering allows baryons and dark matter to exchange momentum, affecting the dynamics of linear density perturbations in the early Universe. We derive constraints to scattering cross sections of the form sigma \\propto v^n, allowing for a wide range of velocity dependencies with n between -4 and 2. We improve and correct previous estimates where they exist, including velocity-independent cross section as well as dark matter millicharge and electromagnetic dipole moments. Lyman-alpha forest data dominates the constraints for n>-3, where the improvement over CMB data alone can be several orders of magnitude. Dark matter-baryon scattering cannot affect the halo mass function on mass scales M>10^{12} M_{solar}. Our results imply, model-independently, that a baryon in the halo of a galaxy lik...

  12. Tying dark matter to baryons with self-interactions.

    Science.gov (United States)

    Kaplinghat, Manoj; Keeley, Ryan E; Linden, Tim; Yu, Hai-Bo

    2014-07-11

    Self-interacting dark matter (SIDM) models have been proposed to solve the small-scale issues with the collisionless cold dark matter paradigm. We derive equilibrium solutions in these SIDM models for the dark matter halo density profile including the gravitational potential of both baryons and dark matter. Self-interactions drive dark matter to be isothermal and this ties the core sizes and shapes of dark matter halos to the spatial distribution of the stars, a radical departure from previous expectations and from cold dark matter predictions. Compared to predictions of SIDM-only simulations, the core sizes are smaller and the core densities are higher, with the largest effects in baryon-dominated galaxies. As an example, we find a core size around 0.3 kpc for dark matter in the Milky Way, more than an order of magnitude smaller than the core size from SIDM-only simulations, which has important implications for indirect searches of SIDM candidates.

  13. Simultaneous Generation of WIMP Miracle-like Densities of Baryons and Dark Matter

    Science.gov (United States)

    McDonald, John

    2012-09-01

    The observed density of dark matter is of the magnitude expected for a thermal relic weakly-interacting massive particle (WIMP). In addition, the observed baryon density is within an order of magnitude of the dark matter density. This suggests that the baryon density is physically related to a typical thermal relic WIMP dark matter density. We present a model which simultaneously generates thermal relic WIMP-like densities for both baryons and dark matter by modifying a large initial baryon asymmetry. Production of unstable scalars carrying baryon number at the LHC would be a clear signature of the model.

  14. Generation of WIMP Miracle-like Densities of Baryons and Dark Matter

    CERN Document Server

    McDonald, John

    2012-01-01

    The observed density of dark matter is of the magnitude expected for a thermal relic weakly-interacting massive particle (WIMP). In addition, the observed baryon density is within an order of magnitude of the dark matter density. This suggests that the baryon density is physically related to a typical thermal relic WIMP dark matter density. We present a model which simultaneously generates thermal relic WIMP-like densities for both baryons and dark matter by modifying a large initial baryon asymmetry. Production of unstable scalars carrying baryon number at the LHC would be a clear signature of the model.

  15. Strange Baryonic Matter and Kaon Condensation

    Science.gov (United States)

    Gazda, D.; Friedman, E.; Gal, A.; Mareš, J.

    In this contribution we address the question whether kaon condensation could occur in strongly interacting self-bound strange hadronic matter. In our comprehensive dynamical relativistic mean-field (RMF) calculations of nuclear and hypernuclear systems containing several antikaons we found saturation of bar K separation energy as well as the associated nuclear and bar K density distributions upon increasing the number of bar K mesons. The saturation pattern was found to be a universal feature of these multi-strangeness configurations. Since in all cases the bar K separation energy does not exceed 200 MeV, we conclude that bar K mesons do not provide the physical "strangeness" degrees of freedom for self-bound strange hadronic matter.

  16. Development, simulation and test of transition radiation detector prototypes for the compressed baryonic matter experiment at the facility for antiproton and ion research

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, Cyrano S.H.

    2014-07-01

    The focus of this thesis is the development of a Transition Radiation Detector (TRD) for the Compressed Baryonic Matter (CBM) experiment at FAIR. The TRD sub-detector will contribute to the global particle identification and track reconstruction of charged particles. The technical design goal for the TRD is to identify 90% electrons with a maximum pion contamination of 1%. The TRD and Ring Image CHerenkov (RICH) detector should reach a common pion rejection of 10{sup 4}, in order to measure charmonium and low-mass vector mesons. The position resolution should be between 200 and 300 μm in the anode wire direction. The most demanding aspect of the CBM TRD design is the high interaction rate of up to 10{sup 7} Hz resulting in a charged particle rate of up to 100 kHz/cm{sup 2} in the central part of the detector planes at SIS300 conditions. It is crucial to find the optimal radiator detector combination with a minimum material budget to limit scattering and background due to conversions and at the same time reach a sufficient pion rejection and position resolution. In this thesis it is confirmed that a Multi-Wire Proportional Counter (MWPC) with a Xe/CO{sub 2} gas thickness of 12mm provides sufficient absorption probability for TR-photons in combination with self-supporting low density PE foam or micro-structured foil radiators. A continuous investigation aiming at an optimal wire and pad-plane geometry, as well as a minimization of the material budget between active gas and radiator has been presented in hard- and software. A minimum photon absorption cross-section of the entrance window was realized with a thermally stretched aluminized Kapton foil, glued to a G11 support grid support frame. This structure limits the mechanical deformation of the entire window to 1mm/mbar. All MWPC prototypes include two wire planes. A symmetric amplification region of 2 x (3, 3.5 or 4)mm is followed by a short drift region of 6, 5 or 4 mm. The drift region reduces the gain

  17. The impact of baryons on the direct detection of dark matter

    Science.gov (United States)

    Kelso, Chris; Savage, Christopher; Valluri, Monica; Freese, Katherine; Stinson, Gregory S.; Bailin, Jeremy

    2016-08-01

    The spatial and velocity distributions of dark matter particles in the Milky Way Halo affect the signals expected to be observed in searches for dark matter. Results from direct detection experiments are often analyzed assuming a simple isothermal distribution of dark matter, the Standard Halo Model (SHM). Yet there has been skepticism regarding the validity of this simple model due to the complicated gravitational collapse and merger history of actual galaxies. In this paper we compare the SHM to the results of cosmological hydrodynamical simulations of galaxy formation to investigate whether or not the SHM is a good representation of the true WIMP distribution in the analysis of direct detection data. We examine two Milky Way-like galaxies from the MaGICC cosmological simulations (a) with dark matter only and (b) with baryonic physics included. The inclusion of baryons drives the shape of the DM halo to become more spherical and makes the velocity distribution of dark matter particles less anisotropic especially at large heliocentric velocities, thereby making the SHM a better fit. We also note that we do not find a significant disk-like rotating dark matter component in either of the two galaxy halos with baryons that we examine, suggesting that dark disks are not a generic prediction of cosmological hydrodynamical simulations. We conclude that in the Solar neighborhood, the SHM is in fact a good approximation to the true dark matter distribution in these cosmological simulations (with baryons) which are reasonable representations of the Milky Way, and hence can also be used for the purpose of dark matter direct detection calculations.

  18. Development, simulation and test of transition radiation detector prototypes for the compressed baryonic matter experiment at the facility for antiproton and ion research

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, Cyrano S.H.

    2014-07-01

    The focus of this thesis is the development of a Transition Radiation Detector (TRD) for the Compressed Baryonic Matter (CBM) experiment at FAIR. The TRD sub-detector will contribute to the global particle identification and track reconstruction of charged particles. The technical design goal for the TRD is to identify 90% electrons with a maximum pion contamination of 1%. The TRD and Ring Image CHerenkov (RICH) detector should reach a common pion rejection of 10{sup 4}, in order to measure charmonium and low-mass vector mesons. The position resolution should be between 200 and 300 μm in the anode wire direction. The most demanding aspect of the CBM TRD design is the high interaction rate of up to 10{sup 7} Hz resulting in a charged particle rate of up to 100 kHz/cm{sup 2} in the central part of the detector planes at SIS300 conditions. It is crucial to find the optimal radiator detector combination with a minimum material budget to limit scattering and background due to conversions and at the same time reach a sufficient pion rejection and position resolution. In this thesis it is confirmed that a Multi-Wire Proportional Counter (MWPC) with a Xe/CO{sub 2} gas thickness of 12mm provides sufficient absorption probability for TR-photons in combination with self-supporting low density PE foam or micro-structured foil radiators. A continuous investigation aiming at an optimal wire and pad-plane geometry, as well as a minimization of the material budget between active gas and radiator has been presented in hard- and software. A minimum photon absorption cross-section of the entrance window was realized with a thermally stretched aluminized Kapton foil, glued to a G11 support grid support frame. This structure limits the mechanical deformation of the entire window to 1mm/mbar. All MWPC prototypes include two wire planes. A symmetric amplification region of 2 x (3, 3.5 or 4)mm is followed by a short drift region of 6, 5 or 4 mm. The drift region reduces the gain

  19. Dense baryonic matter: constraints from recent neutron star observations

    CERN Document Server

    Hell, Thomas

    2014-01-01

    Updated constraints from neutron star masses and radii impose stronger restrictions on the equation of state for baryonic matter at high densities and low temperatures. The existence of two-solar-mass neutron stars rules out many soft equations of state with prominent "exotic" compositions. The present work reviews the conditions required for the pressure as a function of baryon density in order to satisfy these new constraints. Several scenarios for sufficiently stiff equations of state are evaluated. The common starting point is a realistic description of both nuclear and neutron matter based on a chiral effective field theory approach to the nuclear many-body problem. Possible forms of hybrid matter featuring a quark core in the center of the star are discussed using a three-flavor Polyakov--Nambu--Jona-Lasinio (PNJL) model. It is found that a conventional equation of state based on nuclear chiral dynamics meets the astrophysical constraints. Hybrid matter generally turns out to be too soft unless addition...

  20. BASE - The Baryon Antibaryon Symmetry Experiment

    Science.gov (United States)

    Smorra, C.; Blaum, K.; Bojtar, L.; Borchert, M.; Franke, K. A.; Higuchi, T.; Leefer, N.; Nagahama, H.; Matsuda, Y.; Mooser, A.; Niemann, M.; Ospelkaus, C.; Quint, W.; Schneider, G.; Sellner, S.; Tanaka, T.; Van Gorp, S.; Walz, J.; Yamazaki, Y.; Ulmer, S.

    2015-11-01

    The Baryon Antibaryon Symmetry Experiment (BASE) aims at performing a stringent test of the combined charge parity and time reversal (CPT) symmetry by comparing the magnetic moments of the proton and the antiproton with high precision. Using single particles in a Penning trap, the proton/antiproton g-factors, i.e. the magnetic moment in units of the nuclear magneton, are determined by measuring the respective ratio of the spin-precession frequency to the cyclotron frequency. The spin precession frequency is measured by non-destructive detection of spin quantum transitions using the continuous Stern-Gerlach effect, and the cyclotron frequency is determined from the particle*s motional eigenfrequencies in the Penning trap using the invariance theorem. By application of the double Penning-trap method we expect that in our measurements a fractional precision of δg/g 10-9 can be achieved. The successful application of this method to the antiproton will consist a factor 1000 improvement in the fractional precision of its magnetic moment. The BASE collaboration has constructed and commissioned a new experiment at the Antiproton Decelerator (AD) of CERN. This article describes and summarizes the physical and technical aspects of this new experiment.

  1. Forming supermassive black holes by accreting dark and baryon matter

    CERN Document Server

    Hu, J; Lou, Y Q; Zhang, S; Hu, Jian; Shen, Yue; Lou, Yu-Qing; Zhang, Shuangnan

    2006-01-01

    Given a large-scale mixture of self-interacting dark matter (SIDM) particles and baryon matter distributed in the early Universe, we advance here a two-phase accretion scenario for forming supermassive black holes (SMBHs) with masses around $\\sim 10^9 M_{\\odot}$ at high redshifts $z (\\gsim 6)$. The first phase is conceived to involve a rapid quasi-spherical and quasi-steady Bondi accretion of mainly SIDM particles embedded with baryon matter onto seed black holes (BHs) created at redshifts $z\\lsim 30$ by the first generation of massive Population III stars; this earlier phase rapidly gives birth to significantly enlarged seed BH masses of $M_{\\hbox{\\tiny BH},t_1}\\backsimeq 1.4\\times 10^6\\ M_\\odot \\sigma_0/(1\\hbox{cm}^2\\hbox{g}^{-1})(C_s/30\\hbox{km s}^{-1})^4$ during $z\\sim 20-15$, where $\\sigma_0$ is the cross section per unit mass of SIDM particles and $C_s$ is the velocity dispersion in the SIDM halo referred to as an effective "sound speed". The second phase of BH mass growth is envisaged to proceed primar...

  2. Theories relating baryon asymmetry and dark matter: a Mini review

    Directory of Open Access Journals (Sweden)

    Stefano eMorisi

    2014-01-01

    Full Text Available The nature of dark matter and the origin of the baryon asymmetry are two of the deepest mysteries of modern particle physics. In the absence of hints regarding a possible solution to these mysteries, many approaches have been developed to tackle them simultaneously { leading to very diverse and rich models}. We give a short review where we describe the general features of some of these models and an overview on the general problem. We also propose a diagrammatic notation to label the different models.

  3. BASE - The Baryon Antibaryon Symmetry Experiment

    CERN Document Server

    Smorra, C; Bojtar, L.; Borchert, M.; Franke, K.A.; Higuchi, T.; Leefer, N.; Nagahama, H.; Matsuda, Y.; Mooser, A.; Niemann, M.; Ospelkaus, C.; Quint, W.; Schneider, G.; Sellner, S.; Tanaka, T.; Van Gorp, S.; Walz, J.; Yamazaki, Y.; Ulmer, S.

    2015-01-01

    The Baryon Antibaryon Symmetry Experiment (BASE) aims at performing a stringent test of the combined charge parity and time reversal (CPT) symmetry by comparing the magnetic moments of the proton and the antiproton with high precision. Using single particles in a Penning trap, the proton/antiproton $g$-factors, i.e. the magnetic moment in units of the nuclear magneton, are determined by measuring the respective ratio of the spin-precession frequency to the cyclotron frequency. The spin precession frequency is measured by non-destructive detection of spin quantum transitions using the continuous Stern-Gerlach effect, and the cyclotron frequency is determined from the particle's motional eigenfrequencies in the Penning trap using the invariance theorem. By application of the double Penning-trap method we expect that in our measurements a fractional precision of $\\delta g/g$ 10$^{-9}$ can be achieved. The successful application of this method to the antiproton will represent a factor 1000 improvement in the frac...

  4. Baryons and Low-Density Baryonic Matter in 1+1 Dimensional Large N_c QCD with Heavy Quarks

    CERN Document Server

    Adhikari, Prabal; Jamgochian, Arec; Kumar, Nilay

    2012-01-01

    This paper studies baryons and baryonic matter in the combined large N_c and heavy quark mass limits of QCD in 1+1 dimension. In this non-relativistic limit, baryons are composed of N_c quarks that interact, at leading order in N_c, through a color Coulomb potential. Using variational techniques, very accurate calculations of single baryon masses and interaction energies of low-density baryon crystal are performed. These results are used to cross-check a general numerical approach applicable for arbitrary quark masses and baryon densities recently proposed by Bringoltz, which is based on a lattice in a finite box with periodic boundary conditions. The Bringoltz method differs from a previous approach of Salcedo, et al. in its treatment of a finite box effect - namely gauge configurations that wind around the box. One might expect these effects to be small for large enough boxes, in which the baryon density approaches zero to high accuracy at the edges. However, the effects of these windings appear to be quite...

  5. The Angular Momentum of Baryons and Dark Matter Halos Revisited

    Science.gov (United States)

    Kimm, Taysun; Devriendt, Julien; Slyz, Adrianne; Pichon, Christophe; Kassin, Susan A.; Dubois, Yohan

    2011-01-01

    Recent theoretical studies have shown that galaxies at high redshift are fed by cold, dense gas filaments, suggesting angular momentum transport by gas differs from that by dark matter. Revisiting this issue using high-resolution cosmological hydrodynamics simulations with adaptive-mesh refinement (AMR), we find that at the time of accretion, gas and dark matter do carry a similar amount of specific angular momentum, but that it is systematically higher than that of the dark matter halo as a whole. At high redshift, freshly accreted gas rapidly streams into the central region of the halo, directly depositing this large amount of angular momentum within a sphere of radius r = 0.1R(sub vir). In contrast, dark matter particles pass through the central region unscathed, and a fraction of them ends up populating the outer regions of the halo (r/R(sub vir) > 0.1), redistributing angular momentum in the process. As a result, large-scale motions of the cosmic web have to be considered as the origin of gas angular momentum rather than its virialised dark matter halo host. This generic result holds for halos of all masses at all redshifts, as radiative cooling ensures that a significant fraction of baryons remain trapped at the centre of the halos. Despite this injection of angular momentum enriched gas, we predict an amount for stellar discs which is in fair agreement with observations at z=0. This arises because the total specific angular momentum of the baryons (gas and stars) remains close to that of dark matter halos. Indeed, our simulations indicate that any differential loss of angular momentum amplitude between the two components is minor even though dark matter halos continuously lose between half and two-thirds of their specific angular momentum modulus as they evolve. In light of our results, a substantial revision of the standard theory of disc formation seems to be required. We propose a new scenario where gas efficiently carries the angular momentum generated

  6. Magnetic Moments of Octet Baryons in Hot and Dense Nuclear Matter

    CERN Document Server

    Singh, Harpreet; Dahiya, Harleen

    2016-01-01

    We have calculated the in-medium magnetic moments of octet baryons in the presence of hot and dense symmetric nuclear matter. Effective magnetic moments of baryons have been derived from medium modified quark masses within chiral SU(3) quark mean field model.Further, for better insight of medium modification of baryonic magnetic moments, we have considered the explicit contributions from the valence as well as sea quark effects. These effects have been successful in giving the description of baryonic magnetic moments in vacuum. The magnetic moments of baryons are found to vary significantly as a function of density of nuclear medium.

  7. Dark and baryonic matter in the MareNostrum Universe

    Science.gov (United States)

    Gottlöber, S.; Yepes, G.; Khalatyan, A.; Sevilla, R.; Turchaninov, V.

    2006-11-01

    We report some results from one of the largest hydrodynamical cosmological simulations of large scale structures that has been done up to date. The MareNostrum Universe SPH simulation consists of 2 billion particles (2 × 10243) in a cubic box of 500 h-1 Mpc on a side. This simulation has been done in the MareNostrum parallel supercomputer at the Barcelona SuperComputer Center. Due to the large simulated volume and good mass resolution, our simulated catalog of dark matter halos comprises more than half a million objects with masses larger than a typical Milky Way galaxy halo. From this dataset we have studied several statistical properties such as the halo mass function, the distribution of shapes of dark and gas components within halos, the baryon fraction, cumulative void volume etc. This simulation is particularly useful to study the large scale distribution of baryons in the universe as a function of temperature and density. In this paper we also show the time evolution of the gas fractions at large scales.

  8. Baryons Matter: Why Luminous Satellite Galaxies Have Reduced Central Masses

    CERN Document Server

    Zolotov, Adi; Willman, Beth; Governato, Fabio; Pontzen, Andrew; Christensen, Charlotte; Dekel, Avishai; Quinn, Tom; Shen, Sijing; Wadsley, James

    2012-01-01

    Using high resolution cosmological hydrodynamical simulations of Milky Way-massed disk galaxies, we demonstrate that supernovae feedback and tidal stripping lower the central masses of bright (-14 10^9 Msun, Mstar > 10^7 Msun) compared to DM-only simulations. The progenitors of the lower mass satellites are unable to maintain bursty star formation histories, due to both heating at reionization and gas loss from initial star forming events, preserving the steep inner density profile predicted by DM-only simulations. After infall, tidal stripping acts to further reduce the central densities of the luminous satellites, particularly those that enter with cored dark matter halos, increasing the discrepancy in the central masses predicted by baryon+DM and DM-only simulations. We show that DM-only simulations, which neglect the baryonic effects described in this work, produce denser satellites with larger central velocities. We provide a simple correction to the central DM mass predicted for satellites by DM-only s...

  9. Composite bosonic baryon dark matter on the lattice: SU(4) baryon spectrum and the effective Higgs interaction

    CERN Document Server

    Appelquist, Thomas; Brower, Richard C; Buchoff, Michael I; Fleming, George T; Kiskis, Joe; Kribs, Graham D; Lin, Meifeng; Neil, Ethan T; Osborn, James C; Rebbi, Claudio; Rinaldi, Enrico; Schaich, David; Schroeder, Chris; Syritsyn, Sergey; Voronov, Gennady; Vranas, Pavlos; Weinberg, Evan; Witzel, Oliver

    2014-01-01

    We present the spectrum of baryons in a new SU(4) gauge theory with fundamental fermion constituents. The spectrum of these bosonic baryons is of significant interest for composite dark matter theories. Here, we compare the spectrum and properties of SU(3) and SU(4) baryons, and then compute the dark-matter direct detection cross section via Higgs boson exchange for TeV-scale composite dark matter arising from a confining SU(4) gauge sector. Comparison with the latest LUX results leads to tight bounds on the fraction of the constituent-fermion mass that may arise from electroweak symmetry breaking. Lattice calculations of the dark matter mass spectrum and the Higgs-dark matter coupling are performed on quenched $16^{3} \\times 32$, $32^{3} \\times 64$, $48^{3} \\times 96$, and $64^{3} \\times128$ lattices with three different lattice spacings, using Wilson fermions with moderate to heavy pseudoscalar meson masses. Our results lay a foundation for future analytic and numerical study of composite baryonic dark matt...

  10. RH Sneutrino Condensate CDM and the Baryon-to-Dark Matter Ratio

    CERN Document Server

    McDonald, John

    2007-01-01

    The similarity of the observed mass densities of baryons and cold dark matter may be a sign they have a related origin. The baryon-to-dark matter ratio can be understood in the MSSM with right-handed (RH) neutrinos if CDM is due to a d = 4 flat direction condensate of very weakly coupled RH sneutrino LSPs and the baryon asymmetry is generated by Affleck-Dine leptogenesis along a d = 4 (H_{u}L)^2 flat direction. Observable signatures of the model include CDM and baryon isocurvature perturbations and distinctive long-lived NLSP phenomenology.

  11. Dark and baryonic matter in the MareNostrum Universe

    CERN Document Server

    Gottlöber, S; Khalatyan, A; Sevilla, R; Turchaninov, V I

    2006-01-01

    We report some results from one of the largest hydrodynamical cosmological simulations of large scale structures that has been done up to date. The MareNostrum Universe SPH simulation consists of 2 billion particles (2 times 1024^3) in a cubic box of 500 h^-1 Mpc on a side. This simulation has been done in the MareNostrum parallel supercomputer at the Barcelona SuperComputer Center. Due to the large simulated volume and good mass resolution, our simulated catalog of dark matter halos comprises more than half a million objects with masses larger than a typical Milky Way galaxy halo. From this dataset we have studied several statistical properties such as the evolution of the halo mass function, the void distribution, the shapes of dark and gas halos and the large scale distribution of baryons.

  12. Entropy, baryon asymmetry and dark matter from heavy neutrino decays

    Energy Technology Data Exchange (ETDEWEB)

    Buchmueller, W.; Schmitz, K.; Vertongen, G.

    2011-04-15

    The origin of the hot phase of the early universe remains so far an unsolved puzzle. A viable option is entropy production through the decays of heavy Majorana neutrinos whose lifetimes determine the initial temperature. We show that baryogenesis and the production of dark matter are natural by-products of this mechanism. As is well known, the cosmological baryon asymmetry can be accounted for by lepto- genesis for characteristic neutrino mass parameters. We nd that thermal gravitino production then automatically yields the observed amount of dark matter, for the gravitino as the lightest superparticle and typical gluino masses. As an example, we consider the production of heavy Majorana neutrinos in the course of tachyonic preheating associated with spontaneous B-L breaking. A quantitative analysis leads to contraints on the superparticle masses in terms of neutrino masses: For a light neutrino mass of 10{sup -5} eV the gravitino mass can be as small as 200 MeV, whereas a lower neutrino mass bound of 0.01 eV implies a lower bound of 9 GeV on the gravitino mass. The measurement of a light neutrino mass of 0.1 eV would rule out heavy neutrino decays as the origin of entropy, visible and dark matter. (orig.)

  13. The impact of baryons on the direct detection of dark matter

    CERN Document Server

    Kelso, Chris; Valluri, Monica; Freese, Katherine; Stinson, Gregory S; Bailin, Jeremy

    2016-01-01

    The spatial and velocity distributions of dark matter particles in the Milky Way Halo affect the signals expected to be observed in searches for dark matter. Results from direct detection experiments are often analyzed assuming a simple isothermal distribution of dark matter, the Standard Halo Model (SHM). Yet there has been skepticism regarding the validity of this simple model due to the complicated gravitational collapse and merger history of actual galaxies. In this paper we compare the SHM to the results of cosmological hydrodynamical simulations of galaxy formation to investigate whether or not the SHM is a good representation of the true WIMP distribution in the analysis of direct detection data. We examine two Milky Way-like galaxies from the MaGICC cosmological simulations (a) with dark matter only and (b) with baryonic physics included. The inclusion of baryons drives the shape of the DM halo to become more spherical and makes the velocity distribution of dark matter particles less anisotropic espec...

  14. Entropy, Baryon Asymmetry and Dark Matter from Heavy Neutrino Decays

    CERN Document Server

    Buchmuller, W; Vertongen, G

    2011-01-01

    The origin of the hot phase of the early universe remains so far an unsolved puzzle. A viable option is entropy production through the decays of heavy Majorana neutrinos whose lifetimes determine the initial temperature. We show that baryogenesis and the production of dark matter are natural by-products of this mechanism. As is well known, the cosmological baryon asymmetry can be accounted for by leptogenesis for characteristic neutrino mass parameters. We find that thermal gravitino production then automatically yields the observed amount of dark matter, for the gravitino as the lightest superparticle and typical gluino masses. As an example, we consider the production of heavy Majorana neutrinos in the course of tachyonic preheating associated with spontaneous B-L breaking. A quantitative analysis leads to contraints on the superparticle masses in terms of neutrino masses: For a light neutrino mass of 10^{-5} eV the gravitino mass can be as small as 200 MeV, whereas a lower neutrino mass bound of 0.01 eV im...

  15. Simultaneous Generation of WIMP Miracle-like Densities of Baryons and Dark Matter

    CERN Document Server

    McDonald, John

    2011-01-01

    The observed density of dark matter is of the magnitude expected for a thermal relic weakly-interacting massive particle (WIMP). In addition, the observed baryon density is within an order of magnitude of the dark matter density. This suggests that the baryon density is physically related to a typical thermal relic WIMP dark matter density. We present a model which simultaneously generates thermal relic WIMP-like densities for both baryons and dark matter by modifying a large initial baryon asymmetry. Dark matter is due to O(100) GeV gauge singlet scalars produced in the annihilation of the O(TeV) coloured scalars which is responsible for the final thermal WIMP-like baryon asymmetry. The requirement of no baryon washout implies that there are two gauge singlet scalars. The low temperature transfer of the asymmetry to conventional baryons can be understood if the long-lived O(TeV) coloured scalars have large hypercharge, |Y| > 4/3. Production of such scalars at the LHC would be a clear signature of the model.

  16. Measurement of matter-antimatter differences in beauty baryon decays at LHCb

    CERN Multimedia

    Merli, Andrea

    2017-01-01

    Differences in the behaviour of matter and antimatter have been observed in $K$ and $B$ meson decays, but not yet in any baryon decay. Such differences are associated with the non-invariance of fundamental interactions under the combined charge-conjugation and parity transformations, known as $C\\!P$ violation. Using data from the LHCb experiment at the Large Hadron Collider, a search is made for $C\\!P$-violating asymmetries in the decay angle distributions of $\\Lambda_b^0$ baryons decaying to $p\\pi^-\\pi^+\\pi^-$ and $p\\pi^-K^+K^-m$ final states. These four-body hadronic decays are a promising place to search for sources of $C\\!P$ violation both within and beyond the Standard Model of particle physics. We find evidence for $C\\!P$ violation in $\\Lambda_b^0$ to $p\\pi^-\\pi^+\\pi^-$ decays with a statistical significance corresponding to 3.3 standard deviations including systematic uncertainties. This represents the first evidence for $C\\!P$ violation in the baryon sector.

  17. Correlation Analysis between Spin, Velocity Shear, and Vorticity of Baryonic and Dark Matter Halos

    Science.gov (United States)

    Liu, L. L.

    2016-05-01

    Using cosmological hydrodynamic simulations, we investigate the alignments between velocity shear, vorticity, and the spin of dark matter halos, and study the correlation between baryonic and dark matter. We find that (1) mis-alignment between vorticity of baryonic and dark matter would develop on scales dark matter; (3) small/massive halos spinning parallel/perpendicular to the host filaments are sensitive to the identification of cosmic web, simulation box size, and resolution. These factors might complicate the connection between the spins of dark matter halos and galaxies, and affect the correlation signal of the alignments of galaxy spin with nearby large-scale structures.

  18. The search for exotic baryons at the HERMES experiment

    Energy Technology Data Exchange (ETDEWEB)

    Deconinck, Wouter

    2008-07-15

    One of the interesting questions of Quantum Chromodynamics, the theory that governs the interactions between quarks and gluons, has been whether it is possible to observe hadrons which can not be explained as a combination of only two or three valence quarks. In numerous searches the existence of these exotic hadrons could not be confirmed. Recently, calculations based on the quark soliton model predicted the narrow exotic baryons {theta}{sup +} and {xi}{sup --}. A narrow resonance identified as the {theta}{sup +} was observed by several experiments at the predicted mass of 1540 MeV, but later followed by several dedicated experiments that could not confirm these positive results. At the HERMES experiment a search for the quasi-real photoproduction of the exotic baryon {theta}{sup +} on a deuterium target and the subsequent decay through pK{sup 0}{sub S} {yields} p{pi}{sup +}{pi}{sup -} revealed a narrow resonance in the pK{sup 0}{sub S} invariant mass distribution at 1528 MeV. In the search for the corresponding antiparticle {xi}{sup --} the result is consistent with zero events. In this thesis we present the search for the exotic baryon {xi}{sup --} on a deuterium target in the data sample used for the observation of the {theta}{sup +}. An upper limit on the cross section of the exotic baryon {xi}{sup --} is determined. The search for the exotic baryon {theta}{sup +} on hydrogen and deuterium targets at the HERMES experiment is extensively discussed. The event mixing method can be used to estimate the distribution of background events. Several difficulties with this method were addressed, but the background description in the case of the exotic baryon {theta}{sup +} remains unconvincing. Between the years 2002 and 2005 the HERMES experiment operated with a magnetic holding field around the hydrogen target. A method for the reconstruction of displaced vertices in this field was developed. The data collected during the years 2006 and 2007 offer an integrated

  19. Strangeness as a probe to baryon-rich QCD matter at NICA

    Energy Technology Data Exchange (ETDEWEB)

    Fukushima, Kenji [The University of Tokyo, Department of Physics, Bunkyo-ku, Tokyo (Japan)

    2016-08-15

    We elucidate a prospect of strangeness fluctuation measurements in the heavy-ion collision at NICA energies. The strangeness fluctuation is sensitive to quark deconfinement. At the same time strangeness has a strong correlation with the baryon number under the condition of vanishing net strangeness, which leads to an enhancement of Λ{sup 0}, Ξ{sup 0}, Ξ{sup -}, and K{sup +} at high baryon density. The baryon density is maximized around the NICA energies, and strangeness should be an ideal probe to investigate quark deconfinement phenomena of baryon-rich QCD matter created at NICA. We also utilize the hadron resonance gas model to estimate a mixed fluctuation of strangeness and baryon number. (orig.)

  20. Sharing but not caring: dark matter and the baryon asymmetry of the universe

    Science.gov (United States)

    Bernal, Nicolás; Fong, Chee Sheng; Fonseca, Nayara

    2016-09-01

    We consider scenarios where Dark Matter (DM) particles carry baryon and/or lepton numbers, which can be defined if there exist operators connecting the dark to the visible sector. As a result, the DM fields become intimately linked to the Standard Model (SM) ones and can be maximally asymmetric just like the ordinary matter. In particular, we discuss minimal scenarios where the DM is a complex scalar or a Dirac fermion coupled to operators with nonzero baryon and/or lepton numbers, and that consist of only SM fields. We consider an initial asymmetry stored in either the SM or the DM sector; the main role of these operators is to properly share the asymmetry between the two sectors, in accordance with observations. After the chemical decoupling, the DM and SM sectors do not care about each other as there is only an ineffective communication between them. Once the DM mass is specified, the Wilson coefficients of these operators are fixed by the requirement of the correct transfer of the asymmetry. We study the phenomenology of this framework at colliders, direct detection and indirect detection experiments. In particular, the LHC phenomenology is very rich and can be tested in different channels such as the two same-sign leptons with two jets, monojet and monojet with a monolepton.

  1. Sharing but not caring: dark matter and the baryon asymmetry of the universe

    Energy Technology Data Exchange (ETDEWEB)

    Bernal, Nicolás [ICTP South American Institute for Fundamental Research, Instituto de Física Teórica, Universidade Estadual Paulista,R. Dr. Bento Teobaldo Ferraz 271, 01140-070 São Paulo (Brazil); Institute of High Energy Physics, Austrian Academy of Sciences,Nikolsdorfer Gasse 18, 1050 Vienna (Austria); Fong, Chee Sheng [Instituto de Física, Universidade de São Paulo,Rua do Matão 1371, 05508-090 São Paulo (Brazil); Fonseca, Nayara [Instituto de Física, Universidade de São Paulo,Rua do Matão 1371, 05508-090 São Paulo (Brazil); DESY,Notkestraße 85, 22607 Hamburg (Germany)

    2016-09-02

    We consider scenarios where Dark Matter (DM) particles carry baryon and/or lepton numbers, which can be defined if there exist operators connecting the dark to the visible sector. As a result, the DM fields become intimately linked to the Standard Model (SM) ones and can be maximally asymmetric just like the ordinary matter. In particular, we discuss minimal scenarios where the DM is a complex scalar or a Dirac fermion coupled to operators with nonzero baryon and/or lepton numbers, and that consist of only SM fields. We consider an initial asymmetry stored in either the SM or the DM sector; the main role of these operators is to properly share the asymmetry between the two sectors, in accordance with observations. After the chemical decoupling, the DM and SM sectors do not care about each other as there is only an ineffective communication between them. Once the DM mass is specified, the Wilson coefficients of these operators are fixed by the requirement of the correct transfer of the asymmetry. We study the phenomenology of this framework at colliders, direct detection and indirect detection experiments. In particular, the LHC phenomenology is very rich and can be tested in different channels such as the two same-sign leptons with two jets, monojet and monojet with a monolepton.

  2. Baryon Spectroscopy - Recent Results from the CBELSA/TAPS Experiment

    CERN Document Server

    Hartmann, Jan

    2016-01-01

    One of the remaining challenges within the standard model is to gain a good understanding of QCD in the non-perturbative regime. One key step toward this aim is baryon spectroscopy, investigating the spectrum and the properties of baryon resonances. To get access to resonances with small $\\pi N$ partial width, photoproduction experiments provide essential information. In order to extract the contributing resonances, partial wave analyses need to be performed. Here, a complete experiment is required to unambiguously determine the contributing amplitudes. This involves the measurement of carefully chosen single and double polarization observables. The CBELSA/TAPS experiment with a longitudinally or transversely polarized target and an energy tagged, linearly or circularly polarized photon beam allows the measurement of a large set of polarization observables. Due to its good energy resolution, high detection efficiency for photons, and the nearly complete solid angle coverage it is ideally suited for the measur...

  3. Baryon symmetric big-bang cosmology. [matter-antimatter symmetry

    Science.gov (United States)

    Stecker, F. W.

    1978-01-01

    The framework of baryon-symmetric big-bang cosmology offers the greatest potential for deducing the evolution of the universe as a consequence of physical laws and processes with the minimum number of arbitrary assumptions as to initial conditions in the big-bang. In addition, it offers the possibility of explaining the photon-baryon ratio in the universe and how galaxies and galaxy clusters are formed, and also provides the only acceptable explanation at present for the origin of the cosmic gamma ray background radiation.

  4. Analysis of instability of systems composed by dark and baryonic matter

    CERN Document Server

    Kremer, Gilberto M

    2015-01-01

    In this work the dynamics of self-gravitating systems composed by dark and baryonic matter was analyzed. Searching for a description of this dynamics, a system of Boltzmann equations for the two constituents and the Poisson equation for the gravitational field were employed. Through the solution of these equations the collapse criterion is determined from a dispersion relation. The collapse occurs in an unstable region where the solutions grow exponentially with time. Two cases were analyzed: (a) collisionless dark and baryonic matter and (b) collisionless baryons with self-interacting dark matter. For the former case it was shown that the unstable region becomes larger if the dispersion velocity of dark matter becomes larger than the one of the baryonic matter. For the later case it was shown that the unstable region becomes smaller by increasing the collision frequency of the self-interacting dark matter. The results obtained were also compared with the case where only the dark matter is present. The models...

  5. Dense baryonic matter in strong coupling lattice gauge theory

    CERN Document Server

    Bringoltz, B

    2004-01-01

    We investigate the strong coupling limit of lattice QCD in the Hamiltonian formulation for systems with non-zero baryon density. In leading order the Hamiltonian looks like an antiferromagnet that is invariant under global U(N_f)xU(N_f) and local SU(N_c). Physically it describes meson dynamics with a fixed background of baryon density. We study this Hamiltonian with several baryon number distributions, and concentrate on the global symmetries of the ground state and on the properties of low lying excitations. In particular, for uniform non-zero baryon density we write the partition function as a path integral that is tractable in the limit of large N_c. We find that the ground state spontaneously breaks chiral symmetry as well as discrete lattice rotations in a way that depends on N_f and the density. The low energy excitations include type I and type II Goldstone bosons. The energies of the latter are of order 1/N_c, and are quadratic in momentum. Bosons of either type can develop anisotropic dispersion rela...

  6. A Skyrme-type proposal for baryonic matter

    CERN Document Server

    Adam, C; Wereszczynski, A

    2010-01-01

    The Skyrme model is a low-energy effective field theory for QCD, where the baryons emerge as soliton solutions. It is, however, difficult within the standard Skyrme model to reproduce the almost exact linear growth of the nuclear masses with the baryon number (topological charge), due to the lack of a Bogomolny bound in this model, which has also hindered analytical progress. Here we identify a submodel within the Skyrme-type low energy effective action which does have a Bogomolny bound and exact solutions, and therefore reproduces the nuclear masses with a high precision (better than one percent). We propose that the terms of the submodel should be included in a low-energy effective field theory description of nuclei and probably even give the main contribution to their masses.

  7. Neutrino mass, dark matter, and Baryon asymmetry via TeV-scale physics without fine-tuning.

    Science.gov (United States)

    Aoki, Mayumi; Kanemura, Shinya; Seto, Osamu

    2009-02-01

    We propose an extended version of the standard model, in which neutrino oscillation, dark matter, and the baryon asymmetry of the Universe can be simultaneously explained by the TeV-scale physics without assuming a large hierarchy among the mass scales. Tiny neutrino masses are generated at the three-loop level due to the exact Z2 symmetry, by which the stability of the dark matter candidate is guaranteed. The extra Higgs doublet is required not only for the tiny neutrino masses but also for successful electroweak baryogenesis. The model provides discriminative predictions especially in Higgs phenomenology, so that it is testable at current and future collider experiments.

  8. Dense baryonic matter in the hidden local symmetry approach: Half-skyrmions and nucleon mass

    Science.gov (United States)

    Ma, Yong-Liang; Harada, Masayasu; Lee, Hyun Kyu; Oh, Yongseok; Park, Byung-Yoon; Rho, Mannque

    2013-07-01

    Hadron properties in dense medium are treated in a unified way in a skyrmion model constructed with an effective Lagrangian, in which the ρ and ω vector mesons are introduced as hidden gauge bosons, valid up to O(p4) terms in chiral expansion including the homogeneous Wess-Zumino terms. All the low energy constants of the Lagrangian—apart from the pion decay constant and the vector meson mass—are fixed by the master formula derived from the relation between the five-dimensional holographic QCD and the four-dimensional hidden local symmetry Lagrangian. This Lagrangian allows one to pin down the density n1/2 at which the skyrmions in medium fractionize into half-skyrmions, bringing in a drastic change in the equation of state of dense baryonic matter. We find that the U(1) field that figures in the Chern-Simons term in the five-dimensional holographic QCD action or equivalently the ω field in the homogeneous Wess-Zumino term in the dimensionally reduced hidden local symmetry action plays a crucial role in the half-skyrmion phase. The importance of the ω degree of freedom may be connected to what happens in the instanton structure of elementary baryon noticed in holographic QCD. The most striking and intriguing in what is found in the model is that the pion decay constant that smoothly drops with increasing density in the skyrmion phase stops decreasing at n1/2 and remains nearly constant in the half-skyrmion phase. In accordance with the large Nc consideration, the baryon mass also stays nonscaling in the half-skyrmion phase. This feature which is reminiscent of the parity-doublet baryon model with a chirally invariant mass m0 is supported by the nuclear effective field theory with the parameters of the Lagrangian scaling modified at the skyrmion-half-skyrmion phase transition. It also matches with one-loop renormalization group analysis based on hidden local symmetry. A link between a nonvanishing m0 and the origin of nucleon mass distinctive from

  9. Lattice QCD for Baryon Rich Matter - Beyond Taylor Expansions

    Science.gov (United States)

    Bornyakov, V.; Boyda, D.; Goy, V.; Molochkov, A.; Nakamura, A.; Nikolaev, A.; Zakharov, V. I.

    2016-12-01

    We discuss our study for exploring the QCD phase diagram based on the lattice QCD. To go beyond the Taylor expansion and to reach higher density regions, we employ the canonical approach. In order to produce lattice data which meet experimental situation as much as possible, we propose a canonical approach with the charge and baryon number. We present our lattice QCD GPU code for this project which employs the clover improved Wilson fermions and Iwasaki gauge action to investigate pure imaginary chemical potential.

  10. Impact of baryon physics on dark matter structures: a detailed simulation study of halo density profiles

    CERN Document Server

    Duffy, Alan R; Kay, Scott T; Vecchia, Claudio Dalla; Battye, Richard A; Booth, C M

    2010-01-01

    The back-reaction of baryons on the dark matter halo density profile is of great interest, not least because it is an important systematic uncertainty when attempting to detect the dark matter. Here, we draw on a large suite of high resolution cosmological hydrodynamical simulations, to systematically investigate this process and its dependence on the baryonic physics associated with galaxy formation. The inclusion of baryons results in significantly more concentrated density profiles if radiative cooling is efficient and feedback is weak. The dark matter halo concentration can in that case increase by as much as 30 (10) per cent on galaxy (cluster) scales. The most significant effects occur in galaxies at high redshift, where there is a strong anti-correlation between the baryon fraction in the halo centre and the inner slope of both the total and the dark matter density profiles. If feedback is weak, isothermal inner profiles form, in agreement with observations of massive, early-type galaxies. However, we ...

  11. Analysis of instability of systems composed by dark and baryonic matter

    Science.gov (United States)

    Kremer, Gilberto M.; André, Raíla

    2016-10-01

    In this work, the dynamics of self-gravitating systems composed by dark and baryonic matter is analyzed. Searching for a description of this dynamics, a system of collisionless Boltzmann equations for the two constituents and the Poisson equation for the gravitational field are employed. Through the solution of these equations, the collapse criterion is determined from a dispersion relation. The collapse occurs in an unstable region where the solutions grow exponentially with time. It is shown that the unstable region becomes larger if the dispersion velocity of dark matter becomes larger than the one of the baryonic matter. The results obtained are also compared with the case where only the dark matter is present. The model of the present work has a higher limit of instability and therefore exhibited an advantage in the structure formation.

  12. The thermal evolution of nuclear matter at zero temperature and definite baryon number density in chiral perturbation theory

    CERN Document Server

    Li, Xiao-ya; Wang, Bin; Sun, Win-min; Zong, Hong-shi

    2008-01-01

    The thermal properties of cold dense nuclear matter are investigated with chiral perturbation theory. The evolution curves for the baryon number density, baryon number susceptibility, pressure and the equation of state are obtained. The chiral condensate is calculated and our result shows that when the baryon chemical potential goes beyond $1150 \\mathrm{MeV}$, the absolute value of the quark condensate decreases rapidly, which indicates a tendency of chiral restoration.

  13. Revisiting the gravitino dark matter and baryon asymmetry from Q-ball decay in gauge mediation

    Energy Technology Data Exchange (ETDEWEB)

    Kasuya, Shinta, E-mail: kasuya@kanagawa-u.ac.jp [Department of Mathematics and Physics, Kanagawa University, Kanagawa 259-1293 (Japan); Max-Planck-Institut für Kernphysik, PO Box 103980, 69029 Heidelberg (Germany); Kawasaki, Masahiro [Institute for Cosmic Ray Research, the University of Tokyo, Chiba 277-8582 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, the University of Tokyo, Chiba 277-8582 (Japan); Yamada, Masaki [Institute for Cosmic Ray Research, the University of Tokyo, Chiba 277-8582 (Japan)

    2013-10-07

    We reconsider the Q-ball decay and reinvestigate the scenario that the amount of the baryons and the gravitino dark matter is naturally explained by the decay of the Q balls in the gauge-mediated SUSY breaking. We refine the decay rates into baryons, NLSPs, and gravitinos, and estimate their branching ratios based on the consideration of Pauli blocking. We obtain a smaller branching into gravitinos than the previous estimate, and the NLSPs are more produced by the Q-ball decay. However, the efficient annihilations of NLSPs occur afterward so that their abundance does not spoil the successful BBN and they only produce negligible amount of the gravitinos to the dark matter density by their decay. In this way, we find that the scenario with the direct production of the gravitino dark matter from the Q-ball decay works naturally.

  14. Evolution of Mass and Velocity Field in the Cosmic Web: Comparison between Baryonic and Dark Matter

    Science.gov (United States)

    Zhu, Weishan; Feng, Long-Long

    2017-03-01

    We investigate the evolution of the cosmic web since z = 5 in grid-based cosmological hydrodynamical simulations, focusing on the mass and velocity fields of both baryonic and cold dark matter. The tidal tensor of density is used as the main method for web identification, with λ th = 0.2–1.2. The evolution trends in baryonic and dark matter are similar, although moderate differences are observed. Sheets appear early, and their large-scale pattern may have been set up by z = 3. In terms of mass, filaments supersede sheets as the primary collapsing structures from z ∼ 2–3. Tenuous filaments assembled with each other to form prominent ones at z < 2. In accordance with the construction of the frame of the sheets, the cosmic divergence velocity, v div, was already well-developed above 2–3 Mpc by z = 3. Afterwards, the curl velocity, v curl, grew dramatically along with the rising of filaments, becoming comparable to v div, for <2–3 Mpc at z = 0. The scaling of v curl can be described by the hierarchical turbulence model. The alignment between the vorticity and the eigenvectors of the shear tensor in the baryonic matter field resembles that in the dark matter field, and is even moderately stronger between {\\boldsymbol{ω }} and {{\\boldsymbol{e}}}1, and ω and {{\\boldsymbol{e}}}3. Compared with dark matter, there is slightly less baryonic matter found residing in filaments and clusters, and its vorticity developed more significantly below 2–3 Mpc. These differences may be underestimated because of the limited resolution and lack of star formation in our simulation. The impact of the change of dominant structures in overdense regions at z ∼ 2–3 on galaxy formation and evolution is shortly discussed.

  15. Relating the baryon asymmetry to the thermal relic dark matter density

    Science.gov (United States)

    McDonald, John

    2011-04-01

    We present a generic framework, baryomorphosis, which modifies the baryon asymmetry to be naturally of the order of a typical thermal relic weakly interacting massive particle (WIMP) density. We consider a simple scalar-based model to show how this is possible. This model introduces a sector in which a large initial baryon asymmetry is injected into particles (”annihilons”), ϕB, ϕ^B, of mass ˜100GeV-1TeV. ϕBϕ^B annihilations convert the initial ϕB, ϕ^B asymmetry to a final asymmetry with a thermal relic WIMP-like density. This subsequently decays to a conventional baryon asymmetry whose magnitude is naturally related to the density of thermal relic WIMP dark matter. In this way the two coincidences of baryons and dark matter, i.e. why their densities are similar to each other and why they are both similar to a WIMP thermal relic density (the “WIMP miracle”), may be understood. The model may be tested by the production of annihilons at colliders.

  16. Hadron resonance gas and mean-field nuclear matter for baryon number fluctuations

    CERN Document Server

    Fukushima, Kenji

    2014-01-01

    We give an estimate for the skewness and the kurtosis of the baryon number distribution in two representative models; i.e., models for a hadron resonance gas and relativistic mean-field nuclear matter. We emphasize formal similarity between these two descriptions. The hadron resonance gas leads to a deviation from the Skellam distribution if quantum statistical correlation is taken into account at high baryon density, but this effect is not strong enough to explain fluctuation data seen in the beam-energy scan at RHIC/STAR. In the calculation of mean-field nuclear matter the density correlation with the vector \\omega-field rather than the effective mass with the scalar \\sigma-field renders the kurtosis suppressed at higher baryon density so as to account for the observed behavior of the kurtosis. We finally discuss the difference between the baryon number and the proton number fluctuations from correlation effects in isospin space. Our numerical results suggest that such effects are only minor even in the cas...

  17. Marriage à-la-MOND: Baryonic dark matter in galaxy clusters and the cooling flow puzzle

    Science.gov (United States)

    Milgrom, Mordehai

    2008-05-01

    I start with a brief introduction to MOND phenomenology and its possible roots in cosmology—a notion that may turn out to be the most far reaching aspect of MOND. Next I discuss the implications of MOND for the dark matter (DM) doctrine: MOND's successes imply that baryons determine everything. For DM this would mean that the puny tail of leftover baryons in galaxies wags the hefty DM dog. This has to occur in many intricate ways, and despite the haphazard construction history of galaxies—a very tall order. I then concentrate on galaxy clusters in light of MOND, which still requires some yet undetected cluster dark matter, presumably in some baryonic form (CBDM). This CBDM might contribute to the heating of the X-ray emitting gas and thus alleviate the cooling flow puzzle. MOND, qua theory of dynamics, does not directly enter the microphysics of the gas; however, it does force a new outlook on the role of DM in shaping the cluster gas dynamics: MOND tells us that the cluster DM is not cold dark matter, is not so abundant, and is not expected in galaxies; it is thus not subject to constraints on baryonic DM in galaxies. The mass in CBDM required in a whole cluster is, typically, similar to that in hot gas, but is rather more centrally concentrated, totally dominating the core. The CBDM contribution to the baryon budget in the universe is thus small. Its properties, deduced for isolated clusters, are consistent with the observations of the "bullet cluster". Its kinetic energy reservoir is much larger than that of the hot gas in the core, and would suffice to keep the gas hot for many cooling times. Heating can be effected in various ways depending on the exact nature of the CBDM, from very massive black holes to cool, compact gas clouds.

  18. Interplay of mesonic and baryonic degrees of freedom in quark matter

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Naseemuddin

    2015-11-03

    In this work we study the influence of mesonic and baryonic fluctuations on the phase diagram of quark matter with two flavors. By examining the hadronization process and related techniques, we derive effective low-energy models, where the gluons are integrated out. To be able to compare our model calculations with lattice results at finite chemical potential, we investigate a QCD-like theory with two colors, where the sign-problem is absent. To this end we introduce a quark-meson-diquark model, where the bosonic diquarks play the role of colorless, baryonic degrees of freedom competing with the mesons. To access the phase diagram and determine the phases of chiral and diquark condensation, we employ a functional renormalization group approach allowing for a systematic non-perturbative truncation scheme. Interesting phenomena arise that are known from condensed matter physics, as the BEC-BSC crossover and a phase of condensation within domains. We explore the impact of running wave function renormalizations and Yukawa couplings for the quarks and the boson fields on top of the scale dependence of the effective potential. In the course of this we discuss the Silver Blaze property and its realization within a functional approach. In parallel, we formulate a quark-meson-diquark-baryon model for physical QCD as a low-energy effective theory for baryonic matter at high density, and discuss the relevance of the diquark and baryon degrees of freedom. In this sense, we compute a phase diagram for QCD from functional methods, including a color superconducting phase.

  19. A search for non-baryonic dark matter using an ionisation bolometer in the edelweiss experiment; Recherche de matiere sombre non-baryonique au moyen d`un bolometre a ionisation dans le cadre de l`experience edelweiss

    Energy Technology Data Exchange (ETDEWEB)

    Di Stefano, Ph. [CEA Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee]|[Paris-11 Univ., 91 - Orsay (France)

    1998-09-24

    The EDELWEISS experiment is an underground direct-detection search for hypothetical supersymmetric WIMPs that might solve the problem of dark matter. We have employed a cryogenic 70 g germanium ionisation bolometer, in which a WIMP would scatter elastically off a nucleus, creating both a heat and an ionisation signal. To offset the various electronic noises present in our necessarily small signals, we have s applied an optimal filtering technique in the frequency domain. This allows us to reach resolutions of 1.2 keV FWHM at 122 keV on north channels. It also provides good separation right down to low energies between the expected signal of nuclear recoils, and the photonic background of electron recoils which ionize more for a given energy. Calibration data show that we are able to reject 99.7 % of this background, while keeping 95% of the signal. However, our 1.17 kg.days of data searching for WIMPs show a third population encroaching on the expected signal. This is probably due to low energy photons or electrons interacting in the outer layers of the crystal, where charges are incompletely collected. Nevertheless, by trading off half of the conserved signal, we still manage to reject 98.5 % of the background. Thus the raw rate of 40 evts/d/kg/keV yields a conservative 90 % upper limit on the signal of 0.6 evts/d/kg/keV. This represents nearly a three orders of magnitude improvement for EDELWEISS, and puts the predicted supersymmetric phase space within two orders of magnitude. (author) 196 refs.

  20. Production of the doubly charmed baryons at the SELEX experiment - The double intrinsic charm approach

    Science.gov (United States)

    Koshkarev, Sergey; Anikeev, Vladimir

    2017-02-01

    The high production rate and > 0.33 of the doubly charmed baryons measured by the SELEX experiment is not amenable to perturbative QCD analysis. In this paper we calculate the production of the doubly heavy baryons with the double intrinsic charm Fock states whose existence is rigorously predicted by QCD. The production rate and the longitudinal momentum distribution are both reproduced. We also show that the production rates of the doubly charmed baryons and double J / ψ production observed by NA3 collaboration are comparable. Recent experimental results are reviewed. The production cross section of the doubly charmed baryons at a fixed-target experiment at the LHC is presented.

  1. Baryonic impact on the dark matter distribution in Milky Way-size galaxies and their satellites

    CERN Document Server

    Zhu, Qirong; Maji, Moupiya; Li, Yuexing; Springel, Volker; Hernquist, Lars

    2015-01-01

    We study the impact of baryons on the distribution of dark matter in a Milky Way-size halo by comparing a high-resolution, moving-mesh cosmological simulation with its dark matter-only counterpart. We identify three main processes related to baryons -- adiabatic contraction, tidal disruption and reionization -- which jointly shape the dark matter distribution in both the main halo and its subhalos. The relative effect of each baryonic process depends strongly on the subhalo mass. For massive subhalos with maximum circular velocity $v_{\\rm max} > 35 km/s$, adiabatic contraction increases the dark matter concentration, making these halos less susceptible to tidal disruption. For low-mass subhalos with $v_{\\rm max} < 20 km/s$, reionization effectively reduces their mass on average by $\\approx$ 30% and $v_{\\rm max}$ by $\\approx$ 20%. For intermediate subhalos with $20 km/s < v_{\\rm max} < 35 km/s$, which share a similar mass range as the classical dwarf spheroidals, strong tidal truncation induced by the...

  2. The angular momentum of baryons and dark matter halos revisited

    CERN Document Server

    Kimm, Taysun; Slyz, Adrianne; Pichon, Christophe; Kassin, Susan A; Dubois, Yohan

    2011-01-01

    Recent theoretical studies have shown that galaxies at high redshift are fed by cold, dense gas filaments, suggesting angular momentum transport by gas differs from that by dark matter. Revisiting this issue using high-resolution cosmological hydrodynamics simulations with adaptive mesh refinement, we find that at the time of accretion, gas and dark matter do carry a similar amount of specific angular momentum, but that it is systematically higher than that of the dark matter halo as a whole. At high redshift, freshly accreted gas rapidly streams into the central region of the halo, directly depositing this large amount of angular momentum within a sphere of radius r=0.1rvir. In contrast, dark matter particles pass through the central region unscathed, and a fraction of them ends up populating the outer regions of the halo (r/rvir>0.1), redistributing angular momentum in the process. As a result, large-scale motions of the cosmic web have to be considered as the origin of gas angular momentum rather than its ...

  3. Quasiparticle Theory of Transport Coefficients for Hadronic Matter at Finite Temperature and Baryon Density

    CERN Document Server

    Albright, M

    2016-01-01

    We develop a flexible quasiparticle theory of transport coefficients of hot hadronic matter at finite baryon density. We begin with a hadronic quasiparticle model which includes a scalar and a vector mean field. Quasiparticle energies and the mean fields depend on temperature and baryon chemical potential. Starting with the quasiparticle dispersion relation, we derive the Boltzmann equation and use the Chapman-Enskog expansion to derive formulas for the shear and bulk viscosities and thermal conductivity. We obtain both relaxation time approximation formulas and more general integral equations. Throughout the work, we explicitly enforce the Landau-Lifshitz conditions of fit and ensure the theory is thermodynamically self-consistent. The derived formulas should be useful for predicting the transport coefficients of the hadronic phase of matter produced in heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC) and at other accelerators.

  4. The baryonic Tully-Fisher Relation predicted by cold dark matter cosmogony

    CERN Document Server

    Desmond, Harry

    2012-01-01

    The baryonic Tully-Fisher Relation (TFR) is a tight relationship observed between baryonic mass and rotational velocity in spiral galaxies. Providing a theoretical basis for the TFR in the Cold Dark Matter (CDM) paradigm has proved problematic: simple calculations suggest too low a slope and too high a scatter. This paper aims to develop a rigorous prediction for the relation in the context of CDM by accounting for all relevant TFR-independent effects observed in numerical simulations of dark matter haloes, including their expected scatter. It is demonstrated that consistent treatment of these effects goes a large way towards reconciling the CDM prediction with the data; the normalisation becomes almost perfect, athough the slope remains somewhat too low. The predicted scatter is indeed too large, but may be reduced to near that of the data by accouting for observational selection effects.

  5. Marriage \\`a-la-MOND: Baryonic dark matter in galaxy clusters and the cooling flow puzzle

    CERN Document Server

    Milgrom, Mordehai

    2007-01-01

    I start with a brief introduction to MOND phenomenology and its possible roots in cosmology--a notion that may turn out to be the most far reaching aspect of MOND. Next I discuss the implications of MOND for the dark matter (DM) doctrine: MOND's successes imply that baryons determine everything. For DM this would mean that the puny tail of leftover baryons in galaxies wags the hefty DM dog. This has to occur in many intricate ways, and despite the haphazard construction history of galaxies--a very tall order. I then concentrate on galaxy clusters in light of MOND, which still requires some yet undetected cluster dark matter, presumably in some baryonic form (CBDM). This CBDM might contribute to the heating of the x-ray emitting gas and thus alleviate the cooling-flow puzzle. MOND, qua theory of dynamics, does not directly enter the microphysics of the gas; however, it does force a new outlook on the role of DM in shaping the cluster gasdynamics: MOND tells us that the cluster DM is not cold dark matter, is no...

  6. Understanding the internal dynamics of elliptical galaxies without non-baryonic dark matter

    CERN Document Server

    Dabringhausen, J; Famaey, B; Fellhauer, M

    2016-01-01

    Assuming virial equilibrium and Newtonian dynamics, low-mass early-type galaxies have larger velocity dispersions than expected from the amount of baryons they contain. The conventional interpretation of this finding is that their dynamics is dominated by non-baryonic matter. However, there is also strong evidence that many low-mass early-type galaxies formed as tidal dwarf galaxies, which would contain almost no dark matter. Using an extensive catalogue of early-type galaxies, we therefore discuss how the internal dynamics of early-type galaxies in general can be understood by replacing the assumption of non-baryonic dark matter with two alternative assumptions. The first assumption is that Milgromian dynamics (i.e., MOND) is valid, which changes the effective gravitational force in the weak-field limit. The second assumption is that binary stars affect the observed line-of-sight velocity dispersions. Some moderate discrepancies between observed and predicted velocity dispersions remain also when these effec...

  7. Dark and baryonic matter in the MareNostrum Universe

    OpenAIRE

    Gottloeber, S.; Yepes, G.; Khalatyan, A.; Sevilla, R.; Turchaninov, V.

    2006-01-01

    We report some results from one of the largest hydrodynamical cosmological simulations of large scale structures that has been done up to date. The MareNostrum Universe SPH simulation consists of 2 billion particles (2 times 1024^3) in a cubic box of 500 h^-1 Mpc on a side. This simulation has been done in the MareNostrum parallel supercomputer at the Barcelona SuperComputer Center. Due to the large simulated volume and good mass resolution, our simulated catalog of dark matter halos comprise...

  8. Skyrmions, half-skyrmions and nucleon mass in dense baryonic matter

    Science.gov (United States)

    Ma, Yong-Liang; Harada, Masayasu; Lee, Hyun Kyu; Oh, Yongseok; Rho, Mannque

    2014-04-01

    We explore the hadron properties in dense baryonic matter in a unified way by using a Skyrme model constructed with an effective Lagrangian which includes the ρ and ω vector mesons as hidden gauge bosons and is valid up to O(p4) in chiral expansion including the homogeneous Wess-Zumino terms. With the two input values of pion decay constant and the lowest lying vector meson mass which can be fixed in free space, all the other low energy constants in the effective Lagrangian are determined by their master formulas derived from holographic QCD models, which allows us to study the baryonic matter properties with no additional free parameters and thus without ambiguities. We find that the ω field that figures in the homogeneous Wess-Zumino term plays a crucial role in the skyrmion structure and its matter properties. The most striking and intriguing observation is that the pion decay constant that smoothly drops with increasing density in the Skyrmion phase stops decreasing at n1/2 at which the skyrmions in medium fractionize into half-skyrmions and remains nearly constant in the half-skyrmion phase. In accordance with the large Nc consideration, the baryon mass also stays non-scaling in the half-skyrmion phase. This feature is supported by the nuclear effective field theory with the parameters of the Lagrangian scaling modified at the skyrmion-half-skyrmion phase transition. Our exploration also uncovers the crucial role of the ω meson in multi-baryon systems as well as in the structure of a single skyrmion.

  9. Neutrino masses, dark matter and baryon asymmetry of the Universe

    CERN Document Server

    Ahriche, Amine

    2014-01-01

    In this work, we try to explain the neutrino mass and mixing data radiatively at three-loop by extending the standard model (SM) with two charged singlet scalars and three right handed (RH) neutrinos. Here, the lightest RH neutrino is a dark matter candidate that gives a relic density in agreement with the recent Planck data, the model can be consistent with the neutrino oscillation data, lepton flavor violating processes, the electroweak phase transition can be strongly first order; and the charged scalars may enhance the branching ratio $h\\rightarrow\\gamma\\gamma$, where as $h\\rightarrow\\gamma Z$ get can get few percent suppression. We also discuss the phenomenological implications of the RH neutrinos at the collider.

  10. Investigation of avalanche photodiodes radiation hardness for baryonic matter studies

    CERN Document Server

    Kushpil, V; Ladygin, V P; Kugler, A; Kushpil, S; Svoboda, O; Tlustý, P

    2015-01-01

    Modern avalanche photodiodes (APDs) with high gain are good device candidates for light readout from detectors applied in relativistic heavy ion collisions experiments. The results of the investigations of the APDs properties from Zecotek, Ketek and Hamamatsu manufacturers after irradiation using secondary neutrons from cyclotron facility U120M at NPI of ASCR in \\v{R}e\\v{z} are presented. The results of the investigations can be used for the design of the detectors for the experiments at NICA and FAIR.

  11. The phase diagram of nuclear and quark matter at high baryon density

    CERN Document Server

    Fukushima, Kenji

    2013-01-01

    We review theoretical approaches to explore the phase diagram of nuclear and quark matter at high baryon density. We first look over the basic properties of quantum chromodynamics (QCD) and address how to describe various states of QCD matter. In our discussions on nuclear matter we cover the relativistic mean-field model, the chiral perturbation theory, and the approximation based on the large-Nc limit where Nc is the number of colors. We then explain the liquid-gas phase transition and the inhomogeneous meson condensation in nuclear matter with emphasis put on the relevance to quark matter. We commence the next part focused on quark matter with the bootstrap model and the Hagedorn temperature. Then we turn to properties associated with chiral symmetry and exposit theoretical descriptions of the chiral phase transition. There emerge some quark-matter counterparts of phenomena seen in nuclear matter such as the liquid-gas phase transition and the inhomogeneous structure of the chiral condensate. The third reg...

  12. Dense baryonic matter in conformally-compensated hidden local symmetry: Vector manifestation and chiral symmetry restoration

    Science.gov (United States)

    Ma, Yong-Liang; Harada, Masayasu; Lee, Hyun Kyu; Oh, Yongseok; Park, Byung-Yoon; Rho, Mannque

    2014-08-01

    We find that, when the dilaton is implemented as a (pseudo-)Nambu-Goldstone boson using a conformal compensator or "conformon" in a hidden gauge symmetric Lagrangian written to O(p4) from which baryons arise as solitons, namely, skyrmions, the vector manifestation and chiral symmetry restoration at high density predicted in hidden local symmetry theory—which is consistent with Brown-Rho scaling—are lost or sent to infinite density. It is shown that they can be restored if in medium the behavior of the ω field is taken to deviate from that of the ρ meson in such a way that the flavor U(2) symmetry is strongly broken at increasing density. The hitherto unexposed crucial role of the ω meson in the structure of elementary baryon and multibaryon systems is uncovered in this work. In the state of half-skyrmions to which the skyrmions transform at a density n1/2≳n0 (where n0 is the normal nuclear matter density), characterized by the vanishing (space averaged) quark condensate but nonzero pion decay constant, the nucleon mass remains more or less constant at a value ≳60% of the vacuum value, indicating a large component of the nucleon mass that is not associated with the spontaneous breaking of chiral symmetry. We discuss its connection to the chiral-invariant mass m0 that figures in the parity-doublet baryon model.

  13. The impact of baryons on the spins and shapes of dark matter haloes

    CERN Document Server

    Bryan, S E; Duffy, A R; Schaye, J; Vecchia, C Dalla; Booth, C M

    2012-01-01

    We use numerical simulations to investigate how the statistical properties of dark matter (DM) haloes are affected by the baryonic processes associated with galaxy formation. We focus on how these processes influence the spin and shape of a large number of DM haloes covering a wide range of mass scales, from dwarf galaxies to clusters, at redshifts zero, one and two. The haloes are extracted from the OverWhelmingly Large Simulations, a suite of state-of-the-art high-resolution cosmological simulations run with a range of feedback prescriptions. We find that the median spin parameter in DM-only simulations is independent of mass, redshift and cosmology. Baryons increase the spin of the DM in the central region (< 0.25r_{200}) by up to 50 per cent when feedback is weak or absent. This increase can be attributed to the transfer of angular momentum from baryons to the DM. We also present fits to the mass dependence of the DM halo shape at both low and high redshift. At z=0 the sphericity (triaxiality) is negat...

  14. Cosmological phase transition, baryon asymmetry and dark matter Q-balls

    CERN Document Server

    Krylov, E; Rubakov, V

    2013-01-01

    We consider a mechanism of dark matter production in the course of first order phase transition. We assume that there is an asymmetry between X- and anti-X-particles of dark sector. In particular, it may be related to the baryon asymmetry. We also assume that the phase transition is so strongly first order, that X-particles do not permeate into the new phase. In this case, as the bubbles of old phase collapse, X-particles are packed into Q-balls with huge mass defect. These Q-balls compose the present dark matter. We find that the required present dark matter density is obtained for the energy scale of the theory in the ballpark of 1-10 TeV. As an example we consider a theory with effective potential of one-loop motivated form.

  15. Influence of baryons on the spatial distribution of matter: higher order correlation functions

    Institute of Scientific and Technical Information of China (English)

    Xiao-Jun Zhu; Jun Pan

    2012-01-01

    Physical processes involving baryons could leave a non-negligible imprint on the distribution of cosmic matter.A series of simulated data sets at high resolution with identical initial conditions are employed for count-in-cell analysis,including one N-body pure dark matter run,one with only adiabatic gas and one with dissipative processes.Variances and higher order cumulants Sn of dark matter and gas are estimated.It is found that physical processes with baryons mainly affect distributions of dark matter at scales less than 1 h-1 Mpc.In comparison with the pure dark matter run,adiabatic processes alone strengthen the variance of dark matter by ~ 10% at a scale of 0.1 h-1 Mpc,while the Sn parameters of dark matter only mildly deviate by a few percent.The dissipative gas run does not differ much from the adiabatic run in terms of variance for dark matter,but renders significantly different Sn parameters describing the dark matter,bringing about a more than 10% enhancement to S3 at 0.1 h-1 Mpc and z = 0 and being even larger at a higher redshift.Distribution patterns of gas in two hydrodynamical simulations are quite different.Variance of gas at z = 0 decreases by ~ 30% in the adiabatic simulation but by ~ 60% in the nonadiabatic simulation at 0.1 h-1 Mpc.The attenuation is weaker at larger scales but is still obvious at ~ 10 h-1 Mpc.Sn parameters of gas are biased upward at scales <~ 4 h-1 Mpc,and dissipative processes show an ~ 84% promotion at z = 0 to S3 at 0.1 h-1 Mpc in contrast with the ~ 7% change in the adiabatic run.The segregation in clustering between gas and dark matter could have dramatic implications on modeling distributions of galaxies and relevant cosmological applications demanding fine details of matter distribution in a strongly nonlinear regime.

  16. The impact of baryonic processes on the two-point correlation functions of galaxies, subhaloes and matter

    CERN Document Server

    van Daalen, Marcel P; McCarthy, Ian G; Booth, C M; Vecchia, Claudio Dalla

    2013-01-01

    The observed clustering of galaxies and the cross-correlation of galaxies and mass (a measure of galaxy-galaxy lensing) provide important constraints on both cosmology and models of galaxy formation. Even though the dissipation, and more importantly the feedback processes associated with galaxy formation are thought to affect the distribution of matter, essentially all models used to predict clustering data are based on dark matter only simulations. Here, we use large hydrodynamical simulations to investigate how galaxy formation affects the autocorrelation functions of galaxies, subhaloes, as well as their cross-correlation with matter. We show that the changes due to the inclusion of baryons are not limited to small scales and are even present in samples selected by subhalo mass. Samples selected by subhalo mass cluster ~10% more strongly in a baryonic run on scales r ~ 1Mpc/h or larger, and this difference increases for smaller separations. While the inclusion of baryons boosts the clustering at fixed subh...

  17. Why Comparable? A Multiverse Explanation of the Dark Matter-Baryon Coincidence

    CERN Document Server

    Bousso, Raphael

    2013-01-01

    The densities of dark and baryonic matter are comparable: \\zeta = \\rho_D / \\rho_B ~ O(1). This is surprising because they are controlled by different combinations of low-energy physics parameters. Here we consider the probability distribution over \\zeta in the landscape. We argue that the Why Comparable problem can be solved without detailed anthropic assumptions, and independently of the nature of dark matter. Overproduction of dark matter suppresses the probability like 1/(1+\\zeta), if the causal patch is used to regulate infinities. This suppression can counteract a prior distribution favoring large \\zeta, selecting \\zeta ~ O(1). This effect not only explains the Why Comparable coincidence but also renders otherwise implausible models of dark matter viable. For the special case of axion dark matter, Wilczek and independently Freivogel have already noted that a 1/(1+\\zeta) suppression prevents overproduction of a GUT-scale QCD axion. If the dark matter is the LSP, the effect can explain the moderate fine-tu...

  18. Sharing but not Caring: Dark Matter and the Baryon Asymmetry of the Universe

    CERN Document Server

    Bernal, Nicolás; Fonseca, Nayara

    2016-01-01

    We consider scenarios where Dark Matter (DM) particles carry baryon and/or lepton numbers, which can be defined if there exist operators connecting the dark to the visible sector. As a result, the DM fields become intimately linked to the Standard Model (SM) ones and can be maximally asymmetric just like the ordinary matter. In particular, we discuss minimal scenarios where the DM is a complex scalar or a Dirac fermion coupled to operators with nonzero baryon and/or lepton numbers, and that consist of only SM fields. We consider an initial asymmetry stored in either the SM or the DM sector; the main role of these operators is to properly $share$ the asymmetry between the two sectors, in accordance with observations. After the chemical decoupling, the DM and SM sectors do $not$ $care$ about each other as there is only an ineffective communication between them. Once the DM mass is specified, the Wilson coefficients of these operators are fixed by the requirement of the correct transfer of the asymmetry. We stud...

  19. A Census of Baryons and Dark Matter in an Isolated, Milky Way-sized Elliptical Galaxy

    CERN Document Server

    Humphrey, Philip J; Canizares, Claude R; Fabian, Andrew C; Miller, Jon M

    2010-01-01

    We present a study of the dark and luminous matter in the isolated elliptical galaxy NGC720, based on deep X-ray data taken with Chandra and Suzaku. The gas is reliably measured to ~R2500, allowing us to place good constraints on the enclosed mass and baryon fraction (fb) within this radius (M2500=1.6e12+/-0.2e12 Msun, fb(2500)=0.10+/-0.01; systematic errors are <~20%). The data indicate that the hot gas is close to hydrostatic, which is supported by good agreement with a kinematical analysis of the dwarf satellite galaxies. We confirm a dark matter (DM) halo at ~20-sigma. Assuming an NFW DM profile, our physical model for the gas distribution enables us to obtain meaningful constraints at scales larger than R2500, revealing that most of the baryons are in the hot gas. We find that fb within Rvir is consistent with the Cosmological value, confirming theoretical predictions that a ~Milky Way-mass (Mvir=3.1e12+/-0.4e12 Msun) galaxy can sustain a massive, quasi-hydrostatic gas halo. While fb is higher than th...

  20. Cuspy no more: how outflows affect the central dark matter and baryon distribution in Λ cold dark matter galaxies

    Science.gov (United States)

    Governato, F.; Zolotov, A.; Pontzen, A.; Christensen, C.; Oh, S. H.; Brooks, A. M.; Quinn, T.; Shen, S.; Wadsley, J.

    2012-05-01

    We examine the evolution of the inner dark matter (DM) and baryonic density profile of a new sample of simulated field galaxies using fully cosmological, Λ cold dark matter (ΛCDM), high-resolution SPH+N-Body simulations. These simulations include explicit H2 and metal cooling, star formation (SF) and supernovae-driven gas outflows. Starting at high redshift, rapid, repeated gas outflows following bursty SF transfer energy to the DM component and significantly flatten the originally 'cuspy' central DM mass profile of galaxies with present-day stellar masses in the 104.5-109.8 M⊙ range. At z= 0, the central slope of the DM density profile of our galaxies (measured between 0.3 and 0.7 kpc from their centre) is well fitted by ρDM ∝ rα with α≃-0.5 + 0.35 log10(M★/108 M⊙), where M★ is the stellar mass of the galaxy and 4 < log M★ < 9.4. These values imply DM profiles flatter than those obtained in DM-only simulations and in close agreement with those inferred in galaxies from the THINGS and LITTLE THINGS surveys. Only in very small haloes, where by z= 0 SF has converted less than ˜0.03 per cent of the original baryon abundance into stars, outflows do not flatten the original cuspy DM profile out to radii resolved by our simulations. The mass (DM and baryonic) measured within the inner 500 pc of each simulated galaxy remains nearly constant over 4 orders of magnitudes in stellar mass for M★ < 109 M⊙. This finding is consistent with estimates for faint Local Group dwarfs and field galaxies. These results address one of the outstanding problems faced by the CDM model, namely the strong discrepancy between the original predictions of cuspy DM profiles and the shallower central DM distribution observed in galaxies.

  1. Dark matter annihilation in the milky way galaxy: effects of baryonic compression.

    Science.gov (United States)

    Prada, F; Klypin, A; Flix, J; Martínez, M; Simonneau, E

    2004-12-10

    If the dark matter (DM), which is considered to constitute most of the mass of galaxies, is made of supersymmetric particles, the central region of our Galaxy should emit gamma rays produced by their annihilation. We use detailed models of the Milky Way to make accurate estimates of continuum gamma-ray fluxes. We argue that the most important effect, which was previously neglected, is the compression of the dark matter due to the infall of baryons to the galactic center: it boosts the expected signal by a factor 1000. To illustrate this effect, we computed the expected gamma fluxes in the minimal supergravity scenario. Our models predict that the signal could be detected at high confidence levels by imaging atmospheric C erenkov telescopes assuming that neutralinos make up most of the DM in the Universe.

  2. Effects of the UY(1 ) Chern-Simons term and its baryonic contribution on matter asymmetries and hypermagnetic fields

    Science.gov (United States)

    Rostam Zadeh, S.; Gousheh, S. S.

    2017-03-01

    In this paper, we study the significance of the UY(1 ) Chern-Simons term in general, and its baryonic contribution in particular, for the evolution of the matter asymmetries and the hypermagnetic field in the temperature range 100 GeV ≤T ≤10 TeV . We show that an initial helical hypermagnetic field, denoted by BY(0 ), can grow matter asymmetries from zero initial value. However, the growth which is initially quadratic with respect to BY(0 ) saturates for values larger than a critical value. The inclusion of the baryonic contribution reduces this critical value, leading to smaller final matter asymmetries. Meanwhile, BY(TEW) becomes slightly larger than BY(0 ). In the absence of the UY(1 ) Chern-Simons term, the final values of matter asymmetries grow without saturation. Conversely, we show that an initial matter asymmetry can grow an initial seed of a hypermagnetic field, provided the Chern-Simons term is taken into account. The growth process saturates when the matter asymmetry drops abruptly. When the baryonic contribution is included, the saturation occurs at an earlier time, and BY(TEW) becomes larger. We also show that the baryonic asymmetry and the magnetic field strength can be within the acceptable range of present day data, provided the inverse cascade process is also taken into account; however, the magnetic field scale obtained from this simple model is much lower than the ones usually assumed for gamma-ray propagation.

  3. Baryon Resonances

    CERN Document Server

    Oset, E; Sun, Bao Xi; Vacas, M J Vicente; Ramos, A; Gonzalez, P; Vijande, J; Torres, A Martinez; Khemchandani, K

    2009-01-01

    In this talk I show recent results on how many excited baryon resonances appear as systems of one meson and one baryon, or two mesons and one baryon, with the mesons being either pseudoscalar or vectors. Connection with experiment is made including a discussion on old predictions and recent results for the photoproduction of the $\\Lambda(1405)$ resonance, as well as the prediction of one $1/2^+$ baryon state around 1920 MeV which might have been seen in the $\\gamma p \\to K^+ \\Lambda$ reaction.

  4. Baryon Resonances

    Energy Technology Data Exchange (ETDEWEB)

    Oset, E. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Sarkar, S. [Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064 (India); Sun Baoxi [Institute of Theoretical Physics, College of Applied Sciences, Beijing University of Technology, Beijing 100124 (China); Vicente Vacas, M.J. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Ramos, A. [Departament d' Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona, 08028 Barcelona (Spain); Gonzalez, P. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Vijande, J. [Departamento de Fisica Atomica Molecular y Nuclear and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Martinez Torres, A. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Khemchandani, K. [Centro de Fisica Computacional, Departamento de Fisica, Universidade de Coimbra, P-3004-516 Coimbra (Portugal)

    2010-04-01

    In this talk I show recent results on how many excited baryon resonances appear as systems of one meson and one baryon, or two mesons and one baryon, with the mesons being either pseudoscalar or vectors. Connection with experiment is made including a discussion on old predictions and recent results for the photoproduction of the {lambda}(1405) resonance, as well as the prediction of one 1/2{sup +} baryon state around 1920 MeV which might have been seen in the {gamma}p{yields}K{sup +}{lambda} reaction.

  5. Baryon oscillations in galaxy and matter power-spectrum covariance matrices

    CERN Document Server

    Neyrinck, Mark C

    2007-01-01

    We investigate large-amplitude baryon acoustic oscillations (BAO's) in off-diagonal entries of cosmological power-spectrum covariance matrices. These covariance-matrix BAO's describe the increased attenuation of power-spectrum BAO's caused by upward fluctuations in large-scale power. We derive an analytic approximation to covariance-matrix entries in the BAO regime, and check the analytical predictions using N-body simulations. These BAO's look much stronger than the BAO's in the power spectrum, but seem detectable only at about a one-sigma level in gigaparsec-scale galaxy surveys. In estimating cosmological parameters using matter or galaxy power spectra, including the covariance-matrix BAO's can have a several-percent effect on error-bar widths for some parameters directly related to the BAO's, such as the baryon fraction. Also, we find that including the numerous galaxies in small haloes in a survey can reduce error bars in these cosmological parameters more than the simple reduction in shot noise might su...

  6. CFHTLenS: The relation between galaxy dark matter haloes and baryons from weak gravitational lensing

    CERN Document Server

    Velander, Malin; Hoekstra, Henk; Coupon, Jean; Erben, Thomas; Heymans, Catherine; Hildebrandt, Hendrik; Kitching, Thomas D; Mellier, Yannick; Miller, Lance; Van Waerbeke, Ludovic; Bonnett, Christopher; Fu, Liping; Giodini, Stefania; Hudson, Michael J; Kuijken, Konrad; Rowe, Barnaby; Schrabback, Tim; Semboloni, Elisabetta

    2013-01-01

    We present a study of the relation between dark matter halo mass and the baryonic content of host galaxies, quantified through luminosity and stellar mass. Our investigation uses 154 deg2 of Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS) lensing and photometric data, obtained from the CFHT Legacy Survey. We employ a galaxy-galaxy lensing halo model which allows us to constrain the halo mass and the satellite fraction, and our analysis is limited to lenses at redshifts between 0.2 and 0.4. We express the relationship between halo mass and baryonic observable as a power law. For the luminosity-halo mass relation we find a slope of 1.56+0.04-0.06 and a normalisation of 1.26+0.07-0.06x10^13 h70^-1 Msun for red galaxies, while for blue galaxies the best-fit slope is 0.73+0.09-0.08 and the normalisation is 0.16+/-0.03x10^13 h70^-1 Msun. Similarly, we find a best-fit slope of 1.49+0.06-0.04 and a normalisation of 1.30+0.05-0.09x10^13 h70^-1 Msun for the stellar mass-halo mass relation of red galaxies, whil...

  7. Baryonic Distributions in Galaxy Dark Matter Haloes I: New Observations of Neutral and Ionized Gas Kinematics

    CERN Document Server

    Richards, Emily E; Barnes, K L; Staudaher, S; Dale, D A; Braun, T T; Wavle, D C; Dalcanton, J J; Bullock, J S; Chandar, R

    2016-01-01

    We present a combination of new and archival neutral hydrogen (HI) observations and new ionized gas spectroscopic observations for sixteen galaxies in the statistically representative EDGES kinematic sample. HI rotation curves are derived from new and archival radio synthesis observations from the Very Large Array (VLA) as well as processed data products from the Westerbork Radio Synthesis Telescope (WSRT). The HI rotation curves are supplemented with optical spectroscopic integral field unit (IFU) observations using SparsePak on the WIYN 3.5 m telescope to constrain the central ionized gas kinematics in twelve galaxies. The full rotation curves of each galaxy are decomposed into baryonic and dark matter halo components using 3.6$\\mu$m images from the Spitzer Space Telescope for the stellar content, the neutral hydrogen data for the atomic gas component, and, when available, CO data from the literature for the molecular gas component. Differences in the inferred distribution of mass are illustrated under fixe...

  8. Influence of baryons on the orbital structure of dark matter haloes

    CERN Document Server

    Bryan, S E; Kay, S T; Schaye, J; Vecchia, C Dalla; Booth, C M

    2011-01-01

    We explore the dynamical signatures imprinted by baryons on dark matter haloes during the formation process using the OverWhelmingly Large Simulations (OWLS), a set of state-of-the-art high resolution cosmological hydrodynamical simulations. We present a detailed study of the effects of the implemented feedback prescriptions on the orbits of dark matter particles, stellar particles and subhaloes, analysing runs with no feedback, with stellar feedback and with feedback from supermassive black holes. We focus on the central regions (0.25 r_{200}) of haloes with virial masses ~ 6 x 10^{13} (~ 7 x 10^{11}) Msun/h at z = 0(2). We also investigate how the orbital content of these haloes depends on several key parameters such as their mass, redshift and dynamical state. The results of spectral analyses of the orbital content of these simulations are compared, and the change in fraction of box, tube and irregular orbits are quantified. Box orbits are found to dominate the orbital structure of dark matter haloes in co...

  9. Addressing the too big to fail problem with baryon physics and sterile neutrino dark matter

    CERN Document Server

    Lovell, Mark R; Bose, Sownak; Boyarsky, Alexey; Cole, Shaun; Frenk, Carlos S; Ruchayskiy, Oleg

    2016-01-01

    N-body dark matter simulations of structure formation in the $\\Lambda$CDM model predict a population of subhalos within Galactic halos that have higher central densities than inferred for satellites of the Milky Way, a tension known as the `too big to fail' problem. Proposed solutions include baryonic effects, a smaller mass for the Milky Way halo, and warm dark matter. We test these three possibilities using a semi-analytic model of galaxy formation to generate luminosity functions for Milky Way halo-analogue satellite populations, the results of which are then coupled to the Jiang & van den Bosch model of subhalo stripping to predict the subhalo $V_\\mathrm{max}$ functions for the 10 brightest satellites. We find that selecting the brightest satellites (as opposed to the most massive) and modelling the expulsion of gas by supernovae at early times increases the likelihood of generating the observed Milky Way satellite $V_\\mathrm{max}$ function. The preferred halo mass is $6\\times10^{11}M_{\\odot}$, which ...

  10. Cosmological perturbation theory for baryons and dark matter I. One-loop corrections in the RPT framework

    Energy Technology Data Exchange (ETDEWEB)

    Somogyi, Gabor [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Zurich Univ. (Switzerland). Inst. for Theoretical Physics; Smith, Robert E. [Zurich Univ. (Switzerland). Inst. for Theoretical Physics

    2009-10-15

    We generalize the ''renormalized'' perturbation theory (RPT) formalism of M. Crocce and R. Scoccimarro (2006) to deal with multiple fluids in the Universe and here we present the complete calculations up to the one-loop level in the RPT. We apply this approach to the problem of following the nonlinear evolution of baryon and cold dark matter (CDM) perturbations, evolving from the distinct sets of initial conditions, from the high redshift post-recombination Universe right through to the present day. In current theoretical and numerical models of structure formation, it is standard practice to treat baryons and CDM as an effective single matter fluid - the so called dark matter only modeling. In this approximation, one uses a weighed sum of late time baryon and CDM transfer functions to set initial mass fluctuations. In this paper we explore whether this approach can be employed for high precision modeling of structure formation. We show that, even if we only follow the linear evolution, there is a large-scale scale-dependent bias between baryons and CDM for the currently favored WMAP5 {lambda}CDM model. This time evolving bias is significant (> 1%) until the present day, when it is driven towards unity through gravitational relaxation processes. Using the RPT formalism we test this approximation in the non-linear regime. We show that the non-linear CDM power spectrum in the 2-component fluid differs from that obtained from an effective mean-mass 1-component fluid by {proportional_to} 3% on scales of order k {proportional_to} 0.05 h Mpc{sup -1} at z = 10, and by {proportional_to} 0.5% at z = 0. However, for the case of the non-linear evolution of the baryons the situation is worse and we find that the power spectrum is suppressed, relative to the total matter, by {proportional_to} 15% on scales k {proportional_to} 0.05 hMpc{sup -1} at z = 10, and by {proportional_to} 3 - 5% at z = 0. Importantly, besides the suppression of the spectrum, the

  11. Astrophysical constraints on dark-matter Q-balls in the presence of baryon-violating operators

    CERN Document Server

    Cotner, Eric

    2016-01-01

    Supersymmetric extensions of the standard model predict the existence of non-topological solitons, Q-balls. Assuming the standard cosmological history preceded by inflation, Q-balls can form in the early universe and can make up the dark matter. The relatively large masses of such dark-matter particles imply a low number density, making direct detection very challenging. The strongest limits come from the existence of neutron stars because, if a baryonic Q-ball is captured by a neutron star, the Q-ball can absorb the baryon number releasing energy and eventually destroying a neutron star. However, in the presence of baryon number violating higher-dimension operators, the growth of a Q-ball inside a neutron star is hampered once the Q-ball reaches a certain size. We re-examine the limits and identify some classes of higher-dimensional operators for which supersymmetric Q-balls can account for dark matter. The present limits leave a wide range of parameters available for dark matter in the form of supersymmetri...

  12. Baryon-antibaryon asymmetry in central rapidity region at LHC with the ALICE experiment

    CERN Document Server

    Broz, Michal

    The Large Hadron Collider (LHC) provided the first proton-proton collisions in the period of November-December 2009. Since then, a large data sample has been recorded by all LHC experiments. This event sample allows us to study more and more exotic particles and events. The ALICE (A Large Ion Collider Experiment) experiment, though designed primarily to study heavy ion collisions, has a rich proton-proton physics program. The characteristic features of ALICE are its very low-momentum cut-off, the low material budget and the excellent particle identification (PID) and vertexing capabilities. In this thesis, I discuss the results from the analysis of proton-proton collisions at the different LHC energies (√s = 900 GeV, 2.76 TeV and 7 TeV). I concentrate on the antibaryon-to-baryon ratio study which is of great importance for description of baryon number transport and it can allow to determine the carrier of the baryon number as well as to give an information on baryon structure itself. In particular, the mult...

  13. The origin of dark matter, matter-anti-matter asymmetry, and inflation

    CERN Document Server

    Mazumdar, Anupam

    2011-01-01

    A rapid phase of accelerated expansion in the early universe, known as inflation, dilutes all matter except the vacuum induced quantum fluctuations. These are responsible for seeding the initial perturbations in the baryonic matter, the non-baryonic dark matter and the observed temperature anisotropy in the cosmic microwave background (CMB) radiation. To explain the universe observed today, the end of inflation must also excite a thermal bath filled with baryons, an amount of baryon asymmetry, and dark matter. We review the current understanding of inflation, dark matter, mechanisms for generating matter-anti-matter asymmetry, and the prospects for testing them at ground and space based experiments.

  14. Simulations of Baryon Acoustic Oscillations II: Covariance matrix of the matter power spectrum

    CERN Document Server

    Takahashi, Ryuichi; Takada, Masahiro; Matsubara, Takahiko; Sugiyama, Naoshi; Kayo, Issha; Nishizawa, Atsushi J; Nishimichi, Takahiro; Saito, Shun; Taruya, Atsushi

    2009-01-01

    We use 5000 cosmological N-body simulations of 1(Gpc/h)^3 box for the concordance LCDM model in order to study the sampling variances of nonlinear matter power spectrum. We show that the non-Gaussian errors can be important even on large length scales relevant for baryon acoustic oscillations (BAO). Our findings are (1) the non-Gaussian errors degrade the cumulative signal-to-noise ratios (S/N) for the power spectrum amplitude by up to a factor of 2 and 4 for redshifts z=1 and 0, respectively. (2) There is little information on the power spectrum amplitudes in the quasi-nonlinear regime, confirming the previous results. (3) The distribution of power spectrum estimators at BAO scales, among the realizations, is well approximated by a Gaussian distribution with variance that is given by the diagonal covariance component. (4) For the redshift-space power spectrum, the degradation in S/N by non-Gaussian errors is mitigated due to nonlinear redshift distortions. (5) For an actual galaxy survey, the additional shot...

  15. Dense Baryonic Matter in Hidden Local Symmetry Approach: Half-Skyrmions and Nucleon Mass

    CERN Document Server

    Ma, Yong-Liang; Lee, Hyun Kyu; Oh, Yongseok; Park, Byung-Yoon; Rho, Mannque

    2013-01-01

    Hadron properties in dense medium are treated in a unified way in a skyrmion model constructed with an effective Lagrangian, in which the rho and omega vector mesons are introduced as hidden gauge bosons, valid up to O(p^4) terms in chiral expansion including the homogeneous Wess-Zumino terms. All the low energy constants - apart from f_pi and m_rho - are fixed by the master formula derived from the relation between 5-D hQCD and 4-D HLS. This allows one to pin down the density n_1/2 at which the skyrmions in medium fractionize into half-skyrmions, bringing in a drastic change in the EoS of dense matter. We find that the U(1) field that figures in the CS term in the hQCD action or equivalently the omega field in the hWZ term in the dimensionally reduced HLS action plays a crucial role in the half-skyrmion phase. The importance of the omega degree of freedom may be connected to what happens in the instanton structure of elementary baryon noticed in hQCD. The most striking and intriguing in what is found in the ...

  16. Baryon Resonances in the STAR Experiment at RHIC

    Directory of Open Access Journals (Sweden)

    Witt Richard

    2015-01-01

    Full Text Available We present measurements of mass, width, and yields of the Δ(1232++, Σ(1385 and Λ(1520 from p + p, d+Au, and Au+Au collisions at √sNN = 200 GeV in the STAR experiment at Brookhaven National Laboratory’s Relativistic Heavy-Ion Collider (RHIC. These measurements are discussed in the context of re-scattering and regeneration. We also discuss preliminary measurements of the Ξ(1530 and possibilities for upcoming measurements based on recently collected data.

  17. The DAMIC Dark Matter Experiment

    Energy Technology Data Exchange (ETDEWEB)

    de Mello Neto, J. R.T. [Federal Univ. of Rio de Janeiro (Brazil). et al

    2015-10-07

    The DAMIC (DArk Matter In CCDs) experiment uses high-resistivity, scientific-grade CCDs to search for dark matter. The CCD’s low electronic noise allows an unprecedently low energy threshold of a few tens of eV; this characteristic makes it possible to detect silicon recoils resulting from interactions of low-mass WIMPs. In addition, the CCD’s high spatial resolution and the excellent energy response results in very effective background identification techniques. The experiment has a unique sensitivity to dark matter particles with masses below 10 GeV/c2. Previous results have motivated the construction of DAMIC100, a 100 grams silicon target detector currently being installed at SNOLAB. The mode of operation and unique imaging capabilities of the CCDs, and how they may be exploited to characterize and suppress backgrounds are discussed, as well as physics results after one year of data taking.

  18. Octet Baryon Magnetic Moments from Lattice QCD: Approaching Experiment from the Three-Flavor Symmetric Point

    CERN Document Server

    Parreno, Assumpta; Tiburzi, Brian C; Wilhelm, Jonas; Chang, Emmanuel; Detmold, William; Orginos, Kostas

    2016-01-01

    Lattice QCD calculations with background magnetic fields are used to determine the magnetic moments of the octet baryons. Computations are performed at the physical value of the strange quark mass, and two values of the light quark mass, one corresponding to the SU(3) flavor-symmetric point, where the pion mass is ~ 800 MeV, and the other corresponding to a pion mass ~ 450 MeV. The moments are found to exhibit only mild pion-mass dependence when expressed in terms of appropriately chosen magneton units---the natural baryon magneton. This suggests that simple extrapolations can be used to determine magnetic moments at the physical point, and extrapolated results are found to agree with experiment within uncertainties. A curious pattern is revealed among the anomalous baryon magnetic moments which is linked to the constituent quark model, however, careful scrutiny exposes additional features. Relations expected to hold in the large-Nc limit of QCD are studied; and, in one case, the quark model prediction is sig...

  19. Measurement of the {Lambda}{sub c} charmed baryon production and the study of the {Lambda}{sub c} baryon semi-leptonic decays by the DELPHI experiment at LEP; Mesure de la production du baryon charme {Lambda}{sub c} et etude des desintegrations semi-leptoniques de baryon {Lambda}{sub c} par l`experience DELPHI au LEP

    Energy Technology Data Exchange (ETDEWEB)

    Bertini, D. [Lyon-1 Univ., 69 (France)

    1997-04-24

    By using the data accumulated in the DELPHI experiment from 1992 to 1994 we present the results of the production rate measurement of {Lambda}{sub c} charmed baryons generated in the bb-bar and cc-bar events. For these measurements we reconstructed entirely the {Lambda}{sub c} baryons decaying in pK{pi}. Then we select a set of bottom baryons {Lambda}{sub b}{sup 0} by means of its semi-leptonic decays in {Lambda}{sub c}{sup +}l{sup -}{nu}{sub l}-bar. The study of distribution of these events as a function of the transfer momentum allowed estimating for the first time the slope of the {Lambda}{sub b}{sup 0} form factor. (author) 93 refs.

  20. Exploring the simplest purely baryonic decay processes

    CERN Document Server

    Geng, C Q; Rodrigues, Eduardo

    2016-01-01

    We propose to search for purely baryonic decay processes at the LHCb experiment. In particular, we concentrate on the decay $\\Lambda_b^0\\to p\\bar pn$, which is the simplest purely baryonic decay mode, with solely spin-1/2 baryons involved. We predict its decay branching ratio to be ${\\cal B}(\\Lambda_b^0\\to p\\bar pn)=(2.0^{+0.3}_{-0.2})\\times 10^{-6}$, which is sufficiently large to make the decay mode accessible to LHCb. Though not considered in general, purely baryonic decays could shed light on the puzzle of the baryon number asymmetry in the universe by means of a better understanding of the baryonic nature of our matter world. As such, they constitute a yet unexplored class of decay processes worth investigating. Our study can be extended to the purely baryonic decays of $\\Lambda_b^0\\to p\\bar p \\Lambda$, $\\Lambda_b^0\\to \\Lambda \\bar p\\Lambda$ and $\\Lambda_b^0\\to \\Lambda\\bar \\Lambda\\Lambda$, as well as other similar anti-triplet $b$-baryon decays, such as $\\Xi_b^{0,-}$.

  1. Puffing up early-type galaxies by baryonic mass loss: numerical experiments

    CERN Document Server

    Ragone-Figueroa, Cinthia

    2011-01-01

    We present numerical simulations of the effect of baryonic mass loss on the structure of a spheroidal stellar system, embedded in a dark matter halo. This process could be caused either by QSO/starburst driven galactic winds, promptly ejecting from Early Type Galaxies (ETGs) the residual gas (galactic winds), or by stellar mass returned to the ISM in the final stages of stellar evolution. We find that a conceivable loss of about 50% of the baryonic mass can produce a significant size increase, which could contribute to the claimed size evolution of ETGs since z about 2. However, most (all in the case of QSO driven winds) of the puffing up occurs when the stellar population are much younger than the estimated ages of compact high-z ETGs. We conclude that the putative expansion caused by galactic winds is still not observed, while that due to stellar evolution could contribute to, but not dominate, the evolution of the mass-size relationship of ETGs observed so far.

  2. Development of PID counter for charmed baryon spectroscopy experiment at J-PARC

    Energy Technology Data Exchange (ETDEWEB)

    Yamaga, T. [Research Center for Nuclear Physics (RCNP), Osaka University, 10-1, Mihogaoka, Ibaraki-shi, Osaka 567-0047 (Japan); Ishikawa, T. [ELPH, Tohoku University, 1-2-1, Mikamine, Taihaku-ku, Sendai-shi, Miyagi (Japan); Miyachi, Y. [Department of Physics, Yamagata University, 1-4-12, Shirakawa-cho, Yamagata-shi, Yamagata 990-8560 (Japan); Morino, Y. [RIKEN Nishina Center, RIKEN, 2-1, Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Nakano, T.; Noumi, H. [Research Center for Nuclear Physics (RCNP), Osaka University, 10-1, Mihogaoka, Ibaraki-shi, Osaka 567-0047 (Japan); Ozawa, K. [KEK, 1-1, Oho, Tsukuba-shi, Ibaraki 305-0801 (Japan); Shirotori, K.; Sugaya, Y. [Research Center for Nuclear Physics (RCNP), Osaka University, 10-1, Mihogaoka, Ibaraki-shi, Osaka 567-0047 (Japan); Tanida, K. [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2014-12-01

    We have proposed an experiment for studying charmed baryons via the p(π{sup −},D{sup ⁎−}) reaction at the J-PARC high-momentum beam line. Charmed baryons will be measured by a missing mass method. Scattered D{sup ⁎−} will be reconstructed by detecting its decay chain of D{sup ⁎−}→D{sup ¯0}π{sup −}→K{sup +}π{sup −}π{sup −}. We designed a Ring Imaging Cherenkov (RICH) counter with two radiators, aerogel and C{sub 4}F{sub 10} of refractive indices 1.04 and 1.00137, respectively, in order to identify pions and kaons in a wide momentum range from 2 to 16 GeV/c. Spherical mirrors will be used to focus Cherenkov photons to the photon sensor alloys. The performance of the designed RICH counter is evaluated by a Monte-Carlo simulation based on GEANT4. Detection efficiency for scattered particles averaged over π and K is found to be 99%. Wrong particle identification ratios of pions and protons to kaons are 0.1% and 0.14%, respectively. The background level in the inclusive p(π{sup −},D{sup ⁎−}) spectrum increases only 5% due to the wrong identifications. - Highlights: • We design the PID counter for using charmed baryon spectroscopy experiment at JPARC. • The designed PID counter was studied with GEANT4 simulation and expected particle distribution in the experiment. • The estimated efficiency of pion and kaon is about 99% and wrong ID ratio is small enough.

  3. The impact of the supersonic baryon-dark matter velocity difference on the z~20 21cm background

    CERN Document Server

    McQuinn, Matthew

    2012-01-01

    Recently, Tseliakhovich and Hirata (2010) showed that during the cosmic Dark Ages the baryons were typically moving supersonically with respect to the dark matter with a spatially variable Mach number. Such supersonic motion may source shocks that heat the Universe. This motion may also suppress star formation in the first halos. Even a small amount of coupling of the 21cm signal to this motion has the potential to vastly enhance the 21cm brightness temperature fluctuations at 15matter-baryon relative velocity, v_bc (in contrast to prior simulations). We find that the supersonic velocity difference dramatically suppresses structure formation at 10-100 comoving kpc scales, it sources shocks throug...

  4. Baryon Spectroscopy - Recent results from the Crystal Barrel Experiment at ELSA -*

    Directory of Open Access Journals (Sweden)

    Schmidt C.

    2010-04-01

    Full Text Available To understand the spectrum and the properties of baryon resonances, the CBELSA/TAPS experiment investigates the photoproduction off the nucleon using linearly, circularly polarized or unpolarized photons impinging on a polarized or unpolarized target. Preliminary results on first double polarization observables have been obtained for the reactions $vec{gamma}{p}$ → pπ0 and $vec{gamma}{p}$ → pη using both circular and linear polarized photons on a longitudinally polarized target. This data will finally provide important information for the partial wave analyzes used to extract the resonances from the data.

  5. The baryon-decuplet in the chiral dynamics of Lambda-hyperons in nuclear matter

    CERN Document Server

    Camalich, J M

    2006-01-01

    We study the long range part of the $\\Lambda$-hyperon optical potential in nuclei using Quantum Many Body techniques and flavor-SU(3) Chiral Lagrangians as starting point. More precisely, we study the contributions to the $\\Lambda$-hyperon optical potential due to the long-range two-pion exchange, with $\\Sigma$ and $\\Sigma^*$ baryons in the internal baryonic lines and considering Nh and $\\Delta$h excitations. We also consider the contribution to the spin-orbit potentials that comes out from these terms. Our results support a natural explanation of the smallness of the $\\Lambda$-nuclear spin-orbit interaction and shows the importance of the $\\Sigma^*$ and $\\Delta$ degrees of freedom for the hyperon-nucleus interactions.

  6. DEAP-3600 dark matter experiment

    CERN Document Server

    Fatemighomi, Nasim

    2016-01-01

    DEAP-3600 is a single phase liquid argon (LAr) dark matter experiment, located 2 km underground at SNOLAB, in Sudbury, Canada. The detector has 1 tonne fiducial mass of LAr. The target sensitivity to spin-independent scattering of 100 GeV weakly interacting massive particles (WIMPs) is 10$^{-46}$ cm$^{2}$. The DEAP-3600 background target is $<$ 0.6 background events in the WIMP region of interest in 3 tonne-years. The strategies to achieve this background include pulse shape discrimination to mitigate electron recoil and using ultra low radioactive materials for detector construction. Furthermore, to reduce neutron and alpha backgrounds, the DEAP-3600 acrylic vessel was sanded in situ to mitigate radon exposure of surfaces during construction and fabrication. The experiment is currently in the commissioning phase and will begin physics data taking later this year. This paper presents an overview of the experiment, its cross-section sensitivity to WIMPs and its current status.

  7. The Entire Virial Radius of the Fossil Cluster RXJ1159+5531: II. Dark Matter and Baryon Fraction

    CERN Document Server

    Buote, David A; Gastaldello, Fabio; Brighenti, Fabrizio

    2016-01-01

    In this second paper on the entire virial region of the relaxed fossil cluster RXJ1159+5531, we present a hydrostatic analysis of the hot intracluster medium (ICM). For a model consisting of ICM, stellar mass from the central galaxy (BCG), and an NFW dark matter (DM) halo, we obtain good descriptions of the projected radial profiles of ICM emissivity and temperature. The BCG stellar mass is clearly detected with M_star/L_K = 0.61 +/- 0.11 solar, consistent with stellar population synthesis models for a Milky-Way IMF. We obtain a halo concentration, c_200 =8.4 +/- 1.0, and virial mass, M_200 = 7.9 +/- 0.6 x 10^13 M_sun. For its mass, the inferred concentration is larger than most relaxed halos produced in cosmological simulations with Planck parameters, consistent with RXJ1159+5531 forming earlier than the general halo population. The baryon fraction at r_200, f_b,200 = 0.134 +/- 0.007, is slightly below the Planck value (0.155) for the universe. When we account for the stellar baryons associated with non-cent...

  8. The variation of rotation curve shapes as a signature of the effects of baryons on dark matter density profiles

    Science.gov (United States)

    Brook, Chris B.

    2015-12-01

    Rotation curves of galaxies show a wide range of shapes, which can be paramaterized as scatter in Vrot(1 kpc)/Vmax , i.e. the ratio of the rotation velocity measured at 1 kpc and the maximum measured rotation velocity. We examine whether the observed scatter can be accounted for by combining scatters in disc scalelengths, the concentration-halo mass relation, and the M⋆-Mhalo relation. We use these scatters to create model galaxy populations; when housed within dark matter haloes that have universal, Navarro, Frenk & White density profiles, the model does not match the lowest observed values of Vrot(1 kpc)/Vmax and has too little scatter in Vrot(1 kpc)/Vmax compared to observations. By contrast, a model using a mass-dependent dark matter profile, where the inner slope is determined by the ratio of M⋆/Mhalo, produces galaxies with low values of Vrot(1 kpc)/Vmax and a much larger scatter, both in agreement with observation. We conclude that the large observed scatter in Vrot(1 kpc)/Vmax favours density profiles that are significantly affected by baryonic processes. Alternative dark matter core formation models such as self-interacting dark matter may also account for the observed variation in rotation curve shapes, but these observations may provide important constraints in terms of core sizes, and whether they vary with halo mass and/or merger history.

  9. Future prospects of baryon istability search in p-decay and n n(bar) oscillation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ball, S.J.; Kamyshkov, Y.A. [ed.

    1996-11-01

    These proceedings contain thirty-one papers which review both the theoretical and the experimental status and near future of baryon instability research. Baryon instability is investigated from the vantage point of supersymmetric and unified theories. The interplay between baryogenesis and antimatter is examined. Double beta decay experiments are discussed. The huge Icarus experiment is described with its proton decay capabilities. Neutron-antineutron oscillations investigations are presented, especially efforts with ultra-cold neutrons. Individual papers are indexed separately on the Energy Data Base.

  10. Exploring high-density baryonic matter: Maximum freeze-out density

    Energy Technology Data Exchange (ETDEWEB)

    Randrup, Joergen [Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Cleymans, Jean [University of Cape Town, UCT-CERN Research Centre and Department of Physics, Rondebosch (South Africa)

    2016-08-15

    The hadronic freeze-out line is calculated in terms of the net baryon density and the energy density instead of the usual T and μ{sub B}. This analysis makes it apparent that the freeze-out density exhibits a maximum as the collision energy is varied. This maximum freeze-out density has μ{sub B} = 400 - 500 MeV, which is above the critical value, and it is reached for a fixed-target bombarding energy of 20-30 GeV/N well within the parameters of the proposed NICA collider facility. (orig.)

  11. Electrical conductivity of hadronic matter from different possible mesonic and baryonic thermal fluctuations

    CERN Document Server

    Ghosh, Sabyasachi

    2016-01-01

    Electromagnetic current-current correlators in pionic and nucleonic medium have been evaluated in the static limit to obtain electrical conductivities for pion and nucleon components respectively, where former decreases and latter one increases with the variation of temperature $T$ and baryon chemical potential $\\mu_N$. Therefore, total electrical conductivity of pion and nucleon system exhibits a valley structure in the $T$-$\\mu_N$ plane. To get non-divergent and finite values of correlators, finite thermal widths of medium constituents, pion and nucleon have been considered, where these thermal widths have been determined from the in-medium scattering probabilities of pion and nucleon with other mesonic and baryonic resonances, based on effective hadronic model. At $\\mu_N=0$, the results of present work are more or less agrees with the results of earlier works and its finite $\\mu_N$ extension show a decreasing nature of electrical conductivity for hadronic medium during spanning from freeze out line to quar...

  12. Charmed baryons from LHCb

    CERN Document Server

    Ogilvy, Stephen

    2015-01-01

    The vast amount of $c\\overline{c}$ production that can be recorded by the LHCb detector makes it an ideal environment to study the hadronic production of charmed baryons, along with the properties of their decays. We briefly describe the LHCb experiment and the triggering mechanisms it uses for recording charm production. Previous charmed baryon results from LHCb are detailed, with a description of the future plans for the charmed baryon programme.

  13. Molecular dynamics simulation for the baryon-quark phase transition at finite baryon density

    Energy Technology Data Exchange (ETDEWEB)

    Akimura, Y. [Saitama University, Department of physics, Sakura-Ku, Saitama City (Japan); Japan Atomic Energy Research Institute, Advanced Science Research Center, Tokai (Japan); Maruyama, T.; Chiba, S. [Japan Atomic Energy Research Institute, Advanced Science Research Center, Tokai (Japan); Yoshinaga, N. [Saitama University, Department of physics, Sakura-Ku, Saitama City (Japan)

    2005-09-01

    We study the baryon-quark phase transition in the molecular dynamics (MD) of the quark degrees of freedom at finite baryon density. The baryon state at low baryon density, and the deconfined quark state at high baryon density are reproduced. We investigate the equations of state of matters with different u-d-s compositions. It is found that the baryon-quark transition is sensitive to the quark width. (orig.)

  14. Charmed baryons at LHCb

    CERN Document Server

    Naik, Paras

    2016-01-01

    The LHCb detector is an excellent instrument for studying the production and decay of charmed baryons in $pp$ collisions, due to efficient triggering mechanisms that capture the copious production of $c\\overline{c}$ at the Large Hadron Collider. The LHCb experiment and its charmed baryon results from LHCb are detailed, with a description of our future plans.

  15. Cuspy No More: How Outflows Affect the Central Dark Matter and Baryon Distribution in Lambda CDM Galaxies

    CERN Document Server

    Governato, F; Pontzen, A; Christensen, C; Oh, S H; Brooks, A M; Quinn, T; Shen, S; Wadsley, J

    2012-01-01

    We examine the evolution of the inner dark matter (DM) and baryonic density profile of a new sample of simulated field galaxies using fully cosmological, Lambda CDM, high resolution SPH + N-Body simulations. These simulations include explicit H2 and metal cooling, star formation (SF) and supernovae (SNe) driven gas outflows. Starting at high redshift, rapid, repeated gas outflows following bursty SF transfer energy to the DM component and significantly flatten the originally `cuspy' central DM mass profile of galaxies with present day stellar masses in the 10^4.5 -- 10^9.8 Msolar range. At z=0, the central slope of the DM density profile of our galaxies (measured between 0.3 and 0.7 kpc from their centre) is well fitted by rhoDM propto r^alpha with alpha \\simeq -0.5 + 0.35 log_10(Mstar/10^8Msolar) where Mstar is the stellar mass of the galaxy and 4 < log_10 Mstar < 9.4. These values imply DM profiles flatter than those obtained in DM--only simulations and in close agreement with those inferred in galaxi...

  16. Searching for Cooling Signatures in Strong Lensing Galaxy Clusters: Evidence Against Baryons Shaping the Matter Distribution in Cluster Cores

    CERN Document Server

    Blanchard, Peter K; McDonald, Michael; Dahle, Hakon; Gladders, Michael D; Sharon, Keren; Mushotzky, Richard

    2013-01-01

    The process by which the mass density profile of certain galaxy clusters becomes centrally concentrated enough to produce high strong lensing (SL) cross-sections is not well understood. It has been suggested that the baryonic condensation of the intra-cluster medium (ICM) due to cooling may drag dark matter to the cores and thus steepen the profile. In this work, we search for evidence of ongoing ICM cooling in the first large, well-defined sample of strong lensing selected galaxy clusters in the range 0.1 0.2 and shows no statistically significant deviation from the total cluster population. Specific star formation rates, as traced by the strength of the 4000 angstrom break, D_4000, are also consistent with the general cluster population. Finally, we use optical imaging of the SL clusters to measure the angular separation, R_arc, between the arc and the center of mass of each lensing cluster in our sample and test for evidence of changing [OII] emission and D_4000 as a function of R_arc, a proxy observable ...

  17. The Impact of Baryonic Physics on the Structure of Dark Matter Halos: the View from the FIRE Cosmological Simulations

    Science.gov (United States)

    Keung Chan, Tsang; Keres, Dusan; Oñorbe, Jose; Hopkins, Philip F.; Muratov, Alexander; Faucher-Giguere, Claude-Andre; Quataert, Eliot

    2016-06-01

    We study the distribution of cold dark matter (CDM) in cosmological simulations from the FIRE (Feedback In Realistic Environments) project, which incorporates explicit stellar feedback in the multi-phase ISM, with energetics from stellar population models. We find that stellar feedback, without ``fine-tuned'' parameters, greatly alleviates small-scale problems in CDM. Feedback causes bursts of star formation and outflows, altering the DM distribution. As a result, the inner slope of the DM halo profile (α) shows a strong mass dependence: profiles are shallow at Mh ˜ 1010-1011 M⊙ and steepen at higher/lower masses. The resulting core sizes and slopes are consistent with observations. Because the star formation efficiency, Ms/Mh is strongly halo mass dependent, a rapid change in α occurs around Mh ˜1010M⊙, (Ms˜106-107M⊙) as sufficient feedback energy becomes available to perturb the DM. Large cores are not established during the period of rapid growth of halos because of ongoing DM mass accumulation. Instead, cores require several bursts of star formation after the rapid buildup has completed. Stellar feedback dramatically reduces circular velocities in the inner kpc of massive dwarfs; this could be sufficient to explain the ``Too Big To Fail'' problem without invoking non-standard DM. Finally, feedback and baryonic contraction in Milky Way-mass halos produce DM profiles slightly shallower than the Navarro-Frenk-White profile, consistent with the normalization of the observed Tully-Fisher relation.

  18. How Density Environment Changes the Influence of the Dark Matter-Baryon Streaming Velocity on the Cosmological Structure Formation

    CERN Document Server

    Ahn, Kyungjin

    2016-01-01

    We study the dynamical effect of relative velocities between dark matter and baryonic fluids, which remained supersonic after the epoch of recombination. The impact of this supersonic motion on the formation of cosmological structures was first formulated by Tseliakhovich & Hirata (2010), in terms of the linear theory of small-scale fluctuations coupled to large-scale, relative velocities in mean-density regions. In their formalism, they limited the large-scale density environment to be those of the global mean density. We improve on their formulation by allowing variation in the density environment as well as the relative velocities. This leads to a new type of coupling between large-scale and small-scale modes. We find that the small-scale fluctuation grows in a biased way: faster in the overdense environment and slower in the underdense environment. We also find that the net effect on the global power spectrum of the density fluctuation is to boost its overall amplitude from the prediction by Tseliakho...

  19. The clustering of baryonic matter. II: halo model and hydrodynamic simulations

    CERN Document Server

    Fedeli, C; Velliscig, M; Van Daalen, M; Schaye, J; Hoekstra, H

    2014-01-01

    We recently developed a generalization of the halo model in order to describe the spatial clustering properties of each mass component in the Universe, including hot gas and stars. In this work we discuss the complementarity of the model with respect to a set of cosmological simulations including hydrodynamics of different kinds. We find that the mass fractions and density profiles measured in the simulations do not always succeed in reproducing the simulated matter power spectra, the reason being that the latter encode information from a much larger range in masses than that accessible to individually resolved structures. In other words, this halo model allows one to extract information on the growth of structures from the spatial clustering of matter, that is complementary with the information coming from the study of individual objects. We also find a number of directions for improvement of the present implementation of the model, depending on the specific application one has in mind. The most relevant one...

  20. How baryonic feedback processes can affect dark matter halos: a stochastic model

    Science.gov (United States)

    Freundlich, J.; El-Zant, A.; Combes, F.

    2016-12-01

    Feedback processes from stars and active galactic nuclei result in gas density fluctuations which can contribute to `heating' dark matter haloes, decrease their density at the center and hence form more realistic `cores' than the steep `cusps' predicted by cold dark matter (CDM) simulations. We present a theoretical model deriving this effect from first principles: stochastic density variations in the gas distribution perturb the gravitational potential and hence affect the halo particles. We analytically derive the velocity dispersion imparted to the CDM particles and the corresponding relaxation time, and further perform numerical simulations to show that the assumed process can indeed lead to the formation of a core in an initially cuspy halo within a timescale comparable to the derived relaxation time. This suggests that feedback-induced cusp-core transformations observed in hydrodynamic simulations of galaxy formation may be understood and parametrized in relatively simple terms.

  1. Spinodal instabilities of baryon-rich quark matter in heavy ion collisions

    CERN Document Server

    Li, Feng

    2016-01-01

    Using the test-particle method to solve the transport equation derived from the Nambu-Jona-Lasino (NJL) model, we study how phase separation occurs in an expanding quark matter like that in a heavy ion collision. To test our method, we first investigate the growth rates of unstable modes of quark matter in a static cubic box and find them to agree with the analytical results that were previously obtained using the linear response theory. In this case, we also find the higher-order scaled density moments to increase with time and saturate at values significantly larger than one, which corresponds to a uniform density distribution, after the phase separation. The skewness of the quark number event-by-event distribution in a small sub-volume of the system is also found to increase, but this feature disappears if the sub-volume is large. For the expanding quark matter, two cases are considered with one using a blast-wave model for the initial conditions and the other using initial conditions from a mulple-phase t...

  2. DAMIC: a novel dark matter experiment

    CERN Document Server

    Aguilar-Arevalo, Alexis A; Butner, Melissa J; Cancelo, Gustavo; Chavarria, Alvaro; D'Olivo, Juan Carlos; Vigil, Juan Cruz Estrada; Moroni, Guillermo Fernandez; Izraelevitch, Federico; Kilminster, Ben; Lawson, Ian T; Marsal, Fernando; Molina, Jorge; Privitera, Paolo; Schwarz, Tom; Haro, Miguel Sofo; Tiffenberg, Javier; Trillaud, Frederic; Zhou, Jing

    2013-01-01

    DAMIC (Dark Matter in CCDs) is a novel dark matter experiment that has unique sensitivity to dark matter particles with masses below 10 GeV. Due to its low electronic readout noise (R.M.S. ~3 e-) this instrument is able to reach a detection threshold below 0.5 keV nuclear recoil energy, making the search for dark matter particles with low masses possible. We report on early results and experience gained from a detector that has been running at SNOLAB from Dec 2012. We also discuss the measured and expected backgrounds and present the plan for future detectors to be installed in 2014.

  3. DAMIC: a novel dark matter experiment

    Energy Technology Data Exchange (ETDEWEB)

    Tiffenberg, Javier; Bertou, Xavier [Centro Atomico Bariloche; Butner, Melissa J. [Fermilab; Cancelo, Gustavo [Fermilab; Chavarria, Alvaro [Chicago U., KICP; D' Olivo, Juan Carlos [Mexico U., ICN; Estrada Vigil, Juan Cruz [Fermilab; Moroni, Guillermo Fernandez [Bahia Blanca, U. Natl. Del Sur; Izraelevitch, Federico [Fermilab; Kilminster, Ben [Zurich U.; Lawson, Ian T. [SNOLAB, Lively; Marsal, Fernando [Asuncion Natl. U.; Molina, Jorge [Asuncion Natl. U.; Privitera, Paolo [Chicago U., KICP; Schwarz, Tom [Michigan U.; Sofo haro, Miguel [Centro Atomico Bariloche; Tiffenberg, Javier [Fermilab; Trillaud, Frederic [Mexico U.; Zhou, Jing [Chicago U., KICP

    2013-10-24

    DAMIC (Dark Matter in CCDs) is a novel dark matter experiment that has unique sensitivity to dark matter particles with masses below 10 GeV. Due to its low electronic readout noise (R.M.S. ~3 e-) this instrument is able to reach a detection threshold below 0.5 keV nuclear recoil energy, making the search for dark matter particles with low masses possible. We report on early results and experience gained from a detector that has been running at SNOLAB from Dec 2012. We also discuss the measured and expected backgrounds and present the plan for future detectors to be installed in 2014.

  4. First results from the H sub 0 di-baryon search and hyperon production measurements by the AGS Experiment 896.

    CERN Document Server

    Caines, H; Bellwied, R; Bennett, M; Boemi, D; Bonner, B; Caccia, Z; Christie, W; Cina, G; Costa, S; Crawford, H; Cronqvist, M; Debbe, R; Engelage, J; Flores, I; Greiner, L; Hallman, T; Hoffman, G; Huang, H; Humanic, T J; Igo, G; Insolia, A; Jensen, P; Judd, E; Kainz, K; Kaplan, M; Kelly, S; Kotov, I; Kunde, G; Lindstrom, P; Ljubicic, T; Llope, W J; Lo Curto, G; Longacre, R; Lynn, D; Madansky, L; Mahzeh, N; Milosevich, Z; Mitchell, J T; Mitchell, J; Nehmeh, S; Nociforo, C; Paganis, S; Pandey, S U; Potenza, R; Platner, E; Riley, P; Russ, D; Saulys, A; Schambach, J; Sheen, J; Stokley, C; Sugarbaker, E R; Takahashi, J; Tang, J; Trentalange, S; Tricomi, A; Tull, C; Tuvé, C; Whitfield, J; Wilson, K

    1999-01-01

    The AGS Experiment 896 was designed to study strangeness production in Au--Au collisions at 11.6A GeV/c, in particular the formation of a six-quark di-baryon the H sub 0. Heavy ion collisions provide favorable conditions for the H sub 0 formation either via coalescence of two LAMBDA particles (owing to the large LAMBDA production cross section) or direct production from the possible formation of a quark-gluon plasma. E896 also measured strange meson and baryon distributions from mid-rapidity. Preliminary results from this experiment are presented as well as details of the expected sensitivity for the H sub 0 search.

  5. A Testable Conspiracy: Simulating Baryonic Effects on Self-Interacting Dark Matter Halos

    CERN Document Server

    Elbert, Oliver D; Kaplinghat, Manoj; Garrison-Kimmel, Shea; Graus, Andrew S; Rocha, Miguel

    2016-01-01

    We investigate the response of self-interacting dark matter (SIDM) halos to the growth of galaxy potentials using idealized simulations, each run in tandem with standard collisionless Cold Dark Matter (CDM). We find a greater diversity in the SIDM halo profiles compared to the CDM halo profiles. If the stellar gravitational potential strongly dominates in the central parts of a galaxy, then SIDM halos can be as dense as CDM halos on observable scales. For extreme cases with highly compact disks core collapse can occur, leading to SIDM halos that are denser and cuspier than their CDM counterparts. If the stellar potential is not dominant, then SIDM halos retain constant density cores with densities far below CDM predictions. When a disk potential is present, the inner SIDM halo becomes \\em{more flattened} in the disk plane than the CDM halo. These results are in excellent quantitative agreement with the predictions of Kaplinghat et al. (2014). We also simulated a galaxy cluster halo with a central stellar dist...

  6. The clustering of baryonic matter. II: halo model and hydrodynamic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Fedeli, C. [INAF - Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna (Italy); Semboloni, E.; Velliscig, M.; Daalen, M. Van; Schaye, J.; Hoekstra, H., E-mail: cosimo.fedeli@oabo.inaf.it, E-mail: sembolon@strw.leidenuniv.nl, E-mail: velliscig@strw.leidenuniv.nl, E-mail: daalen@strw.leidenuniv.nl, E-mail: schaye@strw.leidenuniv.nl, E-mail: hoekstra@strw.leidenuniv.nl [Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden (Netherlands)

    2014-08-01

    We recently developed a generalization of the halo model in order to describe the spatial clustering properties of each mass component in the Universe, including hot gas and stars. In this work we discuss the complementarity of the model with respect to a set of cosmological simulations including hydrodynamics of different kinds. We find that the mass fractions and density profiles measured in the simulations do not always succeed in reproducing the simulated matter power spectra, the reason being that the latter encode information from a much larger range in masses than that accessible to individually resolved structures. In other words, this halo model allows one to extract information on the growth of structures from the spatial clustering of matter, that is complementary with the information coming from the study of individual objects. We also find a number of directions for improvement of the present implementation of the model, depending on the specific application one has in mind. The most relevant one is the necessity for a scale dependence of the bias of the diffuse gas component, which will be interesting to test with future detections of the Warm-Hot Intergalactic Medium. This investigation confirms the possibility to gain information on the physics of galaxy and cluster formation by studying the clustering of mass, and our next work will consist of applying the halo model to use future high-precision cosmic shear surveys to this end.

  7. Analytic model for the matter power spectrum, its covariance matrix, and baryonic effects

    CERN Document Server

    Mohammed, Irshad

    2014-01-01

    We develop a model for the matter power spectrum as the sum of quasi-linear Zeldovich approximation and even powers of $k$, i.e., $A_0 - A_2k^2 + A_4k^4 - ...$, compensated at low $k$. The model can predict the true power spectrum to a few percent accuracy up to $k \\sim 0.7\\ h \\rm{Mpc}^{-1}$, over a wide range of redshifts and models, including massive neutrino models. We write a simple form of the covariance matrix as a sum of Gaussian part and $A_0$ variance and we find that it reproduces well the simulations. We investigate the super-sample variance effect and show it induces a relation between the Zeldovich term and $A_0$ that differs from the amplitude change, allowing it to be modeled as an additional parameter that can be determined from the data. The $A_n$ coefficients contain information about cosmology, in particular the amplitude of fluctuations $\\sigma_8$. We explore their information content, showing that $A_0$ contains the bulk of amplitude information, scaling as $\\sigma_8^{3.9}$, which allows ...

  8. Constraining the Baryon-Dark Matter Relative Velocity with the Large-Scale 3-Point Correlation Function of the SDSS BOSS DR12 CMASS Galaxies

    CERN Document Server

    Slepian, Zachary; Blazek, Jonathan A; Brownstein, Joel R; Chuang, Chia-Hsun; Gil-Marín, Héctor; Ho, Shirley; Kitaura, Francisco-Shu; McEwen, Joseph E; Percival, Will J; Ross, Ashley J; Rossi, Graziano; Seo, Hee-Jong; Slosar, Anže; Vargas-Magaña, Mariana

    2016-01-01

    We search for a galaxy clustering bias due to a modulation of galaxy number with the baryon-dark matter relative velocity resulting from recombination-era physics. We find no detected signal and place the constraint $b_v < 0.01$ on the relative velocity bias for the CMASS galaxies. This bias is an important potential systematic of Baryon Acoustic Oscillation (BAO) method measurements of the cosmic distance scale using the 2-point clustering. Our limit on the relative velocity bias indicates a systematic shift of no more than $0.3\\%$ rms in the distance scale inferred from the BAO feature in the BOSS 2-point clustering, well below the $1\\%$ statistical error of this measurement. This constraint is the most stringent currently available and has important implications for the ability of upcoming large-scale structure surveys such as DESI to self-protect against the relative velocity as a possible systematic.

  9. Hybrid Baryons

    CERN Document Server

    Page, P R

    2003-01-01

    We review the status of hybrid baryons. The only known way to study hybrids rigorously is via excited adiabatic potentials. Hybrids can be modelled by both the bag and flux-tube models. The low-lying hybrid baryon is N 1/2^+ with a mass of 1.5-1.8 GeV. Hybrid baryons can be produced in the glue-rich processes of diffractive gamma N and pi N production, Psi decays and p pbar annihilation.

  10. Dark matter direct-detection experiments

    CERN Document Server

    Undagoitia, Teresa Marrodan

    2015-01-01

    In the past decades, several detector technologies have been developed with the quest to directly detect dark matter interactions and to test one of the most important unsolved questions in modern physics. The sensitivity of these experiments has improved with a tremendous speed due to a constant development of the detectors and analysis methods, proving uniquely suited devices to solve the dark matter puzzle, as all other discovery strategies can only indirectly infer its existence. Despite the overwhelming evidence for dark matter from cosmological indications at small and large scales, a clear evidence for a particle explaining these observations remains absent. This review summarises the status of direct dark matter searches, focussing on the detector technologies used to directly detect a dark matter particle producing recoil energies in the keV energy scale. The phenomenological signal expectations, main background sources, statistical treatment of data and calibration strategies are discussed.

  11. Dark Matter and Experiments for its Identification

    Directory of Open Access Journals (Sweden)

    V. Singh

    2015-08-01

    Full Text Available After Fritz Zwicky, through various theoretical models, several dark matter events have been proposed. But none of them is yet discovered. Recent experiment shows that only around 5% of the total matters present in the whole universe are visual. Rest matter is still unknown to us by any present experimental tools. This leads that detection of dark matter is one of the very challenging & curios goal for experimental physicists. For the search of suitable dark matter candidates and for rear physics events, High Purity Germanium detectors, Spherical gaseous chamber detector and few more hybrid-detectors are suitable for these purposes. We proposed that any suitable detector hosted under deep sea water will be more effective than the under ground or mountain caverns.

  12. Dark matter direct-detection experiments

    Science.gov (United States)

    Marrodán Undagoitia, Teresa; Rauch, Ludwig

    2016-01-01

    In recent decades, several detector technologies have been developed with the quest to directly detect dark matter interactions and to test one of the most important unsolved questions in modern physics. The sensitivity of these experiments has improved with a tremendous speed due to a constant development of the detectors and analysis methods, proving uniquely suited devices to solve the dark matter puzzle, as all other discovery strategies can only indirectly infer its existence. Despite the overwhelming evidence for dark matter from cosmological indications at small and large scales, clear evidence for a particle explaining these observations remains absent. This review summarises the status of direct dark matter searches, focusing on the detector technologies used to directly detect a dark matter particle producing recoil energies in the keV energy scale. The phenomenological signal expectations, main background sources, statistical treatment of data and calibration strategies are discussed.

  13. Dynamical response of dark matter to galaxy evolution affects direct-detection experiments

    Science.gov (United States)

    Petersen, Michael S.; Katz, Neal; Weinberg, Martin D.

    2016-12-01

    Over a handful of rotation periods, dynamical processes in barred galaxies induce nonaxisymmetric structure in dark matter halos. Using n -body simulations of a Milky Way-like barred galaxy, we identify both a trapped dark matter component, a shadow bar, and a strong response wake in the dark matter distribution that affects the predicted dark matter detection rates for current experiments. The presence of a baryonic disk, together with well-known dynamical processes (e.g. spiral structure and bar instabilities), increases the dark matter density in the disk plane. We find that the magnitude of the combined stellar and shadow bar evolution, when isolated from the effect of the axisymmetric gravitational potential of the disk, accounts for >30 % of this overall increase in disk-plane density. This is significantly larger than that of previously claimed deviations from the standard halo model. The dark matter density and kinematic wakes driven by the Milky Way bar increase the detectability of dark matter overall, especially for the experiments with higher vmin . These astrophysical features increase the detection rate by more than a factor of 2 when compared to the standard halo model and by a factor of 10 for experiments with high minimum recoil energy thresholds. These same features increase (decrease) the annual modulation for low (high) minimum recoil energy experiments. We present physical arguments for why these dynamics are generic for barred galaxies such as the Milky Way rather than contingent on a specific galaxy model.

  14. Search for non-baryonic dark matter with cryogenic detectors based on ionisation and heat detection. Analysis of experimental data from the Edelweiss-I experiment; Recherche de la matiere noire non-baryonique a l'aide de detecteurs cryogeniques a double composante ionisation et chaleur: Analyse et Interpretation des donnees de l'experience EDELWEISS-I

    Energy Technology Data Exchange (ETDEWEB)

    Sanglard, V

    2005-11-15

    The method of direct detection of WIMPs (weakly interactive massive particles) that are present in the halo of our galaxy rests on the detection of their interaction with a target nucleus. The Edelweiss experiment uses this technique with 3 cryogenic detectors operating on 2 modes ionization and heat. Each detector is made of a 320 g germanium crystal with 2 faces equipped with electrodes. In order to improve the collection of charges, an amorphous layer of Ge or Si is laid between the crystal surface and the electrodes. The validation of the detector system has been made with Co{sup 57} and Cs{sup 137} gamma sources and a Cf{sup 252} neutron source. We present a comparison with simulation results and experimental data for the validation of the response to nuclear recoils. The whole experimental data collected by Edelweiss-I from 2000 till 2003 has been analysed. 40 events have been selected, 6 among them with an energy over 30 keV. Limits for the interaction cross-section between a WIMP and a nucleon have been deduced from the experimental data. The Yellin method has enabled us to determine a limit without knowing the background noise. The best sensitivity appears to be 1.5*10{sup -6} pb for a WIMP's mass of 80 GeV/c{sup 2} and a confidence level of 90 per cent. In terms of events, the limit for an energy range of 30 - 100 keV is 0.12 events per kg and per day. (A.C.)

  15. Boosted Dark Matter at Neutrino Experiments

    CERN Document Server

    Necib, Lina; Wongjirad, Taritree; Conrad, Janet M

    2016-01-01

    Current and future neutrino experiments can be used to discover dark matter, not only in searches for dark matter annihilating to neutrinos, but also in scenarios where dark matter itself scatters off Standard Model particles in the detector. In this work, we study the sensitivity of different neutrino detectors to a class of models called boosted dark matter, in which a subdominant component of a dark sector acquires a large Lorentz boost today through annihilation of a dominant component in a dark matter-dense region, such as the galactic center or dwarf spheroidal galaxies. This analysis focuses on the sensitivity of different neutrino detectors, specifically the Cherenkov-based Super-K and the future argon-based DUNE to boosted dark matter that scatters off electrons. We study the dependence of the expected limits on the experimental features, such as energy threshold, volume and exposure in the limit of constant scattering amplitude. We highlight experiment-specific features that enable current and futur...

  16. Measurements of A0 and A0B Baryon Properties in the Atlas Experiment

    CERN Document Server

    Scheirich, daniel

    To study the bound system of 3 valence quarks, Lambda and Lambda_b baryons represent ideal particles, since they are produced in relatively high quantities at the Large Hadron Collider (LHC) and decay into fully reconstructible final states. This thesis summarizes results of two important measurements with Lambda and Lambda_b baryons: a measurement of the Lambda_b lifetime and mass, and a measurement of the Lambda polarization in minimum bias and di-jet events. The Lambda_b lifetime is predictable within a framework of the heavy quark expansion (HQE) calculations, which is widely and successfully used in b-physics. In past decade, the Lambda_b lifetime has received some special attention due to a discrepancy between the theoretical prediction and experimental results. The measurement presented here improves on the precision of the previous measurements and helps resolving this discrepancy. The Lambda_b lifetime and mass are measured to be tau(Lambda_b) = 1.449 +- 0.036 +- 0.017 ps and m(Lambda_b) = 5619.7 +- ...

  17. Impact of finite density on spectroscopic parameters of decuplet baryons

    CERN Document Server

    Azizi, K; Sundu, H

    2016-01-01

    The decuplet baryons, $\\Delta$, $\\Sigma^{*}$, $\\Xi^{*}$ and $\\Omega^{-}$, are studied in nuclear matter by using the in-medium QCD sum rules. By fixing the three momentum of the particles under consideration at the rest frame of the medium, the negative energy contributions are removed. It is obtained that the parameters of the $\\Delta$ baryon are more affected by the medium against the $\\Omega^{-}$ state, containing three strange quarks, whose mass and residue do not affected by the medium, considerably. We also find the vector and scalar self energies of these baryons in nuclear matter. By the recent progresses at $\\bar{P}$ANDA experiment at FAIR it may be possible to study the in-medium properties of such states even the multi-strange $\\Xi^{*}$ and $\\Omega^{-}$ systems in near future.

  18. The Light Dark Matter eXperiment

    Science.gov (United States)

    Colegrove, Owen; LDMX Collaboration

    2017-01-01

    The Light Dark Matter eXperiment (LDMX) proposes a high-statistics search for low-mass dark matter at a new experimental facility, Dark Sector Experiments at LCLS-II (DASEL), at SLAC. LDMX employs the missing momentum technique, where electrons scattering in a thin target can produce dark matter via ``dark bremsstrahlung'' that are not observed in the detector. To identify these rare signal events, LDMX individually tags incoming beam-energy electrons, unambiguously associates them with low energy, moderate transverse-momentum recoils of the incoming electron, and establishes the absence of any additional forward-recoiling charged particles or neutral hadrons. LDMX will employ low mass tracking to tag incoming beam-energy electrons with high purity and cleanly reconstruct recoils. A high-speed, granular calorimeter with MIP sensitivity is used to reject the high rate of bremsstrahlung background at trigger level while working in tandem with a hadronic calorimeter to veto rare photo nuclear reactions. Ultimately, LDMX aims to probe thermal dark matter over most of the viable sub-GeV mass range to a decisive level of sensitivity. This talk will summarize the current status of the LDMX design and performance studies and progress in developing the DASEL beamline.

  19. Baryon Number Violation

    CERN Document Server

    Babu, K S; Al-Binni, U; Banerjee, S; Baxter, D V; Berezhiani, Z; Bergevin, M; Bhattacharya, S; Brice, S; Brock, R; Burgess, T W; Castellanos, L; Chattopadhyay, S; Chen, M-C; Church, E; Coppola, C E; Cowen, D F; Cowsik, R; Crabtree, J A; Davoudiasl, H; Dermisek, R; Dolgov, A; Dutta, B; Dvali, G; Ferguson, P; Perez, P Fileviez; Gabriel, T; Gal, A; Gallmeier, F; Ganezer, K S; Gogoladze, I; Golubeva, E S; Graves, V B; Greene, G; Handler, T; Hartfiel, B; Hawari, A; Heilbronn, L; Hill, J; Jaffe, D; Johnson, C; Jung, C K; Kamyshkov, Y; Kerbikov, B; Kopeliovich, B Z; Kopeliovich, V B; Korsch, W; Lachenmaier, T; Langacker, P; Liu, C-Y; Marciano, W J; Mocko, M; Mohapatra, R N; Mokhov, N; Muhrer, G; Mumm, P; Nath, P; Obayashi, Y; Okun, L; Pati, J C; Pattie, R W; Phillips, D G; Quigg, C; Raaf, J L; Raby, S; Ramberg, E; Ray, A; Roy, A; Ruggles, A; Sarkar, U; Saunders, A; Serebrov, A; Shafi, Q; Shimizu, H; Shiozawa, M; Shrock, R; Sikdar, A K; Snow, W M; Soha, A; Spanier, S; Stavenga, G C; Striganov, S; Svoboda, R; Tang, Z; Tavartkiladze, Z; Townsend, L; Tulin, S; Vainshtein, A; Van Kooten, R; Wagner, C E M; Wang, Z; Wehring, B; Wilson, R J; Wise, M; Yokoyama, M; Young, A R

    2013-01-01

    This report, prepared for the Community Planning Study - Snowmass 2013 - summarizes the theoretical motivations and the experimental efforts to search for baryon number violation, focussing on nucleon decay and neutron-antineutron oscillations. Present and future nucleon decay search experiments using large underground detectors, as well as planned neutron-antineutron oscillation search experiments with free neutron beams are highlighted.

  20. The Dynamical Response of Dark Matter to Galaxy Evolution Affects Direct-Detection Experiments

    CERN Document Server

    Petersen, Michael S; Weinberg, Martin D

    2016-01-01

    Over a handful of rotation periods, dynamical processes in barred galaxies induce non-axisymmetric structure in dark matter halos. Using n-body simulations of a Milky Way-like barred galaxy, we identify both a trapped dark-matter component, a shadow bar, and a strong response wake in the dark-matter distribution that affects the predicted dark-matter detection rates for current experiments. The presence of a baryonic disk together with well-known dynamical processes (e.g. spiral structure and bar instabilities) increase the dark matter density in the disk plane. We find that the magnitude of the combined stellar and shadow bar evolution, when isolated from the effect of the axisymmetric gravitational potential of the disk, accounts for >30% of this overall increase in disk-plane density. This is significantly larger that of previously claimed deviations from the standard halo model. The dark-matter density and kinematic wakes driven by the Milky Way bar increase the detectability of dark matter overall, espec...

  1. The XENONnT Dark Matter Experiment

    Science.gov (United States)

    Aprile, Elena; Xenon Collaboration

    2017-01-01

    With XENON1T ready to search for dark matter with the highest sensivity of any experiment to-date the XENON collaboration started to secure funding and resources to upgrade the detector by the end of 2018- phase which we refer to as XENONnT. The XENONnT experiment will utilize the already-built-and-tested XENON1T infrastructures, such as the cryogenic system, Kr distillation system and Xe storage and recovery system, with the main upgrade of the time projection chamber (TPC). The upgraded XENONnT detector will be filled with 7.5-ton ultra-pure liquid xenon, tripling the active liquid xenon target mass of XENON1T. About 500 low-radioactive three-inch R11410 PMTs will be used. Background from internal sources such as radon will be reduced. It will enable another order of magnitude improvement in dark matter search sensitivity compared to that of XENON1T, or accumulate statistics if a positive dark matter signal is observed by XENON1T. The detailed TPC upgrade plan, the background control and reduction techniques, the predicted sensitivity reach will be presented.

  2. Dark Matter search with the AMS-02 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Cardano, Francesco Maria [University of Perugia, Via Pascoli n. 1, Perugia (Italy)], E-mail: cardano@fisica.unipg.it

    2008-04-01

    Late astrophysical and cosmological measurements have shown how {approx}83% of matter of the Universe is dark and non-baryonic. Supersymmetric extensions of the Standard Model can provide a good candidate as main component of Dark Matter in the neutralino {chi}. In this framework, the magnetic spectrometer AMS-02 has been conceived for the precision measurement on board of the ISS of composition and energy spectrum of cosmic rays over a wide energy range, providing the potential to detect contribution to charged particle fluxes from neutralino annihilation. Due to the general faintness of expected Dark Matter contributions to cosmic ray spectra, interesting research channels are those for which the standard astrophysical background is expected to be low, like antimatter ones. Results of various MC analysis of AMS potential in the measurement of positron, antiproton and antideuteron fluxes are presented.

  3. Chemical and dynamics properties of heavy ion collisions at RHIC energies by the measurement of the production of the doubly strange baryons in the STAR experiment; Proprietes chimiques et dynamiques des collisions d'ions lourds aux energies du RHIC par la mesure de la production des baryons doublement etranges dans l'experience STAR

    Energy Technology Data Exchange (ETDEWEB)

    Estienne, M

    2005-04-15

    Lattice QCD calculations predict, at {mu}{sub B} {approx} 0, a crossover from ordinary hadronic matter to a Quark Gluon Plasma. Heavy ion collisions have been proposed to recreate it in the laboratory and to study its properties. The Au+Au, d+Au collisions at {radical}(S{sub NN}) = 200 GeV and the Au+Au ones at 62.4 GeV delivered at RHIC have been probed by the measurement of the {xi} particles in the STAR experiment. Their yield evolution with collision energy and system size gives size to the chemical properties of the reaction in the framework of hadronic and statistical models. The {xi} R{sub CP} shows: (1) a meson/baryon dependence for 2 < {sub pT} < 5 GeV/c well reproduced by quark coalescence and recombination models, (2) the formation of a dense matter signed by a R{sub CP} suppression at {sub pT} > 3 GeV/c, (3) strong interactions between constituents suggesting the existence of strong collectivity in the medium. The {xi} transverse flow seems to be interesting to probe the early stage the collision with presumably partonic degrees of freedom. (author)

  4. The MiniCLEAN Dark Matter Experiment

    CERN Document Server

    Hime, Andrew

    2011-01-01

    The MiniCLEAN dark matter experiment will exploit a single-phase liquid-argon detector instrumented with photomultiplier tubes submerged in the cryogen with nearly 4pi coverage of a 500 kg (150 kg) target (fiducial) mass. The high light yield and unique properties of the scintillation time-profile provide effective defense against radioactive background through pulse-shape discrimination and event-position reconstruction. The detector is designed also for a liquid-neon target that allows for an independent verification of signal and background and a test of the expected dependence of the WIMP-nucleus interaction rate.

  5. The DEAP-3600 Dark Matter Experiment

    CERN Document Server

    ,

    2015-01-01

    The DEAP-3600 experiment uses 3.6 tons of liquid argon for a sensitive dark matter search, with a sensitivity to the spin-independent WIMP-nucleon cross-section of $10^{-46}$ cm$^2$ at 100 GeV WIMP mass. This high sensitivity is achievable due to the large target mass and the very low backgrounds in the spherical acrylic detector design as well as at the unique SNOLAB facility in Sudbury, Canada. Pulse shape discrimination is used to reject electromagnetic backgrounds from the WIMP induced nuclear recoil signal. We started taking commissioning data in early 2015 with vacuum and later gas inside the detector. Argon fill is expected in winter 2015. An overview and status of the DEAP-3600 experiment are presented in this paper, with an emphasis on control and mitigation of detector backgrounds.

  6. Density-dependent effective baryon-baryon interaction from chiral three-baryon forces

    Science.gov (United States)

    Petschauer, Stefan; Haidenbauer, Johann; Kaiser, Norbert; Meißner, Ulf-G.; Weise, Wolfram

    2017-01-01

    A density-dependent effective potential for the baryon-baryon interaction in the presence of the (hyper)nuclear medium is constructed, based on the leading (irreducible) three-baryon forces derived within SU(3) chiral effective field theory. We evaluate the contributions from three classes: contact terms, one-pion exchange and two-pion exchange. In the strangeness-zero sector we recover the known result for the in-medium nucleon-nucleon interaction. Explicit expressions for the ΛN in-medium potential in (asymmetric) nuclear matter are presented. Our results are suitable for implementation into calculations of (hyper)nuclear matter. In order to estimate the low-energy constants of the leading three-baryon forces we introduce the decuplet baryons as explicit degrees of freedom and construct the relevant terms in the minimal non-relativistic Lagrangian. With these, the constants are estimated through decuplet saturation. Utilizing this approximation we provide numerical results for the effect of the three-body force in symmetric nuclear matter and pure neutron matter on the ΛN interaction. A moderate repulsion that increases with density is found in comparison to the free ΛN interaction.

  7. Three Baryon Interaction Generated by Determinant Interaction of Quarks

    CERN Document Server

    Ohnishi, Akira; Morita, Kenji

    2016-01-01

    We discuss the three-baryon interaction generated by the determinant interaction of quarks, known as the Kobayashi-Maskawa-'t Hooft (KMT) interaction. The expectation value of the KMT interaction operator is calculated in fully-antisymmetrized quark-cluster model wave functions for one-, two- and three-octet baryon states. The three-baryon potential from the KMT interaction is found to be repulsive for $NN\\Lambda$ and $N\\Lambda\\Lambda$ systems, while it is zero for the $NNN$ system. The strength and range of the three-baryon potential are found to be comparable to those for the $NNN$ three-body potential obtained in lattice QCD simulations. The contribution to the $\\Lambda$ single particle potential in nuclear matter is found to be 0.28 MeV and 0.73 MeV in neutron matter and symmetric nuclear matter at normal nuclear density, respectively. These repulsive forces are not enough to solve the hyperon puzzle, but may be measured in high-precision hyperisotope experiments.

  8. Large scale distribution of total mass versus luminous matter from Baryon Acoustic Oscillations: First search in the SDSS-III BOSS Data Release 10

    CERN Document Server

    Soumagnac, M T; Sabiu, C G; Loeb, A; Ross, A J; Abdalla, F B; Balan, S T; Lahav, O

    2016-01-01

    Baryon Acoustic Oscillations (BAOs) in the early Universe are predicted to leave an as yet undetected signature on the relative clustering of total mass versus luminous matter. A detection of this effect would provide an important confirmation of the standard cosmological paradigm and constrain alternatives to dark matter as well as non-standard fluctuations such as Compensated Isocurvature Perturbations (CIPs). We conduct the first observational search for this effect, by comparing the number-weighted and luminosity-weighted correlation functions, using the SDSS-III BOSS Data Release 10 CMASS sample. When including CIPs in our model, we formally obtain evidence at $3.2\\sigma$ of the relative clustering signature and a limit that matches the existing upper limits on the amplitude of CIPs. However, various tests suggest that these results are not yet robust, perhaps due to systematic biases in the data. The method developed in this Letter, used with more accurate future data such as that from DESI, is likely t...

  9. Excited baryons

    Energy Technology Data Exchange (ETDEWEB)

    Mukhopadhyay, N.C.

    1986-01-01

    The status of the theory of the low-energy approach to hadron structure is reviewed briefly by surveying a few relevant models. A few examples of tests needed to sort out the predictions of different models pertaining to the quark-gluon structure of hadrons are discussed, and given the resulting physics objectives, a few experimental options for excited baryon research at CFBAF are suggested. (LEW)

  10. Baryon Number Current in Chiral Soliton Model

    Institute of Scientific and Technical Information of China (English)

    LiXiguo

    2003-01-01

    Last year two exotic and narrow baryons, θ+(1540) and Ξ3/2--(1862), which are pentaquark states have been reported by several group. Their minimal quark content are uudds and ddssu, respectively. The θ+(1540) baryon was observed in few independent experiments. Its hypercharge, Y=2. The exotic baryon is an isosinglet. The Ξ3/2--(1862) baryon was also observed in the Ξ-π- invariant mass spectrum in proton-proton scattering at the CERN SPS . The search of exotic baryons was motivated by the flavor SU(3) extension of

  11. Results from the LUX dark matter experiment

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Markus, E-mail: markus.horn@yale.edu [Yale University, Dept. of Physics, 217 Prospect St., New Haven CT 06511 (United States); Akerib, D.S [Case Western Reserve University, Dept. of Physics, 10900 Euclid Ave, Cleveland, OH 44106 (United States); Araújo, H.M. [Imperial College London, High Energy Physics, Blackett Laboratory, London SW7 2BZ (United Kingdom); Bai, X. [South Dakota School of Mines and Technology, 501 East St Joseph St., Rapid City SD 57701 (United States); Bailey, A.J. [Imperial College London, High Energy Physics, Blackett Laboratory, London SW7 2BZ (United Kingdom); Balajthy, J. [University of Maryland, Dept. of Physics, College Park, MD 20742 (United States); Bernard, E. [Yale University, Dept. of Physics, 217 Prospect St., New Haven CT 06511 (United States); Bernstein, A. [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, CA 94551 (United States); Bradley, A. [Case Western Reserve University, Dept. of Physics, 10900 Euclid Ave, Cleveland, OH 44106 (United States); Byram, D. [University of South Dakota, Dept. of Physics, 414E Clark St., Vermillion, SD 57069 (United States); Cahn, S.B. [Yale University, Dept. of Physics, 217 Prospect St., New Haven CT 06511 (United States); Carmona-Benitez, M.C. [University of California Santa Barbara, Dept. of Physics, Santa Barbara, CA (United States); Chan, C.; Chapman, J.J. [Brown University, Dept. of Physics, 182 Hope St., Providence, RI 02912 (United States); Chiller, A.A.; Chiller, C. [University of South Dakota, Dept. of Physics, 414E Clark St., Vermillion, SD 57069 (United States); Currie, A. [Imperial College London, High Energy Physics, Blackett Laboratory, London SW7 2BZ (United Kingdom); Viveiros, L. de [LIP-Coimbra, Department of Physics, University of Coimbra, Rua Larga, 3004-516 Coimbra (Portugal); Dobi, A. [University of Maryland, Dept. of Physics, College Park, MD 20742 (United States); and others

    2015-06-01

    The LUX (Large Underground Xenon) experiment aims at the direct detection of dark matter particles via their collisions with xenon nuclei. The 370 kg two-phase liquid xenon time projection chamber measures simultaneously the scintillation and ionization from interactions in the target. The ratio of these two signals provides very good discrimination between potential nuclear recoil and electronic recoil signals to search for WIMP-nucleon scattering. The LUX detector operates at the Sanford Underground Research Facility (Lead, South Dakota, USA) since February 2013. First results were presented in late 2013 setting the world's most stringent limits on WIMP-nucleon scattering cross-sections over a wide range of WIMP masses. A 300 day run beginning in 2014 will further improve the sensitivity and new calibration techniques will reduce systematics for the WIMP signal search.

  12. First results from the H{sub 0} di-baryon search and hyperon production measurements by the AGS Experiment 896

    Energy Technology Data Exchange (ETDEWEB)

    Caines, H.; Albergo, S.; Bellwied, R.; Bennett, M.; Boemi, D.; Bonner, B.; Caccia, Z.; Christie, W.; Cina, G.; Costa, S.; Crawford, H.; Cronqvist, M.; Debbe, R.; Engelage, J.; Flores, I.; Greiner, L.; Hallman, T.; Hoffman, G.; Huang, H.; Humanic, T.J.; Igo, G.; Insolia, A.; Jensen, P.; Judd, E.; Kainz, K.; Kaplan, M.; Kelly, S.; Kotov, I.; Kunde, G.; Lindstrom, P.; Ljubicic, T.; Llope, W.; Lo Curto, G.; Longacre, R.; Lynn, D.; Madansky, L.; Mahzeh, N.; Milosevich, Z.; Mitchell, J.T; Mitchell, J.; Nehmeh, S.; Nociforo, C.; Paganis, S.; Pandey, S.U.; Potenza, R.; Platner, E.; Riley, P.; Russ, D.; Saulys, A.; Schambach, J.; Sheen, J.; Stokley, C.; Sugarbaker, E.; Takahashi, J.; Tang, J.; Trentalange, S.; Tricomi, A.; Tull, C.; Tuve, C.; Whitfield, J.; Wilson, K

    1999-12-27

    The AGS Experiment 896 was designed to study strangeness production in Au--Au collisions at 11.6A GeV/c, in particular the formation of a six-quark di-baryon the H{sub 0}. Heavy ion collisions provide favorable conditions for the H{sub 0} formation either via coalescence of two {lambda} particles (owing to the large {lambda} production cross section) or direct production from the possible formation of a quark-gluon plasma. E896 also measured strange meson and baryon distributions from mid-rapidity. Preliminary results from this experiment are presented as well as details of the expected sensitivity for the H{sub 0} search.

  13. Detector Simulation and WIMP Search Analysis for the Cryogenic Dark Matter Search Experiment

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, Kevin [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2013-06-01

    Astrophysical and cosmological measurements on the scales of galaxies, galaxy clusters, and the universe indicate that 85% of the matter in the universe is composed of dark matter, made up of non-baryonic particles that interact with cross-sections on the weak scale or lower. Hypothetical Weakly Interacting Massive Particles, or WIMPs, represent a potential solution to the dark matter problem, and naturally arise in certain Standard Model extensions. The Cryogenic Dark Matter Search (CDMS) collaboration aims to detect the scattering of WIMP particles from nuclei in terrestrial detectors. Germanium and silicon particle detectors are deployed in the Soudan Underground Laboratory in Minnesota. These detectors are instrumented with phonon and ionization sensors, which allows for discrimination against electromagnetic backgrounds, which strike the detector at rates orders of magnitude higher than the expected WIMP signal. This dissertation presents the development of numerical models of the physics of the CDMS detectors, implemented in a computational package collectively known as the CDMS Detector Monte Carlo (DMC). After substantial validation of the models against data, the DMC is used to investigate potential backgrounds to the next iteration of the CDMS experiment, known as SuperCDMS. Finally, an investigation of using the DMC in a reverse Monte Carlo analysis of WIMP search data is presented.

  14. Positronium Portal into Hidden Sector: A new Experiment to Search for Mirror Dark Matter

    CERN Document Server

    Crivelli, Paolo; Gendotti, Ulisse; Gninenko, Sergei; Rubbia, Andre

    2010-01-01

    The understanding of the origin of dark matter has great importance for cosmology and particle physics. Several interesting extensions of the standard model dealing with solution of this problem motivate the concept of hidden sectors consisting of SU(3)xSU(2)_LxU(1)_Y singlet fields. Among these models, the mirror matter model is certainly one of the most interesting. The model explains the origin of parity violation in weak interactions, it could also explain the baryon asymmetry of the Universe and provide a natural ground for the explanation of dark matter. The mirror matter could have a portal to our world through photon-mirror photon mixing (epsilon). This mixing would lead to orthopositronium (o-Ps) to mirror orthopositronium oscillations, the experimental signature of which is the apparently invisible decay of o-Ps. In this paper, we describe an experiment to search for the decay o-Ps -> invisible in vacuum by using a pulsed slow positron beam and a massive 4pi BGO crystal calorimeter. The developed hi...

  15. Revisiting First-Year College Students' Mattering: Social Support, Academic Stress, and the Mattering Experience

    Science.gov (United States)

    Rayle, Andrea Dixon; Chung, Kuo-Yi

    2008-01-01

    In this study, Nancy Schlossberg's (1989) theory of college students' mattering to others was revisited. Mattering is the experience of others depending on us, being interested in us, and being concerned with our fate. The relationships of gender, mattering to college friends and the college environment, and friend and family social support with…

  16. Density-dependent effective baryon-baryon interaction from chiral three-baryon forces

    CERN Document Server

    Petschauer, Stefan; Kaiser, Norbert; Meißner, Ulf-G; Weise, Wolfram

    2016-01-01

    A density-dependent effective potential for the baryon-baryon interaction in the presence of the (hyper)nuclear medium is constructed, based on the leading (irreducible) three-baryon forces derived within SU(3) chiral effective field theory. We evaluate the contributions from three classes: contact terms, one-pion exchange and two-pion exchange. In the strangeness-zero sector we recover the known result for the in-medium nucleon-nucleon interaction. Explicit expressions for the Lambda-nucleon in-medium potential in (asymmetric) nuclear matter are presented. Our results are suitable for implementation into calculations of (hyper)nuclear matter. In order to estimate the low-energy constants of the leading three-baryon forces we introduce the decuplet baryons as explicit degrees of freedom and construct the relevant terms in the minimal non-relativistic Lagrangian. With these, the constants are estimated through decuplet saturation. Utilizing this approximation we provide numerical results for the effect of the ...

  17. CP violation in strange baryon decays: A report from Fermilab experiment 871

    Energy Technology Data Exchange (ETDEWEB)

    James, C.; Volk, J. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Chan, A.; Chen, Y.C.; Ho, C.; Teng, P.K. [Academia Sinica, Nankang, Taipei 11529, Taiwan, Republic of (China); Choong, W.S.; Fuzesy, R.; Gidal, G.; Luk, K.B.; Turko, B.; Zyla, P. [University of California and Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States); Felix, J.; Moreno, G.; Sosa, M. [University of Guanajuato, 37000 Leon (Mexico); Burnstein, R.A.; Chakravorty, A.; Kaplan, D.M.; Lederman, L.M.; Luebke, W.; Rajaram, D.; Rubin, H.A.; White, C.G.; White, S.L. [Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Leros, N.; Perroud, J.P. [University of Lausanne, CH-1015 Lausanne (Switzerland); Gustafson, H.R.; Longo, M.J.; Lopez, F. [University of Michigan, Ann Arbor, Michigan 48109 (United States); Papavassiliou, V. [New Mexico State University, Las Cruces, New Mexico 88003 (United States); Clark, K.; Jenkins, M. [University of South Alabama, Mobile, Alabama 36688 (United States); Dukes, E.C.; Durandet, C.; Holmstrom, T.; Huang, M.; Nelson, K. [University of Virginia, Charlottesville, Virginia 22901 (United States)

    1999-02-01

    Fermilab experiment 871, {ital HyperCP}, is a search for direct CP violation in {Xi} and {Lambda} hyperon decays. A non-zero value in the asymmetry parameter A, defined in terms of the decay parameter products {alpha}{sub {Xi}}{alpha}{sub {Lambda}} and {alpha}{sub {bar {Xi}}}{alpha}{sub {bar {Lambda}}}, would be unambiguous evidence for direct CP violation. The first data-taking run finished at the end of 1997 and accumulated over one billion {Xi}{sup {minus}} and {bar {Xi}}{sup +} decays. A sensitivity in A of {approx}10{sup {minus}4} is expected. A review of CP violation in hyperon decays is given, the {ital HyperCP} detector is described, and the status of the data analysis is discussed. {copyright} {ital 1999 American Institute of Physics.}

  18. Progress Toward Understanding Baryon Resonances

    CERN Document Server

    Crede, Volker

    2013-01-01

    The composite nature of baryons manifests itself in the existence of a rich spectrum of excited states, in particular in the important mass region 1-2 GeV for the light-flavoured baryons. The properties of these resonances can be identified by systematic investigations using electromagnetic and strong probes, primarily with beams of electrons, photons, and pions. After decades of research, the fundamental degrees of freedom underlying the baryon excitation spectrum are still poorly understood. The search for hitherto undiscovered but predicted resonances continues at many laboratories around the world. Recent results from photo- and electroproduction experiments provide intriguing indications for new states and shed light on the structure of some of the known nucleon excitations. The continuing study of available data sets with consideration of new observables and improved analysis tools have also called into question some of the earlier findings in baryon spectroscopy. Other breakthrough measurements have be...

  19. Review of dark matter direct detection experiments

    Indian Academy of Sciences (India)

    Rupak Mahapatra

    2012-11-01

    Matter, as we know it, makes up less than 5% of the Universe. Various astrophysical observations have confirmed that one quarter of the Universe and most of the matter content in the Universe is made up of dark matter. The nature of dark matter is yet to be discovered and is one of the biggest questions in physics. Particle physics combined with astrophysical measurements of the abundance gives rise to a dark matter candidate called weakly interacting massive particle (WIMP). The low density of WIMPs in the galaxies and the extremely weak nature of the interaction with ordinary matter make detection of the WIMP an extraordinarily challenging task, with abundant fakes from various radioactive and cosmogenic backgrounds with much stronger electromagnetic interaction. The extremely weak nature of the WIMP interaction dictates detectors that have extremely low naturally occurring radioactive background, a large active volume (mass) of sensitive detector material to maximize statistics, a highly efficient detector-based rejection mechanism for the dominant electromagnetic background and sophisticated analysis techniques to reject any residual background. This paper reviews currently available major technologies being pursued by various collaborations, with special emphasis on the cryogenic Ge detector technology used by the Cryogenic Dark Matter Search Collaboration (CDMS).

  20. Baryonic Torii

    CERN Document Server

    Gudnason, Sven Bjarke

    2014-01-01

    We study a Skyrme-type model with a potential term motivated by Bose-Einstein condensates (BECs), which we call the BEC Skyrme model. We consider two flavors of the model, the first is the Skyrme model and the second has a sixth-order derivative term instead of the Skyrme term; both with the added BEC-motivated potential. The model contains toroidally shaped Skyrmions and they are characterized by two integers P and Q, representing the winding numbers of two complex scalar fields along the toroidal and poloidal cycles of the torus, respectively. The baryon number is B=PQ. We find stable Skyrmion solutions for P=1,2,3,4,5 with Q=1, while for P=6 and Q=1 it is only metastable. We further find that configurations with higher Q>1 are all unstable and split into Q configurations with Q=1.

  1. Galilean Equivalence for Galactic Dark Matter

    CERN Document Server

    Kesden, M; Kesden, Michael; Kamionkowski, Marc

    2006-01-01

    Satellite galaxies of the Milky Way experience a tidal disruption as they orbit in the Milky Way's dark halo. While the bound core of the satellite remains dominated by dark matter, the tidally disrupted stars behave like purely baryonic tracers of the Milky Way's potential well. If dark matter experiences a stronger self attraction than visible matter, stars will preferentially gain rather than lose energy during tidal disruption. This leads to a relative enhancement in the trailing as compared to the leading tidal stream. We show that the absence of a strong asymmetry in the surface brightness of the leading and trailing tidal streams already constrains the equivalence of acceleration of dark matter and baryons in a gravitational field to less than ten percent--thus ruling out a recently proposed mechanism to clear dwarf galaxies from voids. Future observations should be sensitive at the percent level to departures from the equivalence of dark matter and baryons.

  2. The C-4 Dark Matter Experiment

    CERN Document Server

    Bonicalzi, R M; Colaresi, J; Fast, J E; Fields, N E; Fuller, E S; Hai, M; Hossbach, T W; Kos, M S; Orrell, J L; Overman, C T; Reid, D J; VanDevender, B A; Wiseman, C; Yocum, K M

    2012-01-01

    We describe the experimental design of C-4, an expansion of the CoGeNT dark matter search to four identical detectors each approximately three times the mass of the p-type point contact germanium diode presently taking data at the Soudan Underground Laboratory. Expected reductions of radioactive backgrounds and energy threshold are discussed, including an estimate of the additional sensitivity to low-mass dark matter candidates to be obtained with this search.

  3. The C-4 dark matter experiment

    Science.gov (United States)

    Bonicalzi, R. M.; Collar, J. I.; Colaresi, J.; Fast, J. E.; Fields, N. E.; Fuller, E. S.; Hai, M.; Hossbach, T. W.; Kos, M. S.; Orrell, J. L.; Overman, C. T.; Reid, D. J.; VanDevender, B. A.; Wiseman, C.; Yocum, K. M.

    2013-06-01

    We describe the experimental design of C-4, an expansion of the CoGeNT dark matter search to four identical detectors each approximately three times the mass of the p-type point contact germanium diode presently taking data at the Soudan Underground Laboratory. Expected reductions of radioactive backgrounds and energy threshold are discussed, including an estimate of the additional sensitivity to low-mass dark matter candidates to be obtained with this search.

  4. The Cryogenic Dark Matter Search (CDMS-II) Experiment: First Results from the Soudan Mine

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Clarence Leeder [Stanford Univ., CA (United States)

    2004-09-01

    There is an abundance of evidence that the majority of the mass of the universe is in the form of non-baryonic non-luminous matter that was non-relativistic at the time when matter began to dominate the energy density. Weakly Interacting Massive Particles, or WIMPs, are attractive cold dark matter candidates because they would have a relic abundance today of ~0.1 which is consistent with precision cosmological measurements. WIMPs are also well motivated theoretically. Many minimal supersymmetric extensions of the Standard Model have WIMPs in the form of the lightest supersymmetric partner, typically taken to be the neutralino. The CDMS II experiment searches for WIMPs via their elastic scattering off of nuclei. The experiment uses Ge and Si ZIP detectors, operated at <50 mK, which simultaneously measure the ionization and athermal phonons produced by the scattering of an external particle. The dominant background for the experiment comes from electromagnetic interactions taking place very close to the detector surface. Analysis of the phonon signal from these interactions makes it possible to discriminate them from interactions caused by WIMPs. This thesis presents the details of an important aspect of the phonon pulse shape analysis known as the ''Lookup Table Correction''. The Lookup Table Correction is a position dependent calibration of the ZIP phonon response which improves the rejection of events scattering near the detector surface. The CDMS collaboration has recently commissioned its experimental installation at the Soudan Mine. This thesis presents an analysis of the data from the first WIMP search at the Soudan Mine. The results of this analysis set the world's lowest exclusion limit making the CDMS II experiment at Soudan the most sensitive WIMP search to this date.

  5. Direct detection experiments explained with mirror dark matter

    Science.gov (United States)

    Foot, R.

    2014-01-01

    Recently, the CDMS/Si experiment has observed a low energy excess of events in their dark matter search. In light of this new result we update the mirror dark matter explanation of the direction detection experiments. We find that the DAMA, CoGeNT, CRESST-II and CDMS/Si data can be simultaneously explained by halo ∼Fe‧ interactions provided that vrot≈200 km/s. Other parameter space is also possible. Forthcoming experiments, including CDMSlite, CDEX, COUPP, LUX, C-4, … should be able to further scrutinize mirror dark matter and closely related hidden sector models in the near future.

  6. Direct detection experiments explained with mirror dark matter

    CERN Document Server

    Foot, R

    2014-01-01

    Recently, the CDMS/Si experiment has observed a low energy excess of events in their dark matter search. In light of this new result we update the mirror dark matter explanation of the direction detection experiments. We find that the DAMA, CoGeNT, CRESST-II and CDMS/Si data can be simultaneously explained by halo $\\sim Fe'$ interactions provided that $v_{rot} \\approx 200$ km/s. Other parameter space is also possible. Forthcoming experiments, including CDMSlite, CDEX, COUPP, LUX, C-4,... should be able to further scrutinize mirror dark matter and closely related hidden sector models in the near future.

  7. Fundamental statistical limitations of future dark matter direct detection experiments

    NARCIS (Netherlands)

    Strege, C.; Trotta, F.; Bertone, G.; Peter, A.H.G.; Scott, P.

    2012-01-01

    We discuss irreducible statistical limitations of future ton-scale dark matter direct detection experiments. We focus in particular on the coverage of confidence intervals, which quantifies the reliability of the statistical method used to reconstruct the dark matter parameters and the bias of the r

  8. The Adolescent Mattering Experience: Gender Variations in Perceived Mattering, Anxiety, and Depression

    Science.gov (United States)

    Dixon, Andrea L.; Scheidegger, Corey; McWhirter, J. Jeffries

    2009-01-01

    Individuals who perceive that they matter to others are likely to experience lower anxiety and depression levels. The effects of young adolescents' perceived mattering on their anxiety and depression levels were examined. Results indicated that female adolescents reported lower anxiety levels but greater depression levels than did male…

  9. Baryon symmetric big bang cosmology

    Science.gov (United States)

    Stecker, F. W.

    1978-01-01

    Both the quantum theory and Einsteins theory of special relativity lead to the supposition that matter and antimatter were produced in equal quantities during the big bang. It is noted that local matter/antimatter asymmetries may be reconciled with universal symmetry by assuming (1) a slight imbalance of matter over antimatter in the early universe, annihilation, and a subsequent remainder of matter; (2) localized regions of excess for one or the other type of matter as an initial condition; and (3) an extremely dense, high temperature state with zero net baryon number; i.e., matter/antimatter symmetry. Attention is given to the third assumption, which is the simplest and the most in keeping with current knowledge of the cosmos, especially as pertains the universality of 3 K background radiation. Mechanisms of galaxy formation are discussed, whereby matter and antimatter might have collided and annihilated each other, or have coexisted (and continue to coexist) at vast distances. It is pointed out that baryon symmetric big bang cosmology could probably be proved if an antinucleus could be detected in cosmic radiation.

  10. Dark matter at the SHiP experiment

    Directory of Open Access Journals (Sweden)

    Timiryasov Inar

    2016-01-01

    Full Text Available We study prospects of dark matter searches in the SHiP experiment. SHiP (Search for Hidden Particles is the recently proposed fixed target experiment which will exploit the high-intensity beam of 400 GeV protons from the CERN SPS. In addition to the hidden sector detector, SHiP will be equipped with the ντ detector, which presumably would be sensitive to dark matter particles. We describe appropriate production and detection channels and estimate SHiP’s sensitivity for a scalar dark matter coupled to the Standard model through the vector mediator.

  11. The Cryogenic Dark Matter Search low ionization-threshold experiment

    Energy Technology Data Exchange (ETDEWEB)

    Basu Thakur, Ritoban [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2014-01-01

    Over 80 years ago we discovered the presence of Dark Matter in our universe. Endeavors in astronomy and cosmology are in consensus with ever improving precision that Dark Matter constitutes an essential 27% of our universe. The Standard Model of Particle Physics does not provide any answers to the Dark Matter problem. It is imperative that we understand Dark Matter and discover its fundamental nature. This is because, alongside other important factors, Dark Matter is responsible for formation of structure in our universe. The very construct in which we sit is defined by its abundance. The Milky Way galaxy, hence life, wouldn't have formed if small over densities of Dark Matter had not caused sufficient accretion of stellar material. Marvelous experiments have been designed based on basic notions to directly and in-directly study Dark Matter, and the Cryogenic Dark Matter Search (CDMS) experiment has been a pioneer and forerunner in the direct detection field. Generations of the CDMS experiment were designed with advanced scientific upgrades to detect Dark Matter particles of mass O(100) GeV/c2. This mass-scale was set primarily by predictions from Super Symmetry. Around 2013 the canonical SUSY predictions were losing some ground and several observations (rather hints of signals) from various experiments indicated to the possibility of lighter Dark Matter of mass O(10) GeV/c2. While the SuperCDMS experiment was probing the regular parameter space, the CDMSlite experiment was conceived to dedicatedly search for light Dark Matter using a novel technology. "CDMSlite" stands for CDMS - low ionization threshold experiment. Here we utilize a unique electron phonon coupling mechanism to measure ionization generated by scattering of light particles. Typically signals from such low energy recoils would be washed under instrumental noise. In CDMSlite via generation of Luke-Neganov phonons we can detect the small ionization energies, amplified in

  12. Thermodynamics of Hot Hadronic Gases at Finite Baryon Densities

    Science.gov (United States)

    Albright, Michael Glenn

    matter. This generalizes previous works by incorporating baryon chemical potential and a vector mean field into the formalism. We show that the theory is thermodynamically self-consistent and it obeys the Landau-Lifshitz conditions of fit. The formulas should be very useful for predicting transport coefficients in future heavy-ion collision experiments at RHIC and other colliders. This thesis is based upon work published in Refs. [1, 2, 3]. [1] M. Albright, J. Kapusta, and C. Young, Phys. Rev. C 90 , 024915 (2014). [2] M. Albright, J. Kapusta, and C. Young, Phys. Rev. C 92 , 044904 (2015). [3] M. Albright and J. Kapusta, submitted to Phys. Rev. C, preprint, arXiv:1508.02696.

  13. Validity - a matter of resonant experience

    DEFF Research Database (Denmark)

    Revsbæk, Line

    across researcher’s past experience from the case study and her own life. The autobiographic way of analyzing conventional interview material is exemplified with a case of a junior researcher researching newcomer innovation of others, drawing on her own experience of being newcomer in work community...

  14. Capturing experience: a matter of contextualising events

    NARCIS (Netherlands)

    Nack, F.-M.

    2004-01-01

    This paper explores the notion of experience in the context of dynamic and interactive environments, such as web-based musea, where neither the individual user requirements nor the requested material can be predicted in advance. A definition of experiences for the particular context is introduced on

  15. Capturing experience - a matter of contextualising events

    NARCIS (Netherlands)

    Nack, F.-M.

    2003-01-01

    This paper explores the notion of experience in the context of dynamic and interactive environments, such as web-based musea, where neither the individual user requirements nor the requested material can be predicted in advance. A definition of experiences for the particular context is introduced on

  16. Detectors calibration and research of luminescent materials for non baryonic dark matter detection; Calibration de detecteurs et recherche de materiaux luminescents pour la detection de la matiere noire non baryonique

    Energy Technology Data Exchange (ETDEWEB)

    Messous, M.Y.

    1995-03-01

    This work is dedicated to the characterization of luminescent materials in order to build bolometers for the simultaneous detection of heat an light in the search for WIMPs (Weakly Interacting Massive Particles) candidates for non baryonic dark matter. These double bolometers should enable the identification and measurement of recoil ions after collision between a WIMPs and material nucleus. In our search for highly luminescent materials, we have studied the emission spectra, the time response and the spectra response resulting from laser excitation or ionizing particles bombardment of some crystals such as CaF{sub 2}(Eu), CaF{sub 2}, CeF{sub 3}(Ce) and In{sub 2}Si{sub 2}O{sub 7}. These studies were conducted down to liquid Helium temperature (4 K). After showing the good performance of CaF{sub 2}(Eu) scintillator, we have measured the quenching effect resulting from {sup 19}F and Ca ions recoil in CaF{sub 2}(Eu). This was done at the 14 MeV Tandem accelerator of Bruyeres-Le-Chatel with a pulsed neutron beam, simulating the WIMPs. The data obtained allowed the exploitation of the results of the BPRS (Beijing - Rome - Paris - Saclay) experiments carried out at Gran-Sasso. This results showed a gain of up to an order of magnitude in the exclusion graph of axially coupled WIMPs compared to NaI. With the apparatus developed at IPN Lyon (Nuclear Physical Institute of Lyon), we have also measured the ionization induced by Ge ion recoils in Germanium detector, which is one of the most promising crystals for WIMPs detection in the energy range of 2.8 keV-37.8 keV. An ionization efficiency of 24% to 29% was obtained. (author). refs., figs., tabs.

  17. Connecting the Baryons: Multiwavelength Data for SKA HI Surveys

    CERN Document Server

    Meyer, Martin; Obreschkow, Danail; Driver, Simon; Staveley-Smith, Lister; Zwaan, Martin

    2015-01-01

    The science achievable with SKA HI surveys will be greatly increased through the combination of HI data with that at other wavelengths. These multiwavelength datasets will enable studies to move beyond an understanding of HI gas in isolation to instead understand HI as an integral part of the highly complex baryonic processes that drive galaxy evolution. As they evolve, galaxies experience a host of environmental and feedback influences, many of which can radically impact their gas content. Important processes include: accretion (hot and cold mode, mergers), depletion (star formation, galactic winds, AGN), phase changes (ionised/atomic/molecular), and environmental effects (ram pressure stripping, tidal effects, strangulation). Governing all of these to various extents is the underlying dark matter distribution. In turn, the result of these processes can significantly alter the baryonic states in which material is finally observed (stellar populations, dust, chemistry) and its morphology (galaxy type, bulge/d...

  18. Baryon Number Violating Scalar Diquarks at the LHC

    CERN Document Server

    Baldes, Iason; Volkas, Raymond R

    2011-01-01

    Baryon number violating (BNV) processes are heavily constrained by experiments searching for nucleon decay and neutron-antineutron oscillations. If the baryon number violation occurs via the third generation quarks, however, we may be able to avoid the nucleon stability constraints, thus making such BNV interactions accessible at the LHC. In this paper we study a specific class of BNV extensions of the standard model (SM) involving diquark and leptoquark scalars. After an introduction to these models we study one promising extension in detail, being interested in particles with mass of O(TeV). We calculate limits on the masses and couplings from neutron-antineutron oscillations and dineutron decay for couplings to first and third generation quarks. We explore the possible consequences of such a model on the matter-antimatter asymmetry. We shall see that for models which break the global baryon minus lepton number symmetry, (B-L), the most stringent constraints come from the need to preserve a matter-antimatte...

  19. An Overview of Dark Matter Experiments at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    James Boyce

    2012-09-01

    Dark Matter research at Jefferson Lab started in 2006 with the LIght Pseudoscalar and Scalar Search (LIPSS) collaboration to check the validity of results reported by the PVLAS collaboration. In the intervening years interest in dark matter laboratory experiments has grown at Jefferson Lab. Current research underway or in planning stages probe various mass regions covering 14 orders of magnitude: from 10{sup -6} eV to 100 MeV. This presentation will be an overview of our dark matter efforts, three of which focus on the hypothesized A' gauge boson.

  20. Why Death Matters: Understanding Gameworld Experience

    Directory of Open Access Journals (Sweden)

    Lisbeth Klastrup

    2007-06-01

    Full Text Available This article presents a study of the staging and implementation of death and the death penalty in a number of popular MMOGs and relates it to players general experience of gameworlds. Game mechanics, writings and stories by designers and players, and the results of an online survey are analysed and discussed. The study shows that the death penalty is implemented much in the same way across worlds; that death can be both trivial and non-trivial, part of the grind of everyday life, or essential in the creation of heroes, depending on context. In whatever function death may serves, it is argued that death plays an important part in the shaping and emergence of the social culture of a world, and in the individual players experience of life within it.

  1. The Inner Experience of Living Matter

    DEFF Research Database (Denmark)

    Sørensen, Asger

    The dialectical aspect in the work of George Bataille is often neglected. At the suggestion of Foucault and Derrida, Bataille is most often even taken to be a non-dialectical thinker. But Bataille worked intensely with Hegel's ideas, his thought was expressed in Hegelian terms, and both his...... epistemology and his ontology can be considered a determinate negation of Hegel's position in the Phenomenology. This is shown, first, by analyzing Bataille's notions of `inner experience', and, second, by showing how Bataille extends dialectics to the natural, non-human realm, and even conceives the link...

  2. Dark matter effective field theory scattering in direct detection experiments

    Energy Technology Data Exchange (ETDEWEB)

    Schneck, K.; Cabrera, B.; Cerdeno, D. G.; Mandic, V.; Rogers, H. E.; Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Barker, D.; Basu Thakur, R.; Bauer, D. A.; Billard, J.; Borgland, A.; Brandt, D.; Brink, P. L.; Bunker, R.; Caldwell, D. O.; Calkins, R.; Chagani, H.; Chen, Y.; Cooley, J.; Cornell, B.; Crewdson, C. H.; Cushman, Priscilla B.; Daal, M.; Di Stefano, P. C.; Doughty, T.; Esteban, L.; Fallows, S.; Figueroa-Feliciano, E.; Godfrey, G. L.; Golwala, S. R.; Hall, Jeter C.; Harris, H. R.; Hofer, T.; Holmgren, D.; Hsu, L.; Huber, M. E.; Jardin, D. M.; Jastram, A.; Kamaev, O.; Kara, B.; Kelsey, M. H.; Kennedy, A.; Leder, A.; Loer, B.; Lopez Asamar, E.; Lukens, W.; Mahapatra, R.; McCarthy, K. A.; Mirabolfathi, N.; Moffatt, R. A.; Morales Mendoza, J. D.; Oser, S. M.; Page, K.; Page, W. A.; Partridge, R.; Pepin, M.; Phipps, A.; Prasad, K.; Pyle, M.; Qiu, H.; Rau, W.; Redl, P.; Reisetter, A.; Ricci, Y.; Roberts, A.; Saab, T.; Sadoulet, B.; Sander, J.; Schnee, R. W.; Scorza, S.; Serfass, B.; Shank, B.; Speller, D.; Toback, D.; Upadhyayula, S.; Villano, A. N.; Welliver, B.; Wilson, J. S.; Wright, D. H.; Yang, X.; Yellin, S.; Yen, J. J.; Young, B. A.; Zhang, J.

    2015-05-01

    We examine the consequences of the effective eld theory (EFT) of dark matter-nucleon scattering or current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. We demonstrate that spectral di*erences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. We also discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.

  3. Dark matter effective field theory scattering in direct detection experiments

    Energy Technology Data Exchange (ETDEWEB)

    Schneck, K.; Cabrera, B.; Cerdeño, D. G.; Mandic, V.; Rogers, H. E.; Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Barker, D.; Basu Thakur, R.; Bauer, D. A.; Billard, J.; Borgland, A.; Brandt, D.; Brink, P. L.; Bunker, R.; Caldwell, D. O.; Calkins, R.; Chagani, H.; Chen, Y.; Cooley, J.; Cornell, B.; Crewdson, C. H.; Cushman, P.; Daal, M.; Di Stefano, P. C. F.; Doughty, T.; Esteban, L.; Fallows, S.; Figueroa-Feliciano, E.; Godfrey, G. L.; Golwala, S. R.; Hall, J.; Harris, H. R.; Hofer, T.; Holmgren, D.; Hsu, L.; Huber, M. E.; Jardin, D. M.; Jastram, A.; Kamaev, O.; Kara, B.; Kelsey, M. H.; Kennedy, A.; Leder, A.; Loer, B.; Lopez Asamar, E.; Lukens, P.; Mahapatra, R.; McCarthy, K. A.; Mirabolfathi, N.; Moffatt, R. A.; Morales Mendoza, J. D.; Oser, S. M.; Page, K.; Page, W. A.; Partridge, R.; Pepin, M.; Phipps, A.; Prasad, K.; Pyle, M.; Qiu, H.; Rau, W.; Redl, P.; Reisetter, A.; Ricci, Y.; Roberts, A.; Saab, T.; Sadoulet, B.; Sander, J.; Schnee, R. W.; Scorza, S.; Serfass, B.; Shank, B.; Speller, D.; Toback, D.; Upadhyayula, S.; Villano, A. N.; Welliver, B.; Wilson, J. S.; Wright, D. H.; Yang, X.; Yellin, S.; Yen, J. J.; Young, B. A.; Zhang, J.

    2015-05-18

    We examine the consequences of the effective field theory (EFT) of dark matter-nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. Here. we demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. In conclusion, we discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.

  4. Dark matter effective field theory scattering in direct detection experiments

    CERN Document Server

    Schneck, K; Cerdeno, D G; Mandic, V; Rogers, H E; Agnese, R; Anderson, A J; Asai, M; Balakishiyeva, D; Barker, D; Thakur, R Basu; Bauer, D A; Billard, J; Borgland, A; Brandt, D; Brink, P L; Bunker, R; Caldwell, D O; Calkins, R; Chagani, H; Chen, Y; Cooley, J; Cornell, B; Crewdson, C H; Cushman, P; Daal, M; Di Stefano, P C F; Doughty, T; Esteban, L; Fallows, S; Figueroa-Feliciano, E; Godfrey, G L; Golwala, S R; Hall, J; Harris, H R; Hofer, T; Holmgren, D; Hsu, L; Huber, M E; Jardin, D M; Jastram, A; Kamaev, O; Kara, B; Kelsey, M H; Kennedy, A; Leder, A; Loer, B; Asamar, E Lopez; Lukens, P; Mahapatra, R; McCarthy, K A; Mirabolfathi, N; Moffatt, R A; Mendoza, J D Morales; Oser, S M; Page, K; Page, W A; Partridge, R; Pepin, M; Phipps, A; Prasad, K; Pyle, M; Qiu, H; Rau, W; Redl, P; Reisetter, A; Ricci, Y; Roberts, A; Saab, T; Sadoulet, B; Sander, J; Schnee, R W; Scorza, S; Serfass, B; Shank, B; Speller, D; Toback, D; Upadhyayula, S; Villano, A N; Welliver, B; Wilson, J S; Wright, D H; Yang, X; Yellin, S; Yen, J J; Young, B A; Zhang, J

    2015-01-01

    We examine the consequences of the effective field theory (EFT) of dark matter-nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. We demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. We also discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.

  5. Direct Dark Matter Search with the CRESST II Experiment

    CERN Document Server

    Schieck, J; Bento, A; Bucci, C; Canonica, L; Defay, X; Erb, A; Feilitzsch, F v; Iachellini, N Ferreiro; Gorla, P; Guetlein, A; Hauff, D; Jochum, J; Kiefer, M; Kluck, H; Kraus, H; Lanfranchi, J-C; Loebell, J; Mancuso, M; Muenster, A; Pagliarone, C; Petricca, F; Potzel, W; Pröbst, F; Puig, R; Reindl, F; Schaeffner, K; Schoenert, S; Seidel, W; Stahlberg, M; Stodolsky, L; Strandhagen, C; Strauss, R; Tanzke, A; Thi, H H Trinh; Turkoglu, C; Uffinger, M; Ulrich, A; Usherov, I; Wawoczny, S; Willers, M; Wueustrich, M; Zoeller, A

    2016-01-01

    The quest for the particle nature of dark matter is one of the big open questions of modern physics. A well motivated candidate for dark matter is the so-called WIMP - a weakly interacting massive particle. Recently several theoretically well-motivated models with dark matter candidates in a mass region below the WIMP mass-scale gained also a lot of interest, theoretically and experimentally. The CRESST II experiment located at the Gran Sasso laboratory in Italy is optimised for the detection of the elastic scattering of these low-mass dark matter particles with ordinary matter. We show the results obtained with an improved detector setup with increased radio purity and enhanced background rejection and the results obtained with a dedicated low-threshold analysis of a single conventional detector module. The limit achieved is the most stringent limit achieved for direct dark matter experiments in the mass region below 1.8 GeV/$c^{2}$. We will discuss the expected performance for new small CRESST-type detector...

  6. Baryon number violation catalysed by grand unified monopoles

    CERN Document Server

    Ellis, Jonathan Richard; Olive, Keith A

    1982-01-01

    It has been recognized for some time that grand unified monopoles may catalyze Delta B not=0 processes. The authors obtain model-independent upper bounds on the rates for such reactions from the survival of the baryon number generated in the early Universe and from present-day baryon stability. These constraints are compatible with recent estimates of large baryon number violating monopole cross sections, but a monopole flux close to present experimental upper limits could be detectable in forthcoming baryon decay experiments. The authors mention signatures for monopole-induced baryon 'decay' and point out that it could be used to solve the energy crisis.

  7. Dark Matter

    OpenAIRE

    Einasto, Jaan

    2013-01-01

    I give a review of the development of the concept of dark matter. The dark matter story passed through several stages from a minor observational puzzle to a major challenge for theory of elementary particles. Modern data suggest that dark matter is the dominant matter component in the Universe, and that it consists of some unknown non-baryonic particles. Dark matter is the dominant matter component in the Universe, thus properties of dark matter particles determine the structure of the cosmic...

  8. Search for inelastic dark matter with the CDMS II experiment

    CERN Document Server

    Ahmed, Z; Arrenberg, S; Bailey, C N; Balakishiyeva, D; Baudis, L; Bauer, D A; Brink, P L; Bruch, T; Bunker, R; Cabrera, B; Caldwell, D O; Cooley, J; Silva, E do Couto e; Cushman, P; Daal, M; DeJongh, F; Di Stefano, P; Dragowsky, M R; Duong, L; Fallows, S; Figueroa-Feliciano, E; Filippini, J; Fox, J; Fritts, M; Golwala, S R; Hall, J; Hennings-Yeomans, R; Hertel, S A; Holmgren, D; Hsu, L; Huber, M E; Kamaev, O; Kiveni, M; Kos, M; Leman, S W; Liu, S; Mahapatra, R; Mandic, V; McCarthy, K A; Mirabolfathi, N; Moore, D; Nelson, H; Ogburn, R W; Phipps, A; Pyle, M; Qiu, X; Ramberg, E; Rau, W; Razeti, M; Reisetter, A; Resch, R; Saab, T; Sadoulet, B; Sander, J; Schnee, R W; Seitz, D N; Serfass, B; Sundqvist, K M; Tarka, M; Wikus, P; Yellin, S; Yoo, J; Young, B A; Zhang, J

    2010-01-01

    Results are presented from a reanalysis of the entire five-tower data set acquired with the Cryogenic Dark Matter Search (CDMS II) experiment at the Soudan Underground Laboratory, with an exposure of 969 kg-days. The analysis window was extended to a recoil energy of 150 keV, and an improved surface-event background-rejection cut was defined to increase the sensitivity of the experiment to the inelastic dark matter (IDM) model. Three dark matter candidates were found between 25 keV and 150 keV. The probability to observe three or more background events in this energy range is 11%. Due to the occurrence of these events the constraints on the IDM parameter space are slightly less stringent than those from our previous analysis, which used a narrower energy window of 10-100 keV.

  9. Production of the Doubly Heavy Baryons, $B_c$ meson and the Tetra-c-quark at the Fixed-target Experiment at the LHC with double intrinsic heavy approach

    CERN Document Server

    Koshkarev, Sergey

    2016-01-01

    In the paper we discuss production of the $B_c$ meson, the doubly heavy baryons and the tetra-c-quark at the future fixed-target experiment at the LHC (AFTER@LHC) with the doubly intrinsic heavy mechanism. The production cross sections are present.

  10. A NEW EXPERIMENT SEARCHING FOR DARK MATTER AT CERN

    CERN Multimedia

    2016-01-01

    The NA64 experiment started operations at CERN’s North Area earlier this year. It uses a unique setup to hunt down a specific type of dark matter particle called the dark photon. Some theories suggest that dark matter consists of a family of new particles and forces. In addition to gravity, dark-matter particles could interact with visible matter through a new force, which has so far escaped detection. Just as the electromagnetic force is carried by the photon, this dark force is thought to be transmitted by a particle called the dark photon. It is predicted to have a subtle interaction (a “mixing”, in particle-physics jargon) with the regular photon and therefore act as a mediator between visible and dark matter. CERN’s NA64 experiment looks for signatures of this visible-dark interaction using a simple but powerful physics concept: the conservation of energy. A beam of electrons coming from the Super Proton Synchrotron accelerator, whose initial energy is very precisely known (100 G

  11. Phases of Strongly Interacting Matter in the Brahms Experiment

    Science.gov (United States)

    Staszel, P.

    2007-11-01

    We review results obtained by the BRAHMS experiment at the Relativistic Heavy Ion Collider (RHIC) for the systems of Au + Au and Cu + Cu colliding at √ {sNN} = 200 GeV and at 62.4 GeV, and p + p colliding at √ {sNN} = 200 GeV. The observed number of charged particles produced per unit of rapidity in the central rapidity region indicates that a high energy density system is produced at the initial stage of the Au + Au reaction. Analysis of anti-particle to particle ratios as a function of rapidity and collision energy reveal that particle populations at the chemical freeze-out stage for heavy-ion reactions at and above SPS energies are controlled by the baryon chemical potential. We present rapidity dependent bar {p}/π - ratios within 0 < y < 3 for Au + Au and Cu + Cu at √ {sNN} = 200 GeV. The ratios are enhanced in nucleus-nucleus collisions as compared to p + p collisions. The particle ratios are discussed in terms of their system size and rapidity dependence. From comparison of RAA for different systems and energies it is found that RAA increases with decreasing collision energy, decreasing system size, and when going towards more peripheral collisions. However, RAA shows only a very weak dependence on rapidity (for 0 < y < 3.2), both for pions and protons.

  12. Holographic heavy ion collisions with baryon charge

    CERN Document Server

    Casalderrey-Solana, Jorge; van der Schee, Wilke; Triana, Miquel

    2016-01-01

    We numerically simulate collisions of charged shockwaves in Einstein-Maxwell theory in anti-de Sitter space as a toy model of heavy ion collisions with non-zero baryon charge. The stress tensor and the baryon current become well described by charged hydrodynamics at roughly the same time. The effect of the charge density on generic observables is typically no larger than 15\\%. %The rapidity profile of the charge is wider than the profile of the local energy density. We find significant stopping of the baryon charge and compare our results with those in heavy ion collision experiments.

  13. Baryon stopping and quark-gluon plasma production at RHIC and LHC

    Energy Technology Data Exchange (ETDEWEB)

    Lyakhov, K.

    2008-08-15

    Strong chromofields developed at early stages of relativistic heavy-ion collisions give rise to the collective deceleration of net baryons from colliding nuclei. We have solved classical equations of motion for baryonic slabs under the action of time-dependent chromofield. We have studied sensitivity of the slab trajectories and their final rapidities to the initial strength and decay pattern of the chromofield as well as to the back reaction of produced plasma. This mechanism can naturally explain significant baryon stopping observed at RHIC, an average rapidity loss left angle {delta}y right angle {approx} 2. Using a Bjorken hydrodynamical model with particle producing source we also study the evolution of partonic plasma produced as the result of chromofield decay. Due to the delayed formation and expansion of plasma its maximum energy density is much lower than the initial energy density of the chromofield. It is shown that the net-baryon and produced parton distributions are strongly correlated in the rapidity space. The shape of net-baryon spectra in midrapidity region found in the BRAHMS experiment cannot be reproduced by only one value of chromofield energy density parameter {epsilon}{sub 0}, even if one takes into account novel mechanisms as fluctuations of color charges generated on the slab surface, and weak interaction of baryon-rich matter with produced plasma. The further step to improve our results is to take into account rapidity dependence of saturation momentum as explained in thesis. Different values of parameter {epsilon}{sub 0} has been tried for different variants of chromofield decay to fit BRAHMS data for net-baryon rapidity distribution. In accordance with our analysis, data for fragmentation region correspond to the lower chromofield energy densities than mid-rapidity region. {chi}{sup 2} analysis favors power-law of chromofield decay with corresponding initial chromofield energy density of order {epsilon}{sub f}=30 GeV/fm{sup 3}. (orig.)

  14. Boosted Dark Matter at the Deep Underground Neutrino Experiment

    CERN Document Server

    Alhazmi, Haider; Mohlabeng, Gopolang; Park, Jong-Chul

    2016-01-01

    We investigate the detection prospects of a non-standard dark sector in the context of boosted dark matter. We consider a scenario where two stable particles have a large mass difference and the heavier particle accounts for most of dark matter in our current universe. The heavier candidate is assumed to have no interaction with the standard model particles at tree-level, hence evading existing constraints. Although subdominant, the lighter dark matter particles are efficiently produced via pair-annihilation of the heavier ones in the center of the Galaxy or the Sun. The large Lorentz boost enables detection of the non-minimal dark sector in large volume terrestrial experiments via exchange of a light dark photon with electrons or nuclei. Various experiments designed for neutrino physics and proton decay are examined in detail, including Super-K and Hyper-K. In this study, we focus on the sensitivity of the far detector at the Deep Underground Neutrino Experiment for boosted dark matter produced in the center...

  15. The baryon content of the Cosmic Web

    Science.gov (United States)

    Eckert, Dominique; Jauzac, Mathilde; Shan, HuanYuan; Kneib, Jean-Paul; Erben, Thomas; Israel, Holger; Jullo, Eric; Klein, Matthias; Massey, Richard; Richard, Johan; Tchernin, Céline

    2015-01-01

    Big-Bang nucleosynthesis indicates that baryons account for 5% of the Universe’s total energy content[1]. In the local Universe, the census of all observed baryons falls short of this estimate by a factor of two[2,3]. Cosmological simulations indicate that the missing baryons have not yet condensed into virialised halos, but reside throughout the filaments of the cosmic web: a low-density plasma at temperature 105–107 K known as the warm-hot intergalactic medium (WHIM)[3,4,5,6]. There have been previous claims of the detection of warm baryons along the line of sight to distant blazars[7,8,9,10] and hot gas between interacting clusters[11,12,13,14]. These observations were however unable to trace the large-scale filamentary structure, or to estimate the total amount of warm baryons in a representative volume of the Universe. Here we report X-ray observations of filamentary structures of ten-million-degree gas associated with the galaxy cluster Abell 2744. Previous observations of this cluster[15] were unable to resolve and remove coincidental X-ray point sources. After subtracting these, we reveal hot gas structures that are coherent over 8 Mpc scales. The filaments coincide with over-densities of galaxies and dark matter, with 5-10% of their mass in baryonic gas. This gas has been heated up by the cluster's gravitational pull and is now feeding its core. PMID:26632589

  16. Integrating In Dark Matter Astrophysics at Direct Detection Experiments

    CERN Document Server

    Friedland, Alexander

    2013-01-01

    We study the capabilities of the MAJORANA DEMONSTRATOR, a neutrinoless double-beta decay experiment currently under construction at the Sanford Underground Laboratory, as a light WIMP detector. For a cross section near the current experimental bound, the MAJORANA DEMONSTRATOR should collect hundreds or even thousands of recoil events. This opens up the possibility of simultaneously determining the physical properties of the dark matter and its local velocity distribution, directly from the data. We analyze this possibility and find that allowing the dark matter velocity distribution to float considerably worsens the WIMP mass determination. This result is traced to a previously unexplored degeneracy between the WIMP mass and the velocity dispersion. We simulate spectra using both isothermal and Via Lactea II velocity distributions and comment on the possible impact of streams. We conclude that knowledge of the dark matter velocity distribution will greatly facilitate the mass and cross section determination f...

  17. Octet baryon electromagnetic form factors in nuclear medium

    CERN Document Server

    Ramalho, G; Thomas, A W

    2012-01-01

    We study the octet baryon electromagnetic form factors in nuclear matter using the covariant spectator quark model extended to the nuclear matter regime. The parameters of the model in vacuum are fixed by the study of the octet baryon electromagnetic form factors. In nuclear matter the changes in hadron properties are calculated by including the relevant hadron masses and the modification of the pion-baryon coupling constants calculated in the quark-meson coupling model. In nuclear matter the magnetic form factors of the octet baryons are enhanced in the low $Q^2$ region, while the electric form factors show a more rapid variation with $Q^2$. The results are compared with the modification of the bound proton electromagnetic form factors observed at Jefferson Lab. In addition, the corresponding changes for the bound neutron are predicted.

  18. Heavy Flavor Baryons at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Kuhr, Thomas

    2011-09-01

    The Tevatron experiments CDF and D0 have filled many empty spots in the spectrum of heavy baryons over the last few years. The most recent results are described in this article: The first direct observation of the {Xi}{sub b}{sup 0}, improved measurements of {Sigma}{sub b} properties, a new measurement of the {Lambda}{sub b} {yields} J/{psi}{Lambda} branching ratio, and a high-statistics study of charm baryons.

  19. A direct measurement of the baryonic mass function of galaxies & implications for the galactic baryon fraction

    CERN Document Server

    Papastergis, Emmanouil; Huang, Shan; Giovanelli, Riccardo; Haynes, Martha P

    2012-01-01

    We use both an HI-selected and an optically-selected galaxy sample to directly measure the abundance of galaxies as a function of their "baryonic" mass (stars + atomic gas). Stellar masses are calculated based on optical data from the Sloan Digital Sky Survey (SDSS) and atomic gas masses are calculated using atomic hydrogen (HI) emission line data from the Arecibo Legacy Fast ALFA (ALFALFA) survey. By using the technique of abundance matching, we combine the measured baryonic function (BMF) of galaxies with the dark matter halo mass function in a LCDM universe, in order to determine the galactic baryon fraction as a function of host halo mass. We find that the baryon fraction of low-mass halos is much smaller than the cosmic value, even when atomic gas is taken into account. We find that the galactic baryon deficit increases monotonically with decreasing halo mass, in contrast with previous studies which suggested an approximately constant baryon fraction at the low-mass end. We argue that the observed baryon...

  20. Baryon form factors

    CERN Document Server

    Kubis, B; Meißner, Ulf G; Mei{\\ss}ner, Ulf-G.

    1999-01-01

    We calculate the form factors of the baryon octet in the framework of heavy baryon chiral perturbation theory. The calculated charge radius of the show that kaon loop effects can play a significant role in the neutron electric form factor. Furthermore. we derive generalized Caldi-Pagels relations between various charge radii which are free of chiral loop effects.

  1. Geneva University: Dark matter Search with the CDMS experiment

    CERN Multimedia

    Université de Genève

    2011-01-01

    Geneva University Physics Department 24, quai Ernest-Ansermet CH-1211 Geneva 4 Tel: (022) 379 62 73 Fax: (022) 379 69 92   Wednesday 21 September 2011 PARTICLE PHYSICS SEMINAR at 17.00 hrs – Stückelberg Auditorium “ Dark matter Search with the CDMS experiment ” Par Dr. Sebastian Arrenberg, Université de Zürich The Cryogenic Dark Matter Search experiment (CDMS) employs a total of 30 germanium and silicon detectors at the Soudan Underground Laboratory to detect weakly interacting massive particles (WIMPs) via their scattering from the target nuclei. Previous CDMS results, released in December 2009, set the world leading limit on the spin-independent WIMP-nucleon cross section above WIMP masses of ~50 GeV/c2 assuming elastic scattering.  In a subsequent analysis we investigated the inelastic dark matter scenario which was proposed to reconcile the disagreement between the results of DAMA/LIBRA and other existing dark matter searc...

  2. Signatures of Hierarchical Clustering in Dark Matter Detection Experiments

    CERN Document Server

    Stiff, D; Frieman, Joshua A

    2001-01-01

    In the cold dark matter model of structure formation, galaxies are assembled hierarchically from mergers and the accretion of subclumps. This process is expected to leave residual substructure in the Galactic dark halo, including partially disrupted clumps and their associated tidal debris. We develop a model for such halo substructure and study its implications for dark matter (WIMP and axion) detection experiments. We combine the Press-Schechter model for the distribution of halo subclump masses with N-body simulations of the evolution and disruption of individual clumps as they orbit through the evolving Galaxy to derive the probability that the Earth is passing through a subclump or stream of a given density. Our results suggest that it is likely that the local complement of dark matter particles includes a 1-5% contribution from a single clump. The implications for dark matter detection experiments are significant, since the disrupted clump is composed of a `cold' flow of high-velocity particles. We desc...

  3. Results from the DarkSide-50 Dark Matter Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Alden [Univ. of California, Los Angeles, CA (United States)

    2016-01-01

    While there is tremendous astrophysical and cosmological evidence for dark matter, its precise nature is one of the most significant open questions in modern physics. Weakly interacting massive particles (WIMPs) are a particularly compelling class of dark matter candidates with masses of the order 100 GeV and couplings to ordinary matter at the weak scale. Direct detection experiments are aiming to observe the low energy (<100 keV) scattering of dark matter off normal matter. With the liquid noble technology leading the way in WIMP sensitivity, no conclusive signals have been observed yet. The DarkSide experiment is looking for WIMP dark matter using a liquid argon target in a dual-phase time projection chamber located deep underground at Gran Sasso National Laboratory (LNGS) in Italy. Currently filled with argon obtained from underground sources, which is greatly reduced in radioactive 39Ar, DarkSide-50 recently made the most sensitive measurement of the 39Ar activity in underground argon and used it to set the strongest WIMP dark matter limit using liquid argon to date. This work describes the full chain of analysis used to produce the recent dark matter limit, from reconstruction of raw data to evaluation of the final exclusion curve. The DarkSide- 50 apparatus is described in detail, followed by discussion of the low level reconstruction algorithms. The algorithms are then used to arrive at three broad analysis results: The electroluminescence signals in DarkSide-50 are used to perform a precision measurement of ii longitudinal electron diffusion in liquid argon. A search is performed on the underground argon data to identify the delayed coincidence signature of 85Kr decays to the 85mRb state, a crucial ingredient in the measurement of the 39Ar activity in the underground argon. Finally, a full description of the WIMP search is given, including development of cuts, efficiencies, energy scale, and exclusion

  4. Recent Progress in Understanding the Baryon Resonance Spectrum

    Science.gov (United States)

    Crede, Volker

    2017-01-01

    Baryons are complex systems of confined quarks and gluons and exhibit the characteristic spectra of excited states. These states are sensitive to the details of quark confinement, which is only poorly understood with quantum chromodynamics (QCD), the fundamental theory of the strong interaction. To gain insight into this complex dynamics, the baryonic excitation spectrum has been studied for many years. The key question remains what are the relevant degrees of freedom for the resonance physics of QCD. Are the so-called constituent quarks the most efficient way to describe reaction amplitudes and the excitation spectrum of QCD with light quarks? To what extent are diquark correlations, gluonic modes or hadronic degrees of freedom important in this physics? In recent years, lattice-QCD has made significant progress toward understanding the spectra of hadrons, reducing statistical uncertainties and employing robust techniques for spin identication. However, a calculation of the physical excited baryon spectrum is still a tough challenge with present computing power. On the experimental side, high-energy electrons and photons are a remarkably clean probe of hadronic matter, providing a microscope for examining atomic nuclei and the strong nuclear force. Significant progress has been achieved with the recent availability of new polarization data, utilizing polarized beams and/or polarized targets at various laboratories worldwide, e.g. Jefferson Lab in the United States. These are important steps toward so-called complete experiments that will allow us to unambiguously determine the scattering amplitudes in the underlying reactions and to identify resonance contributions. In this presentation, I will give an overview of the excited baryon program and I will discuss the current (experimental) status of the nucleon excitation spectrum. Support is acknowledged from the Department of Energy grant #DE-FG02-92ER40735.

  5. Searching for light dark matter with the SLAC millicharge experiment.

    Science.gov (United States)

    Diamond, M; Schuster, P

    2013-11-27

    New sub-GeV gauge forces ("dark photons") that kinetically mix with the photon provide a promising scenario for MeV-GeV dark matter and are the subject of a program of searches at fixed-target and collider facilities around the world. In such models, dark photons produced in collisions may decay invisibly into dark-matter states, thereby evading current searches. We reexamine results of the SLAC mQ electron beam dump experiment designed to search for millicharged particles and find that it was strongly sensitive to any secondary beam of dark matter produced by electron-nucleus collisions in the target. The constraints are competitive for dark photon masses in the ~1-30 MeV range, covering part of the parameter space that can reconcile the apparent (g-2)(μ) anomaly. Simple adjustments to the original SLAC search for millicharges may extend sensitivity to cover a sizable portion of the remaining (g-2)(μ) anomaly-motivated region. The mQ sensitivity is therefore complementary to ongoing searches for visible decays of dark photons. Compared to existing direct-detection searches, mQ sensitivity to electron-dark-matter scattering cross sections is more than an order of magnitude better for a significant range of masses and couplings in simple models.

  6. Charmed baryons on the lattice

    CERN Document Server

    Padmanath, M

    2015-01-01

    We discuss the significance of charm baryon spectroscopy in hadron physics and review the recent developments of the spectra of charmed baryons in lattice calculations. Special emphasis is given on the recent studies of highly excited charm baryon states. Recent precision lattice measurements of the low lying charm and bottom baryons are also reviewed.

  7. decays to baryons

    Indian Academy of Sciences (India)

    Torsten Leddig

    2012-11-01

    From inclusive measurements, it is known that about 7% of all mesons decay into final states with baryons. In these decays, some striking features become visible compared to mesonic decays. The largest branching fractions come with quite moderate multiplicities of 3–4 hadrons. We note that two-body decays to baryons are suppressed relative to three- and four-body decays. In most of these analyses, the invariant baryon–antibaryon mass shows an enhancement near the threshold. We propose a phenomenological interpretation of this quite common feature of hadronization to baryons.

  8. Final Results of the PICASSO Dark Matter Search Experiment

    CERN Document Server

    Behnke, E; Bhattacharjee, P; Dai, X; Das, M; Davour, A; Debris, F; Dhungana, N; Farine, J; Fines-Neuschild, M; Gagnebin, S; Giroux, G; Grace, E; Jackson, C M; Kamaha, A; Krauss, C B; Lafrenière, M; Laurin, M; Lawson, I; Lessard, L; Levine, I; Marlisov, D; Martin, J -P; Mitra, P; Noble, A J; Plante, A; Podviyanuk, R; Pospisil, S; Scallon, O; Seth, S; Starinski, N; Stekl, I; Wichoski, U; Zacek, V

    2016-01-01

    The PICASSO dark matter search experiment operated an array of 32 superheated droplet detectors containing 3.2 kg of C$_{4}$F$_{10}$ and collected an exposure of 231.4 kg days at SNOLAB between March 2012 and January 2014. We report on the final results of this experiment which includes for the first time the complete data set and improved analysis techniques including acoustic localization to allow fiducialization and removal of higher activity regions within the detectors. No signal consistent with dark matter was observed. We set limits for spin-dependent interactions on protons of $\\sigma_p^{SD}$ = 1.32 $\\times$ 10$^{-2}$ pb (90% C.L.) at a WIMP mass of 20 GeV/c$^{2}$. In the spin-independent sector we exclude cross sections larger than $\\sigma_p^{SI}$ = 4.86 $\\times$ 10$^{-5 }$ pb (90% C.L.) in the region around 7 GeV/c$^{2}$. The pioneering efforts of the PICASSO experiment have paved the way forward for a next generation detector incorporating much of this technology and experience into larger mass bub...

  9. Physics from solar neutrinos in dark matter direct detection experiments

    CERN Document Server

    Cerdeño, David G; Jubb, Thomas; Machado, Pedro A N; Vincent, Aaron C; hm, Céline Bøe

    2016-01-01

    The next generation of dark matter direct detection experiments will be sensitive to both coherent neutrino-nucleus and neutrino-electron scattering. This will enable them to explore aspects of solar physics, perform the lowest energy measurement of the weak angle to date, and probe contributions from new theories with light mediators. In this article, we compute the projected nuclear and electron recoil rates expected in several dark matter direct detection experiments due to solar neutrinos, and use these estimates to infer errors on future measurements of the neutrino fluxes, weak mixing angle and solar observables, as well as to constrain new physics in the neutrino sector. The combined rates of solar neutrino events in second generation experiments (SuperCDMS and LZ) can yield a measurement of the pp flux to 2.5% accuracy via electron recoil, and slightly improve the boron-8 flux determination. Assuming a low-mass argon phase, projected tonne-scale experiments like DARWIN can reduce the uncertainty on bo...

  10. First Dark Matter Results from the XENON100 Experiment

    CERN Document Server

    Aprile, E; Arneodo, F; Askin, A; Baudis, L; Behrens, A; Brown, E; Cardoso, J M R; Choi, B; Cline, D B; Fattori, S; Ferella, A D; Giboni, K -L; Hugenberg, K; Kish, A; Lam, C W; Lamblin, J; Lang, R F; Lim, K E; Lopes, J A M; Undagoitia, T Marrodán; Mei, Y; Fernandez, A J Melgarejo; Ni, K; Oberlack, U; Orrigo, S E A; Pantic, E; Plante, G; Ribeiro, A C C; Santorelli, R; Santos, J M F dos; Schumann, M; Shagin, P; Teymourian, A; Thers, D; Tziaferi, E; Wang, H; Weinheimer, C

    2010-01-01

    The XENON100 experiment, in operation at the Laboratori Nazionali del Gran Sasso in Italy, is designed to search for dark matter WIMPs scattering off 62 kg of liquid xenon in an ultra-low background dual-phase time projection chamber. In this letter, we present first dark matter results from the analysis of 11.17 live days of non-blind data, acquired in October and November 2009. In the selected fiducial target of 40 kg, and within the pre-defined signal region, we observe no events and hence exclude spin-independent WIMP-nucleon elastic scattering cross-sections above 3 x 10^-44 cm^2 for 50 GeV/c^2 WIMPs at 90% confidence level. Below 20 GeV/c^2, this result challenges the interpretation of the CoGeNT or DAMA signals as being due to spin-independent, elastic, light mass WIMP interactions.

  11. High-Energy Neutron Backgrounds for Underground Dark Matter Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yu [Syracuse Univ., NY (United States)

    2016-01-01

    Direct dark matter detection experiments usually have excellent capability to distinguish nuclear recoils, expected interactions with Weakly Interacting Massive Particle (WIMP) dark matter, and electronic recoils, so that they can efficiently reject background events such as gamma-rays and charged particles. However, both WIMPs and neutrons can induce nuclear recoils. Neutrons are then the most crucial background for direct dark matter detection. It is important to understand and account for all sources of neutron backgrounds when claiming a discovery of dark matter detection or reporting limits on the WIMP-nucleon cross section. One type of neutron background that is not well understood is the cosmogenic neutrons from muons interacting with the underground cavern rock and materials surrounding a dark matter detector. The Neutron Multiplicity Meter (NMM) is a water Cherenkov detector capable of measuring the cosmogenic neutron flux at the Soudan Underground Laboratory, which has an overburden of 2090 meters water equivalent. The NMM consists of two 2.2-tonne gadolinium-doped water tanks situated atop a 20-tonne lead target. It detects a high-energy (>~ 50 MeV) neutron via moderation and capture of the multiple secondary neutrons released when the former interacts in the lead target. The multiplicity of secondary neutrons for the high-energy neutron provides a benchmark for comparison to the current Monte Carlo predictions. Combining with the Monte Carlo simulation, the muon-induced high-energy neutron flux above 50 MeV is measured to be (1.3 ± 0.2) ~ 10-9 cm-2s-1, in reasonable agreement with the model prediction. The measured multiplicity spectrum agrees well with that of Monte Carlo simulation for multiplicity below 10, but shows an excess of approximately a factor of three over Monte Carlo prediction for multiplicities ~ 10 - 20. In an effort to reduce neutron backgrounds for the dark matter experiment SuperCDMS SNO- LAB, an active neutron veto was developed

  12. Dark matter

    OpenAIRE

    Einasto, J.

    2011-01-01

    I give a review of the development of the concept of dark matter. The dark matter story passed through several stages from a minor observational puzzle to a major challenge for theory of elementary particles. Modern data suggest that dark matter is the dominant matter component in the Universe, and that it consists of some unknown non-baryonic particles. Properties of dark matter particles determine the structure of the cosmic web.

  13. Aspects of baryon structure in lattice QCD

    Science.gov (United States)

    Babich, Ronald

    Despite the long success of Quantum Chromodynamics (QCD) as the theory of the strong interactions, there remains much to be understood about the structure of hadrons and the consequences of QCD in the nonperturbative regime. Lattice gauge theory, a framework nearly as old as QCD itself, makes calculations in this regime possible, starting from first principles. With advances in theoretical understanding, methods, and computer technology, the lattice has found application to an ever-widening range of problems. In this dissertation, I consider two such problems having to do with the structure of baryons. The first concerns the contribution of sea quarks, and the strange quark in particular, to form factors of the nucleon. This has been a long-standing challenge for the lattice, because such contributions involve the insertion of a current on a quark loop, demanding the full inversion of the discretized Dirac operator, conceptually a large sparse matrix. I discuss methods for addressing this challenge and present a calculation of the strange scalar form factor and the related parameter fTs. The latter is of great theoretical interest, since it enters into the cross section for the scattering of dark matter off nuclei in supersymmetric extensions of the standard model. As such, it represents a major uncertainty in the interpretation of direct detection experiments. I also present results for the strange quark contribution to the nucleon's axial and electromagnetic form factors, which are themselves the subject of active experimental programs. These calculations were performed using the Wilson fermion formulation on a 243 x 64 anisotropic lattice. In the second part of the dissertation, I turn to the valence sector and address the role of diquark correlations in the observed spectrum of hadrons and their properties. A diquark is a correlated pair of quarks, thought to play an important role in certain phenomenological models of hadrons. I present results for baryon wave

  14. Hybrid Baryon Signatures

    CERN Document Server

    Page, P R

    2000-01-01

    We discuss whether a low-lying hybrid baryon should be defined as a three quark - gluon bound state or as three quarks moving on an excited adiabatic potential. We show that the latter definition becomes exact, not only for very heavy quarks, but also for specific dynamics. We review the literature on the signatures of hybrid baryons, with specific reference to strong hadronic decays, electromagnetic couplings, diffractive production and production in psi decay.

  15. 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...

  16. Status of the DAMIC direct dark matter search experiment

    CERN Document Server

    Aguilar-Arevalo, A; Bertou, X; Boule, D; Butner, M; Cancelo, G; Vázquez, A Castañeda; Chavarría, A E; Neto, J R T de Melo; Dixon, S; D'Olivo, J C; Estrada, J; Moroni, G Fernandez; Torres, K P Hernández; Izraelevitch, F; Kavner, A; Kilminster, B; Lawson, I; Liao, J; López, M; Molina, J; Moreno-Granados, G; Pena, J; Privitera, P; Sarkis, Y; Scarpine, V; Schwartz, T; Haro, M Sofo; Tiffenberg, J; Machado, D Torres; Trillaud, F; You, X; Zhou, J

    2015-01-01

    The DAMIC experiment uses fully depleted, high resistivity CCDs to search for dark matter particles. With an energy threshold $\\sim$50 eV$_{ee}$, and excellent energy and spatial resolutions, the DAMIC CCDs are well-suited to identify and suppress radioactive backgrounds, having an unrivaled sensitivity to WIMPs with masses $<$6 GeV/$c^2$. Early results motivated the construction of a 100 g detector, DAMIC100, currently being installed at SNOLAB. This contribution discusses the installation progress, new calibration efforts near the threshold, a preliminary result with 2014 data, and the prospects for physics results after one year of data taking.

  17. Status of the DAMIC Direct Dark Matter Search Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Arevalo, A.; et al.

    2015-09-30

    The DAMIC experiment uses fully depleted, high resistivity CCDs to search for dark matter particles. With an energy threshold $\\sim$50 eV$_{ee}$, and excellent energy and spatial resolutions, the DAMIC CCDs are well-suited to identify and suppress radioactive backgrounds, having an unrivaled sensitivity to WIMPs with masses $<$6 GeV/$c^2$. Early results motivated the construction of a 100 g detector, DAMIC100, currently being installed at SNOLAB. This contribution discusses the installation progress, new calibration efforts near the threshold, a preliminary result with 2014 data, and the prospects for physics results after one year of data taking.

  18. Experiments on extreme states of matter towards HIF at FAIR

    Directory of Open Access Journals (Sweden)

    Sharkov Boris

    2013-11-01

    Full Text Available The Facility for Antiproton and Ion Research in Europe (FAIR will provide worldwide unique accelerator and experimental facilities allowing for a large variety of unprecedented frontier research in extreme state of matter physics and applied science. Indeed, it is the largest basic research project on the roadmap of the European Strategy Forum of Research Infrastructures (ESFRI, and it is cornerstone of the European Research Area. FAIR offers to scientists from the whole world an abundance of outstanding research opportunities, broader in scope than any other contemporary large-scale facility worldwide. More than 2500 scientists are involved in setting up and exploiting the FAIR facility. They will push the frontiers of our knowledge in plasma, nuclear, atomic, hadron and applied physics far ahead, with important implications also for other fields in science such as cosmology, astro and particle physics, and technology. It includes 14 initial experiments, which form the four scientific pillars of FAIR. The main thrust of intense heavy ion and laser beam-matter interaction research focuses on the structure and evolution of extreme state of matter on both a microscopic and on a cosmic scale.

  19. Experiments on extreme states of matter towards HIF at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Sharkov, Boris, E-mail: boris.sharkov@fair-center.eu [FAIR GmbH, Planckstrasse 1, 64291 Darmstadt (Germany); Varentsov, Dmitry [GSI Helmholtzzentrum für Schwerionenforshung GmbH, Planckstrasse 1, 64291 Darmstadt (Germany)

    2014-01-01

    The Facility for Antiproton and Ion Research in Europe (FAIR) will provide worldwide unique accelerator and experimental facilities allowing for a large variety of unprecedented frontier research in extreme state of matter physics and applied science. Indeed, it is the largest basic research project on the roadmap of the European Strategy Forum of Research Infrastructures (ESFRI), and it is cornerstone of the European Research Area. FAIR offers to scientists from the whole world an abundance of outstanding research opportunities, broader in scope than any other contemporary large-scale facility worldwide. More than 2500 scientists are involved in setting up and exploiting the FAIR facility. They will push the frontiers of our knowledge in plasma, nuclear, atomic, hadron and applied physics far ahead, with important implications also for other fields in science such as cosmology, astro and particle physics, and technology. It includes 14 initial experiments, which form the four scientific pillars of FAIR. The main thrust of intense heavy ion and laser beam-matter interaction research focuses on the structure and evolution of extreme state of matter on both a microscopic and on a cosmic scale.

  20. The VIMOS Public Extragalactic Redshift Survey (VIPERS). The matter density and baryon fraction from the galaxy power spectrum at redshift $0.6

    CERN Document Server

    Rota, S; Bel, J; Guzzo, L; Peacock, J A; Wilson, M J; Pezzotta, A; de la Torre, S; Garilli, B; Bolzonella, M; Scodeggio, M; Abbas, U; Adami, C; Bottini, D; Cappi, A; Cucciati, O; Davidson, I; Franzetti, P; Fritz, A; Iovino, A; Krywult, J; Brun, V Le; Fèvre, O Le; Mascagni, D; Małek, K; Marulli, F; Percival, W J; Polletta, M; Pollo, A; Tasca, L A M; Tojeiro, R; Vergani, D; Zanichelli, A; Arnouts, S; Branchini, E; Coupon, J; De Lucia, G; Ilbert, O; Moscardini, L; Moutard, T

    2016-01-01

    We use the final catalogue of the VIMOS Public Extragalactic Redshift Survey (VIPERS) to measure the power spectrum of the galaxy distribution at high redshift, presenting results that extend beyond $z=1$ for the first time. We apply an FFT technique to four independent sub-volumes comprising a total of $51,728$ galaxies at $0.6baryon fraction $\\smash{f_B=\\Omega_B/\\Omega_M=0.220^{+0.058}_{-0.072}}$. These inferences from the high-$z$ galaxy dis...

  1. Dark Matter and Baryons in the Most X-ray Luminous and Merging Galaxy Cluster RX J1347.5-1145

    CERN Document Server

    Bradac, Marusa; Erben, Thomas; McCourt, Michael; Million, Evan; Mantz, Adam; Allen, Steve; Blandford, Roger; Halkola, Aleksi; Hildebrand, Hendrik; Lombardi, Marco; Marshall, Phil; Schneider, Peter; Treu, Tommaso; Kneib, Jean-Paul

    2007-01-01

    The galaxy cluster RX J1347-1145 is one of the most X-ray luminous and most massive clusters known. Its extreme mass makes it a prime target for studying issues addressing cluster formation and cosmology. In this paper we present new high-resolution HST/ACS and Chandra X-ray data. The high resolution and sensitivity of ACS enabled us to detect and quantify several new multiply imaged sources, we now use a total of eight for the strong lensing analysis. Combining this information with shape measurements of weak lensing sources in the central regions of the cluster, we derive a high-resolution, absolutely-calibrated mass map. This map provides the best available quantification of the total mass of the central part of the cluster to date. We compare the reconstructed mass with that inferred from the new Chandra X-ray data, and conclude that both mass estimates agree extremely well in the observed region, namely within 400 / h_70 kpc of the cluster center. In addition we study the major baryonic components (gas a...

  2. Model-independent approach for dark matter phenomenology: Signatures in linear colliders and cosmic positron experiments

    Indian Academy of Sciences (India)

    Shigeki Matsumoto; Nobuchika Okada

    2007-11-01

    We have studied the phenomenology of dark matter at the ILC and cosmic positron experiments based on model-independent approach. We have found a strong correlation between dark matter signatures at the ILC and those in the indirect detection experiments of dark matter. Once the dark matter is discovered in the positron experiments such as the PAMELA, its nature will be investigated in detail at the ILC.

  3. Update on the MiniCLEAN Dark Matter Experiment

    CERN Document Server

    Rielage, K; Bodmer, M; Bourque, R; Buck, B; Butcher, A; Caldwell, T; Chen, Y; Coakley, K; Flores, E; Formaggio, J A; Gastler, D; Giuliani, F; Gold, M; Grace, E; Griego, J; Guerrero, N; Guiseppe, V; Henning, R; Hime, A; Jaditz, S; Kachulis, C; Kearns, E; Kelsey, J; Klein, J R; Latorre, A; Lawson, I; Linden, S; Lopez, F; McKinsey, D N; MacMullin, S; Mastbaum, A; Mei, D -M; Monroe, J; Nikkel, J A; Oertel, J; Gann, G D Orebi; Palladino, K; Perumpilly, G; Rodriguez, L; Schnee, R; Seibert, S; Walding, J; Wang, B; Wang, J; Zhang, C

    2014-01-01

    The direct search for dark matter is entering a period of increased sensitivity to the hypothetical Weakly Interacting Massive Particle (WIMP). One such technology that is being examined is a scintillation only noble liquid experiment, MiniCLEAN. MiniCLEAN utilizes over 500 kg of liquid cryogen to detect nuclear recoils from WIMP dark matter and serves as a demonstration for a future detector of order 50 to 100 tonnes. The liquid cryogen is interchangeable between argon and neon to study the A$^{2}$ dependence of the potential signal and examine backgrounds. MiniCLEAN utilizes a unique modular design with spherical geometry to maximize the light yield using cold photomultiplier tubes in a single-phase detector. Pulse shape discrimination techniques are used to separate nuclear recoil signals from electron recoil backgrounds. MiniCLEAN will be spiked with additional $^{39}$Ar to demonstrate the effective reach of the pulse shape discrimination capability. Assembly of the experiment is underway at SNOLAB and an...

  4. Baryon Spectroscopy and Resonances

    Energy Technology Data Exchange (ETDEWEB)

    Robert Edwards

    2011-12-01

    A short review of current efforts to determine the highly excited state spectrum of QCD, and in particular baryons, using lattice QCD techniques is presented. The determination of the highly excited spectrum of QCD is a major theoretical and experimental challenge. The experimental investigation of the excited baryon spectrum has been a long-standing element of the hadronic-physics program, an important component of which is the search for so-called 'missing resonances', baryonic states predicted by the quark model based on three constituent quarks but which have not yet been observed experimentally. Should such states not be found, it may indicate that the baryon spectrum can be modeled with fewer effective degrees of freedom, such as in quark-diquark models. In the past decade, there has been an extensive program to collect data on electromagnetic production of one and two mesons at Jefferson Lab, MIT-Bates, LEGS, MAMI, ELSA, and GRAAL. To analyze these data, and thereby refine our knowledge of the baryon spectrum, a variety of physics analysis models have been developed at Bonn, George Washington University, Jefferson Laboratory and Mainz. To provide a theoretical determination and interpretation of the spectrum, ab initio computations within lattice QCD have been used. Historically, the calculation of the masses of the lowest-lying states, for both baryons and mesons, has been a benchmark calculation of this discretized, finite-volume computational approach, where the aim is well-understood control over the various systematic errors that enter into a calculation; for a recent review. However, there is now increasing effort aimed at calculating the excited states of the theory, with several groups presenting investigations of the low-lying excited baryon spectrum, using a variety of discretizations, numbers of quark flavors, interpolating operators, and fitting methodologies. Some aspects of these calculations remain unresolved and are the subject of

  5. Strange and multi-strange baryon measurement in Au + Au collisions at 11.6A(GeV/c) with the silicon drift detector array from the AGS experiment E896

    Energy Technology Data Exchange (ETDEWEB)

    Lo Curto, G.; Albergo, S.; Bellwied, R.; Bennett, M.; Boemi, D.; Bonner, B.; Caccia, Z.; Caines, H.; Christie, W.; Cina' , G.; Costa, S.; Crawford, H.; Cronqvist, M.; Debbe, R.; Engelage, J.; Flores, I.; Greiner, L.; Hallman, T.; Hoffman, G.; Huang, H.; Humanic, T.J.; Igo, G.; Insolia, A.; Jensen, P.; Judd, E.; Kainz, K.; Kaplan, M.; Kelly, S.; Kotov, I.; Kunde, G.; Lindstrom, P.; Ljubicic, T.; Llope, W.; Longacre, R.; Lynn, D.; Madansky, L.; Mahzeh, N.; Milosevich, Z.; Mitchell, J.T.; Mitchell, J.; Nehmeh, S.; Nociforo, C.; Paganis, S.; Pandey, S.U.; Potenza, R.; Platner, E.; Riley, P.; Russ, D.; Saulys, A.; Schambach, J.; Sheen, J.; Stokley, C.; Sugarbaker, E.; Takahashi, J.; Tang, J.; Trentalange, S.; Tricomi, A.; Tull, C.; Tuve' , C.; Whitfield, J.; Wilson, K

    1999-12-27

    The main purpose of experiment E896 is to study the production of strange hadrons, in particular the predicted six-quark di-baryon, the H{sub 0}. The placement of the silicon drift detector array (SDDA) close to the target in a 6.2T magnetic field is optimized for the reconstruction of a short lived H{sub 0} as well as of strange baryons ({lambda}, {lambda}-bar, {xi}{sup -}). Simulations show that with the present data sample a detailed study of the {lambda} and {xi}{sup -} yields and distributions may be performed and a clear {lambda}-bar signal might be detected. Simulations as well as a preliminary analysis of the SDDA data will be presented.

  6. Missing Baryons and the Warm-Hot Intergalactic Medium

    CERN Document Server

    Nicastro, F; Elvis, Martin

    2007-01-01

    Stars and gas in galaxies, hot intracluster medium, and intergalactic photo-ionized gas make up at most half of the baryons that are expected to be present in the universe. The majority of baryons are still missing and are expected to be hidden in a web of warm-hot intergalactic medium. This matter was shock-heated during the collapse of density perturbations that led to the formation of the relaxed structures that we see today. Finding the missing baryons and thereby producing a complete inventory of possibly the only detectable component of the energy-mass budget of the universe is crucial to validate or invalidate our standard cosmological model.

  7. Purification for the XENONnT dark matter experiment

    Science.gov (United States)

    Brown, Ethan; Xenon Collaboration

    2017-01-01

    The XENON1T experiment uses 3.5 tons of liquid xenon in a cryogenic detector to search for dark matter. Its upgrade, XENONnT, will similarly house 7.5 tons of liquid xenon. Operation of these large detectors requires continual purification of the xenon in an external purifier, and the need for less than part per billion level oxygen in the xenon, coupled with the large quantity of xenon to be purified, places high demands on the rate of flow through this purification system. Building on the success of the XENON10 and XENON100 experiments, XENON1T circulates gaseous xenon through heated getters at a rate of up to 100 SLPM, pushing commercial pumps to their limits moving this large quantity of gas without interruption for several years. Two upgrades are considered for XENONnT. A custom high-capacity magnetic piston pump based on the one developed for the EXO200 experiment has been scaled up to support the high demands of this much larger experiment. Additionally, a liquid phase circulation and purification system that purifies the cryogenic liquid directly is being developed, which takes advantage of the much smaller volumetric flow demands of liquid relative to gas. The implementation of both upgrades will be presented. Supported by the National Science Foundation.

  8. Exploring the mirror matter interpretation of the DAMA experiment: Has the dark matter problem been solved?

    OpenAIRE

    Foot, R.

    2004-01-01

    The self consistency between the impressive DAMA annual modulation signal and the differential energy spectrum is an important test for dark matter candidates.Mirror matter-type dark matter passes this test while other dark matter candidates, including standard (spin-independent) WIMPs and mini-electric charged particle dark matter, do not do so well.We argue that the unique properties of mirror matter-type dark matter seem to be just those required to fully explain the data, suggesting that ...

  9. Baryogenesis and Dark Matter in $U(1)$ Extensions

    CERN Document Server

    Feng, Wan-Zhe

    2016-01-01

    A brief review is given of some recent works where baryogenesis and dark matter have a common origin within the $U(1)$ extensions of the standard model and of the minimal supersymmetric standard model. The models considered generate the desired baryon asymmetry and the dark matter to baryon ratio. In one model all of the fundamental interactions do not violate lepton number, and the total $B-L$ in the Universe vanishes. In addition, one may also generate a normal hierarchy of neutrino masses and mixings in conformity with the current data. Specifically one can accommodate $\\theta_{13}\\sim 9^{\\circ}$ consistent with the data from Daya Bay reactor neutrino experiment.

  10. Flavour tagging with baryons and a study of two body $\\Lambda_b$ decays with the LHCb experiment

    CERN Document Server

    Storey, James William

    2008-01-01

    The LHCb experiment will perform precision measurements of CP-violation and search for rare B decays at the Large Hadron Collider (LHC), which is due to begin operation in 2008. The LHCb Ring Imaging Cherenkov (RICH) system provides the particle identification crucial for these studies. The Multi-Anode photomultiplier tube (MaPMT)is a candidate photon detector for the LHCb RICH system. Performance studies of the MaPMT in a charged particle beam at CERN demonstrate that the pulse shape of the BeetleMA readout ASIC does not return to zero after 125ns, which will lead to ghost pixel hits and the possible drift of the pedestal outside the dynamic range of the amplifier. Measurement of key CP asymmetries at LHCb requires that the flavour of the B-meson at creation is known. Flavour tagging using protons is shown to have potentially useful tagging performance, but the implementation is found to be challenging. A correlation between b-quark and Lambda flavour is observed for a Lambda produced in the same fragmentati...

  11. Charmed Bottom Baryon Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Zachary S; Detmold, William; Meinel, Stefan; Orginos, Kostas

    2014-11-01

    The spectrum of doubly and triply heavy baryons remains experimentally unexplored to a large extent. Although the detection of such heavy particle states may lie beyond the reach of exper- iments for some time, it is interesting compute this spectrum from QCD and compare results between lattice calculations and continuum theoretical models. Several lattice calculations ex- ist for both doubly and triply charmed as well as doubly and triply bottom baryons. Here, we present preliminary results from the first lattice calculation of doubly and triply heavy baryons including both charm and bottom quarks. We use domain wall fermions for 2+1 flavors (up down and strange) of sea and valence quarks, a relativistic heavy quark action for the charm quarks, and non-relativistic QCD for the heavier bottom quarks. We present preliminary results for the ground state spectrum.

  12. Baryonic Spectroscopy at BESIII

    Science.gov (United States)

    Liu, Fang

    Based on 106 million Ψ(3686) events collected with BESIII detector at BEPCII, some results on excited baryons from the partial wave analysis are presented. In the decay of ψ(3686) to pbar{p}π 0, two new baryonic excited states, Jpc = 1/2 + N(2300) and Jpc = 5/2 - N(2570) are significant, and additional 5 well known N* excited states are observed. In ψ(3686) to pbar{p}η , an excited-nucleon state N(1535) is dominant. In ψ(3686) to K - Λ bar{Ξ} + + c.c., two hyperons Ξ(1690) and Ξ(1820) are observed. In ψ(3686) to Λ bar{Σ }π + c.c., some excited strange baryons bar{Λ }* and Σ* are measured on the Σ+π- and Λπ- mass spectra.

  13. Observing Dark Worlds: A crowdsourcing experiment for dark matter mapping

    CERN Document Server

    Harvey, David; Noah-Vanhoucke, Joyce; Hamner, Ben; Salimans, Tim

    2013-01-01

    We present the results and conclusions from the citizen science competition `Observing Dark Worlds', where we asked participants to calculate the positions of dark matter halos from 120 catalogues of simulated weak lensing galaxy data, using computational methods. In partnership with Kaggle (http://www.kaggle.com), 357 users participated in the competition which saw 2278 downloads of the data and 3358 submissions. We found that the best algorithms improved on the benchmark code, LENSTOOL by > 30% and could measure the positions of > 3x10^14MSun halos to less than 5'' and < 10^14MSun to within 1'. In this paper, we present a brief overview of the winning algorithms with links to available code. We also discuss the implications of the experiment for future citizen science competitions.

  14. Unconventional Ideas for Axion and Dark Matter Experiments

    CERN Document Server

    Caspers, Fritz

    2015-01-01

    In this contribution an entirely different way compared to conventional approaches for axion, hidden photon and dark matter (DM) detection is proposed for discussion. The idea is to use living plants which are known to be very sensitive to all kind of environmental parameters, as detectors. A possible observable in such living plants could be the natural bio-photon level, a kind of metabolism related chemoluminescence. Another observable might be morphological changes or systematic leave movements. However a big problem for such kind of experiment would be the availability of a known, controllable and calibrated DM source. The objective of this small paper is primarily to trigger a debate and not so much to present a well-defined and clearly structured proposal.

  15. Nanostructured Soft Matter Experiment, Theory, Simulation and Perspectives

    CERN Document Server

    Zvelindovsky, Andrei V

    2007-01-01

    This book provides an interdisciplinary overview of a new and broad class of materials under the unifying name Nanostructured Soft Matter. It covers materials ranging from short amphiphilic molecules to block copolymers, proteins, colloids and their composites, microemulsions and bio-inspired systems such as vesicles. The book considers several fundamental questions, including: how self-assembly of various soft materials with internal structure at the nanoscale can be understood, controlled and in future used in the newly emerging field of soft nanotechnology. The book offers readers a view on the subject from different perspectives, combining modern experimental approaches from physical chemistry and physics with various theoretical techniques from physics, mathematics and the most advanced computer modelling. It is the first book of this sort in the field. All chapters are written by leading international experts, bringing together experience from Canada, Germany, Great Britain, Japan, the Netherlands, Russ...

  16. Reducing 68Ge Background in Dark Matter Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Orrell, John L.

    2011-03-01

    Experimental searches for dark matter include experiments with sub-0.5 keV-energy threshold high purity germanium detectors. Experimental efforts, in partnership with the CoGeNT Collaboration operating at the Soudan Underground Laboratory, are focusing on energy threshold reduction via noise abatement, reduction of backgrounds from cosmic ray generated isotopes, and ubiquitous environmental radioactive sources. The most significant cosmic ray produced radionuclide is 68Ge. This paper evaluates reducing this background by freshly mining and processing germanium ore. The most probable outcome is a reduction of the background by a factor of two, and at most a factor of four. A very cost effective alternative is to obtain processed Ge as soon as possible and store it underground for 18 months.

  17. Baryons and Chiral Symmetry

    CERN Document Server

    Liu, Keh-Fei

    2016-01-01

    The relevance of chiral symmetry in baryons is highlighted in three examples in the nucleon spectroscopy and structure. The first one is the importance of chiral dynamics in understanding the Roper resonance. The second one is the role of chiral symmetry in the lattice calculation of $\\pi N \\sigma$ term and strangeness. The third one is the role of chiral $U(1)$ anomaly in the anomalous Ward identity in evaluating the quark spin and the quark orbital angular momentum. Finally, the chiral effective theory for baryons is discussed.

  18. (Hybrid) Baryons Symmetries and Masses

    CERN Document Server

    Page, P R

    1999-01-01

    We construct (hybrid) baryons in the flux-tube model of Isgur and Paton. In the limit of adiabatic quark motion, we build proper eigenstates of orbital angular momentum and construct the flavour, spin and J^P of hybrid baryons from the symmetries of the system. The lowest mass hybrid baryon is estimated at approximately 2 GeV.

  19. Heavy Baryons in a Quark Model

    Energy Technology Data Exchange (ETDEWEB)

    Winston Roberts; Muslema Pervin

    2007-11-14

    A quark model is applied to the spectrum of baryons containing heavy quarks. The model gives masses for the known heavy baryons that are in agreement with experiment, but for the doubly-charmed baryon $\\Xi_{cc}$, the model prediction is too heavy. Mixing between the $\\Xi_Q$ and $\\Xi_Q^\\prime$ states is examined and is found to be small for the lowest lying states. In contrast with this, mixing between the $\\Xi_{bc}$ and $\\Xi_{bc}^\\prime$ states is found to be large, and the implication of this mixing for properties of these states is briefly discussed. We also examine heavy-quark spin-symmetry multiplets, and find that many states in the model can be placed in such multiplets.

  20. Production and decay of charmed baryons

    Science.gov (United States)

    Hosaka, Atsushi; Hiyama, Emiko; Kim, SangHo; Kim, Hyun-Chul; Nagahiro, Hideko; Noumi, Hiroyuki; Oka, Makoto; Shirotori, Kotaro; Yoshida, Tetsuya; Yasui, Shigehiro

    2016-10-01

    In this paper, we discuss reactions involving charmed baryons to explore their unique features. A well known phenomenon, the separation of the two internal motions of the ρ and λ types of a three-quark system is revisited. First we discuss the mass spectrum of low lying excitations as function of the heavy quark mass, smoothly connecting the SU (3) and heavy quark limits. The properties of these modes can be tested in the production and decay reactions of the baryons. For production, we consider a one step process which excites dominantly λ modes. We find abundant production rates for some of the excited states. For decay, we study a pion emission process which provides a clean tool to test the structure of heavy quark systems due to the well controlled low energy dynamics of pions and quarks. Both production and decay of charmed baryons are issues for future experiments at J-PARC.

  1. The Detection of Ultra-faint Low Surface Brightness Dwarf Galaxies in the Virgo Cluster: A Probe of Dark Matter and Baryonic Physics

    Science.gov (United States)

    Giallongo, E.; Menci, N.; Grazian, A.; Fassbender, R.; Fontana, A.; Paris, D.; Pentericci, L.

    2015-11-01

    We have discovered 11 ultra-faint (r ≲ 22.1) low surface brightness (LSB, central surface brightness 23 ≲ μr ≲ 26) dwarf galaxy candidates in one deep Virgo field of just 576 arcmin2 obtained by the Large Binocular Camera at the Large Binocular Telescope. Their association with the Virgo cluster is supported by their distinct position in the central surface brightness—total magnitude plane with respect to the background galaxies of similar total magnitude. They have typical absolute magnitudes and scale sizes, if at the distance of Virgo, in the range -13 ≲ Mr ≲ -9 and 250 ≲ rs ≲ 850 pc, respectively. Their colors are consistent with a gradually declining star formation history with a specific star formation rate of the order of 10-11 yr-1, i.e., 10 times lower than that of main sequence star-forming galaxies. They are older than the cluster formation age and appear to be regular in morphology. They represent the faintest extremes of the population of low luminosity LSB dwarfs that has recently been detected in wider surveys of the Virgo cluster. Thanks to the depth of our observations, we are able to extend the Virgo luminosity function down to Mr ˜ -9.3 (corresponding to total masses M ˜ 107 M⊙), finding an average faint-end slope α ≃ -1.4. This relatively steep slope puts interesting constraints on the nature of the dark matter and, in particular, on warm dark matter (WDM) often invoked to solve the overprediction of the dwarf number density by the standard cold dark matter scenario. We derive a lower limit on the WDM particle mass >1.5 keV.

  2. THE DETECTION OF ULTRA-FAINT LOW SURFACE BRIGHTNESS DWARF GALAXIES IN THE VIRGO CLUSTER: A PROBE OF DARK MATTER AND BARYONIC PHYSICS

    Energy Technology Data Exchange (ETDEWEB)

    Giallongo, E.; Menci, N.; Grazian, A.; Fassbender, R.; Fontana, A.; Paris, D.; Pentericci, L. [INAF—Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monteporzio (Italy)

    2015-11-01

    We have discovered 11 ultra-faint (r ≲ 22.1) low surface brightness (LSB, central surface brightness 23 ≲ μ{sub r} ≲ 26) dwarf galaxy candidates in one deep Virgo field of just 576 arcmin{sup 2} obtained by the Large Binocular Camera at the Large Binocular Telescope. Their association with the Virgo cluster is supported by their distinct position in the central surface brightness—total magnitude plane with respect to the background galaxies of similar total magnitude. They have typical absolute magnitudes and scale sizes, if at the distance of Virgo, in the range −13 ≲ M{sub r} ≲ −9 and 250 ≲ r{sub s} ≲ 850 pc, respectively. Their colors are consistent with a gradually declining star formation history with a specific star formation rate of the order of 10{sup −11} yr{sup −1}, i.e., 10 times lower than that of main sequence star-forming galaxies. They are older than the cluster formation age and appear to be regular in morphology. They represent the faintest extremes of the population of low luminosity LSB dwarfs that has recently been detected in wider surveys of the Virgo cluster. Thanks to the depth of our observations, we are able to extend the Virgo luminosity function down to M{sub r} ∼ −9.3 (corresponding to total masses M ∼ 10{sup 7} M{sub ⊙}), finding an average faint-end slope α ≃ −1.4. This relatively steep slope puts interesting constraints on the nature of the dark matter and, in particular, on warm dark matter (WDM) often invoked to solve the overprediction of the dwarf number density by the standard cold dark matter scenario. We derive a lower limit on the WDM particle mass >1.5 keV.

  3. Problems in baryon spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Capstick, S. [Florida State Univ., Tallahassee, FL (United States)

    1994-04-01

    Current issues and problems in the physics of ground- and excited-state baryons are considered, and are classified into those which should be resolved by CEBAF in its present form, and those which may require CEBAF to undergo an energy upgrade to 8 GeV or more. Recent theoretical developments designed to address these problems are outlined.

  4. The CMU Baryon Amplitude Analysis Program

    Science.gov (United States)

    Bellis, Matt

    2007-05-01

    The PWA group at Carnegie Mellon University has developed a comprehensive approach and analysis package for the purpose of extracting the amplitudes for photoproduced baryon resonances. The end goal is to identify any missing resonances that are predicted by the constituent quark model, but not definitively observed in experiments. The data comes from the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab.

  5. Discretising the velocity distribution for directional dark matter experiments

    CERN Document Server

    Kavanagh, Bradley J

    2015-01-01

    Dark matter (DM) direct detection experiments which are directionally-sensitive may be the only method of probing the full velocity distribution function (VDF) of the Galactic DM halo. We present an angular basis for the DM VDF which can be used to parametrise the distribution in order to mitigate astrophysical uncertainties in future directional experiments and extract information about the DM halo. This basis consists of discretising the VDF in a series of angular bins, with the VDF being only a function of the DM speed $v$ within each bin. In contrast to other methods, such as spherical harmonic expansions, the use of this basis allows us to guarantee that the resulting VDF is everywhere positive and therefore physical. We present a recipe for calculating the event rates corresponding to the discrete VDF for an arbitrary number of angular bins $N$ and investigate the discretisation error which is introduced in this way. For smooth, Standard Halo Model-like distribution functions, only $N=3$ angular bins ar...

  6. Spontaneous Baryogenesis without Baryon Isocurvature

    CERN Document Server

    De Simone, Andrea

    2016-01-01

    We propose a new class of spontaneous baryogenesis models that does not produce baryon isocurvature perturbations. The baryon chemical potential in these models is independent of the field value of the baryon-generating scalar, hence the scalar field fluctuations are blocked from propagating into the baryon isocurvature. We demonstrate this mechanism in simple examples where spontaneous baryogenesis is driven by a non-canonical scalar field. The suppression of the baryon isocurvature allows spontaneous baryogenesis to be compatible even with high-scale inflation.

  7. Tidal Dwarf Galaxies and Missing Baryons

    Directory of Open Access Journals (Sweden)

    Frederic Bournaud

    2010-01-01

    Full Text Available Tidal dwarf galaxies form during the interaction, collision, or merger of massive spiral galaxies. They can resemble “normal” dwarf galaxies in terms of mass, size, and become dwarf satellites orbiting around their massive progenitor. They nevertheless keep some signatures from their origin, making them interesting targets for cosmological studies. In particular, they should be free from dark matter from a spheroidal halo. Flat rotation curves and high dynamical masses may then indicate the presence of an unseen component, and constrain the properties of the “missing baryons,” known to exist but not directly observed. The number of dwarf galaxies in the Universe is another cosmological problem for which it is important to ascertain if tidal dwarf galaxies formed frequently at high redshift, when the merger rate was high, and many of them survived until today. In this paper, “dark matter” is used to refer to the nonbaryonic matter, mostly located in large dark halos, that is, CDM in the standard paradigm, and “missing baryons” or “dark baryons” is used to refer to the baryons known to exist but hardly observed at redshift zero, and are a baryonic dark component that is additional to “dark matter”.

  8. Antibaryonic dark matter

    CERN Document Server

    Gorbunov, D

    2013-01-01

    Assuming existence of (very) heavy fourth generation of quarks and antiquarks we argue that antibaryon composed of the three heavy antiquarks can be light, stable and invisible, hence a good candidate for the Dark matter particle. Such opportunity allows to keep the baryon number conservation for the generation of the visible baryon asymmetry. The dark matter particles traveling through the ordinary matter will annihilate with nucleons inducing proton(neutron)-decay-like events with ~5GeV energy release in outcoming particles.

  9. Recent progress on dense nuclear matter in skyrmion approaches

    Science.gov (United States)

    Ma, YongLiang; Rho, Mannque

    2017-03-01

    The Skyrme model provides a novel unified approach to nuclear physics. In this approach, single baryon, baryonic matter and medium-modified hadron properties are treated on the same footing. Intrinsic density dependence (IDD) reflecting the change of vacuum by compressed baryonic matter figures naturally in the approach. In this article, we review the recent progress on accessing dense nuclear matter by putting baryons treated as solitons, namely, skyrmions, on crystal lattice with accents on the implications in compact stars.

  10. Baryons in the chiral regime

    Energy Technology Data Exchange (ETDEWEB)

    Knippschild, Bastian

    2012-03-05

    Quantum Chromodynamics (QCD) is the theory of strong interactions, one of the four fundamental forces in our Universe. It describes the interaction of gluons and quarks which build up hadrons like protons and neutrons. Most of the visible matter in our universe is made of protons and neutrons. Hence, we are interested in their fundamental properties like their masses, their distribution of charge and their shape. The only known theoretical, non-perturbative and ab initio method to investigate hadron properties at low energies is lattice Quantum Chromodynamics (lattice QCD). However, up-to-date simulations (especially for baryonic quantities) do not achieve the accuracy of experiments. In fact, current simulations do not even reproduce the experimental values for the form factors. The question arises wether these deviations can be explained by systematic effects in lattice QCD simulations. This thesis is about the computation of nucleon form factors and other hadronic quantities from lattice QCD. So called Wilson fermions are used and the u- and d-quarks are treated fully dynamically. The simulations were performed using gauge ensembles with a range of lattice spacings, volumes and pion masses. First of all, the lattice spacing was set to be able to make contact between the lattice results and their experimental complement and to be able to perform a continuum extrapolation. The light quark mass has been computed and found to be m{sub ud}{sup MS}(2 GeV)=3.03(17)(38) MeV. This value is in good agreement with values from experiments and other lattice determinations. Electro-magnetic and axial form factors of the nucleon have been calculated. From these form factors the nucleon radii and the coupling constants were computed. The different ensembles enabled us to investigate systematically the dependence of these quantities on the volume, the lattice spacing and the pion mass. Finally we perform a continuum extrapolation and chiral extrapolations to the physical point

  11. Baryon and time asymmetries of the universe

    CERN Document Server

    Barnaveli, A T; Barnaveli, Andro; Gogberashvili, Merab

    1995-01-01

    This paper is devoted to the investigation of connection between two apparent asymmetries of the nature --- time-asymmetry and Baryon Asymmetry of the Universe (BAU). The brief review of this subjects is given. We consider the particle behavior in curved space-time and the possibility of T- and CPT-violation by the universe expansion. If these symmetries are violated we can dispense with the nonequilibrium condition which is usualy considered as the one of necessary ingredients for BAU-generation. Such mechanism of GUT-scale baryogenesis can provide the observed value of baryon asymmetry. We show this on the example of minimal SU(5) model which usually fails to explain the observed BAU without taking into account gravitational effects. Predominance of matter over antimatter and the cosmological arrow of time (the time-direction in which the Universe expands) seem to be connected facts and, possibly, BAU is the one of observable facts of CPT-violation in nature.

  12. Composite dark matter and direct-search experiments

    CERN Document Server

    Wallemacq, Quentin

    2015-01-01

    We reinterpret the results of the direct searches for dark matter in terms of composite dark matter, i.e. dark matter particles that form neutral bound states, generically called dark atoms, either with ordinary particles, or with other dark matter particles. Three different scenarios are investigated: the O-helium scenario, milli- interacting dark matter and dark anti-atoms. In each of them, dark matter interacts sufficiently strongly with terrestrial matter to be stopped in it before reaching underground detectors. As they drift towards the center of the earth by gravity, these thermal dark atoms are radiatively captured by the atoms of the active medium of underground detectors, which causes the emission of photons that produce the signals through their interactions with the electrons of the medium. This provides a way of reinterpreting the results in terms of electron recoils instead of nuclear recoils. The detailed study of the interactions of O-helium with ordinary matter shows that it is not an accepta...

  13. Baryons and the Borromeo

    Science.gov (United States)

    Roberts, Craig D.; Segovia, Jorge

    2016-11-01

    The kernels in the tangible matter of our everyday experience are composed of light quarks. At least, they are light classically; but they don't remain light. Dynamical effects within the Standard Model of Particle Physics change them in remarkable ways, so that in some configurations they appear nearly massless, but in others possess masses on the scale of light nuclei. Modern experiment and theory are exposing the mechanisms responsible for these remarkable transformations. The rewards are great if we can combine the emerging sketches into an accurate picture of confinement, which is such a singular feature of the Standard Model; and looming larger amongst the emerging ideas is a perspective that leads to a Borromean picture of the proton and its excited states.

  14. Dark matter in voids

    Science.gov (United States)

    Fong, Richard; Doroshkevich, Andrei G.; Turchaninov, Victor I.

    1995-07-01

    The theory of the formation of large-scale structure in the universe through the action of gravitational instability imply the existence of substantial amounts of baryonic dark matter, of the order of 50% of the total baryon content in the universe, in the ``voids'' or under-dense regions seen in the large-scale distribution of galaxies. We discuss also the large-scale structure of dark matter expected in voids and the present and future possibilities for the observation of this baryonic dark matter in ``voids.''

  15. Dark matter in voids

    Energy Technology Data Exchange (ETDEWEB)

    Fong, R. [Department of Physics, University of Durham, Durham, DH1 3LE (United Kingdom); Doroshkevich, A.G. [Keldysh Institute of Applied Mathematics, 125047 Moscow (Russian Federation)]|[Teoretical Astrophysics Centrum, Blegsdamsvej 17, Copenhagen DK 2100 (Denmark); Turchaninov, V.I. [Keldysh Institute of Applied Mathematics, 125047 Moscow (Russian Federation)

    1995-07-01

    The theory of the formation of large-scale structure in the universe through the action of gravitational instability imply the existence of substantial amounts of baryonic dark matter, of the order of 50% of the total baryon content in the universe, in the ``voids`` or under-dense regions seen in the large-scale distribution of galaxies. We discuss also the large-scale structure of dark matter expected in voids and the present and future possibilities for the observation of this baryonic dark matter in ``voids.`` {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  16. Probing the hadron-quark mixed phase at high isospin and baryon density. Sensitive observables

    Energy Technology Data Exchange (ETDEWEB)

    Di Toro, Massimo; Greco, Vincenzo [INFN-Laboratori Nazionali del Sud, Catania (Italy); University of Catania, Physics and Astronomy Dept., Catania (Italy); Colonna, Maria [INFN-Laboratori Nazionali del Sud, Catania (Italy); Shao, Guo-Yun [Xi' an Jiaotong University, Department of Applied Physics, Xi' an (China)

    2016-08-15

    We discuss the isospin effect on the possible phase transition from hadronic to quark matter at high baryon density and finite temperatures. The two-Equation of State (Two-EoS) model is adopted to describe the hadron-quark phase transition in dense matter formed in heavy-ion collisions. For the hadron sector we use Relativistic Mean-Field (RMF) effective models, already tested on heavy-ion collision (HIC). For the quark phase we consider various effective models, the MIT-Bag static picture, the Nambu-Jona-Lasinio (NJL) approach with chiral dynamics and finally the NJL coupled to the Polyakov-loop field (PNJL), which includes both chiral and (de)confinement dynamics. The idea is to extract mixed phase properties which appear robust with respect to the model differences. In particular we focus on the phase transitions of isospin asymmetric matter, with two main results: (i) an earlier transition to a mixed hadron-quark phase, at lower baryon density/chemical potential with respect to symmetric matter; (ii) an ''Isospin Distillation'' to the quark component of the mixed phase, with predicted effects on the final hadron production. Possible observation signals are suggested to probe in heavy-ion collision experiments at intermediate energies, in the range of the NICA program. (orig.)

  17. Effects of Subject-Area Degree and Classroom Experience on New Chemistry Teachers' Subject Matter Knowledge

    Science.gov (United States)

    Nixon, Ryan S.; Campbell, Benjamin K.; Luft, Julie A.

    2016-01-01

    Science teachers need to understand the subject matter they teach. While subject matter knowledge (SMK) can improve with classroom teaching experience, it is problematic that many secondary science teachers leave the profession before garnering extensive classroom experience. Furthermore, many new science teachers are assigned to teach science…

  18. Asymmetric Dark Matter Models and the LHC Diphoton Excess

    DEFF Research Database (Denmark)

    Frandsen, Mads T.; Shoemaker, Ian M.

    2016-01-01

    The existence of dark matter (DM) and the origin of the baryon asymmetry are persistent indications that the SM is incomplete. More recently, the ATLAS and CMS experiments have observed an excess of diphoton events with invariant mass of about 750 GeV. One interpretation of this excess is decays...... have for models of asymmetric DM that attempt to account for the similarity of the dark and visible matter abundances....

  19. The Role of Baryons in Creating Statistically Significant Planes of Satellites around Milky Way-Mass Galaxies

    CERN Document Server

    Ahmed, Sheehan H; Christensen, Charlotte R

    2016-01-01

    We investigate whether the inclusion of baryonic physics influences the formation of thin, coherently rotating planes of satellites such as those seen around the Milky Way and Andromeda. For four Milky Way-mass simulations, each run both as dark matter-only and with baryons included, we are able to identify a planar configuration that significantly maximizes the number of plane satellite members. The maximum plane member satellites are consistently different between the dark matter-only and baryonic versions of the same run due to the fact that satellites are both more likely to be destroyed and to infall later in the baryonic runs. Hence, studying satellite planes in dark matter-only simulations is misleading, because they will be composed of different satellite members than those that would exist if baryons were included. Additionally, the destruction of satellites in the baryonic runs leads to less radially concentrated satellite distributions, a result that is critical to making planes that are statistica...

  20. Dark matter and cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, D.N.

    1992-03-01

    The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the {Omega} = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between ``cold`` and ``hot`` non-baryonic candidates is shown to depend on the assumed ``seeds`` that stimulate structure formation. Gaussian density fluctuations, such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed.

  1. Dark matter and cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, D.N.

    1992-03-01

    The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the {Omega} = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between cold'' and hot'' non-baryonic candidates is shown to depend on the assumed seeds'' that stimulate structure formation. Gaussian density fluctuations, such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed.

  2. Unbound particles in dark matter halos

    Energy Technology Data Exchange (ETDEWEB)

    Behroozi, Peter S.; Loeb, Abraham; Wechsler, Risa H.

    2013-06-13

    We investigate unbound dark matter particles in halos by tracing particle trajectories in a simulation run to the far future (a = 100). We find that the traditional sum of kinetic and potential energies is a very poor predictor of which dark matter particles will eventually become unbound from halos. We also study the mass fraction of unbound particles, which increases strongly towards the edges of halos, and decreases significantly at higher redshifts. We discuss implications for dark matter detection experiments, precision calibrations of the halo mass function, the use of baryon fractions to constrain dark energy, and searches for intergalactic supernovae.

  3. Are narrow mesons, baryons and dibaryons evidence for multiquark states?

    Energy Technology Data Exchange (ETDEWEB)

    Tatischeff, B.; Yonnet, J. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire

    2000-07-01

    Several narrow structures have been progressively observed since the last fifteen years, in di-baryonic invariant mass spectra or in missing mass spectra. More recently, narrow structures were observed in baryonic and now in mesonic mass spectra. Since these small peaks appear at fixed masses, independently of the experiment, they are associated with real states. There is no room to explain these states within classical nuclear physics taking into account baryonic and mesonic degrees of freedom. An interpretation is proposed, which associate these narrow structures with two coloured quark clusters. (authors)

  4. Light baryons and their excitations

    Science.gov (United States)

    Eichmann, Gernot; Fischer, Christian S.; Sanchis-Alepuz, Hèlios

    2016-11-01

    We study ground states and excitations of light octet and decuplet baryons within the framework of Dyson-Schwinger and Faddeev equations. We improve upon similar approaches by explicitly taking into account the momentum-dependent dynamics of the quark-gluon interaction that leads to dynamical chiral symmetry breaking. We perform calculations in both the three-body Faddeev framework and the quark-diquark approximation in order to assess the impact of the latter on the spectrum. Our results indicate that both approaches agree well with each other. The resulting spectra furthermore agree one-to-one with experiment, provided well-known deficiencies of the rainbow-ladder approximation are compensated for. We also discuss the mass evolution of the Roper and the excited Δ with varying pion mass and analyze the internal structure in terms of their partial wave decompositions.

  5. Dynamical Structure of Baryons

    CERN Document Server

    Aleksejevs, A

    2013-01-01

    Compton scattering offers a unique opportunity to study the dynamical structure of hadrons over a wide kinematic range, with polarizabilities characterizing the hadron active internal degrees of freedom. We present calculations and detailed analysis of electric and magnetic and the spin-dependent dynamical polarizabilities for the lowest in mass SU(3) octet of baryons. These extensive calculations are made possible by the recent implementation of semi-automatized calculations in chiral perturbation theory which allows evaluating polarizabilities from Compton scattering up to next-to-the-leading order. The dependencies for the range of photon energies covering the majority of the meson photoproduction channels are analyzed.

  6. Is Baryon Number Conserved?

    Science.gov (United States)

    Pati, Jogesh C.; Salam, Abdus

    We suggest that baryon-number conservation may not be absolute and that an integrally charged quark may disintegrate into two leptons and an antilepton with a coupling strength G Bmp2≲ 10-9. On the other hand, if quarks are much heavier than low-lying hadrons, the decay of a three-quark system like the proton is highly forbidden (proton lifetime ≳ 1028 y). Motivation for these ideas appears to arise within a unified theory of hadrons and leptons and their gauge interactions. We emphasize the consequences of such a possibility for real quark searches.

  7. Stochastic isocurvature baryon fluctuations, baryon diffusion, and primordial nucleosynthesis

    CERN Document Server

    Kurki-Suonio, H; Mathews, G J; Kurki-Suonio, Hannu; Jedamzik, Karsten; Mathews, Grant J

    1996-01-01

    We examine effects on primordial nucleosynthesis from a truly random spatial distribution in the baryon-to-photon ratio (\\eta). We generate stochastic fluctuation spectra characterized by different spectral indices and root-mean-square fluctuation amplitudes. For the first time we explicitly calculate the effects of baryon diffusion on the nucleosynthesis yields of such stochastic fluctuations. We also consider the collapse instability of large-mass-scale inhomogeneities. Our results are generally applicable to any primordial mechanism producing fluctuations in \\eta which can be characterized by a spectral index. In particular, these results apply to primordial isocurvature baryon fluctuation (PIB) models. The amplitudes of scale-invariant baryon fluctuations are found to be severely constrained by primordial nucleosynthesis. However, when the \\eta distribution is characterized by decreasing fluctuation amplitudes with increasing length scale, surprisingly large fluctuation amplitudes on the baryon diffusion ...

  8. Baryons, Neutrinos, Feedback and Weak Gravitational Lensing

    CERN Document Server

    Harnois-Déraps, Joachim; Viola, Massimo; Heymans, Catherine

    2014-01-01

    (Abridged) The effect of baryonic feedback on the dark matter mass distribution is generally considered to be a nuisance to weak gravitational lensing. Measurements of cosmological parameters are affected as feedback alters the cosmic shear signal on angular scales smaller than a few arcminutes. Recent progress on the numerical modelling of baryon physics has shown that this effect could be so large that, rather than being a nuisance, the effect can be constrained with current weak lensing surveys, hence providing an alternative astrophysical insight on one of the most challenging questions of galaxy formation. In order to perform our analysis, we construct an analytic fitting formula that describes the effect of the baryons on the mass power spectrum. This fitting formula is based on three scenarios of the OWL hydrodynamical simulations. It is specifically calibrated for $z<1.5$, where it models the simulations to an accuracy that is better than $2\\%$ for scales $k<10 h\\mbox{Mpc}^{-1}$ and better than ...

  9. First results from the LUX Dark Matter Experiment

    CERN Document Server

    CERN. Geneva

    2013-01-01

    Discovery of the nature of dark matter is internationally recognized as one of the greatest contemporary challenges in science, fundamental to our understanding of the Universe. The most compelling candidates for dark matter are Weakly Interacting Massive Particles (WIMPs) that arise naturally in several models of physics beyond the Standard Model. The discovery of galactic WIMPs would therefore enlighten two of the outstanding problems of modern physics - the matter composition of the Universe and the extrapolation of the Standard Model of particle physics to GUT scales. Although no definitive signal has yet been discovered, the worldwide race towards direct detection has been dramatically accelerated by the remarkable progress and evolution of liquid xenon (LXe) time projection chambers (TPCs). They have shifted the scale of target mass by orders of magnitude whilst simultaneously reducing backgrounds to unprecedented low levels, becoming the leaders of the field and offering the most promising prospects fo...

  10. The Effect of Central Baryonic Cores in Dark Halos on the Evaluation of Strong Lensing Probabilities

    Institute of Scientific and Technical Information of China (English)

    Jie Wang

    2004-01-01

    We present an estimate of the strong lensing probability by dark halos, with emphasis on the role of the baryonic matter arising purely from radiative cooling. We treat the contribution of the cooled baryons optimistically with all the cooled baryons confined within a central core, and including no feedback process from stellar evolution. Our two-component model provides a strong lensing probability that is in good agreement with the observed distribution of multiple images of quasars, provided that the cooled baryons are deposited within a spherical region of radius of 0.1 times the virial radius and follow an isothermal profile. It is pointed out that strong lensing may be used as an additional probe of baryon physics in dark halos though this may meanwhile complicate the test of the inner density profiles of dark matter in halos using the observed strong lensing probability.

  11. A Baryonic Solution to the Missing Satellites Problem

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, Alyson M.; Kuhlen, Michael; Zolotov, Adi; Hooper, Dan

    2013-03-01

    It has been demonstrated that the inclusion of baryonic physics can alter the dark matter densities in the centers of low-mass galaxies, making the central dark matter slope more shallow than predicted in pure cold dark matter simulations. This flattening of the dark matter profile can occur in the most luminous subhalos around Milky Way mass galaxies. Zolotov et al. have suggested a correction to be applied to the central masses of dark matter-only satellites in order to mimic the affect of (1) the flattening of the dark matter cusp due to supernova feedback in luminous satellites and (2) enhanced tidal stripping due to the presence of a baryonic disk. In this paper, we apply this correction to the z = 0 subhalo masses from the high resolution, dark matter-only Via Lactea II (VL2) simulation, and find that the number of massive subhalos is dramatically reduced. After adopting a stellar mass to halo mass relationship for the VL2 halos, and identifying subhalos that are (1) likely to be destroyed by stripping and (2) likely to have star formation suppressed by photo-heating, we find that the number of massive, luminous satellites around a Milky Way mass galaxy is in agreement with the number of observed satellites around the Milky Way or M31. We conclude that baryonic processes have the potential to solve the missing satellites problem

  12. Effects of baryons on the statistical properties of large scale structure of the Universe; Effets des baryons sur les proprietes statistiques des grandes structures de l'Univers

    Energy Technology Data Exchange (ETDEWEB)

    Guillet, T.

    2010-09-23

    Observations of weak gravitational lensing will provide strong constraints on the cosmic expansion history and the growth rate of large scale structure, yielding clues to the properties and nature of dark energy. Their interpretation is impacted by baryonic physics, which are expected to modify the total matter distribution at small scales. My work has focused on determining and modeling the impact of baryons on the statistics of the large scale matter distribution in the Universe. Using numerical simulations, I have extracted the effect of baryons on the power spectrum, variance and skewness of the total density field as predicted by these simulations. I have shown that a model based on the halo model construction, featuring a concentrated central component to account for cool condensed baryons, is able to reproduce accurately, and down to very small scales, the measured amplifications of both the variance and skewness of the density field. Because of well-known issues with baryons in current cosmological simulations, I have extended the central component model to rely on as many observation-based ingredients as possible. As an application, I have studied the effect of baryons on the predictions of the upcoming Euclid weak lensing survey. During the course of this work, I have also worked at developing and extending the RAMSES code, in particular by developing a parallel self-gravity solver, which offers significant performance gains, in particular for the simulation of some astrophysical setups such as isolated galaxy or cluster simulations. (author) [French] Les observations de lentilles faibles gravitationnelles sont en mesure de fournir des pistes quant a la nature de l'energie noire et ses proprietes. Leur interpretation est rendue plus difficile par la physique des baryons qui modifie la distribution totale de matiere a petite echelle. Mon travail s'est axe sur la determination et la modelisation des effets des baryons sur les statistiques de la

  13. Baryon Spectrum Analysis using Covariant Constraint Dynamics

    Science.gov (United States)

    Whitney, Joshua; Crater, Horace

    2012-03-01

    The energy spectrum of the baryons is determined by treating each of them as a three-body system with the interacting forces coming from a set of two-body potentials that depend on both the distance between the quarks and the spin and orbital angular momentum coupling terms. The Two Body Dirac equations of constraint dynamics derived by Crater and Van Alstine, matched with the quasipotential formalism of Todorov as the underlying two-body formalism are used, as well as the three-body constraint formalism of Sazdjian to integrate the three two-body equations into a single relativistically covariant three body equation for the bound state energies. The results are analyzed and compared to experiment using a best fit method and several different algorithms, including a gradient approach, and Monte Carlo method. Results for all well-known baryons are presented and compared to experiment, with good accuracy.

  14. Anomalous Dimensions of Conformal Baryons

    DEFF Research Database (Denmark)

    Pica, Claudio; Sannino, Francesco

    2016-01-01

    We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small, within...

  15. A Collective Model of Baryons

    CERN Document Server

    Bijker, R; Leviatan, A

    1993-01-01

    We propose an algebraic description of the geometric structure of baryons in terms of the algebra $U(7)$. We construct a mass operator that preserves the threefold permutational symmetry and discuss a collective model of baryons with the geometry of an oblate top.

  16. Anomalous Dimensions of Conformal Baryons

    DEFF Research Database (Denmark)

    Pica, Claudio; Sannino, Francesco

    2016-01-01

    We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small, within the $...

  17. The XENON1T Dark Matter Search Experiment

    CERN Document Server

    Aprile, Elena

    2012-01-01

    The worldwide race towards direct dark matter detection in the form of Weakly Interacting Massive Particles (WIMPs) has been dramatically accelerated by the remarkable progress and evolution of liquid xenon time projection chambers (LXeTPCs). With a realistic discovery potential, XENON100 has already reached a sensitivity of $7\\times10^{-45}\\,\

  18. Baryon stopping probes deconfinement

    Science.gov (United States)

    Wolschin, Georg

    2016-08-01

    Stopping and baryon transport in central relativistic Pb + Pb and Au + Au collisions are reconsidered with the aim to find indications for the transition from hadronic to partonic processes. At energies reached at the CERN Super Proton Synchrotron ( √{s_{NN}} = 6.3-17.3 GeV) and at RHIC (62.4 GeV) the fragmentation-peak positions as obtained from the data depend linearly on the beam rapidity and are in agreement with earlier results from a QCD-based approach that accounts for gluon saturation. No discontinuities in the net-proton fragmentation peak positions occur in the expected transition region from partons to hadrons at 6-10GeV. In contrast, the mean rapidity loss is predicted to depend linearly on the beam rapidity only at high energies beyond the RHIC scale. The combination of both results offers a clue for the transition from hard partonic to soft hadronic processes in baryon stopping. NICA results could corroborate these findings.

  19. Krypton and radon background in the PandaX-I dark matter experiment

    Science.gov (United States)

    Li, S.; Chen, X.; Cui, X.; Fu, C.; Ji, X.; Lin, Q.; Liu, J.; Liu, X.; Tan, A.; Wang, X.; Xiao, M.; Xie, P.

    2017-02-01

    We discuss an in-situ evaluation of the 85Kr, 222Rn, and 220Rn background in PandaX-I, a 120-kg liquid xenon dark matter direct detection experiment. Combining with a simulation, their contributions to the low energy electron-recoil background in the dark matter search region are obtained.

  20. Recent Results in Dark Matter Direct Detection Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, Christopher Michael [Univ. of Chicago, IL (United States)

    2012-08-01

    In this dissertation, we study the original excess of low energy events observed by the Co- GeNT collaboration and the annual modulation reported by the DAMA/LIBRA collaboration, and discuss whether these signals could both be the result of the same elastically scattering dark matter particle. We find that, without channeling but when taking into account uncertainties in the relevant quenching factors, a dark matter candidate with a mass of approximately ~7.0 GeV and a cross section with nucleons of σDM-N ~2 x 10-40 cm2 could account for both of these observations. We also compare the region of parameter space favored by DAMA/LIBRA and CoGeNT to the constraints from XENON 10, XENON 100, and CDMS (Si).

  1. XMASS experiment, dark matter search with liquid xenon detector

    Energy Technology Data Exchange (ETDEWEB)

    Minamino, Akihiro, E-mail: minamino@scphys.kyoto-u.ac.j [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan)

    2010-11-01

    The XMASS Collaboration is developing liquid xenon detector for the purpose of direct detection of dark matter in the universe. A prototype detector was developed at Kamioka Observatory to test the basic performance of single phase liquid xenon detector. With the detector, the physical properties of liquid xenon were measured, and the performance of vertex and energy reconstruction and the self-shielding power of liquid xenon for background {gamma}-rays were confirmed.

  2. 暗物质晕和重子物质的自旋、速度剪切场及涡量的相关性分析∗%Correlation Analysis between Spin, Velocity Shear, and Vorticity of Baryonic and Dark Matter Halos

    Institute of Scientific and Technical Information of China (English)

    刘利利

    2016-01-01

    Using cosmological hydrodynamic simulations, we investigate the align-ments between velocity shear, vorticity, and the spin of dark matter halos, and study the correlation between baryonic and dark matter. We find that (1) mis-alignment between vorticity of baryonic and dark matter would develop on scales<0.2h−1 Mpc;(2) the vorticity of baryonic matter exhibits stronger alignment/anti-alignment with the eigenvectors of velocity shear than that of dark matter; (3) small/massive halos spinning parallel/perpendicular to the host filaments are sensitive to the identification of cosmic web, simulation box size, and resolution. These factors might complicate the connection between the spins of dark matter halos and galaxies, and affect the correlation signal of the alignments of galaxy spin with nearby large-scale structures.%在宇宙学流体力学模拟的基础上,通过对速度剪切场、涡量与暗物质晕自旋方向的相关性,以及重子与暗物质之间关系的研究,发现:(1)在小于0.2h−1 Mpc的尺度上,重子物质涡量与暗物质涡量的差异比较明显;(2)重子物质的涡量与速度剪切张量的相关性比暗物质要强;(3)小质量暗物质晕的自旋方向平行于其所在的纤维结构的方向,而大质量暗物质晕的自旋方向垂直于纤维结构的方向,并且这种相关性的强弱依赖于模拟盒子大小以及模拟精度.这些因素会使暗物质晕自旋与星系自旋之间的关系复杂化,也会对星系自旋方向与大尺度环境的相关性产生影响.

  3. Dirac's Covariant Constraint Dynamics Applied to the Baryon Spectrum

    Science.gov (United States)

    Whitney, Joshua; Crater, Horace

    2010-02-01

    A baryon is a hadron containing three quarks in a combination of up, down, strange, charm, or bottom. For prediction of the baryon energy spectrum, a baryon is modeled as a three-body system with the interacting forces coming from a set of two-body potentials that depend on the distance between the quarks, the spin-spin and spin-orbit angular momentum coupling terms, and a tensor term. Techniques and equations are derived from Todorov's work on constraint dynamics and the quasi-potential equation together with Two Body Dirac equations developed by Crater and Van Alstine, and adapted to this specific problem by further use of Sazdjian's N-body constraints dynamics for general confined systems. Baryon spectroscopy results are presented and compared with experiment. Typically, a best fit method is used in the analyses that employ several different algorithms, including a gradient approach, Monte Carlo modeling, and simulated annealing methods. )

  4. Electromagnetic properties of baryons

    Energy Technology Data Exchange (ETDEWEB)

    Haupt, C.

    2006-07-01

    Static observables of bound state systems in field theoretic descriptions are usually extracted from form factors in the limit of vanishing squared four-momentum transfer of the probing exchange particle. On the other hand, static properties in nonrelativistic quantum mechanics can be formulated by means of expectation values involving essentially scalar products of wave functions. The main objective of this work is to show that a synthesis of both approaches is indeed possible - at least if certain restrictions are made to the kind of interactions between the constituents of the bound system - leading to new insights into the structure of static properties. The focus lies especially on the charge radii and magnetic moments of baryons described within a covariant constituent quark model having its field theoretic foundations in the Bethe-Salpeter equation. The current matrix element in the Breit frame between the vertex functions is derived. The charge radius and magnetic moment of a bound three-fermion system is then derived by starting from their usual definition from form factors and in case of the charge radius also from the well-known radius of a charge distribution in classical electrodynamics. In both cases the static limit at the photon point is taken analytically and subsequently the integration over the relative energy variables is done. Finally the vertex functions are replaced by Salpeter amplitudes and the expression is symmetrized over the three fermions. The final results express the charge radius and magnetic moment of the three-fermion system as expectation values with respect to Salpeter amplitudes. The numerical implementation of the analytic results is done within a covariant constituent quark model with quark confinement and a residual instanton interaction accounting for the fine structure of the observed mass spectra. The Salpeter amplitudes which where obtained by solving the Salpeter equation are used to compute the expectation values of

  5. Hyperon Single-Particle Potentials Calculated from SU6 Quark-Model Baryon-Baryon Interactions

    CERN Document Server

    Kohno, M; Fujita, T; Nakamoto, C; Suzuki, Y

    2000-01-01

    Using the SU6 quark-model baryon-baryon interaction recently developed by the Kyoto-Niigata group, we calculate NN, Lambda N and Sigma N G-matrices in ordinary nuclear matter. This is the first attempt to discuss the Lambda and Sigma single-particle potentials in nuclear medium, based on the realistic quark-model potential. The Lambda potential has the depth of more than 40 MeV, which is more attractive than the value expected from the experimental data of Lambda-hypernuclei. The Sigma potential turns out to be repulsive, the origin of which is traced back to the strong Pauli repulsion in the Sigma N (I=3/2) ^3S_1 state.

  6. Effect of gravitational focusing on annual modulation in dark-matter direct-detection experiments.

    Science.gov (United States)

    Lee, Samuel K; Lisanti, Mariangela; Peter, Annika H G; Safdi, Benjamin R

    2014-01-10

    The scattering rate in dark-matter direct-detection experiments should modulate annually due to Earth's orbit around the Sun. The rate is typically thought to be extremized around June 1, when the relative velocity of Earth with respect to the dark-matter wind is maximal. We point out that gravitational focusing can alter this modulation phase. Unbound dark-matter particles are focused by the Sun's gravitational potential, affecting their phase-space density in the lab frame. Gravitational focusing can result in a significant overall shift in the annual-modulation phase, which is most relevant for dark matter with low scattering speeds. The induced phase shift for light O(10)  GeV dark matter may also be significant, depending on the threshold energy of the experiment.

  7. Effective Degrees of Freedom in Baryon Spectroscopy

    Science.gov (United States)

    Santopinto, E.; Ferretti, J.

    2016-10-01

    Three quark and quark-diquark models are characterized by several missing resonances, even if in the latter case the state space is a reduced one. Moreover, even quark-diquark models show some differences in their predictions for missing states. After several years of discussion, we still do not know whether baryons can be completely described in terms of three quark models or if diquark correlations have to be taken into account; another possibility, suggested in Santopinto (Phys Rev C 72:022201, 2005), Ferretti et al. (Phys Rev C 83:065204, 2011) and Galatà and Santopinto (Phys Rev C 86:045202, 2012), is that the previous pictures (three-quark and quark-diquark) represent the dominant descriptions of baryons at different energy scales. New experiments may be planned at Jlab (JLab12), Bes, Belle and LHCb in order to answer this fundamental open question.

  8. Direct detection prospects of dark vectors with xenon-based dark matter experiments

    CERN Document Server

    An, Haipeng; Pospelov, Maxim; Pradler, Josef; Ritz, Adam

    2015-01-01

    Dark matter experiments primarily search for the scattering of WIMPs on target nuclei of well shielded underground detectors. The results from liquid scintillator experiments furthermore provide precise probes of very light and very weakly coupled particles that may be absorbed by electrons. In these proceedings we summarize previously obtained constraints on long-lived dark matter vector particles $V$ (dark photons) in the $0.01-100$ keV mass range. In addition, we provide a first projected sensitivity reach for the upcoming XENON1T dark matter search to detect dark photons.

  9. Exploring SUSY light Higgs boson scenarios via dark matter experiments

    CERN Document Server

    Das, Debottam; Mambrini, Yann

    2010-01-01

    We examine the dark matter phenomenology in supersymmetric light higgs boson scenarios, adapting nonuniversal Higgs masses at the gauge coupling unification scale. The correct relic density is obtained mostly through the annihilation into a pseudoscalar $A$, which gives high values for the self-annihilation cross-section at present times. Our analysis shows that most part of the $A$ pole region can produce detectable gamma-rays and antiproton signals, and still be compatible with with recent direct detection data from XENON100 and CDMS-II.

  10. Searches for Dark Matter with the ATLAS experiment

    CERN Document Server

    Lundberg, Olof; The ATLAS collaboration

    2015-01-01

    ATLAS is a multi-purpose detector aimed at fully exploiting the discovery potential of the proton-proton collisions at a center of mass energy of 8-14 TeV provided by CERN Large Hadron Collider. It is able to precisely identify and measure the properties of electrons, muons, photons, taus and hadronic jets. Thanks to an excellent hermeticity it is able to infer the production of neutrinos and dark matter particles from conservation of momentum using the missing energy observable. This talk will focus on the results of several dedicated searches for WIMP Dark Matter using the ATLAS detector. Among these searches are the so called "Mono-X" searches looking for signatures with large missing momentum recoiling against a gauge boson. We also present searches for decays of the Higgs boson into invisible states and searches for final states with missing transverse energy and third generation quarks. The results are interpreted in terms of Effective Field Theories as well as Simplified Models, and limits on nucleon-W...

  11. Accounting for Baryons in Cosmological Constraints from Cosmic Shear

    CERN Document Server

    Zentner, Andrew R; Dodelson, Scott; Eifler, Tim; Krause, Elisabeth; Hearin, Andrew P

    2012-01-01

    One of the most pernicious theoretical systematics facing upcoming gravitational lensing surveys is the uncertainty introduced by the effects of baryons on the power spectrum of the convergence field. One method that has been proposed to account for these effects is to allow several additional parameters (that characterize dark matter halos) to vary and to fit lensing data to these halo parameters concurrently with the standard set of cosmological parameters. We test this method. In particular, we use this technique to model convergence power spectrum predictions from a set of cosmological simulations. We estimate biases in dark energy equation of state parameters that would be incurred if one were to fit the spectra predicted by the simulations either with no model for baryons, or with the proposed method. We show that neglecting baryonic effect leads to biases in dark energy parameters that are several times the statistical errors for a survey like the Dark Energy Survey. The proposed method to correct for ...

  12. Dark matter universe.

    Science.gov (United States)

    Bahcall, Neta A

    2015-10-06

    Most of the mass in the universe is in the form of dark matter--a new type of nonbaryonic particle not yet detected in the laboratory or in other detection experiments. The evidence for the existence of dark matter through its gravitational impact is clear in astronomical observations--from the early observations of the large motions of galaxies in clusters and the motions of stars and gas in galaxies, to observations of the large-scale structure in the universe, gravitational lensing, and the cosmic microwave background. The extensive data consistently show the dominance of dark matter and quantify its amount and distribution, assuming general relativity is valid. The data inform us that the dark matter is nonbaryonic, is "cold" (i.e., moves nonrelativistically in the early universe), and interacts only weakly with matter other than by gravity. The current Lambda cold dark matter cosmology--a simple (but strange) flat cold dark matter model dominated by a cosmological constant Lambda, with only six basic parameters (including the density of matter and of baryons, the initial mass fluctuations amplitude and its scale dependence, and the age of the universe and of the first stars)--fits remarkably well all the accumulated data. However, what is the dark matter? This is one of the most fundamental open questions in cosmology and particle physics. Its existence requires an extension of our current understanding of particle physics or otherwise point to a modification of gravity on cosmological scales. The exploration and ultimate detection of dark matter are led by experiments for direct and indirect detection of this yet mysterious particle.

  13. The Scientific Reach of Multi-Ton Scale Dark Matter Direct Detection Experiments

    CERN Document Server

    Newstead, Jayden L; Krauss, Lawrence M; Dent, James B; Ferrer, Francesc

    2013-01-01

    The next generation of large scale WIMP direct detection experiments have the potential to go beyond the discovery phase and reveal detailed information about both the particle physics and astrophysics of dark matter. We report here on early results arising from the development of a detailed numerical code modeling the proposed DARWIN detector, involving both liquid argon and xenon targets. We incorporate realistic detector physics, particle physics and astrophysical uncertainties and demonstrate to what extent two targets with similar sensitivities can remove various degeneracies and allow a determination of dark matter cross sections and masses while also probing rough aspects of the dark matter phase space distribution. We find that, even assuming dominance of spin-independent scattering, multi-ton scale experiments still have degeneracies that depend sensitively on the dark matter mass, and on the possibility of isospin violation and inelasticity in interactions. We find that these experiments are best ab...

  14. Disentanglement of Electromagnetic Baryon Properties

    Science.gov (United States)

    Sadasivan, Daniel; Doring, Michael

    2017-01-01

    Through recent advances in experimental techniques, the precise extraction of the spectrum of baryonic resonances and their properties becomes possible. Helicity couplings at the resonance pole are fundamental parameters describing the electromagnetic properties of resonances and enabling the comparison of theoretical models with data. We have extracted them from experiments carried out at Jefferson Lab and other facilities using a multipole analysis within the Julich-Bonn framework. Special attention has been paid to the uncertainties and correlations of helicity couplings. Using the world data on the reaction γp -> ηp , we have calculated, for the first time, the covariance matrix. Our results are useful in several ways. They quantify uncertainties but also correlations of helicity couplings. Second, they can tell us quantitatively how useful a given polarization measurement is. Third, they can tell us how the measurement of a new observable would constrain and disentangle the resonance properties which could be helpful in the design of new experiments. Finally, on the subject of the missing resonance problem, model selection techniques and statistical tests allow us to quantify the significance of whether a resonance exists. Supported by NSF CAREER Grant No. PHY-1452055, NSF PIF Grant No. 1415459, by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177, and by Research Center Julich through the HPC grant jikp07.

  15. Baryon-Baryon Interactions ---Nijmegen Extended-Soft-Core Models---

    Science.gov (United States)

    Rijken, T. A.; Nagels, M. M.; Yamamoto, Y.

    We review the Nijmegen extended-soft-core (ESC) models for the baryon-baryon (BB) interactions of the SU(3) flavor-octet of baryons (N, Lambda, Sigma, and Xi). The interactions are basically studied from the meson-exchange point of view, in the spirit of the Yukawa-approach to the nuclear force problem [H. Yukawa, ``On the interaction of Elementary Particles I'', Proceedings of the Physico-Mathematical Society of Japan 17 (1935), 48], using generalized soft-core Yukawa-functions. These interactions are supplemented with (i) multiple-gluon-exchange, and (ii) structural effects due to the quark-core of the baryons. We present in some detail the most recent extended-soft-core model, henceforth referred to as ESC08, which is the most complete, sophisticated, and successful interaction-model. Furthermore, we discuss briefly its predecessor the ESC04-model [Th. A. Rijken and Y. Yamamoto, Phys. Rev. C 73 (2006), 044007; Th. A. Rijken and Y. Yamamoto, Ph ys. Rev. C 73 (2006), 044008; Th. A. Rijken and Y. Yamamoto, nucl-th/0608074]. For the soft-core one-boson-exchange (OBE) models we refer to the literature [Th. A. Rijken, in Proceedings of the International Conference on Few-Body Problems in Nuclear and Particle Physics, Quebec, 1974, ed. R. J. Slobodrian, B. Cuec and R. Ramavataram (Presses Universitè Laval, Quebec, 1975), p. 136; Th. A. Rijken, Ph. D. thesis, University of Nijmegen, 1975; M. M. Nagels, Th. A. Rijken and J. J. de Swart, Phys. Rev. D 17 (1978), 768; P. M. M. Maessen, Th. A. Rijken and J. J. de Swart, Phys. Rev. C 40 (1989), 2226; Th. A. Rijken, V. G. J. Stoks and Y. Yamamoto, Phys. Rev. C 59 (1999), 21; V. G. J. Stoks and Th. A. Rijken, Phys. Rev. C 59 (1999), 3009]. All ingredients of these latter models are also part of ESC08, and so a description of ESC08 comprises all models so far in principle. The extended-soft-core (ESC) interactions consist of local- and non-local-potentials due to (i) one-boson-exchanges (OBE), which are the members of nonets of

  16. Quantifying the effect of baryon physics on weak lensing tomography

    CERN Document Server

    Semboloni, Elisabetta; Schaye, Joop; van Daalen, Marcel P; McCarthy, Ian J

    2011-01-01

    We use matter power spectra from cosmological hydrodynamic simulations to quantify the effect of baryon physics on the weak gravitational lensing shear signal. The simulations consider a number of processes, such as radiative cooling, star formation, supernovae and feedback from active galactic nuclei (AGN). Van Daalen et al. (2011) used the same simulations to show that baryon physics, in particular the strong feedback that is required to solve the overcooling problem, modifies the matter power spectrum on scales relevant for cosmological weak lensing studies. As a result, the use of power spectra from dark matter simulations can lead to significant biases in the inferred cosmological parameters. We show that the typical biases are much larger than the precision with which future missions aim to constrain the dark energy equation of state, w_0. For instance, the simulation with AGN feedback, which reproduces X-ray and optical properties of groups of galaxies, gives rise to a ~40% bias in w_0. We demonstrate ...

  17. Do Baryons Alter the Halos of Low Surface Brightness Galaxies?

    CERN Document Server

    de Naray, Rachel Kuzio

    2011-01-01

    High-quality observations of dark matter-dominated low surface brightness (LSB) galaxies indicate that, in contrast to the triaxial, centrally-concentrated cuspy halos formed in collisionless simulations of halo assembly, these galaxies reside in round, roughly constant density cored halos. In order to reconcile these data with galaxy formation in the context of LCDM, processes that alter the shape and density structure of the inner halo are required. We compile observational properties of LSB galaxies to evaluate the plausibility that a previously higher baryonic mass content and feedback from star formation can modify the dark matter halos of these galaxies. We also compare the properties of bulgeless disk galaxies formed in recent simulations to the LSB galaxy sample. We find that observational constraints on LSB galaxy star formation histories, structure, and kinematics make it difficult for baryonic physics to sphericalize and decrease the central density of the dark matter halos of LSB galaxies.

  18. Measurement of dileptons with the CBM experiment at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Höhne, C.

    2014-11-15

    The Compressed Baryonic Matter (CBM) experiment at the upcoming Facility for Antiproton and Ion Research (FAIR) will explore the phase diagram of nuclear matter at very high net-baryon densities and moderate temperatures in nucleus–nucleus collisions at beam energies up to 45A GeV. One of the key diagnostic probes is electromagnetic radiation. In order to minimize systematic errors of this challenging measurement, CBM aims at an investigation of dielectron and dimuon pairs in the full mass range from the photon point up to charmonium. The results of performance studies for dilepton measurements and the status of the detector developments are presented.

  19. Tritium calibration of the LUX dark matter experiment

    CERN Document Server

    Akerib, D S; Bai, X; Bailey, A J; Balajthy, J; Beltrame, P; Bernard, E P; Bernstein, A; Biesiadzinski, T P; Boulton, E M; Bradley, A; Bramante, R; Cahn, S B; Carmona-Benitez, M C; Chan, C; Chapman, J J; Chiller, A A; Chiller, C; Currie, A; Cutter, J E; Davison, T J R; de Viveiros, L; Dobi, A; Dobson, J E Y; Druszkiewicz, E; Edwards, B N; Faham, C H; Fiorucci, S; Gaitskell, R J; Gehman, V M; Ghag, C; Gibson, K R; Gilchriese, M G D; Hall, C R; Hanhardt, M; Haselschwardt, S J; Hertel, S A; Hogan, D P; Horn, M; Huang, D Q; Ignarra, C M; Ihm, M; Jacobsen, R G; Ji, W; Kazkaz, K; Khaitan, D; Knoche, R; Larsen, N A; Lee, C; Lenardo, B G; Lesko, K T; Lindote, A; Lopes, M I; Malling, D C; Manalaysay, A G; Mannino, R L; Marzioni, M F; McKinsey, D N; Mei, D M; Mock, J; Moongweluwan, M; Morad, J A; Murphy, A St J; Nehrkorn, C; Nelson, H N; Neves, F; O`Sullivan, K; Oliver-Mallory, K C; Ott, R A; Palladino, K J; Pangilinan, M; Pease, E K; Phelps, P; Reichhart, L; Rhyne, C; Shaw, S; Shutt, T A; Silva, C; Solovov, V N; Sorensen, P; Stephenson, S; Sumner, T J; Szydagis, M; Taylor, D J; Taylor, W; Tennyson, B P; Terman, P A; Tiedt, D R; To, W H; Tripathi, M; Tvrznikova, L; Uvarov, S; Verbus, J R; Webb, R C; White, J T; Whitis, T J; Witherell, M S; Wolfs, F L H; Young, S K; Zhang, C

    2015-01-01

    We present measurements of the electron-recoil (ER) response of the LUX dark matter detector based upon 170,000 highly pure and spatially-uniform tritium decays. We reconstruct the tritium energy spectrum using the combined energy model and find good agreement with expectations. We report the average charge and light yields of ER events in liquid xenon at 180 V/cm and 105 V/cm and compare the results to the NEST model. We also measure the mean charge recombination fraction and its fluctuations, and we investigate the location and width of the LUX ER band. These results provide input to a re-analysis of the LUX Run3 WIMP search.

  20. Average transverse momenta of baryon production at p-p collider experiments and their crucial implications for the high energy hadroproduction physics

    CERN Document Server

    Piskounova, Olga I

    2016-01-01

    The phenomenological approach in the framework of Quark-Gluon String Model (QGSM) has been applied to the description of transverse momentum spectra for the various sorts of baryons in hadroproduction at colliders. The analysis of data on hyperon transverse momentum distributions,dN/dp_t, demonstrates a difference in the dynamics of multiparticle production in proton-proton vs. antiproton-proton collisions in the region of low p_t . The most important contribution in antip-p reaction goes from fragmentation of antidiquark-diquark side of pomeron diagram. The complete study of the energy dependence of average transverse momenta for the energies from sqrt(s)= 0.2 to 7. TeV shows the slight growing of with energy. No dramatic changes were seen on the range from Tevatron to LHC, which may be responsible for "knee" in the cosmic ray proton spectra. The average transverse momentum analysis through the different mass of hadrons reveals some regularity in the mass gaps between the hadron generations. This observatio...

  1. Anomalous Dimensions of Conformal Baryons

    CERN Document Server

    Pica, Claudio

    2016-01-01

    We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small for a wide range of number of flavours. We also find that this is always smaller than the anomalous dimension of the fermion mass operator. These findings challenge the partial compositeness paradigm.

  2. Algebraic Approach to Baryon Structure

    CERN Document Server

    Leviatan, A

    1996-01-01

    We present an algebraic approach to the internal structure of baryons in terms of three constituents. We investigate a collective model in which the nucleon is regarded as a rotating and vibrating oblate top with a prescribed distribution of charges and magnetization. We contrast the collective and single-particle descriptions of baryons and compare the predictions of the model with existing data on masses, electromagnetic elastic and transition form factors and strong decays widths.

  3. Baryon spectrum and chiral dynamics

    CERN Document Server

    Glozman, L Ya

    1995-01-01

    New results on baryon structure and spectrum developed in collaboration with Dan Riska [1-4] are reported. The main idea is that beyond the chiral symmetry spontaneous breaking scale light and strange baryons should be considered as systems of three constituent quarks with an effective confining interaction and a chiral interaction that is mediated by the octet of Goldstone bosons (pseudoscalar mesons) between the constituent quarks.

  4. Galaxy Cluster Baryon Fractions Revisited

    CERN Document Server

    Gonzalez, Anthony H; Zabludoff, Ann I; Zaritsky, Dennis

    2013-01-01

    We measure the baryons contained in both the stellar and hot gas components for twelve galaxy clusters and groups at z~0.1 with M=1-5e14 Msun. This paper improves upon our previous work through the addition of XMM data, enabling measurements of the total mass and masses of each major baryonic component --- ICM, intracluster stars, and stars in galaxies --- for each system. We recover a relation for the stellar mass versus halo mass consistent with our previous result. We confirm that the partitioning of baryons between the stellar and hot gas components is a strong function of M500; the fractions of total mass in stars and X-ray gas within r500 scale as M500^-0.45 and M500^0.26, respectively. We also confirm that the combination of the BCG and intracluster stars is an increasingly important contributor to the stellar baryon budget in lower halo masses. We find a weak, but statistically significant, dependence of the total baryon fraction upon halo mass, scaling as M500^0.16. For M500>2e14, the total baryon fr...

  5. Baryon instability search in large detectors

    Energy Technology Data Exchange (ETDEWEB)

    Moscoso, L. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee

    1996-08-01

    Nucleon decay appears as a consequence of models trying to explain the baryon-antibaryon asymmetry. This has motivated 15 years ago many underground experiments devoted to the search of proton and neutron decay. A very large number of decay channels have been investigated and no evidence has been found yielding lower limits on lifetime which rule out the minimal SU(5) Grand Unified Theory predictions and put severe constraints on more complicated models. Next generation experiments like Super-Kamiokande, which is starting to take data now, ICARUS, whose a 600 ton prototype is under construction, will be sensitive to more complicated models predicting larger lifetimes. (author). 16 refs.

  6. Baryon number segregation at the end of the cosmological quark-hadron transition

    CERN Document Server

    Rezzolla, L

    1996-01-01

    One of the most interesting questions regarding a possible first order cosmological quark--hadron phase transition concerns the final fate of the baryon number contained within the disconnected quark regions at the end of the transition. We here present a detailed investigation of the hydrodynamical evolution of an evaporating quark drop, using a multi-component fluid description to follow the mechanisms of baryon number segregation. With this approach, we are able to take account of the simultaneous effects of baryon number flux suppression at the phase interface, entropy extraction by means of particles having long mean-free-paths, and baryon number diffusion. A range of computations has been performed to investigate the permitted parameter-space and this has shown that significant baryon number concentrations, perhaps even up to densities above that of nuclear matter, represent an inevitable outcome within this scenario.

  7. Do Qualification, Experience and Age Matter for Principals Leadership Styles?

    Directory of Open Access Journals (Sweden)

    Muhammad Javed Sawati

    2013-07-01

    Full Text Available The main focus of present study was to find out the prevalent leadership styles of principals in government schools of Khyber Pakhtunkhwa and to find relationship of leadership styles with qualifications, age and experience of the principals. On the basis of analyzed data, four major leadership styles of the principals were identified as Eclectic, Democratic, Autocratic, and Free-rein. However, a small proportion of the principal had no dominant leadership style. This study shows that principals’ leadership styles have no significant correlation with age, experience and qualification.

  8. Background studies for the EDELWEISS dark matter experiment

    CERN Document Server

    Armengaud, E; Beno\\^\\it, A; Bergé, L; Bergmann, T; Blümer, J; Broniatowski, A; Brudanin, V; Censier, B; Chapellier, M; Charlieux, F; Couedo, F; Coulter, P; Cox, G A; De Jesus, M; Domange, J; Drilien, A -A; Dumoulin, L; Eitel, K; Filosofov, D; Fourches, N; Gascon, J; Gerbier, G; Gros, M; Henry, S; Hervé, S; Heuermann, G; Holtzer, N; Juillard, A; Kleifges, M; Kluck, H; Kozlov, V; Kraus, H; Kudryavtsev, V A; Sueur, H Le; Loaiza, P; Marnieros, S; Menshikov, A; Navick, X-F; Nones, C; Olivieri, E; Pari, P; Paul, B; Rigaut, O; Robinson, M; Rozov, S; Sanglard, V; Schmidt, B; Scorza, S; Siebenborn, B; Semikh, S; Tcherniakhovski, D; Torrento-Coello, A S; Vagneron, L; Walker, R J; Weber, M; Yakushev, E; Zhang, X

    2013-01-01

    The EDELWEISS-II collaboration has completed a direct search for WIMP dark matter using cryogenic Ge detectors (400 g each) and 384 kg$\\times$days of effective exposure. A cross-section of $4.4 \\times 10^{-8}$ pb is excluded at 90% C.L. for a WIMP mass of 85 GeV. The next phase, EDELWEISS-III, aims to probe spin-independent WIMP-nucleon cross-sections down to a few $\\times10^{-9}$ pb. We present here the study of gamma and neutron background coming from radioactive decays in the set-up and shielding materials. We have carried out Monte Carlo simulations for the completed EDELWEISS-II setup with GEANT4 and normalised the expected background rates to the measured radioactivity levels (or their upper limits) of all materials and components. The expected gamma-ray event rate in EDELWEISS-II at 20-200 keV agrees with the observed rate of 82 events/kg/day within the uncertainties in the measured concentrations. The calculated neutron rate from radioactivity of 1.0-3.1 events (90% C.L.) at 20-200 keV in the EDELWEIS...

  9. Deployment and post-deployment experiences in OEF/OIF veterans: relationship to gray matter volume.

    Directory of Open Access Journals (Sweden)

    Robin L Aupperle

    Full Text Available BACKGROUND: Combat-related PTSD has been associated with reduced gray matter volume in regions of the prefrontal and temporal cortex, hippocampus, insula, and amygdala. However, the relationship between gray matter volume and specific deployment and post-deployment experiences has not been investigated. The aim of this study was to delineate how such experiences may contribute to structural brain changes for combat veterans. METHODS: Operation Iraqi Freedom/Operation Enduring Freedom veterans (N = 32 completed magnetic resonance imaging, the Deployment Risk and Resilience Inventory, Alcohol Use Disorders Identification Test, and Clinical Administered PTSD Scale. Voxel-wise Huber robust multiple regressions were used to quantify the relationship between gray matter volume and deployment experiences (combat experiences, military social support and post-deployment symptoms (PTSD, alcohol use. RESULTS: There was an interaction between severity of combat experiences and military social support for orbitofrontal gyrus gray matter volume. Specifically, individuals with more orbitofrontal gyrus gray matter volume reported less combat experiences and higher unit support. Individuals with more severe PTSD symptoms showed reduced gray matter volume within a large temporal region (inferior temporal and parahippocampal gyrus. CONCLUSIONS: The identified association between unit support and orbitofrontal gyrus volume supports two potential resilience mechanisms to be delineated with future longitudinal studies. First, individuals with larger orbitofrontal gyrus may engage in greater quality of social interactions and thus experience combat as less stressful. Second, individuals who experience greater unit support may preserve a larger orbitofrontal gyrus, serving to "protect" them from aversive consequences of combat.

  10. Baryomorphosis: Relating the Baryon Asymmetry to the "WIMP Miracle"

    CERN Document Server

    McDonald, John

    2010-01-01

    We present a generic framework, "baryomorphosis", which modifies the baryon asymmetry to be naturally of the order of a typical thermal relic WIMP density. We consider a simple scalar-based model to show how this is possible. This model introduces a sector in which a large initial baryon asymmetry is injected into particles ("annihilons"), phi_{B}, phi_{B, hat}, of mass ~ 100 GeV - 1 TeV. phi_{B}-phi_{B, hat} annihilations convert the initial phi_{B}, phi_{B, hat} asymmetry to a final asymmetry with a thermal relic WIMP-like density. This subsequently decays to a conventional baryon asymmetry whose magnitude is naturally related to the density of thermal relic WIMP dark matter. In this way the two coincidences of baryons and dark matter i.e. why their densities are similar to each other and why they are both similar to a WIMP thermal relic density (the "WIMP miracle"), may be understood. The model can be tested by the production of annihilons at colliders.

  11. The Inner Regions of Disk Galaxies: A Constant Baryonic Fraction?

    Directory of Open Access Journals (Sweden)

    Federico Lelli

    2014-07-01

    Full Text Available For disk galaxies (spirals and irregulars, the inner circular-velocity gradient dRV0 (inner steepness of the rotation curve correlates with the central surface brightness ∑*,0 with a slope of ~0.5. This implies that the central dynamical mass density scales almost linearly with the central baryonic density. Here I show that this empirical relation is consistent with a simple model where the central baryonic fraction ƒbar,0 is fixed to 1 (no dark matter and the observed scatter is due to differences in the baryonic mass-to-light ratio Mbar / LR (ranging from 1 to 3 in the R-band and in the characteristic thickness of the central stellar component Δz (ranging from 100 to 500 pc. Models with lower baryonic fractions are possible, although they require some fine-tuning in the values of Mbar/LR and Δz. Regardless of the actual value of ƒbar,0, the fact that different types of galaxies do not show strong variations in ƒbar,0 is surprising, and may represent a challenge for models of galaxy formation in a Λ Cold Dark Matter (ΛCDM cosmology.

  12. Q-ball dark matter and baryogenesis in high-scale inflation

    Directory of Open Access Journals (Sweden)

    Shinta Kasuya

    2014-12-01

    Full Text Available We investigate the scenario that one flat direction creates baryon asymmetry of the universe, while Q balls from another direction can be the dark matter in the gauge-mediated supersymmetry breaking for high-scale inflation. Isocurvature fluctuations are suppressed by the fact that the Affleck–Dine field stays at around the Planck scale during inflation. We find that the dark matter Q balls can be detected in IceCube-like experiments in the future.

  13. Lambda alpha, Sigma alpha and Xi alpha potentials derived from the SU6 quark-model baryon-baryon interaction

    CERN Document Server

    Fujiwara, Y; Suzuki, Y

    2006-01-01

    We calculate Lambda alpha, Sigma alpha and Xi alpha potentials from the nuclear-matter G-matrices of the SU6 quark-model baryon-baryon interaction. The alpha-cluster wave function is assumed to be a simple harmonic-oscillator shell-model wave function. A new method is proposed to derive the direct and knock-on terms of the interaction Born kernel from the hyperon-nucleon G-matrices, with explicit treatments of the nonlocality and the center-of-mass motion between the hyperon and alpha. We find that the SU6 quark-model baryon-baryon interactions, FSS and fss2, yield a reasonable bound-state energy for 5 He Lambda, -3.18 -- -3.62 MeV, in spite of the fact that they give relatively large depths for the Lambda single-particle potentials, 46 -- 48 MeV, in symmetric nuclear matter. An equivalent local potential derived from the Wigner transform of the nonlocal Lambda alpha kernel shows a strong energy dependence for the incident Lambda-particle, indicating the importance of the strangeness-exchange process in the o...

  14. Light asymmetric dark matter from new strong dynamics

    DEFF Research Database (Denmark)

    Frandsen, Mads Toudal; Sarkar, Subir; Schmidt-Hoberg, Kai

    2011-01-01

    A ~5 GeV `dark baryon' with a cosmic asymmetry similar to that of baryons is a natural candidate for the dark matter. We study the possibility of generating such a state through dynamical electroweak symmetry breaking, and show that it can share the relic baryon asymmetry via sphaleron interactions...

  15. Physics reach of the XENON1T dark matter experiment

    CERN Document Server

    Aprile, E; Agostini, F; Alfonsi, M; Amaro, F D; Anthony, M; Arazi, L; Arneodo, F; Balan, C; Barrow, P; Baudis, L; Bauermeister, B; Berger, T; Breur, P; Breskin, A; Brown, A; Brown, E; Bruenner, S; Bruno, G; Budnik, R; Bütikofer, L; Cardoso, J M R; Cervantes, M; Cichon, D; Coderre, D; Colijn, A P; Conrad, J; Contreras, H; Cussonneau, J P; Decowski, M P; de Perio, P; Di Gangi, P; Di Giovanni, A; Duchovni, E; Fattori, S; Ferella, A D; Fieguth, A; Franco, D; Fulgione, W; Galloway, M; Garbini, M; Geis, C; Goetzke, L W; Greene, Z; Grignon, C; Gross, E; Hampel, W; Hasterok, C; Itay, R; Kaether, F; Kaminsky, B; Kessler, G; Kish, A; Landsman, H; Lang, R F; Lellouch, D; Levinson, L; Calloch, M Le; Levy, C; Lindemann, S; Lindner, M; Lopes, J A M; Lyashenko, A; Macmullin, S; Manfredini, A; Undagoitia, T Marrodán; Masbou, J; Massoli, F V; Mayani, D; Fernandez, A J Melgarejo; Meng, Y; Messina, M; Micheneau, K; Miguez, B; Molinario, A; Murra, M; Naganoma, J; Oberlack, U; Orrigo, S E A; Pakarha, P; Pelssers, B; Persiani, R; Piastra, F; Pienaar, J; Plante, G; Priel, N; Rauch, L; Reichard, S; Reuter, C; Rizzo, A; Rosendahl, S; Rupp, N; Santos, J M F dos; Sartorelli, G; Scheibelhut, M; Schindler, S; Schreiner, J; Schumann, M; Lavina, L Scotto; Selvi, M; Shagin, P; Simgen, H; Stein, A; Thers, D; Tiseni, A; Trinchero, G; Tunnell, C; von Sivers, M; Wall, R; Wang, H; Weber, M; Wei, Y; Weinheimer, C; Wulf, J; Zhang, Y

    2015-01-01

    The XENON1T experiment is currently in the commissioning phase at the Laboratori Nazionali del Gran Sasso, Italy. In this article we study the experiment's expected sensitivity to the spin-independent WIMP-nucleon interaction cross section, based on Monte Carlo predictions of the electronic and nuclear recoil backgrounds. The total electronic recoil background in $1$ tonne fiducial volume and ($1$, $12$) keV electronic recoil equivalent energy region, before applying any selection to discriminate between electronic and nuclear recoils, is $(1.80 \\pm 0.15) \\cdot 10^{-4}$ ($\\rm{kg} \\cdot day \\cdot keV)^{-1}$, mainly due to the decay of $^{222}\\rm{Rn}$ daughters inside the xenon target. The nuclear recoil background in the corresponding nuclear recoil equivalent energy region ($4$, $50$) keV, is composed of $(0.6 \\pm 0.1)$ ($\\rm{t} \\cdot y)^{-1}$ from radiogenic neutrons, $(1.8 \\pm 0.3) \\cdot 10^{-2}$ ($\\rm{t} \\cdot y)^{-1}$ from coherent scattering of neutrinos, and less than $0.01$ ($\\rm{t} \\cdot y)^{-1}$ from...

  16. Heavy spin-2 Dark Matter

    CERN Document Server

    Babichev, Eugeny; Raidal, Martti; Schmidt-May, Angnis; Urban, Federico; Veermäe, Hardi; von Strauss, Mikael

    2016-01-01

    We provide further details on a recent proposal addressing the nature of the dark sectors in cosmology and demonstrate that all current observations related to Dark Matter can be explained by the presence of a heavy spin-2 particle. Massive spin-2 fields and their gravitational interactions are uniquely described by ghost-free bimetric theory, which is a minimal and natural extension of General Relativity. In this setup, the largeness of the physical Planck mass is naturally related to extremely weak couplings of the heavy spin-2 field to baryonic matter and therefore explains the absence of signals in experiments dedicated to Dark Matter searches. It also ensures the phenomenological viability of our model as we confirm by comparing it with cosmological and local tests of gravity. At the same time, the spin-2 field possesses standard gravitational interactions and it decays universally into all Standard Model fields but not into massless gravitons. Matching the measured DM abundance together with the require...

  17. Molecular dynamics simulation for baryon-quark phase transition at finite temperature and density

    CERN Document Server

    Akimura, Y; Yoshinaga, N; Chiba, S; Akimura, Yuka; Maruyama, Toshiki; Yoshinaga, Naotaka; Chiba, Satoshi

    2005-01-01

    We study the baryon-quark phase transition in a molecular dynamics (MD) of quark degrees of freedom at finite temperature and density. The baryon state at low density and temperature, and the deconfined quark state at high density and temperature are reproduced. We investigate the equations of state of matters with different $u$-$d$-$s$ compositions. Then we draw phase diagrams in the temperature-density plane by this simulation. It is found that the baryon-quark transition is sensitive to the quark width.

  18. Quark confinement mechanism for baryons

    CERN Document Server

    Goncharov, Yu P

    2013-01-01

    The confinement mechanism proposed earlier and then successfully applied to meson spectroscopy by the author is extended over baryons. For this aim the wave functions of baryons are built as tensorial products of those corresponding to the 2-body problem underlying the confinement mechanism of two quarks. This allows one to obtain the Hamiltonian of the quark interactions in a baryon and, accordingly, the possible energy spectrum of the latter. Also one may construct the electric and magnetic form factors of baryon in a natural way which entails the expressions for the root-mean-square radius and anomalous magnetic moment. To ullustrate the formalism in the given Chapter for the sake of simplicity only symmetrical baryons (i.e., composed from three quarks of the same flavours) $\\Delta^{++}$, $\\Delta^{-}$, $\\Omega^-$ are considered. For them the masses, the root-mean-square radii and anomalous magnetic moments are expressed in an explicit analytical form through the parameters of the confining SU(3)-gluonic fi...

  19. Baryon Transition in Holographic QCD

    CERN Document Server

    Li, Siwen

    2015-01-01

    We propose a mechanism of holographic baryon transition in the Sakai-Sugimoto (SS) model: baryons in this model can jump to different states under the mediated effect of gravitons (or glueballs by holography). We consider a time-dependent gravitational perturbation from M5-brane solution of D=11 supergravity and by employing the relations between 11D M-theory and IIA string theory, we get its 10 dimensional counterpart in the SS model. Such a perturbation is received by the D4-branes wrapped on the $S^{4}$ part of the 10D background, namely the baryon vertex. Technically, baryons in the SS model are described by BPST instanton ansatz and their dynamics can be analyzed using the quantum mechanical system in the instanton's moduli space. In this way, different baryonic states are marked by quantum numbers of moduli space quantum mechanics. By holographic spirit, the gravitational perturbation enters the Hamiltonian as a time-dependent perturbation and it is this time-dependent perturbative Hamiltonian produces ...

  20. Can Tonne-Scale Direct Detection Experiments Discover Nuclear Dark Matter?

    CERN Document Server

    Butcher, A; Monroe, J; West, S M

    2016-01-01

    Models of nuclear dark matter propose that the dark sector contains large composite states consisting of dark nucleons in analogy to Standard Model nuclei. We examine the direct detection phenomenology of a particular class of nuclear dark matter model at the current generation of tonne-scale liquid noble experiments, in particular DEAP-3600 and XENON1T. In our chosen nuclear dark matter scenario distinctive features arise in the recoil energy spectra due to the non-point-like nature of the composite dark matter state. We calculate the number of events required to distinguish these spectra from those of a standard point-like WIMP state with a decaying exponential recoil spectrum. In the most favourable regions of nuclear dark matter parameter space, we find that a few tens of events are needed to distinguish nuclear dark matter from WIMPs at the $3\\,\\sigma$ level in a single experiment. Given the total exposure time of DEAP-3600 and XENON1T we find that at best a $2\\,\\sigma$ distinction is possible by these e...

  1. MULTI-LAMBDA MATTER IN A CHIRAL HADRONIC MODEL

    Institute of Scientific and Technical Information of China (English)

    郭华; 杨树; 胡翔; 刘玉鑫

    2001-01-01

    Multi-lambda matter is investigated in the framework of a chiral hadronic model It is shown that multi-lambda matter consisting of {N, A} is a metastable state as the strangeness per baryon and the density of hadronic matter are varied. The effective lambda mass decreases as the baryon density increases, and remains larger than that of the nucleon.

  2. SU(3) flavour breaking and baryon structure

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, A.N.; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe, Hyogo (Japan); Pleiter, D. [Forschungszentrum Juelich GmbH (Germany). Juelich Supercomputing Centre (JSC); Regensburg Univ. (Germany). Institut fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Shanahan, P.; Zanotti, J.M. [Adelaide Univ., SA (Australia). CSSM, School of Chemistry and Physics; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Stueben, H. [Hamburg Univ. (Germany). Regionales Rechenzentrum; Collaboration: QCDSF/UKQCD Collaboration

    2013-11-15

    We present results from the QCDSF/UKQCD collaboration for hyperon electromagnetic form factors and axial charges obtained from simulations using N{sub f}=2+1 flavours of O(a)-improved Wilson fermions. We also consider matrix elements relevant for hyperon semileptonic decays. We find flavour-breaking effects in hyperon magnetic moments which are consistent with experiment, while our results for the connected quark spin content indicates that quarks contribute more to the spin of the {Xi} baryon than they do to the proton.

  3. Leptophilic Dark Matter in Direct Detection Experiments and in the Sun

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, Joachim; Niro, Viviana; Schwetz, Thomas; Zupan, Jure

    2010-11-01

    Dark matter interacting predominantly with leptons instead of nuclear matter has received a lot of interest recently. In this talk, we investigate the signals expected from such 'leptophilic Dark Matter' in direct detection experiments and in experiments looking for Dark Matter annihilation into neutrinos in the Sun. In a model-independent framework, we calculate the expected interaction rates for different scattering processes, including elastic and inelastic scattering off atomic electron shells, as well as loop-induced scattering off atomic nuclei. In those cases where the last effect dominates, leptophilic Dark Matter cannot be distinguished from conventional WIMPs. On the other hand, if inelastic scattering off the electron shell dominates, the expected event spectrum in direct detection experiments is different and would provide a distinct signal. However, we find that the signals in DAMA and/or CoGeNT cannot be explained by invoking leptophilic DM because the predicted and observed energy spectra do not match, and because of neutrino bounds from the Sun.

  4. The baryon number two system in the Chiral Soliton Model

    CERN Document Server

    Sarti, Valentina Mantovani; Vento, Vicente; Park, Byung-Yoon

    2012-01-01

    We study the interaction between two B = 1 states in a Chiral Soliton Model where baryons are described as non-topological solitons. By using the hedgehog solution for the B = 1 states we construct three possible B = 2 configurations to analyze the role of the relative orientation of the hedgehog quills in the dynamics. The strong dependence of the intersoliton interaction on these relative orientations reveals that studies of dense hadronic matter using this model should take into account their implications.

  5. Energy Density and Production Ratios of Baryon from QGP with Diquarks

    Institute of Scientific and Technical Information of China (English)

    MA Zhong-Biao; GAO Chong-Shou

    2005-01-01

    @@ At a very high temperature, the quark matter is a hot and dense matter under the colour deconfinement condition,and quarks can coalescent diquarks. Energy density of this system is figured out. A way to calculate baryon ratios produced from quark gluon plasma with diquarks in relativistic heavy ion collisions is presented.

  6. Leptogenesis and gravity: Baryon asymmetry without decays

    Science.gov (United States)

    McDonald, J. I.; Shore, G. M.

    2017-03-01

    A popular class of theories attributes the matter-antimatter asymmetry of the Universe to CP-violating decays of super-heavy BSM particles in the Early Universe. Recently, we discovered a new source of leptogenesis in these models, namely that the same Yukawa phases which provide the CP violation for decays, combined with curved-spacetime loop effects, lead to an entirely new gravitational mechanism for generating an asymmetry, driven by the expansion of the Universe and independent of the departure of the heavy particles from equilibrium. In this Letter, we build on previous work by analysing the full Boltzmann equation, exploring the full parameter space of the theory and studying the time-evolution of the asymmetry. Remarkably, we find regions of parameter space where decays play no part at all, and where the baryon asymmetry of the Universe is determined solely by gravitational effects.

  7. Decuplet baryons in hot medium

    CERN Document Server

    Azizi, K

    2016-01-01

    The thermal properties of the light decuplet baryons are investigated in the framework of the thermal QCD sum rules. In particular, the behavior of the mass and residue of the $\\Delta$, $\\Sigma^{*}$, $\\Xi^{*}$ and $\\Omega$ baryons with respect to temperature are analyzed taking into account the additional operators coming up in the Wilson expansion at finite temperature. It is found that the mass and residue of these particles remain overall unaffected up to $T\\simeq150~MeV$ but, after this point, they start to diminish, considerably.

  8. Deforming baryons into confining strings

    CERN Document Server

    Hartnoll, S A; Hartnoll, Sean A.; Portugues, Ruben

    2004-01-01

    We find explicit probe D3-brane solutions in the infrared of the Maldacena-Nunez background. The solutions describe deformed baryon vertices: q external quarks are separated in spacetime from the remaining N-q. As the separation is taken to infinity we recover known solutions describing infinite confining strings in ${\\mathcal{N}}=1$ gauge theory. We present results for the mass of finite confining strings as a function of length. We also find probe D2-brane solutions in a confining type IIA geometry, the reduction of a G_2 holonomy M theory background. The interpretation of these solutions as deformed baryons/confining strings is not as straightforward.

  9. Interplay and Characterization of Dark Matter Searches at Colliders and in Direct Detection Experiments

    CERN Document Server

    Malik, Sarah A.; Araujo, Henrique; Belyaev, A.; Bœhm, Céline; Brooke, Jim; Buchmueller, Oliver; Davies, Gavin; De Roeck, Albert; de Vries, Kees; Dolan, Matthew J.; Ellis, John; Fairbairn, Malcolm; Flaecher, Henning; Gouskos, Loukas; Khoze, Valentin V.; Landsberg, Greg; Newbold, Dave; Papucci, Michele; Sumner, Timothy; Thomas, Marc; Worm, Steven

    2015-01-01

    In this White Paper we present and discuss a concrete proposal for the consistent interpretation of Dark Matter searches at colliders and in direct detection experiments. Based on a specific implementation of simplified models of vector and axial-vector mediator exchanges, this proposal demonstrates how the two search strategies can be compared on an equal footing.

  10. Students' Experiences and Perceptions of In-Depth Approaches in Teaching and Understanding Subject Matter

    Science.gov (United States)

    Doumas, Kyriaki

    2012-01-01

    Students' experiences and perceptions of good teaching and understanding in literature and physics during one school year were investigated through in-depth interviews with students in eight Greek high school classes in the first, second and third grade. The pedagogical quality of in-depth teaching and understanding of subject matter, as described…

  11. CP violation and matter effect for a variable earth density in very long baseline experiments

    Energy Technology Data Exchange (ETDEWEB)

    Brahmachari, Biswajoy; Choubey, Sandhya E-mail: sandhya@he.sissa.it; Roy, Probir

    2003-11-03

    The perturbative treatment of subdominant oscillation and matter effect in neutrino beams/superbeams, propagating over long baselines and being used to look for CP violation, is studied here for a general matter density function varying with distance. New lowest order analytic expressions are given for different flavour transition and survival probabilities in a general neutrino mixing basis and a variable earth matter density profile. It is demonstrated that the matter effect in the muon neutrino (antineutrino) flavour survival probability vanishes to this order, provided the depletion, observed for atmospheric muon neutrinos and antineutrinos at super-Kamiokande, is strictly maximal. This result is independent of the earth density profile and the distance L between the source and the detector. In the general variable density case we show that one cannot separate the matter induced asymmetry from a genuine CP effect by keeping two detectors at distances L{sub 1} and L{sub 2} from the source while maintaining a fixed ratio L{sub 1}/E{sub 1}=L{sub 2}/E{sub 2}. This needs to be done numerically and we estimate the asymmetry generated by the earth matter effect with particular density profiles and some chosen parameters for very long baseline neutrino oscillation experiments.

  12. Experience-dependent plasticity in white matter microstructure: Reasoning training alters structural connectivity

    Directory of Open Access Journals (Sweden)

    Allyson P Mackey

    2012-08-01

    Full Text Available Diffusion tensor imaging (DTI techniques have made it possible to investigate white matter plasticity in humans. Changes in DTI measures, principally increases in fractional anisotropy (FA, have been observed following training programs as diverse as juggling, meditation, and working memory. Here, we sought to test whether three months of reasoning training could alter white matter microstructure. We recruited participants (n=23 who were enrolled in a course to prepare for the Law School Admission Test (LSAT, a test that places strong demands on reasoning skills, as well as age- and IQ-matched controls planning to take the LSAT in the future (n=22. DTI data were collected at two scan sessions scheduled three months apart. In trained participants but not controls, we observed decreases in radial diffusivity (RD in white matter connecting frontal cortices, and in mean diffusivity (MD within frontal and parietal lobe white matter. Further, participants exhibiting larger gains on the LSAT exhibited greater decreases in MD in the right internal capsule. In summary, reasoning training altered multiple measures of white matter structure in young adults. While the cellular underpinnings are unknown, these results provide evidence of experience-dependent white matter changes that may not be limited to myelination.

  13. Transition magnetic moments between negative parity heavy baryons

    CERN Document Server

    Aliev, T M; Savci, M

    2015-01-01

    The transition magnetic moments between negative parity, spin-1/2 heavy baryons are studied in framework of the light cone QCD sum rules. By constructing the sum rules for different Lorentz structures, the unwanted contributions coming from negative (positive) to positive (negative) parity transitions are removed. It is found that the magnetic moments between neutral negative parity heavy $\\Xi_Q^{\\prime 0}$ and $\\Xi_Q^0$ baryons are very small. Magnetic moments of the $\\Sigma_Q \\to \\Lambda_Q$ and $ \\Xi_Q^{\\prime \\pm} \\to \\Xi_Q^\\pm$ transitions are quite large and can be measured in further experiments.

  14. The inner regions of disk galaxies: a constant baryonic fraction?

    CERN Document Server

    Lelli, Federico

    2014-01-01

    For disk galaxies (spirals and irregulars), the inner circular-velocity gradient (inner steepness of the rotation curve) correlates with the central surface brightness with a slope of ~0.5. This implies that the central dynamical mass density scales almost linearly with the central baryonic density. Here I show that this empirical relation is consistent with a simple model where the central baryonic fraction f_bar(0) is fixed to 1 (no dark matter) and the observed scatter is due to differences in the baryonic mass-to-light ratio M_bar/L (ranging from 1 to 3 in the R-band) and in the characteristic thickness of the central stellar component dz (ranging from 100 to 500 pc). Models with lower baryonic fractions are possible, although they require some fine-tuning in the values of M_bar/L and dz. Regardless of the actual value of f_bar(0), the fact that different types of galaxies do not show strong variations in f_bar(0) is surprising, and may represent a challenge for models of galaxy formation in a LCDM cosmol...

  15. Dark Galaxies and Lost Baryons (IAU S244)

    Science.gov (United States)

    Davies, Jonathan I.; Disney, Michael J.

    2008-05-01

    Preface; Conference prelims; The HI that barked in the night M. J. Disney; The detection of dark galaxies in blind HI surveys J. I. Davies; Red haloes of galaxies - reservoirs of baryonic dark matter? E. Zackrisson, N. Bergvall, C. Flynn, G. Ostlin, G. Micheva and B. Baldwell; Constraints on dark and visible mass in galaxies from strong gravitational lensing S. Dye and S. Warren; Lost baryons at low redshift S. Mathur, F. Nicastro and R. Williams; Observed properties of dark matter on small spatial scales R. Wyse and G. Gilmore; The mass distribution in spiral galaxies P. Salucci; Connecting lost baryons and dark galaxies via QSO absorption lines T. Tripp; ALFALFA: HI cosmology in the local universe R. Giovanelli; The ALFALFA search for (almost) dark galaxies across the HI mass function M. Haynes; HI clouds detected towards Virgo with the Arecibo Legacy Fast ALFA Survey B. Kent; Cosmic variance in the HI mass function S. Schneider; The Arecibo Galaxy Environments Survey - potential for finding dark galaxies and results so far R. Minchin et al.; Free-floating HI clouds in the M81 group E. Brinks, F. Walter and E. Skillman; Where are the stars in dark galaxies J. Rosenberg, J. Salzer and J. Cannon; The halo by halo missing baryon problem S. McGaugh; The local void is really empty R. Tully; Voids in the local volume: a limit on appearance of a galaxy in a dark matter halo A. Tikhonov and A. Klypin; Dim baryons in the cosmic web C. Impey; A census of baryons in galaxy clusters and groups A. Gonzalez, D. Zaritsky and A. Zabludo; Statistical properties of the intercluster light from SDSS image stacking S. Zibetti; QSO strong gravitational lensing and the detection of dark halos A. Maccio; Strong gravitational lensing: bright galaxies and lost dark-matter L. Koopmans; Mapping the distribution of luminous and dark matter in strong lensing galaxies I. Ferreras, P. Saha, L. Williams and S. Burles; Tidal debris posing as dark galaxies P. Duc, F. Bournaud and E. Brinks

  16. Predictions for Excited Strange Baryons

    Energy Technology Data Exchange (ETDEWEB)

    Fernando, Ishara P.; Goity, Jose L. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-04-01

    An assessment is made of predictions for excited hyperon masses which follow from flavor symmetry and consistency with a 1/N c expansion of QCD. Such predictions are based on presently established baryonic resonances. Low lying hyperon resonances which do not seem to fit into the proposed scheme are discussed.

  17. Algebraic model of baryon resonances

    CERN Document Server

    Bijker, R

    1997-01-01

    We discuss recent calculations of electromagnetic form factors and strong decay widths of nucleon and delta resonances. The calculations are done in a collective constituent model of the nucleon, in which the baryons are interpreted as rotations and vibrations of an oblate top.

  18. Strong decays of qqq baryons

    CERN Document Server

    Bijker, R; Leviatan, A

    1997-01-01

    We study strong decays of nonstrange baryons by making use of the algebraic approach to hadron structure. Within this framework we derive closed expressions for decay widths in an elementary-meson emission model and use these to analyze the experimental data for $N^* \\rightarrow N + \\pi$, $N^* + \\pi$, $\\Delta^* \\rightarrow \\Delta + \\pi$ and $\\Delta^* \\rightarrow \\Delta +

  19. Observation of Two New Xi(-)(b) Baryon Resonances

    NARCIS (Netherlands)

    Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassen, R.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Bettler, M. -O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Bizzeti, A.; Bjornstad, P. M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Campora Perez, D.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carson, L.; Akiba, K. Carvalho; Casanova Mohr, R. C. M.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cauet, Ch.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S. -F.; Chiapolini, N.; Chrzaszcz, M.; Vidal, X. Cid; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Counts, I.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A. C.; Torres, M. Cruz; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; Dean, C. -T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Deleage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Domenico, A.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suarez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. -M.; Evans, T.; Falabella, A.; Faerber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Fernandez Albor, V.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fol, P.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Pardinas, J.; Garofoli, J.; Garra Tico, J.; Garrido, L.; Gascon, D.; Gaspar, C.; Gastaldi, U.; Gauld, R.; Gavardi, L.; Gazzoni, U.; Geraci, A.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Giani, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Goebel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Gandara, M. Grabalosa; Graciani Diaz, R.; Cardoso, L. A. Granado; Grauges, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griftith, P.; Grillo, L.; Gruenberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Hess, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jaton, P.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M.; Kenyon, I. R.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; Van Leerdam, J.; Lees, J. -P.; Lefevre, R.; Leflat, A.; Lefrancois, J.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lowdon, P.; Lucchesi, D.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Benito, C. Mann; Marino, P.; Maerki, R.; Marks, J.; Martellotti, G.; Martinelli, M.; Santos, D. Martinez; Vidal, F. Martinez; Martin Tostes, D.; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; McSkelly, B.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M. -N.; Moggi, N.; Rodriguez, J. Molina; Monteil, S.; Morandin, M.; Morawski, P.; Morda, A.; Morello, M. J.; Moron, J.; Morris, A. -B.; Mountain, R.; Muheim, F.; Mueller, K.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Nicol, M.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obratsov, V.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, C. J. G.; Orlandea, M.; Otalora Goicochea, J. M.; Otto, A.; Owen, P.; Oyanguren, A.; Pal, B. K.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parkes, C.; Parkinson, C. J.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Altarelli, M. Pepe; Perazzini, S.; Perret, P.; Pescatore, L.; Pesen, E.; Petridis, K.; Petrolini, A.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilar, T.; Pinci, D.; Pistone, A.; Playfer, S.; Plo Casasus, M.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Navarro, A. Puig; Punzi, G.; Qian, W.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redi, F.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Perez, P. Rodriguez; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, H.; Ruiz Valls, P.; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M. -H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepp, I.; Sena, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Sheychenko, V.; Shires, A.; Coutinho, R. Silva; Simi, G.; Sirendi, M.; Skidmore, N.; Skillicorn, I.; Skwarnicki, T.; Smith, N. A.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Sterpka, F.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szumlak, T.; T'Jampens, S.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; Van Tilburg, J.; Tisserand, V.; Tobin, M.; Todd, J.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Garcia, M. Ubeda; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valenti, G.; Vallier, A.; Gomez, R. Vazquez; Vazquez Regueiro, P.; Vazquez Sierra, C.; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Barbosa, J. V. V. B. Viana; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voss, C.; de Vries, J. A.; Wraldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Whitehead, M.; Wiedner, D.; Wilkinson, G.; Wilkinson, M.; Williams, M. P.; Williams, M.; Wilschut, H. W.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wyllie, K.; Xie, Y.; Xing, Z.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyae, M.; Zhang, L.; Zhang, W. C.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.

    2015-01-01

    Two structures are observed close to the kinematic threshold in the Xi(0)(b)pi(-) mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb(-1), recorded by the LEICb experiment. In the quark model, two baryonic resonances with quark content bds a

  20. Electroproduction of Baryon Resonances and Strangeness Suppression

    CERN Document Server

    Santopinto, E; Tecocoatzi, H Garcia

    2016-01-01

    We describe the electroproduction ratios of baryon-meson states from nucleon using an extension of the quark model that takes into account the sea. As a result we provide, with no adjustable parameters, the predictions of ratios of exclusive meson-baryon final states: Lambda K , Sigma K, p pion, and n pion. These predictions are in agreement with the new Jlab experimental data showing that sea quarks play an important role in the electroproduction. We also predicted further ratios of exclusive reactions that can be measured and tested in future experiments. In particular, we suggested new experiments on deuterium and tritium. Such measurements can provide crucial test of different predictions concerning the structure of nucleon and its sea quarks helping to solve an outstanding problem. Finally, we computed the so called strangeness suppression factor, lambda s, that is the suppression of strange quark-antiquarks compared to nonstrange pairs, and we found that our finding with this simple extension of the qua...

  1. Testing keV sterile neutrino dark matter in future direct detection experiments

    CERN Document Server

    Campos, Miguel D

    2016-01-01

    We determine constraints on sterile neutrino warm dark matter through direct detection experiments, taking XENON100 and its future stages as example. If keV-scale sterile neutrinos scatter inelastically with bound electrons of the target material, an electron recoil signal is generated. This can be used to set limits on the sterile neutrino mass and its mixing with the active sector. While not competitive with astrophysical constraints from X-ray data, the constraints are the first direct laboratory bounds on sterile neutrino warm dark matter, and will be in some parts of parameter space the strongest limits on keV-scale neutrinos.

  2. Evaluation of (alpha,n) Induced Neutrons as a Background for Dark Matter Experiments

    CERN Document Server

    Mei, D -M; Hime, A

    2008-01-01

    Neutrons from ($\\alpha$,n) reaction through thorium and uranium decays are important sources of background for direct dark matter detection. Neutron yield and energy spectrum from a range of materials that are used to build dark matter detectors are calculated and tabulated. In addition to thorium and uranium decays, we found that $\\alpha$ particles from samarium that is often doped in the window material of photomultiplier (PMT) are also an important source of neutron yield. The results in this paper can be used as the input in the Monte Carlo simulation for many materials that will be used for next generation experiments.

  3. Lowering the radioactivity of the photomultiplier tubes for the XENON1T dark matter experiment

    Energy Technology Data Exchange (ETDEWEB)

    Aprile, E.; Contreras, H.; Goetzke, L.W.; Fernandez, A.J.M.; Messina, M.; Plante, G.; Rizzo, A. [Columbia University, Physics Department, New York, NY (United States); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso (Italy); Gran Sasso Science Institute, L' Aquila (Italy); Bologna Univ., Department of Physics and Astrophysics, Bologna (Italy); INFN, Bologna (Italy); Alfonsi, M. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Arazi, L.; Budnik, R.; Duchovni, E.; Gross, E.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Priel, N.; Vitells, O. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Arisaka, K.; Lyashenko, A.; Meng, Y.; Pantic, E.; Teymourian, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Arneodo, F.; Di Giovanni, A. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Auger, M.; Barrow, P.; Baudis, L.; Behrens, A.; Galloway, M.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F. [University of Zurich, Physik-Institut, Zurich (Switzerland); Balan, C.; Cardoso, J.M.R.; Lopes, J.A.M.; Santos, J.M.F. dos [University of Coimbra, Department of Physics, Coimbra (Portugal); Bauermeister, B.; Fattori, S.; Geis, C.; Grignon, C.; Oberlack, U.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Beltrame, P. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); University of Edinburgh, Edinburgh (United Kingdom); Brown, A.; Lang, R.F.; Macmullin, S.; Pienaar, J.; Reichard, S.; Reuter, C. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Brown, E.; Levy, C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Bruenner, S.; Hampel, W.; Kaether, F.; Lindemann, S.; Lindner, M.; Undagoitia, T.M.; Rauch, L.; Schreiner, J.; Simgen, H.; Weber, M. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Buetikofer, L.; Coderre, D.; Schumann, M. [University of Bern, Albert Einstein Center for Fundamental Physics, Bern (Switzerland); Colijn, A.P.; Decowski, M.P.; Tiseni, A.; Tunnell, C. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); Cussonneau, J.P.; Le Calloch, M.; Masbou, J.; Lavina, L.S.; Thers, D. [Universite de Nantes, Subatech, Ecole des Mines de Nantes, CNRS/In2p3, Nantes (France); Ferella, A.D.; Fulgione, W.; Laubenstein, M. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); Fieguth, A.; Murra, M.; Rosendahl, S.; Weinheimer, C. [Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [Bologna Univ., Department of Physics and Astrophysics, Bologna (Italy); INFN, Bologna (Italy); Miguez, B.; Molinario, A.; Trinchero, G. [INFN-Torino and Osservatorio Astrofisico di Torino, Turin (Italy); Naganoma, J.; Shagin, P.; Wall, R. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Orrigo, S.E.A. [University of Coimbra, Department of Physics, Coimbra (Portugal); IFIC, CSIC-Universidad de Valencia, Valencia (Spain); Persiani, R. [Universite de Nantes, Subatech, Ecole des Mines de Nantes, CNRS/In2p3, Nantes (FR); Bologna Univ., Department of Physics and Astrophysics, Bologna (IT); INFN, Bologna (IT); Collaboration: XENON Collaboration

    2015-11-15

    The low-background, VUV-sensitive 3-inch diameter photomultiplier tube R11410 has been developed by Hamamatsu for dark matter direct detection experiments using liquid xenon as the target material. We present the results from the joint effort between the XENON collaboration and the Hamamatsu company to produce a highly radio-pure photosensor (version R11410-21) for the XENON1T dark matter experiment. After introducing the photosensor and its components, we show the methods and results of the radioactive contamination measurements of the individual materials employed in the photomultiplier production. We then discuss the adopted strategies to reduce the radioactivity of the various PMT versions. Finally, we detail the results from screening 286 tubes with ultra-low background germanium detectors, as well as their implications for the expected electronic and nuclear recoil background of the XENON1T experiment. (orig.)

  4. Lectures on Dark Matter Physics

    Science.gov (United States)

    Lisanti, Mariangela

    Rotation curve measurements from the 1970s provided the first strong indication that a significant fraction of matter in the Universe is non-baryonic. In the intervening years, a tremendous amount of progress has been made on both the theoretical and experimental fronts in the search for this missing matter, which we now know constitutes nearly 85% of the Universe's matter density. These series of lectures provide an introduction to the basics of dark matter physics. They are geared for the advanced undergraduate or graduate student interested in pursuing research in high-energy physics. The primary goal is to build an understanding of how observations constrain the assumptions that can be made about the astro- and particle physics properties of dark matter. The lectures begin by delineating the basic assumptions that can be inferred about dark matter from rotation curves. A detailed discussion of thermal dark matter follows, motivating Weakly Interacting Massive Particles, as well as lighter-mass alternatives. As an application of these concepts, the phenomenology of direct and indirect detection experiments is discussed in detail.

  5. Familon model of dark matter

    Science.gov (United States)

    Burdyuzha, V.; Lalakulich, O.; Ponomarev, Yu.; Vereshkov, G.

    2004-05-01

    If the next fundamental level of matter occurs (preons), then dark matter must consist of familons containing a 'hot' component from massless particles and a 'cold' component from massive particles. During the evolution of the Universe this dark matter occurred up to late-time relativistic phase transitions the temperatures of which were different. Fluctuations created by these phase transitions had a fractal character. As a result the structuration of dark matter (and therefore the baryon subsystem) occurred, and in the Universe some characteristic scales which have caused this phenomenon arise naturally. Familons are collective excitations of non-perturbative preon condensates that could be produced during an earlier relativistic phase transition. For structuration of dark matter (and the baryon component), three generations of particles are necessary. The first generation of particles produced the observed baryon world. The second and third generations produced dark matter from particles that appeared when symmetry between the generations was spontaneously broken.

  6. Familon Model of Dark Matter

    CERN Document Server

    Burdyuzha, V; Ponomarev, Yu; Vereshkov, G

    2008-01-01

    If the next fundamental level of matter occurs (preons) then dark matter must consist of familons containing a "hot" component from massless particles and a "cold" component from massive particles. During evolution of the Universe this dark matter was undergone to late-time relativistic phase transitions temperatures of which were different. Fluctuations created by these phase transitions have had a fractal character. In the result the structurization of dark matter (and therefore the baryon subsystem) has taken place and in the Universe some characteristic scales which have printed this phenomenon arise naturally. Familons are collective excitations of nonperturbative preon condensates which could be produced during more early relativistic phase transition. For structurization of dark matter (and baryon component) three generations of particles are necessary. The first generation of particles has produced the observed baryon world. The second and third generations have produced dark matter from particles whi...

  7. Directional resolution of dish antenna experiments to search for WISPy dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Jaeckel, Joerg; Knirck, Stefan [Institut für theoretische Physik, Universität Heidelberg,Philosophenweg 16, 69120 Heidelberg (Germany)

    2016-01-04

    Dark matter consisting of very light and very weakly interacting particles such as axions, axion-like particles and hidden photons could be detected using reflective surfaces. On such reflectors some of the dark matter particles are converted into photons and, given a suitable geometry, concentrated on the detector. This technique offers sensitivity to the direction of the velocity of the dark matter particles. In this note we investigate how far spherical mirrors can concentrate the generated photons and what this implies for the resolution in directional detection as well as the sensitivity of discovery experiments not aiming for directional resolution. Finally we discuss an improved setup using a combination of a reflecting plane with focussing optics.

  8. Directional Resolution of Dish Antenna Experiments to Search for WISPy Dark Matter

    CERN Document Server

    Jaeckel, Joerg

    2015-01-01

    Dark matter consisting of very light and very weakly interacting particles such as axions, axion-like particles and hidden photons could be detected using reflective surfaces. On such reflectors some of the dark matter particles are converted into photons and, given a suitable geometry, concentrated on the detector. This technique offers sensitivity to the direction of the velocity of the dark matter particles. In this note we investigate how far spherical mirrors can concentrate the generated photons and what this implies for the resolution in directional detection as well as the sensitivity of discovery experiments not aiming for directional resolution. Finally we discuss an improved setup using a combination of a reflecting plane with focussing optics.

  9. Directional resolution of dish antenna experiments to search for WISPy dark matter

    Science.gov (United States)

    Jaeckel, Joerg; Knirck, Stefan

    2016-01-01

    Dark matter consisting of very light and very weakly interacting particles such as axions, axion-like particles and hidden photons could be detected using reflective surfaces. On such reflectors some of the dark matter particles are converted into photons and, given a suitable geometry, concentrated on the detector. This technique offers sensitivity to the direction of the velocity of the dark matter particles. In this note we investigate how far spherical mirrors can concentrate the generated photons and what this implies for the resolution in directional detection as well as the sensitivity of discovery experiments not aiming for directional resolution. Finally we discuss an improved setup using a combination of a reflecting plane with focussing optics.

  10. Reconstruction and study of the multi-strange baryons in ultra-relativistic heavy ion collisions at a center-of-mass energy of 200 GeV, with the Star experiment at RHIC; Reconstruction et etude des baryons multi-etranges dans les collisions d'ions lourds ultra-relativistes a {radical}S{sub NN} = 200 GeV avec l'experience STAR au RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Faivre, J

    2004-10-15

    The study of strangeness production is essential for the understanding of processes occurring in ultra-relativistic heavy ion collisions. Strangeness production is directly linked to the phase of deconfined partons that followed these collisions: the quark and gluon plasma. STAR, one of the 4 experiments at RHIC collider, is a perfect tool for studying the multi-strange {xi} and {omega} particles. We have devised a {xi} and {omega} reconstruction program using signals from the STAR time projection chamber. We have worked out a multi-variable selection method for extracting the signals from the combinative background: the linear discriminant analysis. We have applied it to Au-Au collisions at 200 GeV (in the center of mass frame) to improve the accuracy of previous results. The {omega} and anti-{omega} production rates have been obtained for 3 ranges of centrality as well as their radial flow and their kinetic uncoupling temperatures. The gain on the relative uncertainty is between 15 and 30% according to the variable. The average speed of the radial flow is 0.50 {+-} 0.02 and the kinetic uncoupling temperature is 132 {+-} 20 MeV which indicates that multi-strange baryons uncouple in hadronic medium earlier that lighter particles like pions, kaons and protons. However, uncertainty intervals remain too broad to draw strong conclusions. (A.C.)

  11. A simulation-based study of the neutron backgrounds for NaI dark matter experiments

    CERN Document Server

    Jeon, Eunju

    2015-01-01

    Among the direct search experiments for weakly interacting massive particle (WIMP) dark matter, the DAMA experiment observed an annual modulation signal interpreted as WIMP interactions with a significance of 9.2$\\sigma$. Recently, Jonathan Davis claimed that the DAMA modulation may be interpreted on the basis of the neutron scattering events induced by the muons and neutrinos together. We tried to simulate the neutron backgrounds at the Gran Sasso and Yangyang laboratory with and without the polyethylene shielding to quantify the effects of the ambient neutrons on the direct detection experiments based on the crystals.

  12. Aharonov–Bohm protection of black hole's baryon/skyrmion hair

    Directory of Open Access Journals (Sweden)

    Gia Dvali

    2017-05-01

    Full Text Available The baryon/skyrmion correspondence implies that the baryon number is encoded into a topological surface integral. Under certain conditions that we clarify, this surface integral can be measured by an asymptotic observer in form of an Aharonov–Bohm phase-shift in an experiment in which the skyrmion passes through a loop of a probe string. In such a setup the baryon/skyrmion number must be respected by black holes, despite the fact that it produces no long-range classical field. If initially swallowed by a black hole, the baryon number must resurface in form of a classical skyrmion hair, after the black hole evaporates below a certain critical size. Needless to say, the respect of the baryon number by black holes is expected to have potentially-interesting astrophysical consequences.

  13. Aharonov-Bohm protection of black hole's baryon/skyrmion hair

    CERN Document Server

    Dvali, Gia

    2016-01-01

    The baryon/skyrmion correspondence implies that the baryon number is encoded into a topological surface integral. Under certain conditions that we clarify, this surface integral can be measured by an asymptotic observer in form of an Aharonov-Bohm phase-shift in an experiment in which the skyrmion passes through a loop of a probe string. In such a setup the baryon/skyrmion number must be respected by black holes, despite the fact that it produces no long-range classical field. If initially swallowed by a black hole, the baryon number must resurface in form of a classical skyrmion hair, after the black hole evaporates below a certain critical size. Needless to say, the respect of the baryon number by black holes is expected to have potentially-interesting astrophysical consequences.

  14. The Baryon Acoustic Oscillation Broadband and Broad-beam Array: Design Overview and Sensitivity Forecasts

    CERN Document Server

    Pober, Jonathan C; DeBoer, David R; McDonald, Patrick; McQuinn, Matthew; Aguirre, James E; Ali, Zaki; Bradley, Richard F; Chang, Tzu-Ching; Morales, Miguel F

    2012-01-01

    This work describes a new instrument optimized for a detection of the neutral hydrogen 21cm power spectrum between redshifts of 0.5-1.5: the Baryon Acoustic Oscillation Broadband and Broad-beam (BAOBAB) Array. BAOBAB will build on the efforts of a first generation of 21cm experiments which are targeting a detection of the signal from the Epoch of Reionization at z ~ 10. At z ~ 1, the emission from neutral hydrogen in self-shielded overdense halos also presents an accessible signal, since the dominant, synchrotron foreground emission is considerably fainter than at redshift 10. The principle science driver for these observations are Baryon Acoustic Oscillations in the matter power spectrum which have the potential to act as a standard ruler and constrain the nature of dark energy. BAOBAB will fully correlate dual-polarization antenna tiles over the 600-900MHz band with a frequency resolution of 300 kHz and a system temperature of 50K. The number of antennas will grow in staged deployments, and reconfigurations...

  15. 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)

  16. Effects of subject-area degree and classroom experience on new chemistry teachers' subject matter knowledge

    Science.gov (United States)

    Nixon, Ryan S.; Campbell, Benjamin K.; Luft, Julie A.

    2016-07-01

    Science teachers need to understand the subject matter they teach. While subject matter knowledge (SMK) can improve with classroom teaching experience, it is problematic that many secondary science teachers leave the profession before garnering extensive classroom experience. Furthermore, many new science teachers are assigned to teach science subjects for which they do not hold a degree. This study investigates the SMK of new secondary science teachers assigned to teach chemistry in their first three years of teaching. These new teachers do not have the advantage of years of experience to develop their SMK and half hold a degree in biology rather than chemistry. This qualitative study explores the effects of holding a degree in the subject area one teaches as well as classroom teaching experience on teachers' SMK for two chemistry topics, conservation of mass and chemical equilibrium. Qualitative analysis of semi-structured interviews indicated that the SMK of teachers who had a chemistry degree and more extensive classroom experience was more coherent, chemistry-focused, and sophisticated than that of teachers who lacked this preparation and experience. This study provides evidence that new science teachers' SMK is influenced by both holding a degree in the subject area and having classroom experience.

  17. The Hot and Energetic Universe: The missing baryons and the warm-hot intergalactic medium

    CERN Document Server

    Kaastra, Jelle; Nicastro, Fabrizio; Branchini, Enzo; Schaye, Joop; Cappelluti, Nico; Nevalainen, Jukka; Barcons, Xavier; Bregman, Joel; Croston, Judith; Dolag, Klaus; Ettori, Stefano; Galeazzi, Massimiliano; Ohashi, Takaya; Piro, Luigi; Pointecouteau, Etienne; Pratt, Gabriel; Reiprich, Thomas; Roncarelli, Mauro; Sanders, Jeremy; Takei, Yoh; Ursino, Eugenio

    2013-01-01

    The backbone of the large-scale structure of the Universe is determined by processes on a cosmological scale and by the gravitational interaction of the dominant dark matter. However, the mobile baryon population shapes the appearance of these structures. Theory predicts that most of the baryons reside in vast unvirialized filamentary structures that connect galaxy groups and clusters, but the observational evidence is currently lacking. Because the majority of the baryons are supposed to exist in a large-scale, hot and dilute gaseous phase, X-rays provide the ideal tool to progress our understanding. Observations with the Athena+ X-ray Integral Field Unit will reveal the location, chemical composition, physical state and dynamics of the active population of baryons.

  18. Baryon effects on void statistics in the EAGLE simulation

    CERN Document Server

    Paillas, Enrique; Padilla, Nelson; Tissera, Patricia; Helly, John; Schaller, Matthieu

    2016-01-01

    Cosmic voids are promising tools for cosmological tests due to their sensitivity to dark energy, modified gravity and alternative cosmological scenarios. Most previous studies in the literature of void properties use cosmological N-body simulations of dark matter (DM) particles that ignore the potential effect of baryonic physics. We analyse voids in the mass and subhalo density field in the EAGLE simulations, which follow the evolution of galaxies in a Lambda cold dark matter Universe with state-of-the-art subgrid models for baryonic processes. We study the effect of baryons on void statistics by comparing results with simulations that only follow the evolution of DM, but use the same initial conditions as EAGLE. When using the mass in the simulation, we find that a DM-only simulation produces 24 per cent more voids than a hydrodynamical one, but this difference comes mainly from voids with radii smaller than 5 Mpc. We do not find significant differences in the density profiles between voids in EAGLE and its...

  19. Distinguishing Supersymmetry From Universal Extra Dimensions or Little Higgs Models With Dark Matter Experiments

    CERN Document Server

    Hooper, D; Hooper, Dan; Zaharijas, Gabrijela

    2007-01-01

    There are compelling reasons to think that new physics will appear at or below the TeV-scale. It is not known what form this new physics will take, however. Although The Large Hadron collider is very likely to discover new particles associated with the TeV-scale, it may be difficult for it to determine the nature of those particles, whether superpartners, Kaluza-Klein modes or other states. In this article, we consider how direct and indirect dark matter detection experiments may provide information complementary to hadron colliders, which can be used to discriminate between supersymmetry, models with universal extra dimensions, and Little Higgs theories. We find that, in many scenarios, dark matter experiments can be effectively used to distinguish between these possibilities.

  20. Characteristics and applications of isotopes in products from organic matter in sedimentary rocksby simulated thermal experiments

    Institute of Scientific and Technical Information of China (English)

    陈安定; 张文正; 徐永昌

    1995-01-01

    Isotopic compositions of carbon in the products obtained respectively from 25 sedimentary rocks at an early stage of maturation by the simulated thermogenetic hydrocarbons experiments have been determined. The fractional effect of methane carbon isotope during the thermal maturation of organic matter is observed. Based on the experimental data, the relative equations between δ13C and R0 were established and have been used for differentiation of origins of various kinds of natural gases in the Shan-Gan-Ning Basin.

  1. Supersonic Relative Velocity Effect on the Baryonic Acoustic Oscillation Measurements

    CERN Document Server

    Yoo, Jaiyul; Seljak, Uros

    2011-01-01

    We investigate the effect of supersonic relative velocities between baryons and dark matter, recently shown to arise generically at high redshift, on baryonic acoustic oscillation (BAO) measurements at low redshift. The amplitude of the relative velocity effect at low redshift is model-dependent, but can be parameterized by using an unknown bias. We find that if unaccounted, the relative velocity effect can shift the BAO peak position and bias estimates of the dark energy equation-of-state due to its non-smooth, out-of-phase oscillation structure around the BAO scale. Fortunately, the relative velocity effect can be easily modeled in constraining cosmological parameters without substantially inflating the error budget. We also demonstrate that the presence of the relative velocity effect gives rise to a unique signature in the galaxy bispectrum, which can be utilized to isolate this effect. Future dark energy surveys can accurately measure the relative velocity effect and subtract it from the power spectrum a...

  2. Heavy Baryon Production and Decay

    CERN Document Server

    Dunietz, Isard

    1998-01-01

    The branching ratio B(Lambda_c -> p K- pi+) normalizes the production and decay of charmed and bottom baryons. At present, this crucial branching ratio is extracted dominantly from B.bar -> baryons analyses. This note questions several of the underlying assumptions and predicts sizable B.bar -> D(*) N N'.bar X transitions, which were traditionally neglected. It predicts B(Lambda_c -> p K- pi+) to be significantly larger (0.07 +/- 0.02) than the world average. Some consequences are briefly mentioned. Several techniques to measure B(Lambda_c -> p K- pi+) are outlined with existing or soon available data samples. By equating two recent CLEO results, an appendix obtains B(D0 -> K- pi+)= 0.035 +/- 0.002, which is somewhat smaller than the current world average.

  3. Lost Baryons at Low Redshift

    CERN Document Server

    Mathur, Smita; Williams, Rik J

    2007-01-01

    We review our attempts to discover lost baryons at low redshift with ``X-ray forest'' of absorption lines from the warm-hot intergalactic medium. We discuss the best evidence to date along the Mrk 421 sightline. We then discuss the missing baryons in the Local Group and the significance of the z=0 absorption systems in X-ray spectra. We argue that the debate over the Galactic vs. extragalactic origin of the z=0 systems is premature as these systems likely contain both components. Observations with next generation X-ray missions such as Constellation-X and XEUS will be crucial to map out the warm-hot intergalactic medium.

  4. The Doppler effect on indirect detection of dark matter using dark matter only simulations

    CERN Document Server

    Powell, Devon; Ng, Kenny C Y; Abel, Tom

    2016-01-01

    Indirect detection of dark matter is a major avenue for discovery. However, baryonic backgrounds are diverse enough to mimic many possible signatures of dark matter. In this work, we study the newly proposed technique of dark matter velocity spectroscopy [Speckhard etal. PRL 2016 https://arxiv.org/abs/1507.04744]. The non-rotating dark matter halo and the Solar motion produce a distinct longitudinal dependence of the signal which is opposite in direction to that produced by baryons. Using collisionless dark matter only simulations of Milky Way like halos, we show that this new signature is robust and holds great promise. We develop mock observations by high energy resolution X-ray spectrometer on a sounding rocket, the Micro-X experiment, to our test case, the 3.5 keV line. We show that by using six different pointings, Micro-X can exclude a constant line energy over various longitudes at $\\geq$ 3$\\sigma$. The halo triaxiality is an important effect and it will typically reduce the significance of this signal...

  5. Algebraic model of baryon structure

    CERN Document Server

    Bijker, R

    2000-01-01

    We discuss properties of baryon resonances belonging to the Nucleon, Delta, Sigma, Lambda, Xi and Omega families in a collective string-like model for the nucleon, in which the radial excitations are interpreted as rotations and vibrations of the string configuration. We find good overall agreement with the available data. The main discrepancies are found for low lying S-wave states, in particular N(1535), N(1650), Sigma(1750), Lambda*(1405), Lambda(1670) and Lambda(1800).

  6. Strongly baryon-dominated disk galaxies at the peak of galaxy formation ten billion years ago

    Science.gov (United States)

    Genzel, R.; Schreiber, N. M. Förster; Übler, H.; Lang, P.; Naab, T.; Bender, R.; Tacconi, L. J.; Wisnioski, E.; Wuyts, S.; Alexander, T.; Beifiori, A.; Belli, S.; Brammer, G.; Burkert, A.; Carollo, C. M.; Chan, J.; Davies, R.; Fossati, M.; Galametz, A.; Genel, S.; Gerhard, O.; Lutz, D.; Mendel, J. T.; Momcheva, I.; Nelson, E. J.; Renzini, A.; Saglia, R.; Sternberg, A.; Tacchella, S.; Tadaki, K.; Wilman, D.

    2017-03-01

    In the cold dark matter cosmology, the baryonic components of galaxies—stars and gas—are thought to be mixed with and embedded in non-baryonic and non-relativistic dark matter, which dominates the total mass of the galaxy and its dark-matter halo. In the local (low-redshift) Universe, the mass of dark matter within a galactic disk increases with disk radius, becoming appreciable and then dominant in the outer, baryonic regions of the disks of star-forming galaxies. This results in rotation velocities of the visible matter within the disk that are constant or increasing with disk radius—a hallmark of the dark-matter model. Comparisons between the dynamical mass, inferred from these velocities in rotational equilibrium, and the sum of the stellar and cold-gas mass at the peak epoch of galaxy formation ten billion years ago, inferred from ancillary data, suggest high baryon fractions in the inner, star-forming regions of the disks. Although this implied baryon fraction may be larger than in the local Universe, the systematic uncertainties (owing to the chosen stellar initial-mass function and the calibration of gas masses) render such comparisons inconclusive in terms of the mass of dark matter. Here we report rotation curves (showing rotation velocity as a function of disk radius) for the outer disks of six massive star-forming galaxies, and find that the rotation velocities are not constant, but decrease with radius. We propose that this trend arises because of a combination of two main factors: first, a large fraction of the massive high-redshift galaxy population was strongly baryon-dominated, with dark matter playing a smaller part than in the local Universe; and second, the large velocity dispersion in high-redshift disks introduces a substantial pressure term that leads to a decrease in rotation velocity with increasing radius. The effect of both factors appears to increase with redshift. Qualitatively, the observations suggest that baryons in the early

  7. Transport coefficients of heavy baryons

    Science.gov (United States)

    Tolos, Laura; Torres-Rincon, Juan M.; Das, Santosh K.

    2016-08-01

    We compute the transport coefficients (drag and momentum diffusion) of the low-lying heavy baryons Λc and Λb in a medium of light mesons formed at the later stages of high-energy heavy-ion collisions. We employ the Fokker-Planck approach to obtain the transport coefficients from unitarized baryon-meson interactions based on effective field theories that respect chiral and heavy-quark symmetries. We provide the transport coefficients as a function of temperature and heavy-baryon momentum, and analyze the applicability of certain nonrelativistic estimates. Moreover we compare our outcome for the spatial diffusion coefficient to the one coming from the solution of the Boltzmann-Uehling-Uhlenbeck transport equation, and we find a very good agreement between both calculations. The transport coefficients for Λc and Λb in a thermal bath will be used in a subsequent publication as input in a Langevin evolution code for the generation and propagation of heavy particles in heavy-ion collisions at LHC and RHIC energies.

  8. Soil Organic Matter Dynamics in the Rothamsted Long-term Experiments

    Science.gov (United States)

    MacDonald, A.; Poulton, P.

    2009-04-01

    Soil science research at Rothamsted dates from 1843 when John Bennet Lawes and Joseph Henry Gilbert started the first of a series of what became long-term field experiments. The main object of these experiments was to examine the effect of inorganic and organic fertilisers and manures on crop yield and soil fertility. These "Classical Field Experiments" included studies on winter wheat (Broadbalk 1843), spring barley (Hoos Barley 1852) and permanent grassland (Park Grass 1856). Additional experiments were established in the 20th century to examine the value of ley-arable cropping, including the Highfield and Fosters Ley-arable experiments (1948) and the Woburn Ley-arable experiment (1938). More recently, the effects of incorporating organic manures and cereal straw have been examined. Early results quickly showed the benefits of inorganic N and P fertilisers on crop production, but the effects of contrasting land uses and management practices on soil properties emerged more slowly. Measurements of soil organic carbon (C) and nitrogen (N) in soils taken at intervals from the long-term experiments indicate that the rate of soil organic matter (SOM) accumulation is controlled largely by the balance between the rate of organic matter inputs and its oxidation rate, and that these are strongly influenced by land use and management, soil texture (especially clay content) and climate. A recent examination of soil organic C data from two long-term grassland experiments in the UK (including Park Grass) indicates that any changes observed in soil organic C under long-term grasslands over the past 40 years are more likely to be due to changes in land use and management rather than climate change. Data from the Rothamsted Long-term experiments have been used to develop and test biogeochemical models of C and N dynamics. In particular, the Roth-C model has successfully simulated soil C dynamics in the long-term experiments at Rothamsted and elsewhere. This model uses several

  9. A Study of Double-Charm and Charm-Strange Baryons inElectron-Positron Annihilations

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Adam J.; /SLAC

    2007-10-15

    In this dissertation I describe a study of double-charm and charm-strange baryons based on data collected with the BABAR Detector at the Stanford Linear Accelerator Center. In this study I search for new baryons and make precise measurements of their properties and decay modes. I seek to verify and expand upon double-charm and charm-strange baryon observations made by other experiments. The BABAR Detector is used to measure subatomic particles that are produced at the PEP-II storage rings. I analyze approximately 300 million e+e- {yields} c{bar c} events in a search for the production of double-charm baryons. I search for the double-charm baryons {Xi}{sup +}{sub cc} (containing the quarks ccd) and {Xi}{sup ++}{sub cc} (ccu) in decays to {Lambda}{sup +}{sub c}K{sup -}{pi}{sup +} and {Lambda}{sup +}{sub c}K{sup -}{pi}{sup +}{pi}{sup +}, respectively. No statistically significant signals for their production are found, and upper limits on their production are determined. Statistically significant signals for excited charm-strange baryons are observed with my analysis of approximately 500 million e+e- {yields} c{bar c} events. The charged charm-strange baryons {Xi}{sub c}(2970){sup +}, {Xi}{sub c}(3055){sup +}, {Xi}{sub c}(3123){sup +} are found in decays to {Lambda}{sup +}{sub c}K{sup -}{pi}{sup +}, the same decay mode used in the {Xi}{sup +}{sub cc} search. The neutral charm-strange baryon {Xi}{sub c}(3077){sup 0} is observed in decays to {Lambda}{sup +}{sub c}K{sub 8}{pi}{sup -}. I also search for excited charm-strange baryon decays to {Lambda}{sup +}{sub c}K{sub 8}, {Lambda}{sup +}{sub c}K{sup -}, {Lambda}{sup +}{sub c}K{sub 8}{pi}{sup -}{pi}{sup +}, and {Lambda}{sup +}{sub c}K{sup -}{pi}{sup -}{pi}{sup +}. No significant charm-strange baryon signals a f h these decay modes. For each excited charm-strange baryon state that I observe, I measure its mass, natural width (lifetime), and production rate. The properties of these excited charm-strange baryons and their

  10. Heavy Baryons and QCD Sum Rules

    CERN Document Server

    Yakovlev, O I

    1996-01-01

    We discuss an application of QCD sum rules to the heavy baryons $\\Lambda_Q$ and $\\Sigma_Q$. The predictions for the masses of heavy baryons, residues and Isgur-Wise function are presented. The new results on two loop anomalous dimensions of baryonic currents and QCD radiative corrections (two- and three- loop contributions) to the first two Wilson coefficients in OPE are explicitly presented.

  11. Hadronic molecules in the heavy baryon spectrum

    Science.gov (United States)

    Entem, D. R.; Ortega, P. G.; Fernández, F.

    2016-01-01

    We study possible baryon molecules in the non-strange heavy baryon spectrum. We include configurations with a heavy-meson and a light baryon. We find several structures, in particular we can understand the Λc(2940) as a D*N molecule with JP = 3/2- quantum numbers. We also find D(*)Δ candidates for the recently discovered Xc(3250) resonance.

  12. Dark matter in the nonabelian hidden gauge theory

    CERN Document Server

    Yamanaka, Nodoka; Gongyo, Shinya; Iida, Hideaki

    2015-01-01

    We discuss the dark matter in the hidden gauge theory. We propose a scenario where the mini-inflation dilutes the dark matter density. This scenario is consistent with the current baryon number asymmetry.

  13. Baryon Number Violation and String Topologies

    CERN Document Server

    Sjöstrand, Torbjörn

    2003-01-01

    In supersymmetric scenarios with broken R-parity, baryon number violating sparticle decays become possible. In order to search for such decays, a good understanding of expected event properties is essential. We here develop a complete framework that allows detailed studies. Special attention is given to the hadronization phase, wherein the baryon number violating vertex is associated with the appearance of a junction in the colour confinement field. This allows us to tell where to look for the extra (anti)baryon directly associated with the baryon number violating decay.

  14. New Observations of beauty baryon decays at LHCb

    CERN Document Server

    Vitaly, Andreev

    2014-01-01

    This report describes the work I have done during my summer student association with the LHCb (Large Hadron Collider Beauty Experiment) collaboration at CERN from 30.06 till 26.09.2014. The project was performed in a team with two other summer students. In this report I concentrate on my contribution to the team work. In addition, one section is dedicated to the management framework called “scrum” which we used to collaborate as a team. The goal of my task was to analyze yet unobserved decays of the beauty Lambda-b-0 baryon. This is interesting since the CP violation still remains unobserved in baryons and beauty baryons are generally not well-known yet. LHCb is the first detector where these heavy baryons can be analyzed in detail. In addition these decays may play an important role in other processes and one can gain new insights into the strong interaction. The analysis presented here was performed on the full 2011-2012 LHC run data and includes several decays which are observed for the first time.

  15. Examining CP Symmetry in Strange Baryon Decays

    CERN Document Server

    Luk, K B

    2000-01-01

    Non-conservation of CP symmetry can manisfest itself in non-leptonic hyperon decays as a difference in the decay parameter between the strange-baryon decay and its charge conjugate. By comparing the decay distribution in the $\\Lambda$ helicity frame for the decay sequence $\\Xi^{-} \\to \\Lambda \\pi^{-}$, $\\Lambda \\to p \\pi^{-}$ with that of $\\bar{\\Xi}^{+}$ decay, E756 at Fermilab did not observe any CP-odd effect at the $10^{-2}$ level. The status of a follow-up experiment, HyperCP (FNAL E871), to search for CP violation in charged $\\Xi-\\Lambda$ decay with a sensitivity of $10^{-4}$ is also presented.

  16. On light baryons and their excitations

    CERN Document Server

    Eichmann, Gernot; Sanchis-Alepuz, Helios

    2016-01-01

    We study ground states and excitations of light octet and decuplet baryons within the framework of Dyson-Schwinger and Faddeev equations. We improve upon similar approaches by explicitly taking into account the momentum-dependent dynamics of the quark-gluon interaction that leads to dynamical chiral symmetry breaking. We perform calculations in both the three-body Faddeev framework and the quark-diquark approximation in order to assess the impact of the latter on the spectrum. Our results indicate that both approaches agree well with each other. The resulting spectra furthermore agree one-to-one with experiment, provided well-known deficiencies of the rainbow-ladder approximation are compensated for. We also discuss the mass evolution of the Roper and the excited Delta with varying pion mass and analyse the internal structure in terms of their partial wave decompositions.

  17. First observation of doubly charmed baryons

    Energy Technology Data Exchange (ETDEWEB)

    M. A. Moinester et al.

    2003-09-25

    The SELEX experiment (E781) at Fermilab has observed two statistically compelling high mass states near 3.6 GeV/c{sup 2}, decaying to {Lambda}{sub c}{sup +} K{sup -} {pi}{sup +} and {Lambda}{sub c}{sup +} K{sup -} {pi}{sup +}{pi}{sup +}. These final states are Cabibbo-allowed decay modes of doubly charmed baryons {Xi}{sub cc}{sup +} and {Xi}{sub cc}{sup ++}, respectively. The masses are in the range expected from theoretical considerations, but the spectroscopy is surprising. SELEX also has weaker preliminary evidence for a state near 3.8 GeV/c{sup 2}, a high mass state decaying to {Lambda}{sub c}{sup +} K{sup -} {pi}{sup +}{pi}{sup +}, possibly an excited {Xi}{sub cc}{sup ++} (ccu*). Data are presented and discussed.

  18. The WArP Experiment: A Double-Phase Argon Detector for Dark Matter Searches

    Directory of Open Access Journals (Sweden)

    Andrea Zani

    2014-01-01

    Full Text Available Cryogenic noble liquids emerged in the previous decade as one of the best media to perform WIMP dark matter searches, in particular due to the possibility to scale detector volumes to multiton sizes. The WArP experiment was then developed as one of the first to implement the idea of coupling Argon in liquid and gas phase, in order to discriminate β/γ-interactions from nuclear recoils and then achieve reliable background rejection. Since its construction, other projects spawned, employing Argon and Xenon and following its steps. The WArP 100l detector was assembled in 2008 at the Gran Sasso National Laboratories (LNGS, as the final step of a years-long R&D programme, aimed at characterising the technology of Argon in double phase for dark matter detection. Though it never actually performed a physics run, a technical run was taken in 2011, to characterise the detector response.

  19. a Next-Generation Cavity Microwave Experiment to Search for Dark-Matter Axions

    Science.gov (United States)

    Bibber, K. Van; Stöffl, W.; Anthony, P. L.; Sikivie, P.; Sullivan, N. S.; Tanner, D. B.; Železný, V.; Golubev, N. A.; Kazachenko, O. V.; Kravchuk, L. V.; Kuzmin, V.; Romanov, G. V.; Sekachev, I. V.; Rosenberg, L. J.; Hagmann, C.; Moltz, D. M.; Nezrick, F.; Turner, M. S.; Villa, F.

    We propose a large-scale experimental search for dark-matter axions which may constitute an important fraction of our own galactic halo. As shown by Sikivie,1 dark-matter axions may be detected by their stimulated conversion into monochromatic microwave photons in a tunable high-Q cavity inside a strong magnetic field. The principal improvement in power sensitivity over two earlier pilot experiments (×25) derives from the large-volume high field superconducting magnet (the NASA SUMMA coils). The improvement in mass range (1.5 to 12.6 μeV) will result from the use of several microwave cavity arrays, of 2n cavities each, over the course of the experimental program, rather than a single cavity. We are participating in a joint venture with the Institute for Nuclear Research of the Russian Academy of Sciences to do R&D on metalized precision-formed ceramic microwave cavities for the axion search.

  20. Radon Mitigation for the SuperCDMS-SNOLAB Dark Matter Experiment

    Science.gov (United States)

    Street, Joseph; SuperCDMS Collaboration

    2016-03-01

    Experiments that seek to detect very rare processes, such as interactions of the dark matter particles thought to make up 85% of the mass of the universe, may suffer background interactions from radon daughters that have plated out onto detector surfaces. To reduce these backgrounds, an ultra-low-radon cleanroom was built at the South Dakota School of Mines & Technology. Cleanroom air is supplied by an optimized vacuum-swing-adsorption radon mitigation system that has achieved a > 300 × reduction from an input activity of 58.6 +/- 0.7 Bq/m3 to a cleanroom activity of 0.13 +/- 0.06 Bq/m3. Expected backgrounds due to radon daughters for the SuperCDMS dark matter search will be presented.

  1. Neutrino Masses, Leptogenesis and Decaying Dark Matter

    CERN Document Server

    Chen, Chuan-Hung; Zhuridov, Dmitry V

    2009-01-01

    We study a simple extension of the standard model to simultaneously explain neutrino masses, dark matter and the matter-antimatter asymmetry of the Universe. In our model, the baryon asymmetry is achieved by the leptogenesis mechanism, while the decaying dark matter with the lifetime of O(10^26 s) provides a natural solution to the electron and positron excesses in Fermi and PAMELA satellite experiments. In particular, we emphasize that our model is sensitive to the structure at the endpoint around 1 TeV of the Fermi data. In addition, some of new particles proposed in the model are within the reach at the near future colliders, such as the Large Hadron Collider.

  2. Neutrino masses, leptogenesis and decaying dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chuan-Hung [Department of Physics, National Cheng-Kung University, Tainan 701, Taiwan (China); Geng, Chao-Qiang; Zhuridov, Dmitry V., E-mail: physchen@mail.ncku.edu.tw, E-mail: geng@phys.nthu.edu.tw, E-mail: zhuridov@phys.nthu.edu.tw [Department of Physics, National Tsing-Hua University, Hsinchu 300, Taiwan (China)

    2009-10-01

    We study a simple extension of the standard model to simultaneously explain neutrino masses, dark matter and the matter-antimatter asymmetry of the Universe. In our model, the baryon asymmetry is achieved by the leptogenesis mechanism, while the decaying dark matter with the lifetime of O(10{sup 26} s) provides a natural solution to the electron and positron excesses in Fermi and PAMELA satellite experiments. In particular, we emphasize that our model is sensitive to the structure at the endpoint around 1 TeV of the Fermi data. In addition, some of new particles proposed in the model are within the reach at the near future colliders, such as the Large Hadron Collider.

  3. Hunting down systematics in baryon acoustic oscillations after cosmic high noon

    CERN Document Server

    Prada, Francisco; Chuang, Chia-Hsun; Yepes, Gustavo; Klypin, Anatoly A; Kitaura, Francisco-Shu; Gottlober, Stefan

    2014-01-01

    Future dark energy experiments will require better and more accurate theoretical predictions for the baryonic acoustic oscillations (BAO) signature in the spectrum of cosmological perturbations. Here, we use large N-body simulations of the \\LambdaCDM Planck cosmology to study any possible systematic shifts and damping in BAO due to the impact of nonlinear gravitational growth of structure, scale dependent and non-local bias, and redshift-space distortions. The effect of cosmic variance is largely reduced by dividing the tracer power spectrum by that from a BAO-free simulation starting with the same phases. This permits us to study with unprecedented accuracy (better than 0.02% for dark matter and 0.07% for low-bias halos) small shifts of the pristine BAO wavenumbers towards larger k, and non-linear damping of BAO wiggles in the power spectrum of dark matter and halo populations in the redshift range z=0-1. For dark matter, we provide an accurate parametrization of the evolution of \\alpha as a function of the ...

  4. General experiments concerning particle-matter interactions; Experiences interdisciplinaires d'interaction particule-matiere

    Energy Technology Data Exchange (ETDEWEB)

    Dauvergne, D

    2006-07-15

    The author gathers in this document several papers he has already published in order to shed light on different aspects concerning ion-crystal interactions. This document is divided into 3 chapters. In the first chapter the author presents results obtained from experiments dedicated to charge exchanges and energy released by heavy ions in channeling conditions. Different processes involved in ion-electron interactions are considered: The tri-electronic recombination, the electron capture through nuclear excitation (NEEC), resonant transfer and excitation (RTE), resonant transfer and double excitation (RTDE) and electron impact ionization (EII). The second chapter deals with the measurement of nuclear fission times through crystal blocking experiments. The crystal blocking technique allows the measurement in a model-independent way of the recoil distance covered by the excited nucleus during the whole fission process (starting from the initial collision and ending at the scission point). The last chapter is dedicated to the photon impact ionization through the conversion of a high-energy photon into an electron-positron pair.

  5. Physics Potential and Prospects for CUORE and CUORICINO experiments

    OpenAIRE

    Irastorza, I. G.; Morales, A.; Scopel, S.; Cebrian, S

    2001-01-01

    The CUORE (Cryogenic Underground Observatory for Rare Events) experiment projects to construct and operate an array of 1000 cryogenic thermal detectors of a mass of 760 g each to investigate rare events physics, in particular, double beta decay and non baryonic particle dark matter. A first step towards CUORE is CUORICINO, an array of 56 of such bolometers, currently being installed in the Gran Sasso. In this paper we report the physics potential of both stages of the experiment regarding neu...

  6. Study of ψ(3770 decaying to baryon anti-baryon pairs

    Directory of Open Access Journals (Sweden)

    Li-Gang Xia

    2016-05-01

    Full Text Available To study the decays of ψ(3770 going to baryon anti-baryon pairs (BB¯, all available experiments of measuring the cross sections of e+e−→BB¯ at center-of-mass energy ranging from 3.0 GeV to 3.9 GeV are combined. To relate the baryon octets, a model based on the SU(3 flavor symmetry is used and the SU(3 breaking effects are also considered. Assuming the electric and magnetic form factors are equal (|GE|=|GM|, a global fit including the interference between the QED process and the resonant process is performed. The branching fraction of ψ(3770→BB¯ is determined to be (2.4±0.8±0.3×10−5, (1.7±0.6±0.1×10−5, (4.5±0.9±0.1×10−5, (4.5±0.9±0.1×10−5, (2.0±0.7±0.1×10−5, and (2.0±0.7±0.1×10−5 for B=p,Λ,Σ+,Σ0,Ξ− and Ξ0, respectively, where the first uncertainty is from the global fit and the second uncertainty is the systematic uncertainty due to the assumption |GE|=|GM|. They are at least one order of magnitude larger than a simple scaling of the branching fraction of J/ψ/ψ(3686→BB¯.

  7. Baryon Form Factors at Threshold

    Energy Technology Data Exchange (ETDEWEB)

    Baldini Ferroli, Rinaldo [Museo Storico della Fisica e Centro Studi e Ricerche ' E. Fermi' , Rome (Italy); INFN, Laboratori Nazionali di Frascati, Frascati (Italy); Pacetti, Simone [INFN and Dipartimento di Fisica, Universita di Perugia, Perugia (Italy)

    2012-04-15

    An extensive study of the e{sup +}e{sup -}{yields}pp{sup Macron }BABAR cross section data is presented. Two unexpected outcomes have been found: the modulus of the proton form factor is normalized to one at threshold, i.e.: |G{sup p}(4M{sub p}{sup 2})|=1, as a pointlike fermion, and the resummation factor in the Sommerfeld formula is not needed. Other e{sup +}e{sup -} {yields} baryon-antibaryon cross sections show a similar behavior near threshold.

  8. Aspects Of Baryon Number As A U(1) Symmetry

    CERN Document Server

    Pawl, A E

    2005-01-01

    The non-observation of proton decay strongly suggests that baryon number is a global U(1) (phase rotation) symmetry of the low-energy effective Lagrangian of particle physics. In the first half of this thesis, we explore the surprisingly dramatic consequences of this U(1) symmetry for the Affleck-Dine model of baryogenesis. Affleck-Dine baryogenesis is a popular model for the creation of a matter-antimatter asymmetry which relys on setting a complex scalar field into phase rotation. The phase symmetry of the Lagrangian has all important effect oil the evolution of this scalar field. The baryon number symmetry need not be restricted to a global symmetry. There is growing evidence from string theory, in fact, that global U(1) symmetries must have a gauge origin. In the second half of this thesis, we consider the details of how two different approaches to breaking a, gauged U(1) baryon symmetry would function in a universe with a low Planck scale. A universe with a low Planck scale (Mpl ∼ 103 GeV) has r...

  9. The Axion Dark Matter Experiment: Big Science with a (relatively) Small Team

    Science.gov (United States)

    Carosi, Gianpaolo

    2016-03-01

    The idea of the solitary physicist tinkering alone in a lab was my image of how science was done growing up (mostly influenced by popular culture). Of course this is not generally how experimental physics is done now days with examples of experiments at the LHC now involving thousands of scientists. In this talk I will describe my experience in a relatively modest project, the Axion Dark Matter eXperiment (ADMX), which involves only a few dozen scientists at various universities and national labs. I will outline ADMX's humble beginnings at Lawrence Livermore National Laboratory (LLNL), where it began in the mid-1990s, and describe how the collaboration has evolved and grown throughout the years, as we pursue our elusive quarry: the dark-matter axion. Supported by DOE Grants DE-FG02-97ER41029, DE-FG02-96ER40956, DE- AC52-07NA27344, DE-AC03-76SF00098, and the Livermore LDRD program.

  10. CALIS - a CALibration Insertion System for the DarkSide-50 dark matter search experiment

    CERN Document Server

    Agnes, P; Alexander, T; Alton, A K; Asner, D M; Back, H O; Baldin, B; Biery, K; Bocci, V; Bonfini, G; Bonivento, W; Bossa, M; Bottino, B; Brigatti, A; Brodsky, J; Budano, F; Bussino, S; Cadeddu, M; Cadonati, L; Cadoni, M; Calaprice, F; Canci, N; Candela, A; Caravati, M; Cariello, M; Carlini, M; Catalanotti, S; Cavalcante, P; Chepurnov, A; Cicalo, C; Cocco, A G; Covone, G; D'Angelo, D; D'Incecco, M; Davini, S; De Cecco, S; De Deo, M; De Vincenzi, M; Derbin, A; Devoto, A; Di Eusanio, F; Di Pietro, G; Dionisi, C; Edkins, E; Empl, A; Fan, A; Fiorillo, G; Fomenko, K; Forster, G; Franco, D; Gabriele, F; Galbiati, C; Giagu, S; Giganti, C; Giovanetti, G K; Goretti, A M; Granato, F; Grandi, L; Gromov, M; Guan, M; Guardincerri, Y; Hackett, B R; Herner, K; Hughes, D; Humble, P; Hungerford, E V; Ianni, Al; Ianni, An; James, I; Johnson, T N; Jollet, C; Keeter, K; Kendziora, C L; Koh, G; Korablev, D; Korga, G; Kubankin, A; Li, X; Lissia, M; Loer, B; Lombardi, P; Longo, G; Ma, Y; Machulin, I N; Mandarano, A; Mari, S M; Maricic, J; Marini, L; Martoff, C J; Meregaglia, A; Meyers, P D; Milincic, R; Miller, J D; Montanari, D; Monte, A; Mount, B J; Muratova, V N; Musico, P; Napolitano, J; Agasson, A Navrer; Odrowski, S; Orsini, M; Ortica, F; Pagani, L; Pallavicini, M; Pantic, E; Parmeggiano, S; Pelczar, K; Pelliccia, N; Pocar, A; Pordes, S; Pugachev, D A; Qian, H; Randle, K; Ranucci, G; Razeti, M; Razeto, A; Reinhold, B; Renshaw, A L; Rescigno, M; Riffard, Q; Romani, A; Rossi, B; Rossi, N; Rountree, D; Sablone, D; Saggese, P; Saldanha, R; Sands, W; Savarese, C; Schlitzer, B; Segreto, E; Semenova, D A; Shields, E; Singh, P N; Skorokhvatov, M D; Smirnov, O; Sotnikov, A; Stanford, C; Suvorov, Y; Tartaglia, R; Tatarowicz, J; Testera, G; Tonazzo, A; Trinchese, P; Unzhakov, E V; Verducci, M; Vishneva, A; Vogelaar, B; Wada, M; Walker, S; Wang, H; Wang, Y; Watson, A W; Westerdale, S; Wilhelmi, J; Wojcik, M M; Xiang, Xi; Xiao, X; Xu, J; Yang, C; Zec, A; Zhong, W; Zhu, C; Zuzel, G

    2016-01-01

    This paper describes the design, fabrication, commissioning and use of a CALibration source Insertion System (CALIS) in the DarkSide-50 direct dark matter search experiment. CALIS deploys radioactive sources into the liquid scintillator veto to characterize the detector response and detection efficiency of the DarkSide-50 Liquid Argon Time Projection Chamber, and the surrounding 30 t organic liquid scintillator neutron veto. It was commissioned in September 2014 and has been used successfully in several gamma and neutron source campaigns since then. A description of the hardware and an excerpt of calibration analysis results are given below.

  11. Observational constraints of stellar collapse: Diagnostic probes of nature's extreme matter experiment

    Directory of Open Access Journals (Sweden)

    Chris L. Fryer

    2014-04-01

    Full Text Available Supernovae are Nature's high-energy, high density laboratory experiments, reaching densities in excess of nuclear densities and temperatures above 10 MeV. Astronomers have built up a suite of diagnostics to study these supernovae. If we can utilize these diagnostics, and tie them together with a theoretical understanding of supernova physics, we can use these cosmic explosions to study the nature of matter at these extreme densities and temperatures. Capitalizing on these diagnostics will require understanding a wide range of additional physics. Here we review the diagnostics and the physics neeeded to use them to learn about the supernova engine, and ultimate nuclear physics.

  12. Observational Constraints of Stellar Collapse: Diagnostic Probes of Nature's Extreme Matter Experiment

    CERN Document Server

    Fryer, C L; Grefenstette, B W; Wong, T -W

    2014-01-01

    Supernovae are Nature's high-energy, high density laboratory experiments, reaching densities in excess of nuclear densities and temperatures above 10MeV. Astronomers have built up a suite of diagnostics to study these supernovae. If we can utilize these diagnostics, and tie them together with a theoretical understanding of supernova physics, we can use these cosmic explosions to study the nature of matter at these extreme densities and temperatures. Capitalizing on these diagnostics will require understanding a wide range of additional physics. Here we review the diagnostics and the physics needed to use them to learn about the supernova engine, and ultimate nuclear physics.

  13. CALIS - a CALibration Insertion System for the DarkSide-50 dark matter search experiment

    Energy Technology Data Exchange (ETDEWEB)

    Agnes, P.; et al.

    2012-12-28

    This paper describes the design, fabrication, commissioning and use of a CALibration source Insertion System (CALIS) in the DarkSide-50 direct dark matter search experiment. CALIS deploys radioactive sources into the liquid scintillator veto to characterize the detector response and detection efficiency of the DarkSide-50 Liquid Argon Time Projection Chamber, and the surrounding 30 t organic liquid scintillator neutron veto. It was commissioned in September 2014 and has been used successfully in several gamma and neutron source campaigns since then. A description of the hardware and an excerpt of calibration analysis results are given below.

  14. Dark matter in Draco and the Local Group Implications for direct detection experiments

    CERN Document Server

    Moore, B; Stadel, J; Quinn, T; Lake, G; Ghigna, S; Governato, F; Moore, Ben; Calcaneo-Roldan, Carlos; Stadel, Joachim; Quinn, Tom; Lake, George; Ghigna, Sebastiano; Governato, Fabio

    2001-01-01

    We use a cosmological simulation of the Local Group to make quantitative and speculative predictions for direct detection experiments. Cold dark matter (CDM) halos form via a complex series of mergers, accretion events and violent relaxation which precludes the formation of significant caustic features predicted by axially symmetric collapse. The halo density profiles are combined with observational constraints on the galactic mass distribution to constrain the local density of cold dark matter to lie in the range 0.18 <~ rho_CDM(R_solar)/GeV cm^-3 <~ 0.30. In velocity space, coherent streams of dark matter from tidally disrupted halos fill the halo and provide a tracer of the merging hierarchy. The particle velocities within triaxial CDM halos cannot be approximated by a simple Maxwellian distribution and is radially biased at the solar position. The detailed phase space structure within the solar system will depend on the early merger history of the progenitor halos and the importance of major mergers...

  15. Bent by baryons: the low mass galaxy-halo relation

    CERN Document Server

    Sawala, Till; Fattahi, Azadeh; Navarro, Julio F; Bower, Richard G; Crain, Robert A; Vecchia, Claudio Dalla; Furlong, Michelle; Jenkins, Adrian; McCarthy, Ian G; Qu, Yan; Schaller, Matthieu; Schaye, Joop; Theuns, Tom

    2014-01-01

    The relation between galaxies and dark matter halos is of vital importance for evaluating theoretical predictions of structure formation and galaxy formation physics. We show that the widely used method of abundance matching based on dark matter only simulations fails at the low mass end because two of its underlying assumptions are broken: only a small fraction of low mass (below 10^9.5 solar masses) halos host a visible galaxy, and halos grow at a lower rate due to the effect of baryons. In this regime, reliance on dark matter only simulations for abundance matching is neither accurate nor self-consistent. We find that the reported discrepancy between observational estimates of the halo masses of dwarf galaxies and the values predicted by abundance matching does not point to a failure of LCDM, but simply to a failure to account for baryonic effects. Our results also imply that the Local Group contains only a few hundred observable galaxies in contrast with the thousands of faint dwarfs that abundance matchi...

  16. Mean-field Approach to the Derivation of Baryon Superpotential from Matrix Model

    CERN Document Server

    Suzuki, H

    2003-01-01

    We discuss how to obtain the superpotential of the baryons and mesons for SU(N) gauge theories with N flavour matter fields from matrix integral. We apply the mean-field approximation for the matrix integral. Assuming the planar limit of the self-consistency equation, we show that the result almost agrees with the field theoretical result.

  17. A Low-Threshold Analysis of Data from the Cryogenic Dark Matter Search Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bunker, Raymond [Univ. of California, Santa Barbara, CA (United States)

    2011-12-01

    Although dark matter appears to constitute over 80% of the matter in the Universe, its composition is a mystery. Astrophysical observations suggest that the luminous portions of the Galaxy are embedded in a halo of darkmatter particles. Weakly Interacting Massive Particles (WIMPs) are the most studied class of dark-matter candidates and arise naturally within the context of many weak-scale supersymmetric theories. Direct-detection experiments like the Cryogenic Dark Matter Search (CDMS) strive to discern the kinetic energy of recoiling nuclei resulting from WIMP interactions with terrestrial matter. This is a considerable challenge in which the low (expected) rate of WIMP interactions must be distinguished from an overwhelming rate due to known types of radiation. An incontrovertible positive detection has remained elusive. However, a few experiments have recorded data that appear consistent with a low-mass WIMP. This thesis describes an attempt to probe the favored parameter space. To increase sensitivity to low-mass WIMPs, a low-threshold technique with improved sensitivity to small energy depositions is applied to CDMS shallowsite data. Four germanium and two silicon detectors were operated between December 2001 and June 2002, yielding 118 days of exposure. By sacrificing some of the CDMS detectors’ ability to discriminate signal from background, energy thresholds of ~1 and ~2 keV were achieved for three of the germanium and both silicon detectors, respectively. A large number of WIMP candidate events are observed, most of which can be accounted for by misidentification of background sources. No conclusive evidence for a low-mass WIMP signal is found. The observed event rates are used to set upper limits on the WIMPnucleon scattering cross section as a function of WIMP mass. Interesting parameter space is excluded for WIMPs with masses below ~9GeV/c2. Under standard assumptions, the parameter space favored by interpretations of other experiments

  18. The effect of baryons on redshift space distortions and cosmic density and velocity fields in the EAGLE simulation

    Science.gov (United States)

    Hellwing, Wojciech A.; Schaller, Matthieu; Frenk, Carlos S.; Theuns, Tom; Schaye, Joop; Bower, Richard G.; Crain, Robert A.

    2016-09-01

    We use the Evolution and Assembly of GaLaxies and their Environments (EAGLE) galaxy formation simulation to study the effects of baryons on the power spectrum of the total matter and dark matter distributions and on the velocity fields of dark matter and galaxies. On scales k ≳ 4 h Mpc-1 the effect of baryons on the amplitude of the total matter power spectrum is greater than 1 per cent. The back-reaction of baryons affects the density field of the dark matter at the level of ˜3 per cent on scales of 1 ≤ k/( h Mpc-1) ≤ 5. The dark matter velocity divergence power spectrum at k ≲ 0.5 h Mpc-1 is changed by less than 1 per cent. The 2D redshift space power spectrum is affected at the level of ˜6 per cent at |k|≳ 1 h Mpc^{-1} (for μ > 0.5), but for |k|≤ 0.4 h Mpc^{-1} it differs by less than 1 per cent. We report vanishingly small baryonic velocity bias for haloes: the peculiar velocities of haloes with M200 > 3 × 1011 M⊙ (hosting galaxies with M* > 109 M⊙) are affected at the level of at most 1 km s-1, which is negligible for 1 per cent-precision cosmology. We caution that since EAGLE overestimates cluster gas fractions it may also underestimate the impact of baryons, particularly for the total matter power spectrum. Nevertheless, our findings suggest that for theoretical modelling of redshift space distortions and galaxy velocity-based statistics, baryons and their back-reaction can be safely ignored at the current level of observational accuracy. However, we confirm that the modelling of the total matter power spectrum in weak lensing studies needs to include realistic galaxy formation physics in order to achieve the accuracy required in the precision cosmology era.

  19. Baryon and lepton violation in astrophysics.

    Science.gov (United States)

    Kolb, E. W.

    The cosmological and astrophysical significance of baryon and lepton number violating process is the subject of this paper. The possibility of baryon-number violating processes in the electroweak transition in the early universe is reviewed. The implications of lepton-number violation via Nambu-Goldstone bosons are discussed in detail.

  20. Baryon spectroscopy and the omega minus

    Energy Technology Data Exchange (ETDEWEB)

    Samios, N.P.

    1994-12-31

    In this report, I will mainly discuss baryon resonances with emphasis on the discovery of the {Omega}{sup {minus}}. However, for completeness, I will also present some data on the meson resonances which together with the baryons led to the uncovering of the SU(3) symmetry of particles and ultimately to the concept of quarks.

  1. Baryon number violation in future accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Tracas, N.D.; Zoupanos, G.

    1989-03-30

    As a demonstration of the possibility to observe baryon number violation in the next generation of accelerators we present a semirealistic GUT in which proton decay is forbidden and the unification scale is at approx. = 10/sup 3-4/ TeV, leading therefore to observable baryon number violating processes.

  2. Exactly solvable models of baryon structure

    CERN Document Server

    Bijker, R

    1998-01-01

    We present a qualitative analysis of the gross features of baryon spectroscopy (masses and form factors) in terms of various exactly solvable models. It is shown that a collective model, in which baryon resonances are interpreted as rotations and vibrations of an oblate symmetric top, provides a good starting point for a more detailed quantitative study.

  3. Exactly solvable models of baryon structure

    Energy Technology Data Exchange (ETDEWEB)

    Bijker, R. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico. Apartado Postal 70-543, 04510 Mexico D.F. (Mexico); Leviatan, A. [Racah Institute of Physics, The Hebrew University. Jerusalem 91904, Israel (Israel)

    1998-12-31

    We present a qualitative analysis of the gross features of baryon spectroscopy (masses and form factors) in terms of various exactly solvable models. It is shown that a collective model, in which baryon resonances are interpreted as rotations and vibrations of an oblate symmetric top, provides a good starting point for a more detailed quantitative study. (Author)

  4. (Hybrid) Baryons Quantum Numbers and Adiabatic Potentials

    CERN Document Server

    Page, P R

    1999-01-01

    We construct (hybrid) baryons in the flux-tube model of Isgur and Paton. In the limit of adiabatic quark motion, we build proper eigenstates of orbital angular momentum and indicate the flavour, spin, chirality and J^P of (hybrid) baryons. The adiabatic potential is calculated as a function of the quark positions.

  5. Pathways to Rare Baryonic B Decays

    CERN Document Server

    Hou Wei Shu; Hou, Wei-Shu

    2001-01-01

    We point out new ways to search for charmless baryonic B decays: baryon pair production in association with $\\eta^\\prime$ is very likely as large as or even a bit larger than two body $K\\pi/\\pi\\pi$ modes. We extend our argument, in weaker form, to $B\\to \\gamma + X_s$ and $\\ell\

  6. A rotating string model versus baryon spectra

    CERN Document Server

    Sonnenschein, Jacob

    2014-01-01

    We continue our program of describing hadrons as rotating strings with massive endpoints. In this paper we propose models of baryons and confront them with the baryon Regge trajectories. We show that these are best fitted by a model of a single string with a quark at one endpoint and a diquark at the other. This model is preferred over the Y-shaped string model with a quark at each endpoint. We show how the model follows from a stringy model of the holographic baryon which includes a baryonic vertex connected with $N_c$ strings to flavor probe branes. From fitting to baryonic data we find that there is no clear evidence for a non-zero baryonic vertex mass, but if there is such a mass it should be located at one of the string endpoints. The available baryon trajectories in the angular momentum plane $(J,M^2)$, involving light, strange, and charmed baryons, are rather well fitted when adding masses to the string endpoints, with a single universal slope $\\alp = 0.95$ GeV$^{-2}$. Most of the results for the quark...

  7. Baryon form factors in chiral perturbation theory

    CERN Document Server

    Kubis, B; Kubis, Bastian; Meissner, Ulf-G.

    2001-01-01

    We analyze the electromagnetic form factors of the ground state baryon octet to fourth order in relativistic baryon chiral perturbation theory. Predictions for the \\Sigma^- charge radius and the \\Lambda-\\Sigma^0 transition moment are found to be in excellent agreement with the available experimental information. Furthermore, the convergence behavior of the hyperon charge radii is shown to be more than satisfactory.

  8. The Photon-Baryon Governed Universe

    Directory of Open Access Journals (Sweden)

    Laszlo A. Marosi

    2012-01-01

    Full Text Available In a previous paper we postulated that the repulsive force responsible for the universal expansion is associated with the excitation of the empty space (quantum vacuum and the excitation energy is represented by the energy of the cosmic microwave background (CMB. In this paper, we show that the concept of the repulsive space expanding photon field (i can successfully be applied to explain the local velocity anomaly of the Milky Way Galaxy as shown by Faber and Burstein (1998 and Tully (1998, (ii offers a convincing explanation of the still disputed question of the cosmological expansion on local and intergalactic scales discussed by Cooperstock et al. (1998, and (iii explains the redshift (RS of the CMB in accordance with the law of energy conservation without the need for dark matter (DM and dark energy (DE. Probably the most remarkable result of this model (abbreviated as photon/baryon: PB model in the following discussion is that the individual voids building up the soup-bubble- (SB- like galaxy distribution are the governing dynamical components of the universal expansion. Further consequence implies that the universe is considerably older than the interpretation of the Hubble constant as expansion velocity suggests.

  9. Baryon Acoustic Oscillations reconstruction with pixels

    CERN Document Server

    Obuljen, Andrej; Castorina, Emanuele; Viel, Matteo

    2016-01-01

    Gravitational non-linear evolution induces a shift in the position of the baryon acoustic oscillations (BAO) peak together with a damping and broadening of its shape that bias and degrades the accuracy with which the position of the peak can be determined. BAO reconstruction is a technique developed to undo part of the effect of non-linearities. We present a new reconstruction method that consists in displacing pixels instead of galaxies and whose implementation is easier than the standard reconstruction method. We show that our method is equivalent to the standard reconstruction technique in the limit where the number of pixels becomes very large. This method is particularly useful in surveys where individual galaxies are not resolved, as in 21cm intensity mapping observations. We validate our method by reconstructing mock pixelated maps, that we build from the distribution of matter and halos in real- and redshift-space, from a large set of numerical simulations. We find that our method is able to decrease ...

  10. The PANDA experiment: physics goals and experimental setup

    Directory of Open Access Journals (Sweden)

    Boca Gianluigi

    2014-05-01

    Full Text Available PANDA (antiProton ANnihilation at DArmstadt is an experiment that will run at the GSI laboratory, Darmstadt, Germany, in 2019. A high intensity antiproton beam with momentum up to 15 GeV/c will collide on a fixed proton target (pellet target or jet target. A wide range of physics topics will be investigated: char- monium states and open charm states above the DD¯$D\\overline D $ threshold; exotic states like glueballs, oddballs, hybrids, multiquarks, molecules; the spectroscopy of the excited states of strange and charm baryons; non-perturbative QCD dynamics in the pp¯$p\\overline p $ production cross section of charm and strange baryons and their spin correlations; the behaviour of hadrons in nuclear matter; hypernuclear physics; electromagnetic proton form factors in the timelike region; the CP violation in the charm sector, rare and forbidden decays of charm baryons and mesons.

  11. Superconducting dipole magnet for the CBM experiment at FAIR

    Directory of Open Access Journals (Sweden)

    Kurilkin P.

    2017-01-01

    Full Text Available The scientific goal of the CBM (Compressed Baryonic Matter experiment at FAIR (Darmstadt is to explore the phase diagram of strongly interacting matter at highest baryon densities. The physics program of the CBM experiment is complimentary to the programs to be realized at MPD and BMN facilities at NICA and will start with beam derived by the SIS100 synchrotron. The 5.15 MJ superconducting dipole magnet will be used in the silicon tracking system of the CBM detector. The magnet will provide a magnetic field integral of 1 Tm which is required to obtain a momentum resolution of 1% for the track reconstruction. The results of the development of dipole magnet of the CBM experiment are presented.

  12. Electromagnetic properties of light and heavy baryons in the relativistic quark model

    Energy Technology Data Exchange (ETDEWEB)

    Nicmorus Marinescu, Diana

    2007-06-14

    One of the main challenges of nowadays low-energy physics remains the description of the internal structure of hadrons, strongly connected to the electromagnetic properties of matter. In this vein, the success of the relativistic quark model in the analysis of the hadron structure constitutes a solid motivation for the study carried out throughout this work. The relativistic quark model is extended to the investigation of static electromagnetic properties of both heavy and light baryons. The bare contributions to the magnetic moments of the single-, double- and triple-heavy baryons are calculated. Moreover, the relativistic quark model allows the study of the electromagnetic properties of the light baryon octet incorporating meson cloud contributions in a perturbative manner. The long disputed values of the multipole ratios E2/M1 and C2/M1 and the electromagnetic form factors of the N{yields}{delta}{gamma} transition are successfully reproduced. The relativistic quark model can be viewed as a quantum field theory approach based on a phenomenological Lagrangian coupling light and heavy baryons to their constituent quarks. In our approach the baryon is a composite object of three constituent quarks, at least in leading order. The effective interaction Lagrangian is written in terms of baryon and constituent quark fields. The effective action preserves Lorentz covariance and gauge invariance. The main ingredients of the model are already introduced at the level of the interaction Lagrangian: the three-quark baryon currents, the Gaussian distribution of the constituent quarks inside the baryon and the compositeness condition which sets an upper limit for the baryon-quark vertex. The S-matrix elements are expressed by a set of Feynman quark-diagrams. The model contains only few parameters, namely, the cut-off parameter of the Gaussian quark distribution and the free quark propagator, which are unambiguously determined from the best fit to the data. The heavy quark limit

  13. Pion mean fields and heavy baryons

    CERN Document Server

    Yang, Ghil-Seok; Polyakov, Maxim V; Praszałowicz, Michał

    2016-01-01

    We show that the masses of the lowest-lying heavy baryons can be very well described in a pion mean-field approach. We consider a heavy baryon as a system consisting of the $N_c-1$ light quarks that induce the pion mean field, and a heavy quark as a static color source under the influence of this mean field. In this approach we derive a number of \\textit{model-independent} relations and calculate the heavy baryon masses using those of the lowest-lying light baryons as input. The results are in remarkable agreement with the experimental data. In addition, the mass of the $\\Omega_b^*$ baryon is predicted.

  14. Strangeness in the baryon ground states

    CERN Document Server

    Semke, A

    2012-01-01

    We compute the strangeness content of the baryon ground states based on an analysis of recent lattice simulations of the BMW, PACS, LHPC and HSC groups for the pion-mass dependence of the baryon masses. Our results rely on the relativistic chiral Lagrangian and large-$N_c$ sum rule estimates of the counter terms relevant for the baryon masses at N$^3$LO. A partial summation is implied by the use of physical baryon and meson masses in the one-loop contributions to the baryon self energies. A simultaneous description of the lattice results of the BMW, LHPC, PACS and HSC groups is achieved. We predict the pion- and strangeness sigma terms and the pion-mass dependence of the octet and decuplet ground states at different strange quark masses.

  15. First Observation of a Family of Double-Charm Baryons

    CERN Document Server

    Russ, J S

    2002-01-01

    The SELEX experiment (E781) at Fermilab has candidates for high mass states decaying to Lambda_c+ K- pi+ and Lambda_c+ K- pi+ pi+, Cabibbo-allowed decay modes of doubly-charmed baryons Xi_cc+ and Xi_cc++. The masses are consistent with theoretical considerations, but the spectroscopy is surprising. Limited lifetime information suggests that tau_{Xi_cc++} \\sim tau_{Xi_cc+}.

  16. Operating the GridPix detector in dark matter search experiments

    Energy Technology Data Exchange (ETDEWEB)

    Schön, R., E-mail: rolfs@nikhef.nl [National Institute for Subatomic Physics Nikhef, Science Park 105, 1098 XG, Amsterdam (Netherlands); Alfonsi, M. [National Institute for Subatomic Physics Nikhef, Science Park 105, 1098 XG, Amsterdam (Netherlands); Hemink, G. [National Institute for Subatomic Physics Nikhef, Science Park 105, 1098 XG, Amsterdam (Netherlands); University of Twente, Drienerloolaan 5, 7522 NB, Enschede (Netherlands); Decowski, M.P.; Bakel, N. van; Graaf, H. van der [National Institute for Subatomic Physics Nikhef, Science Park 105, 1098 XG, Amsterdam (Netherlands)

    2013-08-01

    The DARWIN (dark matter WIMP search with noble liquids) design study aims to use liquid argon and liquid xenon targets to look for nuclear recoils due to weakly interacting massive particles (WIMPs). To measure the recoil energy in dual-phase noble gas time projection chambers the combination of scintillation and ionisation detection is used to discriminate nuclear from electron recoils. Current experiments use an array of photomultiplier tubes to detect the primary scintillation and the ionisation electrons via secondary scintillation in the gas phase. Within the research framework for DARWIN, one candidate for an alternative direct charge readout is GridPix, a micro-pattern gaseous detector composed of a Micromegas-like amplification grid over the Timepix 65k pixel readout chip. It can achieve a single-electron detection efficiency of up to 98% and has thus great potential to identify the ionisation electrons in dark matter search experiments. The main challenges for this application are low outgassing, thermal robustness, and operation in pure (thus quencher-free) noble gas. To investigate its applicability we operated a GridPix detector in an argon cryostat. We proved GridPix's performance in pure argon. The gas amplification was confirmed in pure argon in the broad temperature range from 300 K down to 87 K. Additionally, we discuss results of thermal tests of GridPix devices at liquid xenon temperature in a dry nitrogen atmosphere.

  17. First Results from the Cryogenic Dark Matter Search Experiment at the Deep Site

    Energy Technology Data Exchange (ETDEWEB)

    Mandic, Vuk [Univ. of California, Berkeley, CA (United States)

    2004-06-01

    The Cryogenic Dark Matter Search (CDMS) experiment is designed to search for dark matter in the form of the Weakly Interacting Massive Particles (WIMPs). For this purpose, CDMS uses detectors based on crystals of Ge and Si, operated at the temperature of 20 mK, and providing a two-fold signature of an interaction: the ionization and the athermal phonon signals. The two signals, along with the passive and active shielding of the experimental setup, and with the underground experimental sites, allow very effective suppression and rejection of different types of backgrounds. This dissertation presents the commissioning and the results of the first WIMP-search run performed by the CDMS collaboration at the deep underground site at the Soudan mine in Minnesota. We develop different methods of suppressing the dominant background due to the electron-recoil events taking place at the detector surface and we apply these algorithms to the data set. These results place the world's most sensitive limits on the WIMP-nucleon spin-independent elastic-scattering cross-section. Finally, they examine the compatibility of the supersymmetric WIMP-models with the direct-detection experiments (such as CDMS) and discuss the implications of the new CDMS result on these models.

  18. Overview of recent results from the STAR experiment

    CERN Document Server

    Mustafa, Mustafa

    2016-01-01

    The Solenoidal Tracker at RHIC (STAR) experiment utilizes its excellent mid-rapidity tracking and particle identifica- tion capabilities to study the emergent properties of Quantum Chromodynamics (QCD). The STAR heavy-ion program at vanishingly small baryon density is aimed to address questions about the quantitative properties of the strongly- interacting Quark Gluon Plasma (QGP) matter created in high energy collisions ({\\eta}/s, $\\hat{q}$, chirality, transport parameters, heavy quark diffusion coefficients ...). At finite baryon density the questions concern the phases of nuclear matter and the QCD phase diagram, namely: what is the onset collision energy for the formation of QGP? What is the nature of phase transition in heavy-ion collisions? Are there two phase transition regions? If yes, where is the critical point situated? At Quark Matter 2015, the STAR collaboration has presented a wealth of new experimental results which address these questions. In these proceedings I highlight a few of those result...

  19. Overview of recent results from the STAR experiment

    Science.gov (United States)

    Mustafa, Mustafa

    2016-12-01

    The Solenoidal Tracker at RHIC (STAR) experiment utilizes its excellent mid-rapidity tracking and particle identification capabilities to study the emergent properties of Quantum Chromodynamics (QCD). The STAR heavy-ion program at vanishingly small baryon density is aimed to address questions about the quantitative properties of the strongly-interacting Quark Gluon Plasma (QGP) matter created in high energy collisions (η / s, q ˆ , chirality, transport parameters, heavy quark diffusion coefficients…). At finite baryon density, the questions concern the phases of nuclear matter (the QCD phase diagram) and the nature of the phase transition, namely: what is the onset collision energy for the formation of QGP? What is the nature of phase transition in heavy-ion collisions? Are there two phase transition regions? If yes, where is the critical point situated? At Quark Matter 2015, the STAR collaboration has presented a wealth of new experimental results which address these questions. In these proceedings I highlight a few of those results.

  20. Matter and gravitons in the gravitational collapse

    CERN Document Server

    Casadio, Roberto; Giusti, Andrea

    2016-01-01

    We consider the effects of gravitons in the collapse of baryonic matter that forms a black hole. We first note that the effective number of (soft off-shell) gravitons that account for the (negative) Newtonian potential energy generated by the baryons is conserved and always in agreement with the area law of black holes. Moreover, their (positive) interaction energy reproduces the expected post-Newtonian correction and becomes of the order of the total ADM mass of the system when the size of the collapsing object approaches its gravitational radius. This supports a scenario in which the gravitational collapse of regular baryonic matter produces a corpuscular black hole without singularity.

  1. Dark Matter Search in a Beam-Dump eXperiment (BDX) at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    Battaglieri, M. [Univ. of Genova (Italy). National Institute for Nuclear Physics. et al

    2016-07-05

    MeV-GeV dark matter (DM) is theoretically well motivated but remarkably unexplored. This proposal presents the MeV-GeV DM discovery potential for a $\\sim$1 m$^3$ segmented CsI(Tl) scintillator detector placed downstream of the Hall A beam-dump at Jefferson Lab, receiving up to 10$^{22}$ electrons-on-target (EOT) in 285 days. This experiment (Beam-Dump eXperiment or BDX) would be sensitive to elastic DM-electron and to inelastic DM scattering at the level of 10 counts per year, reaching the limit of the neutrino irreducible background. The distinct signature of a DM interaction will be an electromagnetic shower of few hundreds of MeV, together with a reduced activity in the surrounding active veto counters. A detailed description of the DM particle $\\chi$ production in the dump and subsequent interaction in the detector has been performed by means of Monte Carlo simulations. Different approaches have been used to evaluate the expected backgrounds: the cosmogenic background has been extrapolated from the results obtained with a prototype detector running at INFN-LNS (Italy), while the beam-related background has been evaluated by GEANT4 Monte Carlo simulations. The proposed experiment will be sensitive to large regions of DM parameter space, exceeding the discovery potential of existing and planned experiments in the MeV-GeV DM mass range by up to two orders of magnitude.

  2. Holography, charge and baryon asymmetry

    CERN Document Server

    Mongan, T R

    2009-01-01

    The holographic principle indicates the finite number of bits of information available on the particle horizon describes all physics within the horizon. Linking information on the horizon with Standard Model particles requires a holographic model describing constituents (preons) of Standard Model particles in terms of bits of information on the horizon. Standard Model particles have charges 0, 1/3, 2/3 or 1 in units of the electron charge e, so bits in a preon model must be identified with fractional charge. Energy must be transferred to change the state of a bit, and labeling the low energy state of a bit e/3n and the high energy state -e/3n amounts to defining electric charge. Any such charged preon model will produce more protons than anti-protons at the time of baryogenesis and require baryon asymmetry. It will also produce more positrons than electrons, as suggested by astrophysical measurements.

  3. Baryon Number Fluctuations in Quasi-particle Model

    CERN Document Server

    Zhao, Ameng; Zong, Hongshi

    2016-01-01

    Baryon number fluctuations are sensitive to the QCD phase transition and QCD critical point. According to the Feynman rules of finite-temperature field theory, we calculated various order moments and cumulants of the baryon number distributions in the quasi-particle model of quark gluon plasma. Furthermore, we compared our results with the experimental data measured by the STAR experiment at RHIC. It is found that the experimental data can be well described by the model for the colliding energies above 30 GeV and show large discrepancies at low energies. It can put new constraint on qQGP model and also provide a baseline for the QCD critical point search in heavy-ion collisions at low energies.

  4. A review on the relativistic effective field theory with parameterized couplings for nuclear matter and neutron stars

    Science.gov (United States)

    Vasconcellos, C. A. Zen

    2015-12-01

    Nuclear science has developed many excellent theoretical models for many-body systems in the domain of the baryon-meson strong interaction for the nucleus and nuclear matter at low, medium and high densities. However, a full microscopic understanding of nuclear systems in the extreme density domain of compact stars is still lacking. The aim of this contribution is to shed some light on open questions facing the nuclear many-body problem at the very high density domain. Here we focus our attention on the conceptual issue of naturalness and its role in shaping the baryon-meson phase space dynamics in the description of the equation of state (EoS) of nuclear matter and neutrons stars. In particular, in order to stimulate possible new directions of research, we discuss relevant aspects of a recently developed relativistic effective theory for nuclear matter within Quantum Hadrodynamics (QHD) with genuine many-body forces and derivative natural parametric couplings. Among other topics we discuss in this work the connection of this theory with other known effective QHD models of the literature and its potentiality in describing a new physics for dense matter. The model with parameterized couplings exhausts the whole fundamental baryon octet (n, p, Σ-, Σ0, Σ+, Λ, Ξ-, Ξ0) and simulates n-order corrections to the minimal Yukawa baryon couplings by considering nonlinear self-couplings of meson fields and meson-meson interaction terms coupled to the baryon fields involving scalar-isoscalar (σ, σ∗), vector-isoscalar (ω, ɸ), vector-isovector (ϱ) and scalar-isovector (δ) virtual sectors. Following recent experimental results, we consider in our calculations the extreme case where the Σ- experiences such a strong repulsion that its influence in the nuclear structure of a neutron star is excluded at all. A few examples of calculations of properties of neutron stars are shown and prospects for the future are discussed.

  5. Low radioactivity argon dark matter search results from the DarkSide-50 experiment

    CERN Document Server

    Agnes, P; Albuquerque, I F M; Alexander, T; Alton, A K; Arisaka, K; Back, H O; Baldin, B; Biery, K; Bonfini, G; Bossa, M; Bottino, B; Brigatti, A; Brodsky, J; Budano, F; Bussino, S; Cadeddu, M; Cadonati, L; Cadoni, M; Calaprice, F; Canci, N; Candela, A; Cao, H; Cariello, M; Carlini, M; Catalanotti, S; Cavalcante, P; Chepurnov, A; Cocco, A G; Covone, G; Crippa, L; D'Angelo, D; D'Incecco, M; Davini, S; De Cecco, S; De Deo, M; De Vincenzi, M; Derbin, A; Devoto, 25 A; Di Eusanio, F; Di Pietro, G; Edkins, E; Empl, A; Fan, A; Fiorillo, G; Fomenko, K; Forster, G; Franco, D; Gabriele, F; Galbiati, C; Giganti, C; Goretti, A M; Granato, F; Grandi, L; Gromov, M; Guan, M; Guardincerri, Y; Hackett, B R; Herner, K; Hungerford, E V; Ianni, Al; Ianni, An; James, I; Jollet, C; Keeter, K; Kendziora, C L; Kobychev, V; Koh, G; Korablev, D; Korga, G; Kubankin, A; Li, X; Lissia, M; Lombardi, P; Luitz, S; Ma, Y; Machulin, I N; Mandarano, A; Mari, S M; Maricic, J; Marini, L; Martoff, C J; Meregaglia, A; Meyers, P D; Miletic, T; Milincic, R; Montanari, D; Monte, A; Montuschi, M; Monzani, M; Mosteiro, P; Mount, B J; Muratova, V N; Musico, P; Napolitano, J; Nelson, A; Odrowski, S; Orsini, M; Ortica, F; Pagani, L; Pallavicini, M; Pantic, E; Parmeggiano, S; Pelczar, K; Pelliccia, N; Perasso, S; Pocar, A; Pordes, S; Pugachev, D A; Qian, H; Randle, K; Ranucci, G; Razeto, A; Reinhold, B; Renshaw, A L; Romani, A; Rossi, B; Rossi, N; Rountree, D; Sablone, D; Saggese, P; Saldanha, R; Sands, W; Sangiorgio, S; Savarese, C; Segreto, E; Semenov, D A; Shields, E; Singh, P N; Skorokhvatov, M D; Smallcomb, M; Smirnov, O; Sotnikov, A; Stanford, C; Suvorov, Y; Tartaglia, R; Tatarowicz, J; Testera, G; Tonazzo, A; Trinchese, P; Unzhakov, E V; Vishneva, A; Vogelaar, B; Wada, M; Walker, S; Wang, H; Wang, Y; Watson, A W; Westerdale, S; Wilhelmi, J; Wojcik, M M; Xiang, X; Xu, J; Yang, C; Yoo, J; Zavatarelli, S; Zec, A; Zhong, W; Zhu, C; Zuzel, G

    2015-01-01

    The DarkSide-50 dark matter search reports the first results obtained using a target of low-radioactivity argon extracted from underground sources. The experiment is located at the Laboratori Nazionali del Gran Sasso and uses a two-phase time projection chamber as a detector. A total of 155 kg of low radioactivity argon has been obtained, and we have determined that underground argon is depleted in Ar-39 by a factor (1.4 +- 0.2) x 10^3 relative to atmospheric argon. The underground argon was also found to contain (2.05 +- 0.13) mBq/kg of Kr-85. We found no evidence for dark matter in the form of WIMPs in 70.9 live-days of data with a fiducial mass of (36.9 +- 0.6) kg. When combined with our preceding search with an atmospheric argon target, we set a 90 % C.L. upper limit on the WIMP-nucleon spin-independent cross section of 2.0 x 10^-44 cm^2 (8.6 x 10^-44 cm^2, 8.0 x 10^-43 cm^2 ) for a WIMP mass of 100 GeV/c^2 (1 TeV/c^2 , 10 TeV/c^2 ).

  6. Proton acceleration experiments and warm dense matter research using high power lasers

    Energy Technology Data Exchange (ETDEWEB)

    Roth, M; Alber, I; Guenther, M; Harres, K [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Bagnoud, V [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Brown, C R D [Plasma Physics Group, Imperial College London, SW7 2BZ (United Kingdom); Clarke, R; Heathcote, R; Li, B [STFC, Rutherford Appleton Laboratory (RAL), Chilton, Didcot, OX14 OQX (United Kingdom); Daido, H [Photo Medical Research Center, JAEA, Kizugawa-City, Kyoto 619-0215 (Japan); Fernandez, J; Flippo, K; Gaillard, S; Gauthier, C [Los Alamos National Laboratory (LANL), Los Alamos, NM 87545 (United States); Geissel, M [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Glenzer, S; Kritcher, A; Kugland, N; LePape, S [Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States); Gregori, G, E-mail: markus.roth@physik.tu-darmstadt.d [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom)

    2009-12-15

    The acceleration of intense proton and ion beams by ultra-intense lasers has matured to a point where applications in basic research and technology are being developed. Crucial for harvesting the unmatched beam parameters driven by the relativistic electron sheath is the precise control of the beam. In this paper we report on recent experiments using the PHELIX laser at GSI, the VULCAN laser at RAL and the TRIDENT laser at LANL to control and use laser accelerated proton beams for applications in high energy density research. We demonstrate efficient collimation of the proton beam using high field pulsed solenoid magnets, a prerequisite to capture and transport the beam for applications. Furthermore, we report on two campaigns to use intense, short proton bunches to isochorically heat solid targets up to the warm dense matter state. The temporal profile of the proton beam allows for rapid heating of the target, much faster than the hydrodynamic response time thereby creating a strongly coupled plasma at solid density. The target parameters are then probed by x-ray Thomson scattering to reveal the density and temperature of the heated volume. This combination of two powerful techniques developed during the past few years allows for the generation and investigation of macroscopic samples of matter in states present in giant planets or the interior of the earth.

  7. VUV light reflectivity measurements from PTFE in Liquid Xenon for the LZ Dark Matter experiment

    Science.gov (United States)

    Pushkin, Kirill; LZ Collaboration

    2016-03-01

    The LUX-Zeplin (LZ) collaboration is the next generation of the experiment to search for Dark Matter in the Universe with a dual-phase detector based on liquid xenon (LXe) with a target mass of 7 ton. LXe dual phase detectors are very sensitive probes to search for WIMP dark matter interactions. The LZ collaboration is conducting R&D to study VUV light reflectivity from PTFE (Teflon) in LXe. Teflon is used in dual phase detectors both as an electrical insulator and as reflector of VUV scintillation light (~175 nm) to improve photon detection with photomultiplier tubes (PMTs). However, experimental data for the reflectance of VUV light from PTFE in LXe is not sufficiently conclusive. We present a new technique of measuring the light reflectivity from PTFE by varying the fractional area of the PMT in the detector. PTFE reflectivity measurements were performed as a function of Teflon wall thickness in the range of 2 mm to 9.5 mm. The method, apparatus and experimental results will be presented.

  8. More about the light baryon spectrum

    CERN Document Server

    Eichmann, Gernot

    2016-01-01

    We discuss the light baryon spectrum obtained from a recent quark-diquark calculation, implementing non-pointlike diquarks that are self-consistently calculated from their Bethe-Salpeter equations. We examine the orbital angular momentum content in the baryons' rest frame and highlight the fact that baryons carry all possible values of L compatible with their spin, without the restriction P=(-1)^L which is only valid nonrelativistically. We furthermore investigate the meaning of complex conjugate eigenvalues of Bethe-Salpeter equations, their possible connection with 'anomalous' states, and we propose a method to eliminate them from the spectrum.

  9. More About the Light Baryon Spectrum

    Science.gov (United States)

    Eichmann, Gernot

    2017-03-01

    We discuss the light baryon spectrum obtained from a recent quark-diquark calculation, implementing non-pointlike diquarks that are self-consistently calculated from their Bethe-Salpeter equations. We examine the orbital angular momentum content in the baryons' rest frame and highlight the fact that baryons carry all possible values of L compatible with their spin, without the restriction P=(-1)^L which is only valid nonrelativistically. We furthermore investigate the meaning of complex conjugate eigenvalues of Bethe-Salpeter equations, their possible connection with `anomalous' states, and we propose a method to eliminate them from the spectrum.

  10. A spectral representation for baryon to meson and baryon to photon transition distribution amplitudes

    CERN Document Server

    Pire, Bernard; Szymanowski, Lech

    2010-01-01

    We construct a spectral representation for the transition distribution amplitudes (TDAs), i.e. matrix elements of three quark correlators which arise e.g. in the description of baryon to meson and baryon to photon transitions within the factorization approach to hard exclusive reactions. We generalize for these quantities the notion of double distributions introduced in the context of generalized parton distributions. We propose the generalization of A.Radyushkin's factorized Ansatz for the case of baryon to meson and baryon to photon TDAs. Our construction opens the way to modeling of baryon to meson and baryon to photon TDAs in their complete domain of definition and quantitative estimates of cross-sections for various hard exclusive reactions.

  11. Low-mass dark matter search results from full exposure of PandaX-I experiment

    CERN Document Server

    Xiao, Xiang; Tan, Andy; Chen, Yunhua; Cui, Xiangyi; Fang, Deqing; Fu, Changbo; Giboni, Karl L; Gong, Haowei; Guo, Guodong; He, Ming; Ji, Xiangdong; Ju, Yonglin; Lei, Siao; Li, Shaoli; Lin, Qing; Liu, Huaxuan; Liu, Jianglai; Liu, Xiang; Lorenzon, Wolfgang; Ma, Yugang; Mao, Yajun; Ni, Kaixuan; Pushkin, Kirill; Ren, Xiangxiang; Schubnell, Michael; Shen, Manbing; Shi, Yuji; Stephenson, Scott; Wang, Hongwei; Wang, Jiming; Wang, Meng; Wang, Siguang; Wang, Xuming; Wang, Zhou; Wu, Shiyong; Xiao, Mengjiao; Xie, Pengwei; Yan, Binbin; You, Yinghui; Zeng, Xionghui; Zhang, Tao; Zhao, Li; Zhou, Xiaopeng; Zhu, Zhonghua

    2015-01-01

    We report the results of a weakly-interacting massive particle (WIMP) dark matter search using the full 80.1\\;live-day exposure of the first stage of the PandaX experiment (PandaX-I) located in the China Jin-Ping Underground Laboratory. The PandaX-I detector has been optimized for detecting low-mass WIMPs, achieving a photon detection efficiency of 9.6\\%. With a fiducial liquid xenon target mass of 54.0\\,kg, no significant excess event were found above the expected background. A profile likelihood analysis confirms our earlier finding that the PandaX-I data disfavor all positive low-mass WIMP signals reported in the literature under standard assumptions. A stringent bound on the low mass WIMP is set at WIMP mass below 10\\,GeV/c$^2$, demonstrating that liquid xenon detectors can be competitive for low-mass WIMP searches.

  12. First dark matter search results from the PandaX-I experiment

    Institute of Scientific and Technical Information of China (English)

    XIAO MengJiao; XIAO Xiang; ZHAO Li; CAO XiGuang; CHEN Xun; CHEN YunHua; CUI XiangYi

    2014-01-01

    We report on the first dark-matter (DM) search results from PandaX-Ⅰ,a low threshold dual-phase xenon experiment operating at the China JinPing Underground Laboratory.In the 37-kg liquid xenon target with 17.4 live-days of exposure,no DM particle candidate event was found.This result sets a stringent limit for low-mass DM particles and disfavors the interpretation of previously-reported positive experimental results.The minimum upper limit,3.7 × 10-44 cm2,for the spin-independent isoscalar DM-particle-nucleon scattering cross section is obtained at a DM-particle mass of 49 GeV/c2 at 90% confidence level.

  13. Masses and magnetic moments of ground-state baryons in covariant baryon chiral perturbation theory

    CERN Document Server

    Geng, L S; Alvarez-Ruso, L; Vicente-Vacas, M J

    2012-01-01

    We report on some recent developments in our understanding of the light-quark mass dependence and the SU(3) flavor symmetry breaking corrections to the magnetic moments of the ground-state baryons in a covariant formulation of baryon chiral perturbation theory, the so-called EOMS formulation. We show that this covariant ChPT exhibits some promising features compared to its heavy-baryon and infrared counterparts.

  14. Hydrogen dynamics in soil organic matter as determined by 13C and 2H labeling experiments

    Science.gov (United States)

    Paul, Alexia; Hatté, Christine; Pastor, Lucie; Thiry, Yves; Siclet, Françoise; Balesdent, Jérôme

    2016-12-01

    Understanding hydrogen dynamics in soil organic matter is important to predict the fate of 3H in terrestrial environments. One way to determine hydrogen fate and to point out processes is to examine the isotopic signature of the element in soil. However, the non-exchangeable hydrogen isotopic signal in soil is complex and depends on the fate of organic compounds and microbial biosyntheses that incorporate water-derived hydrogen. To decipher this complex system and to understand the close link between hydrogen and carbon cycles, we followed labeled hydrogen and labeled carbon throughout near-natural soil incubations. We performed incubation experiments with three labeling conditions: 1 - 13C2H double-labeled molecules in the presence of 1H2O; 2 - 13C-labeled molecules in the presence of 2H2O; 3 - no molecule addition in the presence of 2H2O. The preservation of substrate-derived hydrogen after 1 year of incubation (ca. 5 % in most cases) was lower than the preservation of substrate-derived carbon (30 % in average). We highlighted that 70 % of the C-H bonds are broken during the degradation of the molecule, which permits the exchange with water hydrogen. Added molecules are used more for trophic resources. The isotopic composition of the non-exchangeable hydrogen was mainly driven by the incorporation of water hydrogen during microbial biosynthesis. It is linearly correlated with the amount of carbon that is degraded in the soil. The quantitative incorporation of water hydrogen in bulk material and lipids demonstrates that non-exchangeable hydrogen exists in both organic and mineral-bound forms. The proportion of the latter depends on soil type and minerals. This experiment quantified the processes affecting the isotopic composition of non-exchangeable hydrogen, and the results can be used to predict the fate of tritium in the ecosystem or the water deuterium signature in organic matter.

  15. Centrality dependence of ?, baryon and antibaryon production in Pb + Pb collisions at 158 A GeV

    Science.gov (United States)

    Kabana, Sonia; NA52 Collaboration; Ambrosini, G.; Arsenescu, R.; Baglin, C.; Beringer, J.; Borer, K.; Bussière, A.; Dittus, F.; Elsener, K.; Gorodetzky, Ph; Guillaud, J. P.; Hess, P.; Kabana, S.; Klingenberg, R.; Lindén, T.; Lohmann, K. D.; Mommsen, R.; Moser, U.; Pretzl, K.; Schacher, J.; Stoffel, F.; Tuominiemi, J.; Weber, M.

    1999-02-01

    We present new results of the CERN experiment NA52 on the centrality dependence of img23.gif, img24.gif, p, d, p and d production yields near zero transverse momentum and at several rapidities, from 64 img25.gif to 4 img25.gif of the total Pb + Pb cross section. Baryon yields increase nearly linearly and img24.gif yields faster than linearly with the number of participating nucleons img28.gif. The antibaryon yields increase less than linearly with img28.gif, indicating absorption. The centrality and rapidity dependence of the img30.gif ratio indicates Coulomb interaction of the pions with the projectile spectator protons. Within the framework of a coalescence model the radius of the particle source has been estimated from the ratios img31.gif and d /¯ img32.gif. The source radii are similar for matter and antimatter and are found to increase with img33.gif.

  16. Status of the CBM experiment

    Directory of Open Access Journals (Sweden)

    Heuser Johann M.

    2015-01-01

    Full Text Available The Compressed Baryonic Matter (CBM experiment at the Facility for Anti-Proton and Ion Research (FAIR will explore the phase diagram of strongly interacting matter at highest net baryon densities and moderate temperatures. The CBM physics program will be started with beams delivered by the SIS 100 synchrotron, providing energies from 2 to 11 GeV/nucleon for heavy nuclei, up to 14 GeV/nucleon for light nuclei, and 29 GeV for protons. The highest net baryon densities will be explored with ion beams up to 45 GeV/nucleon energy delivered by SIS 300 in the next stage of FAIR. Collision rates up to 107 per second are required to produce very rare probes with unprecedented statistics in this energy range. Their signatures are complex. These conditions call for detector systems designed to meet the extreme requirements in terms of rate capability, momentum and spatial resolution, and a novel DAQ and trigger concept which is not limited by latency but by throughput. The article discusses the development status of the CBM sub-systems for charged particle tracking, vertex detection, electron/muon identification, hadron/time-of-flight measurement, electromagnetic and zero-degree calorimetry, in terms of prototypes and expected physics performance. The concept and development status of CBM’s central detector, the Silicon Tracking System STS are presented in somewhat more detail.

  17. Status of the CBM experiment

    Science.gov (United States)

    Heuser, Johann M.

    2015-05-01

    The Compressed Baryonic Matter (CBM) experiment at the Facility for Anti-Proton and Ion Research (FAIR) will explore the phase diagram of strongly interacting matter at highest net baryon densities and moderate temperatures. The CBM physics program will be started with beams delivered by the SIS 100 synchrotron, providing energies from 2 to 11 GeV/nucleon for heavy nuclei, up to 14 GeV/nucleon for light nuclei, and 29 GeV for protons. The highest net baryon densities will be explored with ion beams up to 45 GeV/nucleon energy delivered by SIS 300 in the next stage of FAIR. Collision rates up to 107 per second are required to produce very rare probes with unprecedented statistics in this energy range. Their signatures are complex. These conditions call for detector systems designed to meet the extreme requirements in terms of rate capability, momentum and spatial resolution, and a novel DAQ and trigger concept which is not limited by latency but by throughput. The article discusses the development status of the CBM sub-systems for charged particle tracking, vertex detection, electron/muon identification, hadron/time-of-flight measurement, electromagnetic and zero-degree calorimetry, in terms of prototypes and expected physics performance. The concept and development status of CBM's central detector, the Silicon Tracking System STS are presented in somewhat more detail.

  18. The effect of baryons on redshift space distortions and cosmic density and velocity fields in the EAGLE simulation

    CERN Document Server

    Hellwing, Wojciech A; Frenk, Carlos S; Theuns, Tom; Schaye, Joop; Bower, Richard G; Crain, Robert A

    2016-01-01

    We use the EAGLE galaxy formation simulation to study the effects of baryons on the power spectrum of the total matter and dark matter distributions and on the velocity fields of dark matter and galaxies. On scales $k\\geq \\sim4{h\\,{\\rm Mpc}^{-1}}$ the effect of baryons on the amplitude of the total-matter power spectrum is greater than $1\\%$. The back-reaction of baryons affects the density field of the dark matter at the level of $\\sim3\\%$ on scales of $1\\leq k/({h\\,{\\rm Mpc}^{-1}})\\leq 5$. The dark matter velocity divergence power spectrum at $k\\leq \\sim0.5{h\\,{\\rm Mpc}^{-1}}$ is changed by less than $1\\%$. The 2D redshift-space power spectrum is affected at the level of $\\sim6\\%$ at $k_\\perp\\geq \\sim1{h\\,{\\rm Mpc}^{-1}}$, but for $k_\\perp\\leq 0.4{h\\,{\\rm Mpc}^{-1}}$ the amplitude differs by less than $1\\%$. We report vanishingly small baryonic velocity bias for haloes: the peculiar velocities of haloes with with $M_{200}>3\\times10^{11}{{\\rm M}_{\\odot}}$ (hosting galaxies with $M_{*}>10^9{{\\rm M}_{\\odot}}$)...

  19. Suppression of Baryon Diffusion and Transport in a Baryon Rich Strongly Coupled Quark-Gluon Plasma.

    Science.gov (United States)

    Rougemont, Romulo; Noronha, Jorge; Noronha-Hostler, Jacquelyn

    2015-11-13

    Five dimensional black hole solutions that describe the QCD crossover transition seen in (2+1)-flavor lattice QCD calculations at zero and nonzero baryon densities are used to obtain predictions for the baryon susceptibility, baryon conductivity, baryon diffusion constant, and thermal conductivity of the strongly coupled quark-gluon plasma in the range of temperatures 130  MeV≤T≤300  MeV and baryon chemical potentials 0≤μ(B)≤400  MeV. Diffusive transport is predicted to be suppressed in this region of the QCD phase diagram, which is consistent with the existence of a critical end point at larger baryon densities. We also calculate the fourth-order baryon susceptibility at zero baryon chemical potential and find quantitative agreement with recent lattice results. The baryon transport coefficients computed in this Letter can be readily implemented in state-of-the-art hydrodynamic codes used to investigate the dense QGP currently produced at RHIC's low energy beam scan.

  20. THE BARYON ACOUSTIC OSCILLATION BROADBAND AND BROAD-BEAM ARRAY: DESIGN OVERVIEW AND SENSITIVITY FORECASTS

    Energy Technology Data Exchange (ETDEWEB)

    Pober, Jonathan C.; Parsons, Aaron R.; McQuinn, Matthew; Ali, Zaki [Astronomy Department, University of California, Berkeley, CA (United States); DeBoer, David R. [Radio Astronomy Laboratory, University of California, Berkeley, CA (United States); McDonald, Patrick [Physics Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Aguirre, James E. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA (United States); Bradley, Richard F. [Astronomy Department and Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA (United States); Chang, Tzu-Ching [Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan (China); Morales, Miguel F. [Department of Physics, University of Washington, Seattle, WA (United States)

    2013-03-15

    This work describes a new instrument optimized for a detection of the neutral hydrogen 21 cm power spectrum between redshifts of 0.5 and 1.5: the Baryon Acoustic Oscillation Broadband and Broad-beam (BAOBAB) array. BAOBAB will build on the efforts of a first generation of 21 cm experiments that are targeting a detection of the signal from the Epoch of Reionization at z {approx} 10. At z {approx} 1, the emission from neutral hydrogen in self-shielded overdense halos also presents an accessible signal, since the dominant, synchrotron foreground emission is considerably fainter than at redshift 10. The principle science driver for these observations are baryon acoustic oscillations in the matter power spectrum which have the potential to act as a standard ruler and constrain the nature of dark energy. BAOBAB will fully correlate dual-polarization antenna tiles over the 600-900 MHz band with a frequency resolution of 300 kHz and a system temperature of 50 K. The number of antennas will grow in staged deployments, and reconfigurations of the array will allow for both traditional imaging and high power spectrum sensitivity operations. We present calculations of the power spectrum sensitivity for various array sizes, with a 35 element array measuring the cosmic neutral hydrogen fraction as a function of redshift, and a 132 element system detecting the BAO features in the power spectrum, yielding a 1.8% error on the z {approx} 1 distance scale, and, in turn, significant improvements to constraints on the dark energy equation of state over an unprecedented range of redshifts from {approx}0.5 to 1.5.

  1. A quarksonic matter at high isospin density

    CERN Document Server

    Cao, Gaoqing; Huang, Xu-Guang

    2016-01-01

    Analogous to the quarkyonic matter at high baryon density in which the quark Fermi seas and the baryonic excitations coexist, it is argued that a "quarksonic matter" phase appears at high isospin density where the quark (antiquark) Fermi seas and the mesonic excitations coexist. We explore this phase in detail in both large $N_c$ and asymptotically free limits: In large $N_c$ limit, we sketch a phase diagram for the quarksonic matter. In the asymptotically free limit, we study the pion superfluidity and thermodynamics of the quarksonic matter by using both perturbative calculations and effective model.

  2. Evolution of Baryon Rich Quark-Gluon Plasma and radiation of Single Photons

    CERN Document Server

    Sastry, S; Mohanty, A K; Srivastava, D K

    2002-01-01

    The (3+1) dimensional expansion of the quark gluon plasma (QGP) produced at finite baryon density has been studied using relativistic hydrodynamical approach. The pressure functional of the equation of state (EoS) has been determined for the interacting nuclear matter with mesons exchange. The EoS has been used to solve hydrodynamical equations using RHLLE algorithm. The space time expansion of the plasma has been studied for the cases of SPS energy and RHIC energy both at finite baryon density and for a hypothetical case of SPS energy at zero baryon density. The space-time evolution is slowed and the life times of QGP and mixed phases are shortened in the presence of finite baryon density. The space time integrated total photon yields have been estimated by convoluting the static emission rates with the space time expansion of the plasma. It has been shown that the total photon yield at zero rapidity is not significantly affected by the baryon density for SPS energy. The total photon yield is unaffected by t...

  3. Warm-hot baryons comprise 5-10 per cent of filaments in the cosmic web

    CERN Document Server

    Eckert, Dominique; Shan, HuanYuan; Kneib, Jean-Paul; Erben, Thomas; Israel, Holger; Jullo, Eric; Klein, Matthias; Massey, Richard; Richard, Johan; Tchernin, Celine

    2015-01-01

    Observations of the cosmic microwave background indicate that baryons account for 5% of the Universe's total energy content. In the local Universe, the census of all observed baryons falls short of this estimate by a factor of two. Cosmological simulations indicate that the missing baryons might not have condensed into virialized haloes, but reside throughout the filaments of the cosmic web (where matter density is larger than average) as a low-density plasma at temperatures of $10^5-10^7$ kelvin, known as the warm-hot intergalactic medium. There have been previous claims of the detection of warm baryons along the line of sight to distant blazars and of hot gas between interacting clusters. These observations were, however, unable to trace the large-scale filamentary structure, or to estimate the total amount of warm baryons in a representative volume of the Universe. Here we report X-ray observations of filamentary structures of gas at $10^7$ kelvin associated with the galaxy cluster Abell 2744. Previous obs...

  4. Baryon asymmetry from primordial black holes

    CERN Document Server

    Hamada, Yuta

    2016-01-01

    We propose a new scenario of the baryogenesis from primordial black holes (PBH). Assuming presence of a microscopic baryon (or lepton) number violation and a CP violating operator such as $\\partial_\\alpha F(\\mathcal{R_{....}} ) J^\\alpha$ where $F(\\mathcal{R_{....}})$ is a scalar function of the Riemann tensor, time evolution of an evaporating black hole generates baryonic (leptonic) chemical potential at the horizon; consequently PBH enumerates asymmetric Hawking radiation between baryons (leptons) and anti-baryons (leptons). Though the operator is higher dimensional and largely suppressed by a high mass scale $M_*$, we show that sufficient amount of asymmetry can be generated for wide range of parameters of the PBH mass $M_{\\rm PBH}$, its abundance $\\Omega_{\\rm PBH}$, and the scale $M_*$.

  5. Baryonic torii: Toroidal baryons in a generalized Skyrme model

    Science.gov (United States)

    Gudnason, Sven Bjarke; Nitta, Muneto

    2015-02-01

    We study a Skyrme-type model with a potential term motivated by Bose-Einstein condensates (BECs), which we call the BEC Skyrme model. We consider two flavors of the model: the first is the Skyrme model, and the second has a sixth-order derivative term instead of the Skyrme term, both with the added BEC-motivated potential. The model contains toroidally shaped Skyrmions, and they are characterized by two integers P and Q , representing the winding numbers of two complex scalar fields along the toroidal and poloidal cycles of the torus, respectively. The baryon number is B =P Q . We find stable Skyrmion solutions for P =1 ,2 ,3 ,4 ,5 with Q =1 , while for P =6 and Q =1 , it is only metastable. We further find that configurations with higher Q >1 are all unstable and split into Q configurations with Q =1 . Finally we discover a phase transition, possibly of first order, in the mass parameter of the potential under study.

  6. Quark matter or new particles?

    Science.gov (United States)

    Michel, F. Curtis

    1988-01-01

    It has been argued that compression of nuclear matter to somewhat higher densities may lead to the formation of stable quark matter. A plausible alternative, which leads to radically new astrophysical scenarios, is that the stability of quark matter simply represents the stability of new particles compounded of quarks. A specific example is the SU(3)-symmetric version of the alpha particle, composed of spin-zero pairs of each of the baryon octet (an 'octet' particle).

  7. Academically Successful African American Male Urban High School Students' Experiences of Mattering to Others at School

    Science.gov (United States)

    Tucker, Catherine; Dixon, Andrea; Griddine, Ke'Shana

    2010-01-01

    Mattering to others has been shown to be a key construct of mental health and wellness. Emerging research links interpersonal mattering and school climate. In this study, the authors use transcendental phenomenology to explore how interpersonal mattering impacts the academic achievement of urban African American males who are academically…

  8. Simulations of radiation pressure experiments narrow down the energy and momentum of light in matter.

    Science.gov (United States)

    Bethune-Waddell, Max; Chau, Kenneth J

    2015-12-01

    Consensus on a single electrodynamic theory has yet to be reached. Discord was seeded over a century ago when Abraham and Minkowski proposed different forms of electromagnetic momentum density and has since expanded in scope with the gradual introduction of other forms of momentum and force densities. Although degenerate sets of electrodynamic postulates can be fashioned to comply with global energy and momentum conservation, hope remains to isolate a single theory based on detailed comparison between force density predictions and radiation pressure experiments. This comparison is two-fold challenging because there are just a handful of quantitative radiation pressure measurements over the past century and the solutions developed from different postulates, which consist of approximate expressions and inferential deductions, are scattered throughout the literature. For these reasons, it is appropriate to conduct a consolidated and comprehensive re-analysis of past experiments under the assumption that the momentum and energy of light in matter are degenerate. We create a combined electrodynamic/fluid dynamic simulation testbed that uses five historically significant sets of electrodynamic postulates, including those by Abraham and Minkowski, to model radiation pressure under diverse configurations with minimal assumptions. This leads to new interpretations of landmark investigations of light momentum, including the Balazs thought experiment, the Jones-Richards and Jones-Leslie measurements of radiation pressure on submerged mirrors, observations of laser-deformed fluid surfaces, and experiments on optical trapping and tractor beaming of dielectric particles. We discuss the merits and demerits of each set of postulates when compared to available experimental evidence and fundamental conservation laws. Of the five sets of postulates, the Abraham and Einstein-Laub postulates provide the greatest consistency with observations and the most physically plausible

  9. Spin-flavor composition of excited baryons

    Science.gov (United States)

    Fernando, Ishara; Goity, Jose

    2015-10-01

    The excited baryon masses are analyzed in the framework of the 1 /Nc expansion using the available physical masses and also the masses obtained in lattice QCD for different quark masses. The baryon states are organized into irreducible representations of SU (6) × O (3) , where the [ 56 ,lP =0+ ] ground state and excited baryons, and the [ 56 ,2+ ] and [ 70 ,1- ] excited states are analyzed. The analyses are carried out to O 1 /Nc and first order in the quark masses. The issue of state identifications is discussed. Numerous parameter independent mass relations result at those orders, among them the well known Gell-Mann-Okubo and Equal Spacing relations, as well as additional relations involving baryons with different spins. It is observed that such relations are satisfied at the expected level of precision. Predictions for physically unknown states for each multiplet are obtained. From the quark-mass dependence of the coefficients in the baryon mass formulas an increasingly simpler picture of the spin-flavor composition of the baryons is observed with increasing pion mass (equivalently, increasing mu , d masses), as measured by the number of significant mass operators. This work was supported in part by DOE Contract No. DE-AC05-06OR23177 under which JSA operates the Thomas Jefferson National Accelerator Facility (J. L. G.), and by the NSF (USA) through Grant PHY-0855789 and PHY-1307413 (I. P. F and J. L. G).

  10. Dance Experience and Associations with Cortical Gray Matter Thickness in the Aging Population

    Directory of Open Access Journals (Sweden)

    Shai Porat

    2016-10-01

    Full Text Available Introduction: We investigated the effect dance experience may have on cortical gray matter thickness and cognitive performance in elderly participants with and without mild cognitive impairment (MCI. Methods: 39 cognitively normal and 48 MCI elderly participants completed a questionnaire regarding their lifetime experience with music, dance, and song. Participants identified themselves as either dancers or nondancers. All participants received structural 1.5-tesla MRI scans and detailed clinical and neuropsychological evaluations. An advanced 3D cortical mapping technique was then applied to calculate cortical thickness. Results: Despite having a trend-level significantly thinner cortex, dancers performed better in cognitive tasks involving learning and memory, such as the California Verbal Learning Test-II (CVLT-II short delay free recall (p = 0.004, the CVLT-II long delay free recall (p = 0.003, and the CVLT-II learning over trials 1-5 (p = 0.001. Discussion: Together, these results suggest that dance may result in an enhancement of cognitive reserve in aging, which may help avert or delay MCI.

  11. Dark matter search in a Beam-Dump eXperiment (BDX) at Jefferson Lab

    CERN Document Server

    Battaglieri, M; De Vita, R; Izaguirre, E; Krnjaic, G; Smith, E; Stepanyan, S; Bersani, A; Fanchini, E; Fegan, S; Musico, P; Osipenko, M; Ripani, M; Santopinto, E; Taiuti, M; Schuster, P; Toro, N; Dalton, M; Freyberger, A; Girod, F -X; Kubarovsky, V; Ungaro, M; De Cataldo, G; De Leo, R; Di Bari, D; Lagamba, L; Nappi, E; Perrino, R; Carpinelli, M; Sipala, V; Aiello, S; Bellini, V; De Napoli, M; Giusa, A; Mammoliti, F; Leonora, E; Noto, F; Randazzo, N; Russo, G; Sperduto, M; Sutera, C; Ventura, C; Barion, L; Ciullo, G; Contalbrigo, M; Lenisa, P; Movsisyan, A; Spizzo, F; Turisini, M; De Persio, F; Cisbani, E; Fanelli, C; Garibaldi, F; Meddi, F; Urciuoli, G M; Pereira, S Anefalos; De Sanctis, E; Hasch, D; Lucherini, V; Mirazita, M; Montgomery, R; Pisano, S; Simi, G; D'Angelo, A; Lanza, L Colaneri L; Rizzo, A; Schaerf, C; Zonta, I; Calvo, D; Filippi, A; Holtrop, M; Peremuzyan, R; Glazier, D; Ireland, D; McKinnon, B; Afanasev, D Sokhan A; Briscoe, B; Kalantarians, N; Fassi, L El; Weinstein, L; Beltrame, P; Murphy, A; Watts, D; Zana, L; Hicks, K

    2014-01-01

    MeV-GeV dark matter (DM) is theoretically well motivated but remarkably unexplored. This Letter of Intent presents the MeV-GeV DM discovery potential for a 1 m$^3$ segmented plastic scintillator detector placed downstream of the beam-dump at one of the high intensity JLab experimental Halls, receiving up to 10$^{22}$ electrons-on-target (EOT) in a one-year period. This experiment (Beam-Dump eXperiment or BDX) is sensitive to DM-nucleon elastic scattering at the level of a thousand counts per year, with very low threshold recoil energies ($\\sim$1 MeV), and limited only by reducible cosmogenic backgrounds. Sensitivity to DM-electron elastic scattering and/or inelastic DM would be below 10 counts per year after requiring all electromagnetic showers in the detector to exceed a few-hundred MeV, which dramatically reduces or altogether eliminates all backgrounds. Detailed Monte Carlo simulations are in progress to finalize the detector design and experimental set up. An existing 0.036 m$^3$ prototype based on the s...

  12. An Experiment and Detection Scheme for Cavity-Based Light Cold Dark Matter Particle Searches

    Directory of Open Access Journals (Sweden)

    Masroor H. S. Bukhari

    2017-01-01

    Full Text Available A resonance detection scheme and some useful ideas for cavity-based searches of light cold dark matter particles (such as axions are presented, as an effort to aid in the on-going endeavors in this direction as well as for future experiments, especially in possibly developing a table-top experiment. The scheme is based on our idea of a resonant detector, incorporating an integrated tunnel diode (TD and GaAs HEMT/HFET (High-Electron Mobility Transistor/Heterogeneous FET transistor amplifier, weakly coupled to a cavity in a strong transverse magnetic field. The TD-amplifier combination is suggested as a sensitive and simple technique to facilitate resonance detection within the cavity while maintaining excellent noise performance, whereas our proposed Halbach magnet array could serve as a low-noise and permanent solution replacing the conventional electromagnets scheme. We present some preliminary test results which demonstrate resonance detection from simulated test signals in a small optimal axion mass range with superior signal-to-noise ratios (SNR. Our suggested design also contains an overview of a simpler on-resonance dc signal read-out scheme replacing the complicated heterodyne read-out. We believe that all these factors and our propositions could possibly improve or at least simplify the resonance detection and read-out in cavity-based DM particle detection searches (and other spectroscopy applications and reduce the complications (and associated costs, in addition to reducing the electromagnetic interference and background.

  13. Dark matter search in a Beam-Dump eXperiment (BDX) at Jefferson Lab

    CERN Document Server

    Battaglieri, M; Caiffi, B; Celentano, A; De Vita, R; Fanchini, E; Marsicano, L; Musico, P; Osipenko, M; Panza, F; Ripani, M; Santopinto, E; Taiuti, M; Bellini, V; Bondí, M; De Napoli, M; Mammoliti, F; Leonora, E; Randazzo, N; Russo, G; Sperduto, M; Sutera, C; Tortorici, F; Baltzell, N; Dalton, M; Freyberger, A; Girod, F X; Kubarovsky, V; Pasyuk, E; Smith, E S; Stepanyan, S; Ungaro, M; Whitlatch, T; Izaguirre, E; Krnjaic, G; Snowden-Ifft, D; Loomba, D; Carpinelli, M; Sipala, V; Schuster, P; Toro, N; Essig, R; Wood, M H; Holtrop, M; Paremuzyan, R; De Cataldo, G; De Leo, R; Di Bari, D; Lagamba, L; Nappi, E; Perrino, R; Balossino, I; Barion, L; Ciullo, G; Contalbrigo, M; Lenisa, P; Movsisyan, A; Spizzo, F; Turisini, M; De Persio, F; Cisbani, E; Garibaldi, F; Meddi, F; Urciuoli, G M; Hasch, D; Lucherini, V; Mirazita, M; Pisano, S; Simi, G; D'Angelo, A; Lanza, L; Rizzo, A; Schaerf, C; Zonta, I; Filippi, A; Fegan, S; Kunkel, M; Bashkanov, M; Beltrame, P; Murphy, A; Smith, G; Watts, D; Zachariou, N; Zana, L; Glazier, D; Ireland, D; McKinnon, B; Sokhan, D; Colaneri, L; Pereira, S Anefalos; Afanasev, A; Briscoe, B; Strakovsky, I; Kalantarians, N; Weinstein, L; Adhikari, K P; Dunne, J A; Dutta, D; Fassi, L El; Ye, L; Hicks, K; Cole, P; Dobbs, S; Fanelli, C

    2016-01-01

    MeV-GeV dark matter (DM) is theoretically well motivated but remarkably unexplored. This proposal presents the MeV-GeV DM discovery potential for a $\\sim$1 m$^3$ segmented CsI(Tl) scintillator detector placed downstream of the Hall A beam-dump at Jefferson Lab, receiving up to 10$^{22}$ electrons-on-target (EOT) in 285 days. This experiment (Beam-Dump eXperiment or BDX) would be sensitive to elastic DM-electron and to inelastic DM scattering at the level of 10 counts per year, reaching the limit of the neutrino irreducible background. The distinct signature of a DM interaction will be an electromagnetic shower of few hundreds of MeV, together with a reduced activity in the surrounding active veto counters. A detailed description of the DM particle $\\chi$ production in the dump and subsequent interaction in the detector has been performed by means of Monte Carlo simulations. Different approaches have been used to evaluate the expected backgrounds: the cosmogenic background has been extrapolated from the result...

  14. A Detailed Look at the First Results from the Large Underground Xenon (LUX) Dark Matter Experiment

    CERN Document Server

    Szydagis, M; Araujo, H M; Bai, X; Bailey, A J; Balajthy, J; Bernard, E; Bernstein, A; Bradley, A; Byram, D; Cahn, S B; Carmona-Benitez, M C; Chan, C; Chapman, J J; Chiller, A A; Chiller, C; Coffey, T; Currie, A; de Viveiros, L; Dobi, A; Dobson, J; Druszkiewicz, E; Edwards, B; Faham, C H; Fiorucci, S; Flores, C; Gaitskell, R J; Gehman, V M; Ghag, C; Gibson, K R; Gilchriese, M G D; Hall, C; Hertel, S A; Horn, M; Huang, D Q; Ihm, M; Jacobsen, R G; Kazkaz, K; Knoche, R; Larsen, N A; Lee, C; Lindote, A; Lopes, M I; Malling, D C; Mannino, R; McKinsey, D N; Mei, D -M; Mock, J; Moongweluwan, M; Morad, J; Murphy, A St J; Nehrkorn, C; Nelson, H; Neves, F; Ott, R A; Pangilinan, M; Parker, P D; Pease, E K; Pech, K; Phelps, P; Reichhart, L; Shutt, T; Silva, C; Solovov, V N; Sorensen, P; O'Sullivan, K; Taylor, D; Tennyson, B; Tiedt, D R; Tripathi, M; Uvarov, S; Verbus, J R; Walsh, N; Webb, R; White, J T; Witherell, M S; Wolfs, F L H; Woods, M; Zhang, C

    2014-01-01

    LUX, the world's largest dual-phase xenon time-projection chamber, with a fiducial target mass of 118 kg and 10,091 kg-days of exposure thus far, is currently the most sensitive direct dark matter search experiment. The initial null-result limit on the spin-independent WIMP-nucleon scattering cross-section was released in October 2013, with a primary scintillation threshold of 2 phe, roughly 3 keVnr for LUX. The detector has been deployed at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, and is the first experiment to achieve a limit on the WIMP cross-section lower than $10^{-45}$ cm$^{2}$. Here we present a more in-depth discussion of the novel energy scale employed to better understand the nuclear recoil light and charge yields, and of the calibration sources, including the new internal tritium source. We found the LUX data to be in conflict with low-mass WIMP signal interpretations of other results.

  15. Search for WIMP dark matter in VBF- and monojet topologies with the ATLAS experiment at 13 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Geisler, Manuel Patrice [Kirchhoff-Institut fuer Physik, Heidelberg (Germany)

    2016-07-01

    The cosmological evidence for Dark Matter is strong, however the nature of Dark Matter is still unknown and it has yet to be detected directly. The presented search with the ATLAS experiment at the LHC, CERN, focuses on WIMP (weakly interacting massive particles) Dark Matter candidates. Different kinds of final states are investigated: both so-called monojets and final states with at least two jets of high transverse momenta and a significant amount of missing transverse momentum. The inclusion of the two-jet selection criteria enhances the sensitivity of this search to vector boson fusion topologies. Furthermore, the selection criteria are optimized in order to suppress background processes that mimic the production of Dark Matter particles. In this talk, further techniques of the search are presented, and aspects of the analysis performed with the 2015 dataset of proton-proton collision at √(s)=13 TeV are covered.

  16. The evolution of future geogenic matter fluxes due Enhanced Weathering: Results from the Antwerp Experiment

    Science.gov (United States)

    Hartmann, Jens; Weiss, Andreas; Struyf, Eric; Schoelynck, Jonas; Meire, Patrick; Amann, Thorben

    2015-04-01

    Understanding the evolution of geogenic matter fluxes in soils due the application of rock products ontop of soils is relevant to evaluate alteration of soil solutions and saturation states of solutes. In the future the practice of applying rock products will continue and areas affected will likely spread (Hartmann et al., 2013). This trend will likely be fuelled by attempts to optimize carbon dioxide removal by increasing biomass production, soil organic carbon stocks, increase crop production or afforestation. All those efforts demand a certain amount of geogenic nutrients, which need to be replaced. To investigate the release patterns and the downward transport of an array of elements, and to study their fate as well as reaction processes, altered through this practice, a mesocosm experiment was established at Antwerp University. Extended results will be presented (c.f., Weiss et al., 2014) focusing on the release and transport of DIC (dissolved inorganic carbon) and Mg (magnesium) in the soil column downwards after the application of 22 kg m-2 olivine powder. Elevated DIC and Mg concentrations are detected in case of olivine is applied to mesocosms with wheat and barley, if compared to the mesocsoms without plants, and without olivine. The change patterns in concentrations and fluxes will be discussed. Hartmann, J., et al. (2013) Enhanced chemical weathering as a geoengineering strategy to reduce atmospheric carbon dioxide, supply nutrients, and mitigate ocean acidification. Reviews of Geophysics; 51(2), 113-149. doi: 10.1002/rog.20004 Weiss, A., et al. (2014) The overlooked compartment of the critical-zone-complex, considering the evolution of future geogenic matter fluxes: Agricultural topsoils. Procedia Earth and Planetary Science, 10, 339-342. doi:10.1016/j.proeps.2014.08.032

  17. Structure and reactions of pentaquark baryons

    Indian Academy of Sciences (India)

    Atsushi Hosaka

    2006-04-01

    We review the current status of the exotic pentaquark baryons. After a brief look at experiments of both positive and negative results, we discuss theoretical methods to study the structure and reactions for the pentaquarks. First we introduce the quark model and the chiral soliton model, where we discuss the relation of mass spectrum and parity with some emphasis on the role of chiral symmetry. It is always useful to picture the structure of the pentaquarks in terms of quarks. As for other methods, we discuss a model-independent method, and briefly mention the results from the lattice and QCD sum rule. Decay properties are then studied in some detail, which is one of the important properties of +. We investigate the relation between the decay width and the quark structure having certain spin-parity quantum numbers. Through these analyses, we consider as plausible quantum numbers of +, = 3/2-. In the last part of this note, we discuss production reactions of + which provide links between the theoretical models and experimental information. We discuss photoproductions and hadron-induced reactions which are useful to explore the nature of +.

  18. Subhalo Demographics in the Illustris Simulation: Effects of Baryons and Halo-to-Halo Variation

    CERN Document Server

    Chua, Kun Ting Eddie; Rodriguez-Gomez, Vicente; Vogelsberger, Mark; Bird, Simeon; Hernquist, Lars

    2016-01-01

    We study the abundance of subhaloes in the hydrodynamical cosmological simulation Illustris, which includes both baryons and dark matter in a $\\Lambda$CDM volume 106.5 Mpc a side. We compare Illustris to its dark matter-only (DMO) analog, Illustris-Dark, and quantify the effects of baryonic processes on the demographics of subhaloes in the host mass range $10^{11}$ to $3 \\times 10^{14} M_\\odot$. We focus on both the evolved ($z=0$) subhalo cumulative mass functions (SHMF) and the statistics of subhaloes ever accreted, i.e. infall subhalo mass function. We quantify the variance in subhalo abundance at fixed host mass and investigate the physical reasons responsible for such scatter. We find that in Illustris, baryonic physics impacts both the infall and $z=0$ subhalo abundance by tilting the DMO function and suppressing the abundance of low-mass subhaloes. The breaking of self-similarity in the subhalo abundance at $z=0$ is enhanced by the inclusion of baryonic physics. The non-monotonic alteration of the evol...

  19. Baryons and their Effects on Planes of Satellites Around Milky Way-Mass Galaxies

    Science.gov (United States)

    Ahmed, Sheehan H.

    2017-01-01

    Both the Milky Way and Andromeda have thin, coherently rotating planes of satellites. In this study I try to find similar satellite planes around four different Milky Way-mass simulations, each run both as dark matter-only and with baryons included. In all halos I am able to identify a planar configuration that significantly maximizes the number of satellites that are members of a plane. The member satellites that make up this maximum plane are consistently different between the dark matter-only and baryonic versions of the same run. In the baryonic runs, satellites are more likely to be destroyed through interactions with the disk, and substructure tends to infall later. Hence, studying satellite planes in dark matter-only simulations is misleading, because they will be composed of different satellite members than those that would exist if baryons were included. Additionally, baryonic runs tend to have less radially concentrated satellite distributions. Since all planes pass through the center of the galaxy, it is much harder to create a plane containing a large number of satellites from a random distribution if the satellites have a low radial concentration. Andromeda’s low radial satellite concentration is possibly a key reason behind why the plane in Andromeda is highly significant. Despite this, when co-rotation is considered, none of the satellite planes identified for the simulated galaxies are as statistically significant as the observed planes around the Milky Way and Andromeda. I will then show that co-rotation in our satellite planes can be attributed to how the satellites are accreted through filaments from the cosmic web. When two sets of opposing filaments contribute, coherent planes are more likely to form, when there are no well-defined filaments, there is a lack of coherent satellite rotation.

  20. Uncoupling of bacterial and terrigenous dissolved organic matter dynamics in decomposition experiments.

    Directory of Open Access Journals (Sweden)

    Daniel P R Herlemann

    Full Text Available The biodegradability of terrigenous dissolved organic matter (tDOM exported to the sea has a major impact on the global carbon cycle, but our understanding of tDOM bioavailability is fragmentary. In this study, the effects of preparative tDOM isolation on microbial decomposition were investigated in incubation experiments consisting of mesocosms containing mesohaline water from the Baltic Sea. Dissolved organic carbon (DOC consumption, molecular DOM composition, bacterial activities, and shifts in bacterial community structure were compared between mesocosms supplemented with riverine tDOM, either as filtered, particle-free river water or as a concentrate obtained by lyophilization/tangential ultrafiltration, and those containing only Baltic Sea water or river water. As shown using ultra-high-resolution mass spectrometry (15 Tesla Fourier-transform ion cyclotron resonance mass spectrometry, FT-ICR-MS covering approximately 4600 different DOM compounds, the three DOM preparation protocols resulted in distinct patterns of molecular DOM composition. However, despite DOC losses of 4-16% and considerable bacterial production, there was no significant change in DOM composition during the 28-day experiment. Moreover, tDOM addition affected neither DOC degradation nor bacterial dynamics significantly, regardless of the tDOM preparation. This result suggested that the introduced tDOM was largely not bioavailable, at least on the temporal scale of our experiment, and that the observed bacterial activity and DOC decomposition mainly reflected the degradation of unknown, labile, colloidal and low-molecular weight DOM, both of which escape the analytical window of FT-ICR-MS. In contrast to the different tDOM preparations, the initial bacterial inoculum and batch culture conditions determined bacterial community succession and superseded the effects of tDOM addition. The uncoupling of tDOM and bacterial dynamics suggests that mesohaline bacterial communities

  1. Search for doubly charmed baryons and study of charmed strange baryons at Belle

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Y.; Iijima, T.; Adachi, I.; Aihara, H.; Asner, D. M.; Aushev, T.; Bakich, A. M.; Bala, A.; Ban, Y.; Bhardwaj, V.; Bhuyan, B.; Bobrov, A.; Bonvicini, G.; Bozek, A.; Bračko, M.; Browder, T. E.; Červenkov, D.; Chekelian, V.; Chen, A.; Cheon, B. G.; Chilikin, K.; Chistov, R.; Cho, K.; Chobanova, V.; Choi, Y.; Cinabro, D.; Dalseno, J.; Danilov, M.; Doležal, Z.; Drásal, Z.; Drutskoy, A.; Dutta, D.; Dutta, K.; Eidelman, S.; Farhat, H.; Fast, J. E.; Ferber, T.; Gaur, V.; Gabyshev, N.; Ganguly, S.; Garmash, A.; Gillard, R.; Goh, Y. M.; Golob, B.; Haba, J.; Hayasaka, K.; Hayashii, H.; He, X. H.; Horii, Y.; Hoshi, Y.; Hou, W. -S.; Hsiung, Y. B.; Inami, K.; Ishikawa, A.; Iwasaki, Y.; Iwashita, T.; Jaegle, I.; Julius, T.; Kang, J. H.; Kato, E.; Kawasaki, T.; Kiesling, C.; Kim, D. Y.; Kim, H. J.; Kim, J. B.; Kim, J. H.; Kim, M. J.; Kim, Y. J.; Klucar, J.; Ko, B. R.; Kodyš, P.; Korpar, S.; Krokovny, P.; Kuhr, T.; Kuzmin, A.; Kwon, Y. -J.; Lee, S. -H.; Li, J.; Li, Y.; Li Gioi, L.; Libby, J.; Liu, Y.; Liventsev, D.; Matvienko, D.; Miyabayashi, K.; Miyata, H.; Mizuk, R.; Moll, A.; Muramatsu, N.; Mussa, R.; Nagasaka, Y.; Nakano, E.; Nakao, M.; Nakazawa, H.; Nayak, M.; Nedelkovska, E.; Ng, C.; Niiyama, M.; Nisar, N. K.; Nishida, S.; Nitoh, O.; Ogawa, S.; Okuno, S.; Pakhlov, P.; Pakhlova, G.; Park, C. W.; Park, H.; Park, H. K.; Pedlar, T. K.; Peng, T.; Pestotnik, R.; Petrič, M.; Piilonen, L. E.; Ritter, M.; Röhrken, M.; Rostomyan, A.; Sahoo, H.; Saito, T.; Sakai, Y.; Sandilya, S.; Santelj, L.; Sanuki, T.; Savinov, V.; Schneider, O.; Schnell, G.; Schwanda, C.; Semmler, D.; Senyo, K.; Seon, O.; Shapkin, M.; Shen, C. P.; Shibata, T. -A.; Shiu, J. -G.; Shwartz, B.; Sibidanov, A.; Sohn, Y. -S.; Sokolov, A.; Solovieva, E.; Stanič, S.; Starič, M.; Steder, M.; Sumihama, M.; Sumiyoshi, T.; Tamponi, U.; Tanida, K.; Tatishvili, G.; Teramoto, Y.; Uchida, M.; Uehara, S.; Uglov, T.; Unno, Y.; Uno, S.; Van Hulse, C.; Vanhoefer, P.; Varner, G.; Vinokurova, A.; Vorobyev, V.; Wagner, M. N.; Wang, C. H.; Wang, M. -Z.; Wang, P.; Watanabe, M.; Watanabe, Y.; Williams, K. M.; Won, E.; Yamashita, Y.; Yashchenko, S.; Zhang, Z. P.; Zhilich, V.; Zhulanov, V.; Zupanc, A.

    2014-03-17

    We report results of a study of doubly charmed baryons and charmed strange baryons. The analysis is performed using a 980 fb-1 data sample collected with the Belle detector at the KEKB asymmetric-energy e+e- collider.

  2. 直接探测暗物质和中国暗物质实验%Dark matter direct detection and China dark matter experiment

    Institute of Scientific and Technical Information of China (English)

    刘书魁; 岳骞

    2015-01-01

    暗物质探测已成为当今科学最重要的课题之一.弱相互作用重粒子(weakly interacting massive particles, WIMPs)是众多理论模型中最有可能的暗物质候选者之一.暗物质直接探测原理是:WIMPs与地面探测器的靶核通过弱相互作用,发生弹性散射,反冲核被弹出,探测器将反冲核能量记录下来,得到暗物质与探测器相互作用的信号.文章介绍了国际上主流的暗物质直接探测的方法、现状以及未来直接探测的路线.还介绍了世界最深地下实验室——中国锦屏地下实验室的现状和二期扩建情况.文章最后详细介绍了中国暗物质合作组的研究历程、探测技术、研究取得的成果和未来规划.%The nature of dark matter in our universe is one of the most challenging prob-lems in science today. A most probable class of dark matter is the weakly interacting massive parti-cles (WIMPs), which exhibit a wide range of features. Current experiments searching for dark matter aim for direct detection via the elastic scattering off ordinary matter in terrestrial detectors. This paper will present the main methods, status and roadmap for the direct detection of dark mat-ter. The world's deepest laboratory, China Jinping underground laboratory and its extension, will also be described. Finally, we will give a detailed introduction to the research history, detection technologies, current results, and future prospects of China dark matter experiment (CDEX).

  3. Gas-Rich Mergers in LCDM: Disk Survivability and the Baryonic Assembly of Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Kyle R.; Bullock, James S.; /UC, Irvine; Wechsler, Risa H.; /KIPAC, Menlo Park /SLAC; Maller, Ariyeh H.; /New York City Coll. Tech.

    2009-08-03

    We use N-body simulations and observationally-normalized relations between dark matter halo mass, stellar mass, and cold gas mass to derive robust expectations about the baryonic content of major mergers out to redshift z {approx} 2. First, we find that the majority of major mergers (m/M > 0.3) experienced by Milky Way size dark matter halos should have been gas-rich, and that gas-rich mergers are increasingly common at high redshift. Though the frequency of major mergers into galaxy halos in our simulations greatly exceeds the observed late-type galaxy fraction, the frequency of gas-poor major mergers is consistent with the observed fraction of bulge-dominated galaxies across the halo mass range M{sub DM} {approx} 10{sup 11} - 10{sup 13} M{sub {circle_dot}}. These results lend support to the conjecture that mergers with high baryonic gas fractions play an important role in building and/or preserving disk galaxies in the universe. Secondly, we find that there is a transition mass below which a galaxy's past major mergers were primarily gas-rich and above which they were gas poor. The associated stellar mass scale corresponds closely to that marking the observed bimodal division between blue, star-forming, disk-dominated systems and red, bulge-dominated systems with old populations. Finally, we find that the overall fraction of a galaxy's cold baryons deposited directly via major mergers is substantial. Approximately 30% of the cold baryonic material in M{sub star} {approx} 10{sup 10} M{sub {circle_dot}} (M{sub DM} {approx} 10{sup 11.5} M{sub {circle_dot}}) galaxies is accreted as cold gas in major mergers. For more massive galaxies with M{sub star} {approx} 10{sup 11} M{sub {circle_dot}} (M{sub DM} {approx} 10{sup 13} M{sub {circle_dot}} the fraction of baryons amassed in mergers is even higher, {approx} 50%, but most of these accreted baryons are delivered directly in the form of stars. This baryonic mass deposition is almost unavoidable, and provides a

  4. The prototype of the Micro Vertex Detector of the CBM Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Koziel, Michal, E-mail: Michal.Koziel@Physik.uni-frankfurt.de; Amar-Youcef, Samir; Bialas, Norbert; Deveaux, Michael; Fröhlich, Ingo; Li, Qiyan; Michel, Jan; Milanović, Borislav; Müntz, Christian; Neumann, Bertram; Schrader, Christoph; Stroth, Joachim; Tischler, Tobias; Weirich, Roland; Wiebusch, Michael

    2013-12-21

    The Compressed Baryonic Matter (CBM) Experiment is one of the core experiments of the future FAIR facility at Darmstadt, Germany. This fixed-target experiment will explore the phase diagram of strongly interacting matter in the regime of highest net baryon densities with numerous probes, among them open charm. Reconstructing those short lived particles requires a vacuum compatible Micro Vertex Detector (MVD) with unprecedented properties. Its sensor technology has to feature a spatial resolution of <5μm, a non-ionizing radiation tolerance of >10{sup 13}n{sub eq}/cm{sup 2}, an ionizing radiation tolerance of >3Mrad and a time resolution of a few 10μs. The MVD-prototype project aimed to study the integration the CMOS Monolithic Active Pixel Sensors foreseen for the MVD into an ultra light (0.3% X{sub 0}) and a vacuum compatible detector system based on a cooling support made of CVD-diamond.

  5. Baryon-baryon bound states in a (2+1)-dimensional lattice QCD model

    Science.gov (United States)

    Faria da Veiga, Paulo A.; O'Carroll, Michael; Schor, Ricardo

    2003-08-01

    We consider bound states of two baryons (antibaryons) in lattice QCD in a Euclidean formulation. For simplicity, we analyze an SU(3) theory with a single flavor in 2+1 dimensions and two-dimensional Dirac matrices. For a small hopping parameter 0<κ≪1 and large glueball mass, we recently showed the existence of a (anti)baryonlike particle, with an asymptotic mass of the order of -3 ln κ and with an isolated dispersion curve, i.e., an upper gap property persisting up to near the meson-baryon threshold, which is of order -5 ln κ. Here, we show that there is no baryon-baryon (or antibaryon-antibaryon) bound state solution to the Bethe-Salpeter equation up to the two-baryon threshold, which is approximately -6 ln κ.

  6. Search for GeV-Scale Sterile Neutrinos Responsible for Active Neutrino Oscillations and Baryon Asymmetry of the Universe

    Directory of Open Access Journals (Sweden)

    S. N. Gninenko

    2012-01-01

    Full Text Available Standard Model fails to explain neutrino oscillations, dark matter, and baryon asymmetry of the Universe. All these problems can be solved with three sterile neutrinos added to SM. Quite remarkably, if sterile neutrino masses are well below the electroweak scale, this modification—Neutrino Minimal Standard Model (νMSM—can be tested experimentally. We discuss a new experiment on search for decays of GeV-scale sterile neutrinos, which are responsible for the matter-antimatter asymmetry generation and for the active neutrino masses. If lighter than 2 GeV, these particles can be produced in decays of charm mesons generated by high energy protons in a target, and subsequently decay into SM particles. To fully explore this sector of νMSM, the new experiment requires data obtained with at least 1020 incident protons on target (achievable at CERN SPS in future and a big volume detector constructed from a large amount of identical single modules, with a total sterile neutrino decay length of few kilometers. The preliminary feasibility study for the proposed experiment shows that it has sensitivity which may either lead to the discovery of new particles below the Fermi scale—right-handed partners of neutrinos—or rule out seesaw sterile neutrinos with masses below 2 GeV.

  7. Searches for Dark Matter and Large Extra Dimensions in Monojet Final States with the ATLAS Experiment

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00286734

    This thesis presents searches for evidence for Weakly Interacting Massive Particles (WIMPs) and Extra Dimensions in proton-proton collisions recorded by the ATLAS experiment at the CERN Large Hadron Collider (LHC). The WIMP is one of the main candidates to constitute the particle content of Dark Matter. Extra Dimensions are introduced in several theories in order to explain the apparent weakness of gravity when compared to the other interactions in Nature. Theories with WIMPs as well as Extra Dimensions can manifest themselves at the LHC, with experimental signatures characterized by an energetic hadronic jet associated with large missing momentum. These signatures are known as monojet signatures, and are investigated in this thesis. The first analysis is performed using L = 20.3 fb$^{-1}$~of proton-proton collisions at $\\sqrt{s}$ = 8 TeV recorded in the ATLAS Run 1. The second analysis is performed using L = 3.2 fb$^{-1}$~of proton-proton collisions at $\\sqrt{s}$ = 13 TeV recorded in the ATLAS Run 2. No sign...

  8. Progress in characterization of the Photomultiplier Tubes for XENON1T Dark Matter Experiment

    CERN Document Server

    Lyashenko, Alexey

    2015-01-01

    We report on the progress in characterization of the Hamamatsu model R11410-21 Photomultiplier tubes (PMTs) for XENON1T dark matter experiment. The absolute quantum efficiency (QE) of the PMT was measured at low temperatures down to -110 $^0$C (a typical the PMT operation temperature in liquid xenon detectors) in a spectral range from 154.5 nm to 400 nm. At -110 $^0$C the absolute QE increased by 10-15\\% at 175 nm compared to that measured at room temperature. A new low power consumption, low radioactivity voltage divider for the PMTs is being developed. The measurement results showed that the PMT with the current version of the divider demonstrated a linear response (within 5\\%) down to 5$\\cdot$10$^4$ photoelectrons at a rate of 200 Hz. The radioactive contamination induced by the PMT and the PMT voltage divider materials satisfies the requirements for XENON1T detector not to exceed a total radioactive contamination in the detector of 0.5 evts/year/1tonn. Most of the PMTs received from the manufacturer showe...

  9. Recovery and Reutilization of Waste Matter from Coffee Preparation. An Experiment for Environmental Science Courses

    Science.gov (United States)

    Orecchio, Santino

    2001-12-01

    This work is designed as an experience for organic and analytical chemistry laboratories in environmental science courses. Coffee grounds were chosen because they are easily available, they are a fine example of a waste product, and the students are familiar with them. The coffee bean is a source of a number of by-products. By comparing the physicochemical characteristics of coffee oil (from the grounds) with those of common oils, it is found that coffee oil shows similarity to palm oil. We hydrolysed the coffee oil and obtained a soap that had good detergent and foaming properties similar to olive oil soap or commercial products. Another beneficial aspect of the coffee bean results from the high content in organic matter (C = 48.9%) of the degreased coffee grounds, which allows their utilization to improve the fertility of soils. The total nitrogen content of the residue is higher than that of many composts and is similar to the nitrogen content of some commercial products employed for house plants. The economical, technical, and environmental advantages that frequently can derive from the recovery of some by-products of foods and beverages, such as the coffee grounds in this example, are evident.

  10. Technical Results from the Surface Run of the LUX Dark Matter Experiment

    CERN Document Server

    Akerib, D S; Bernard, E; Bernstein, A; Bradley, A; Byram, D; Cahn, S B; Carmona-Benitez, M C; Chapman, J J; Coffey, T; Dobi, A; Dragowsky, E; Druszkiewicz, E; Edwards, B; Faham, C H; Fiorucci, S; Gaitskell, R J; Gibson, K R; Gilchriese, M; Hall, C; Hanhardt, M; Ihm, M; Jacobsen, R G; Kastens, L; Kazkaz, K; Knoche, R; Larsen, N; Lee, C; Lesko, K T; Lindote, A; Lopes, M I; Lyashenko, A; Malling, D C; Mannino, R; McKinsey, D N; Mei, D; Mock, J; Moongweluwan, M; Morii, M; Nelson, H; Neves, F; Nikkel, J A; Pangilinan, M; Pech, K; Phelps, P; Rodionov, A; Shutt, T; Silva, C; Skulski, W; Solovov, V N; Sorensen, P; Stiegler, T; Sweany, M; Szydagis, M; Taylor, D; Tripathi, M; Uvarov, S; Verbus, J R; de Viveiros, L; Walsh, N; Webb, R; White, J T; Wlasenko, M; Wolfs, F L H; Woods, M; Zhang, C

    2012-01-01

    We present the results of the three-month above-ground commissioning run of the Large Underground Xenon (LUX) experiment at the Sanford Underground Research Facility located in Lead, South Dakota, USA. LUX is a 370 kg liquid xenon detector that will search for cold dark matter in the form of Weakly Interacting Massive Particles (WIMPs). The commissioning run, conducted with the detector immersed in a water tank, validated the integration of the various sub-systems in preparation of the underground deployment. Using the data collected, we report excellent light collection properties, achieving 8 photoelectrons per keV for 662 keV electron recoils without an applied electric field, measured in the center of the WIMP target. We also find good energy and position resolution in relatively high-energy interactions from a variety of internal and external sources. Finally, we have used the commissioning data to tune the optical properties of our simulation and report updated sensitivity projections for spin-independe...

  11. The Baryon Oscillation Spectroscopic Survey of SDSS-III

    CERN Document Server

    Dawson, Kyle S; Ahn, Christopher P; Anderson, Scott F; Aubourg, Eric; Bailey, Stephen; Barkhouser, Robert H; Bautista, Julian E; Beifiori, Alessandra; Berlind, Andreas A; Bhardwaj, Vaishali; Bizyaev, Dmitry; Blake, Cullen H; Blanton, Michael R; Blomqvist, Michael; Bolton, Adam S; Borde, Arnaud; Bovy, Jo; Brandt, W N; Brewington, Howard; Brinkmann, Jon; Brown, Peter J; Brownstein, Joel R; Bundy, Kevin; Busca, N G; Carithers, William; Carnero, Aurelio R; Carr, Michael A; Chen, Yanmei; Comparat, Johan; Connolly, Natalia; Cope, Frances; Croft, Rupert A C; Cuesta, Antonio J; da Costa, Luiz N; Davenport, James R A; Delubac, Timothee; de Putter, Roland; Dhital, Saurav; Ealet, Anne; Ebelke, Garrett L; Eisenstein, Daniel J; Escoffier, S; Fan, Xiaohui; Ak, N Filiz; Finley, Hayley; Font-Ribera, Andreu; Genova-Santos, R; Gunn, James E; Guo, Hong; Haggard, Daryl; Hall, Patrick B; Hamilton, Jean-Christophe; Harris, Ben; Harris, David W; Ho, Shirley; Hogg, David W; Holder, Diana; Honscheid, Klaus; Huehnerhoff, Joe; Jordan, Beatrice; Jordan, Wendell P; Kauffmann, Guinevere; Kazin, Eyal A; Kirkby, David; Klaene, Mark A; Kneib, Jean-Paul; Goff, Jean-Marc Le; Lee, Khee-Gan; Long, Daniel C; Loomis, Craig P; Lundgren, Britt; Lupton, Robert H; Maia, Marcio A G; Makler, Martin; Malanushenko, Elena; Malanushenko, Viktor; Mandelbaum, Rachel; Manera, Marc; Maraston, Claudia; Margala, Daniel; Masters, Karen L; McBride, Cameron K; McDonald, Patrick; McGreer, Ian D; Mena, Olga; Miralda-Escude, Jordi; Montero-Dorta, Antonio D; Montesano, Francesco; Muna, Demitri; Myers, Adam D; Naugle, Tracy; Nichol, Robert C; Noterdaeme, Pasquier; Olmstead, Matthew D; Oravetz, Audrey; Oravetz, Daniel J; Owen, Russell; Padmanabhan, Nikhil; Palanque-Delabrouille, Nathalie; Pan, Kaike; Parejko, John K; Paris, Isabelle; Percival, Will J; Perez-Fournon, Ismael; Perez-Rafols, Ignasi; Petitjean, Patrick; Pfaffenberger, Robert; Pforr, Janine; Pieri, Matthew M; Prada, Francisco; Price-Whelan, Adrian M; Raddick, M Jordan; Rebolo, Rafael; Rich, James; Richards, Gordon T; Rockosi, Constance M; Roe, Natalie A; Ross, Ashley J; Ross, Nicholas P; Rossi, Graziano; Rubino-Martin, J A; Samushia, Lado; Sanchez, Ariel G; Sayres, Conor; Schmidt, Sarah J; Schneider, Donald P; Scoccola, C G; Seo, Hee-Jong; Shelden, Alaina; Sheldon, Erin; Shen, Yue; Shu, Yiping; Slosar, Anze; Smee, Stephen A; Snedden, Stephanie A; Stauffer, Fritz; Steele, Oliver; Strauss, Michael A; Suzuki, Nao; Swanson, Molly E C; Tal, Tomer; Tanaka, Masayuki; Thomas, Daniel; Tinker, Jeremy L; Tojeiro, Rita; Tremonti, Christy A; Magana, M Vargas; Verde, Licia; Viel, Matteo; Wake, David A; Watson, Mike; Weaver, Benjamin A; Weinberg, David H; Weiner, Benjamin J; West, Andrew A; White, Martin; Wood-Vasey, W M; Yeche, Christophe; Zehavi, Idit; Zhao, Gong-Bo; Zheng, Zheng

    2012-01-01

    The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large scale structure. BOSS uses luminous galaxies to measure BAO to redshifts z<0.7 and observations of neutral hydrogen in the Lyman alpha forest in quasar spectra to constrain BAO over the redshift range 2.15

  12. Streaming Velocities and the Baryon Acoustic Oscillation Scale.

    Science.gov (United States)

    Blazek, Jonathan A; McEwen, Joseph E; Hirata, Christopher M

    2016-03-25

    At the epoch of decoupling, cosmic baryons had supersonic velocities relative to the dark matter that were coherent on large scales. These velocities subsequently slow the growth of small-scale structure and, via feedback processes, can influence the formation of larger galaxies. We examine the effect of streaming velocities on the galaxy correlation function, including all leading-order contributions for the first time. We find that the impact on the baryon acoustic oscillation (BAO) peak is dramatically enhanced (by a factor of ∼5) over the results of previous investigations, with the primary new effect due to advection: if a galaxy retains memory of the primordial streaming velocity, it does so at its Lagrangian, rather than Eulerian, position. Since correlations in the streaming velocity change rapidly at the BAO scale, this advection term can cause a significant shift in the observed BAO position. If streaming velocities impact tracer density at the 1% level, compared to the linear bias, the recovered BAO scale is shifted by approximately 0.5%. This new effect, which is required to preserve Galilean invariance, greatly increases the importance of including streaming velocities in the analysis of upcoming BAO measurements and opens a new window to the astrophysics of galaxy formation.

  13. The small scatter of the baryonic Tully-Fisher relation

    CERN Document Server

    Lelli, Federico; Schombert, James M

    2015-01-01

    In a LCDM cosmology, the baryonic Tully-Fisher relation (BTFR) is expected to show significant intrinsic scatter resulting from the mass-concentration relation of dark matter halos and the baryonic-to-halo mass ratio. We study the BTFR using a sample of 118 disc galaxies (spirals and irregulars) with data of the highest quality: extended HI rotation curves (tracing the outer velocity) and Spitzer photometry at 3.6 $\\mu$m (tracing the stellar mass). Assuming that the stellar mass-to-light ratio (M*/L) is nearly constant at 3.6 $\\mu$m, we find that the scatter, slope, and normalization of the BTFR systematically vary with the adopted M*/L. The observed scatter is minimized for M*/L > 0.5, corresponding to nearly maximal discs in high-surface-brightness galaxies and BTFR slopes close to ~4. For any reasonable value of M*/L, the intrinsic scatter is ~0.1 dex, below general LCDM expectations. The residuals show no correlations with galaxy structural parameters (radius or surface brightness), contrary to the predic...

  14. Strongly Interacting Matter at High Energy Density

    Energy Technology Data Exchange (ETDEWEB)

    McLerran,L.

    2008-09-07

    This lecture concerns the properties of strongly interacting matter (which is described by Quantum Chromodynamics) at very high energy density. I review the properties of matter at high temperature, discussing the deconfinement phase transition. At high baryon density and low temperature, large N{sub c} arguments are developed which suggest that high baryonic density matter is a third form of matter, Quarkyonic Matter, that is distinct from confined hadronic matter and deconfined matter. I finally discuss the Color Glass Condensate which controls the high energy limit of QCD, and forms the low x part of a hadron wavefunction. The Glasma is introduced as matter formed by the Color Glass Condensate which eventually thermalizes into a Quark Gluon Plasma.

  15. Heavy baryon spectroscopy from the lattice

    Energy Technology Data Exchange (ETDEWEB)

    Bowler, K.C.; Kenway, R.D.; Oliveira, O.; Richards, D.G.; Ueberholz, P. [Department of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3JZ (Scotland); Lellouch, L.; Nieves, J.; Sachrajda, C.T.; Stella, N.; Wittig, H. [Physics Department, The University, Southampton SO17 1BJ (United Kingdom)

    1996-09-01

    The results of an exploratory lattice study of heavy baryon spectroscopy are presented. We have computed the full spectrum of the eight baryons containing a single heavy quark, on a 24{sup 3}{times}48 lattice at {beta}=6.2, using an {ital O}({ital a})-improved fermion action. We discuss the lattice baryon operators and give a method for isolating the contributions of the spin doublets ({Sigma},{Sigma}{sup {asterisk}}), ({Xi}{sup {prime}},{Xi}{sup {asterisk}}), and ({Omega},{Omega}{sup {asterisk}}) to the correlation function of the relevant operator. We compare our results with the available experimental data and find good agreement in both the charm and the {ital b}-quark sectors, despite the long extrapolation in the heavy quark mass needed in the latter case. We also predict the masses of several undiscovered baryons. We compute the {Lambda}-pseudoscalar meson and {Sigma}-{Lambda} mass splittings. Our results, which have errors in the range 10{endash}30{percent}, are in good agreement with the experimental numbers. For the {Sigma}{sup {asterisk}}-{Sigma} mass splitting, we find results considerably smaller than the experimental values for both the charm and the {ital b}-flavored baryons, although in the latter case the experimental results are still preliminary. This is also the case for the lattice results for the hyperfine splitting for the heavy mesons. {copyright} {ital 1996 The American Physical Society.}

  16. Strong decays of baryons and missing resonances

    Science.gov (United States)

    Bijker, R.; Ferretti, J.; Galatà, G.; García-Tecocoatzi, H.; Santopinto, E.

    2016-10-01

    We provide results for the open-flavor strong decays of strange and nonstrange baryons into a baryon-vector/pseudoscalar meson pair. The decay amplitudes are computed in the 3P0 pair-creation model, where s s ¯ pair-creation suppression is included for the first time in the baryon sector, in combination with the U (7 ) and hypercentral models. The effects of this s s ¯ suppression mechanism cannot be reabsorbed in a redefinition of the model parameters or in a different choice of the 3P0 model vertex factor. Our results for the decay amplitudes are compared with the existing experimental data and previous 3P0 and elementary meson emission model calculations. In this respect, we show that distinct quark models differ in the number of missing resonances they predict and also in the quantum numbers of states. Therefore, future experimental results will be important in order to disentangle different models of baryon structure. Finally, in the appendixes, we provide some details of our calculations, including the derivation of all relevant flavor couplings with strangeness suppression. This derivation may be helpful to calculate the open-flavor decay amplitudes starting from other models of baryons.

  17. Baryons in the relativistic jets of the stellar-mass black-hole candidate 4U 1630-47.

    Science.gov (United States)

    Trigo, María Díaz; Miller-Jones, James C A; Migliari, Simone; Broderick, Jess W; Tzioumis, Tasso

    2013-12-12

    Accreting black holes are known to power relativistic jets, both in stellar-mass binary systems and at the centres of galaxies. The power carried away by the jets, and, hence, the feedback they provide to their surroundings, depends strongly on their composition. Jets containing a baryonic component should carry significantly more energy than electron-positron jets. Energetic considerations and circular-polarization measurements have provided conflicting circumstantial evidence for the presence or absence of baryons in jets, and the only system in which they have been unequivocally detected is the peculiar X-ray binary SS 433 (refs 4, 5). Here we report the detection of Doppler-shifted X-ray emission lines from a more typical black-hole candidate X-ray binary, 4U 1630-47, coincident with the reappearance of radio emission from the jets of the source. We argue that these lines arise from baryonic matter in a jet travelling at approximately two-thirds the speed of light, thereby establishing the presence of baryons in the jet. Such baryonic jets are more likely to be powered by the accretion disk than by the spin of the black hole, and if the baryons can be accelerated to relativistic speeds, the jets should be strong sources of γ-rays and neutrino emission.

  18. Heavy spin-2 Dark Matter

    Energy Technology Data Exchange (ETDEWEB)

    Babichev, Eugeny [Laboratoire de Physique Théorique, CNRS, Univ. Paris-Sud, Université Paris-Saclay,91405 Orsay (France); UPMC-CNRS, UMR7095, Institut d’Astrophysique de Paris, GReCO,98bis boulevard Arago, F-75014 Paris (France); Marzola, Luca; Raidal, Martti [National Institute of Chemical Physics and Biophysics,Rävala 10, 10143 Tallinn (Estonia); Laboratory of Theoretical Physics, Institute of Physics, University of Tartu,Ravila 14c, 50411 Tartu (Estonia); Schmidt-May, Angnis [Institut für Theoretische Physik, Eidgenössische Technische Hochschule Zürich,Wolfgang-Pauli-Strasse 27, 8093 Zürich (Switzerland); Urban, Federico; Veermäe, Hardi [National Institute of Chemical Physics and Biophysics,Rävala 10, 10143 Tallinn (Estonia); Strauss, Mikael von [UPMC-CNRS, UMR7095, Institut d’Astrophysique de Paris, GReCO,98bis boulevard Arago, F-75014 Paris (France)

    2016-09-12

    We provide further details on a recent proposal addressing the nature of the dark sectors in cosmology and demonstrate that all current observations related to Dark Matter can be explained by the presence of a heavy spin-2 particle. Massive spin-2 fields and their gravitational interactions are uniquely described by ghost-free bimetric theory, which is a minimal and natural extension of General Relativity. In this setup, the largeness of the physical Planck mass is naturally related to extremely weak couplings of the heavy spin-2 field to baryonic matter and therefore explains the absence of signals in experiments dedicated to Dark Matter searches. It also ensures the phenomenological viability of our model as we confirm by comparing it with cosmological and local tests of gravity. At the same time, the spin-2 field possesses standard gravitational interactions and it decays universally into all Standard Model fields but not into massless gravitons. Matching the measured DM abundance together with the requirement of stability constrains the spin-2 mass to be in the 1 to 100 TeV range.

  19. Nuclear matter physics at NICA

    Energy Technology Data Exchange (ETDEWEB)

    Senger, P. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany)

    2016-08-15

    The exploration of the QCD phase diagram is one of the most exciting and challenging projects of modern nuclear physics. In particular, the investigation of nuclear matter at high baryon densities offers the opportunity to find characteristic structures such as a first-order phase transition with a region of phase coexistence and a critical endpoint. The experimental discovery of these prominent landmarks of the QCD phase diagram would be a major breakthrough in our understanding of the properties of nuclear matter. Equally important is the quantitative experimental information on the properties of hadrons in dense matter which may shed light on chiral symmetry restoration and the origin of hadron masses. Worldwide, substantial efforts at the major heavy-ion accelerators are devoted to the clarification of these fundamental questions, and new dedicated experiments are planned at future facilities like CBM at FAIR in Darmstadt and MPD at NICA/JINR in Dubna. In this article the perspectives for MPD at NICA will be discussed. (orig.)

  20. Strange and non-strange baryon and antibaryon production in sulphur-tungsten and sulphur-sulphur interactions at 200 A Gev/c

    Energy Technology Data Exchange (ETDEWEB)

    Holme, A.K.

    1995-11-01

    The author has studied production of strange and multistrange baryons and antibaryons in central sulphur-tungsten, sulphur-sulphur, and lead-lead interactions at relativistic energies. The spectra of strange baryons and antibaryons provide information about the dynamics of hadronic matter under the extreme conditions realised in these collisions. The particle ratios allow the degree and the nature of the flavour equilibrium to be studied, while the transverse mass distributions provide independent information of the temperatures achieved. 143 refs.