WorldWideScience

Sample records for lhc including exotic

  1. Exotic highly ionising particles at the LHC

    CERN Document Server

    De Roeck, A; Mermod, P; Milstead, D; Sloan, T

    2012-01-01

    The experiments at the Large Hadron Collider (LHC) are able to discover or set limits on the production of exotic particles with TeV-scale masses possessing values of electric and/or magnetic charge such that they appear as highly ionising particles (HIPs). In this paper the sensitivity of the LHC experiments to HIP production is discussed in detail. It is shown that a number of different detection methods are required to investigate as fully as possible the charge-mass range. These include direct detection as the HIPs pass through detectors and, in the case of magnetically charged objects, the so-called induction method with which monopoles which stop in accelerator and detector material could be observed. The benefit of using complementary approaches to HIP detection is discussed.

  2. Other Exotic Scenarios at the LHC

    CERN Document Server

    Benslama, K

    2006-01-01

    The considerable center-of-mass energy and luminosity at the LHC will ensure a discovery reach for new particles which extends well into the mlti-TeV region. ATLAS and CMS carried out many studies of the implications of this capability for Beyond the Standard Model Physics. In this talk, I will focus on studies involving extra-dimensions, little higgs, strong symmetry breaking, compositeness and new gauge bosons.

  3. Exotic colored scalars at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Blum, Kfir; Efrati, Aielet; Frugiuele, Claudia; Nir, Yosef [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 7610001 (Israel)

    2017-02-21

    We study the phenomenology of exotic color-triplet scalar particles X with charge |Q|=2/3,4/3,5/3,7/3,8/3 and 10/3. If X is an SU(2){sub W}-non-singlet, mass splitting within the multiplet allows for cascade decays of the members into the lightest state. We study examples where the lightest state, in turn, decays into a three-body W{sup ±}jj final state, and show that in such case the entire multiplet is compatible with indirect precision tests and with direct collider searches for continuum pair production of X down to m{sub X}∼250 GeV. However, bound states S, made of XX{sup †} pairs at m{sub S}≈2m{sub X}, form under rather generic conditions and their decay to diphoton can be the first discovery channel of the model. Furthermore, for SU(2){sub W}-non-singlets, the mode S→W{sup +}W{sup −} may be observable and the width of S→γγ and S→jj may appear large as a consequence of mass splittings within the X-multiplet. As an example we study in detail the case of an SU(2){sub W}-quartet, finding that m{sub X}≃450 GeV is allowed by all current searches.

  4. Single production of an exotic bottom partner at LHC

    International Nuclear Information System (INIS)

    Álvarez, Ezequiel; Rold, Leandro Da; Vietto, Juan Ignacio Sanchez

    2014-01-01

    We study single production and detection at the LHC run II of exotic partners of the bottom quark. For masses larger than 1 TeV single production can dominate over pair production that is suppressed due to phase space. The presence of exotic partners of the bottom is motivated in models aiming to solve the A FB b anomaly measured at LEP and SLC. Minimal models of this type with partial compositeness predict, as the lightest bottom partner, a new fermion V of electric charge −4/3, also called mirror. The relevant coupling for our study is a WVb vertex, which yields a signal that corresponds to a hard W, a hard b-jet and a forward light jet. We design a search strategy for the leptonic decay of the W, which avoids the large QCD multijet background and its large uncertainties. We find that the main backgrounds are W+jets and tt-bar, and the key variables to enhance the signal over them are a hard b-jet and the rapidity of the light jet. We determine the discovery reach for the LHC run II, in particular we predict that, for couplings of order ∼g/10, this signal could be detected at a 95% confidence level with a mass up to 2.4 TeV using the first 100 fb −1

  5. Search for long lived particles at the LHC (SUSY+exotics physics scenarios)

    CERN Document Server

    Romanowska-Rybinska, Katarzyna

    2012-01-01

    Many models of physics Beyond the Standard Model (BSM) predict the existence of new heavy particles with long lifetimes. These particles come in many different types, but have one thing in common, they have very unique signatures at LHC experiments, which makes them easily distinguishable from Standard Model (SM) particles. Finding the signal of any of them would be a clear sign of BSM physics. In this paper we present search strategies and results of seven searches for long-lived exotic particles of different types, both charged and neutral, performed by the ATLAS and CMS experiments with 2011 pp collision data taken at LHC energy $\\sqrt{s}$ = 7 TeV.

  6. Exotic Physics

    OpenAIRE

    Sigamani, Michael

    2016-01-01

    A selection of results for searches for exotic physics at the LHC are presented. These include a search for massive resonances, dark matter with a high energy jet in association with large missing transverse momentum, long-lived neutral particles, and narrow dijet resonances. The results are based on 20/fb of LHC proton-proton collisions at sqrt(s) = 8 TeV taken with the CMS detector.

  7. Combination of Run-1 Exotic Searches in Diboson Final States at the LHC

    CERN Document Server

    Dias, Flavia; Gouzevich, Maxime; Leonidopoulos, Christos; Novaes, Sergio; Oliveira, Alexandra; Pierini, Maurizio; Tomei, Thiago

    2016-01-01

    We perform a statistical combination of the ATLAS and CMS results for the search of a heavy resonance decaying to a pair of vector bosons with the $\\sqrt{s}=8$~TeV datasets collected at the LHC. We take into account six searches in hadronic and semileptonic final states carried out by the two collaborations. We consider only public information provided by ATLAS and CMS in the HEPDATA database and in papers published in refereed journals. The results are interpreted within the context of a few benchmark new physics models, such as models predicting the existence of a \\PWp or a bulk Randall-Sundum spin--2 resonance. We present exclusion limits, $z$-values, $p$-values and best-fit cross sections in different model interpretations for the combined results. Out of several benchmark exotic models considered in this study, a heavy resonance with a production cross section of $\\sim$5~fb and mass between 1.9 and 2.0 TeV is the scenario most consistent with the experimental results. Models in which a heavy resonance de...

  8. Combination of Run-1 Exotic Searches in Diboson Final States at the LHC

    CERN Document Server

    Dias, Flavia; Gouzevich, Maxime; Leonidopoulos, Christos; Novaes, Sergio; Oliveira, Alexandra; Pierini, Maurizio; Tomei, Thiago

    2016-04-26

    We perform a statistical combination of the ATLAS and CMS results for the search of a heavy resonance decaying to a pair of vector bosons with the $\\sqrt{s}=8$~TeV datasets collected at the LHC. We take into account six searches in hadronic and semileptonic final states carried out by the two collaborations. We consider only public information provided by ATLAS and CMS in the HEPDATA database and in papers published in refereed journals. The results are interpreted within the context of a few benchmark new physics models, such as models predicting the existence of a \\PWp or a bulk Randall-Sundum spin--2 resonance. We present exclusion limits, $z$-values, $p$-values and best-fit cross sections in different model interpretations for the combined results. Out of several benchmark exotic models considered in this study, a heavy resonance with a production cross section of $\\sim$5~fb and mass between 1.9 and 2.0 TeV is the scenario most consistent with the experimental results. Models in which a heavy resonance de...

  9. Exotic particles at the LHC. Production via the Higgs portal and WIMP dark matter searches

    Energy Technology Data Exchange (ETDEWEB)

    Hessler, Andre Georg

    2016-09-05

    This thesis addresses two different aspects of the search for Physics Beyond the Standard Model at the Large Hadron Collider (LHC). First, and motivated by the recent discovery of a new interaction mediated by the Higgs boson, we systematically analyze the impact of the Higgs interaction on the production of new particles at the LHC. Second, we investigate the collider signatures of long-lived particles decaying into leptons and invisible energy, and which are predicted to exist in a class of neutrino mass models with a weakly interacting dark matter particle.

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

    CERN Document Server

    Dönigus, Benjamin; Braun-Munzinger, P

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

  11. Searches of exotic Higgs bosons in general mass spectra of the Georgi-Machacek model at the LHC

    International Nuclear Information System (INIS)

    Chiang, Cheng-Wei; Kuo, An-Li; Yamada, Toshifumi

    2016-01-01

    We derive the most general sets of viable mass spectra of the exotic Higgs bosons in the Georgi-Machacek model that are consistent with the theoretical constraints of vacuum stability and perturbative unitarity and the experimental constraints of electroweak precision observables, Zbb̄ coupling and Higgs boson signal strengths. Branching ratios of various cascade decay channels of the doubly-charged Higgs boson in the 5 representation, the singly-charged Higgs boson in 3, and the singlet Higgs boson are further computed. As one of the most promising channels for discovering the model, we study the prospects for detecting the doubly-charged Higgs boson that is produced via the vector boson fusion process and decays into final states containing a pair of same-sign leptons at the 14-TeV LHC and a 100-TeV future pp collider. For this purpose, we evaluate acceptance times efficiency for signals of the doubly-charged Higgs boson with general viable mass spectra and compare it with the standard model background estimates.

  12. Strategy and issues for the LHC upgrades and fair, including longer-term prospects

    CERN Document Server

    Zimmermann, F

    2013-01-01

    This report discusses the time line, goals and key ingredients for the next ten years of LHC operation, including injector upgrade, for the following High Luminosity LHC (HL-LHC), and for the FAIR project. Results from pertinent EuCARD-WP4 workshops on optics, space charge, crab cavities, crystal collimation, and electron cloud are summarized in this context. A Large Hadron electron Collider, LHeC, would be an additional upgrade, further expanding the physics scope of the LHC, to eventually include both ep and γγ Higgs factories (LHeC-HF and SAPPHiRE). Results from relevant topical WP4 workshops are highlighted. The development of magnet and cable technology based on Nb$_{3}$Sn, and HTS, for the HL-LHC prepares the ground for a future higher-energy hadron collider, either in the LHC tunnel, “HELHC” (33 TeV c.m.), or in a new 80- or 100-km tunnel, “VHE-LHC” (100 TeV c.m.). A large new tunnel could also host an ultimate highest-precision e+e- Higgs factory collider, “TLEP,” exhibiting many synergi...

  13. Search for exotic physics with ATLAS

    CERN Document Server

    Delsart, Pierre-Antoine

    2006-01-01

    At the LHC, the program of research in particle physics beyond the Standard Model is extremely rich. With the ATLAS detector, besides SUSY mainstream studies, many exotic theoretical models will be investigated. They range from compositeness of fundamental fermions to extra dimension scenarii through GUT models and include many variants. I shall review some selected typical studies by the ATLAS collaboration on exotic physics, highlighting the discovery prospects and the recent analyses using the latest full detector simulations.

  14. Production of the exotic 1{sup --} hadrons {phi}(2170), X(4260) and Y{sub b}(10890) at the LHC and Tevatron via the Drell-Yan mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Ahmed; Wang, Wei

    2011-03-15

    We calculate the Drell-Yan production cross sections and differential distributions in the transverse momentum and rapidity of the J{sup PC}=1{sup --} exotic hadrons {phi}(2170), X(4260) and Y{sub b}(10890) at the hadron colliders LHC and the Tevatron. These hadrons are tetraquark (four-quark) candidates, with a hidden s anti s, c anti c and b anti b quark pair, respectively. In deriving the distributions and cross sections, we include the order {alpha}{sub s} QCD corrections, resum the large logarithms in the small transverse momentum region in the impact-parameter formalism, and use the state of the art parton distribution functions. Taking into account the data on the production and decays of these vector hadrons from the e{sup +}e{sup -} experiments, we present the production rates for the processes pp(anti p){yields} {phi}(2170)({yields} {phi}(1020){pi}{sup +}{pi}{sup -} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}{sup -})+.., pp(anti p){yields} X(4260)({yields} J/{psi}{pi}{sup +}{pi}{sup -} {yields} {mu}{sup +}{mu}{sup -}{pi}{sup +}{pi}{sup -})+.., and pp(anti p){yields} Y{sub b}(10890)({yields} ({upsilon}(1S), {upsilon}(2S), {upsilon}(3S)){pi}{sup +}{pi}{sup -} {yields} {mu}{sup +}{mu}{sup -}{pi}{sup +}{pi}{sup -})+.. Their measurements at the hadron colliders will provide new experimental avenues to explore the underlying dynamics of these hadrons. (orig.)

  15. Status of SUSY searches at the LHC (including SUSY Higgs bosons)

    CERN Document Server

    Marshall, Zach; The ATLAS collaboration

    2017-01-01

    We review the status of SUSY searches at the LHC, including searches for SUSY Higgs Bosons. ATLAS and CMS have both prepared a large number of search results on the full 2015+2016 dataset, pushing the bounds on SUSY further than ever before.

  16. Exotic atoms

    International Nuclear Information System (INIS)

    Horvath, D.; Lambrecht, R.M.

    1984-01-01

    This bibliography on exotic atoms covers the years 1939 till 1982. The annual entries are headed by an introduction describing the state of affairs of the branch of science and listing the main applications in quantum electrodynamics, particle physics, nuclear physics, atomic physics, chemical physics and biological sciences. The bibliography includes an author index and a subject index. (Auth.)

  17. Exotic heavy baryons at LHC

    International Nuclear Information System (INIS)

    Biro, T.S.; Zimanyi, J.

    1993-06-01

    A heavy bottom-charm six-quark baryon is considered. A semiclassical and a Gaussian estimate show that the octet-octet bbb-ccc configuration can be favoured energetically rather than the singlet-singlet one. This result suggests that a confined bbb-ccc six-quark state may exist. Such objects may be produced in suitable amounts by heavy-ion collisions at Large Hadronic Collider energies. (R.P.) 8 refs. 1 fig

  18. Multiquark exotics

    International Nuclear Information System (INIS)

    Lipkin, H.J.

    1983-01-01

    The question Are Anomalons Multiquark Exotics is discussed. It is concluded that so far there is no convincing experimental evidence for any multiquark exotic bound state nor for any exotic resonance. Except for the delta and S* there are no candidates for bound states and no firm theoretical predictions waiting to be tested. Exotic resonances may exist in the 1.5 to 2.0 GeV region and in the charmed sector, e.g., the charmed-strange exotics. The experimental search for multiquark resonances is still open and active

  19. ATLAS Exotic Searches

    CERN Document Server

    Bousson, Nicolas

    2012-01-01

    Thanks to the outstanding performance of the Large Hadron Collider (LHC) that delivered more than 2 fb^-1 of proton-proton collision data at center-of-mass energy of 7 TeV, the ATLAS experiment has been able to explore a wide range of exotic models trying to address the questions unanswered by the Standard Model of particle physics. Searches for leptoquarks, new heavy quarks, vector-like quarks, black holes, hidden valley and contact interactions are reviewed in these proceedings.

  20. LHC report

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    This week's Report, by Gianluigi Arduini,  will be included in the LHC Physics Day, dedicated to the reviews of the LHC physics results presented at ICHEP 2010. Seehttp://indico.cern.ch/conferenceDisplay.py?confId=102669 

  1. Exotic nuclei

    International Nuclear Information System (INIS)

    Villari, A.C.C.

    1990-01-01

    The actual tendencies to study exotic nuclei; applications of exotic nuclei beams in material study and medicine; recent results obtained by GANIL and Berkeley Laboratories of measurements of binding energy and radii of light nuclei; the future experiences to be carry out in several international laboratories and; proposal of studies in Brazil using Pelletron-USP accelerator and the LINAC superconductor accelerator, in construction in the same laboratory, are presented. (M.C.K.)

  2. Exotic hardrons

    International Nuclear Information System (INIS)

    Landsberg, L.G.

    1994-01-01

    In this review, the present status of the physics of exotic hadrons (mesons and baryons) is considered. It is shown that, that during the last decade, several new meson states were observed, whose properties can hardly be explained in terms of the simple quark model. These particles have become serious candidates for exotic hadrons. The search for narrow, heavy baryons in different production and formation reactions is also discussed. 143 refs., 52 figs., 7 tabs

  3. Operational beams for the LHC

    CERN Document Server

    Papaphilippou, Y.; Rumolo, G.; Manglunki, D.

    2014-01-01

    The variety of beams, needed to set-up in the injectors as requested in the LHC, are reviewed, in terms of priority but also performance expectations and reach during 2015. This includes the single bunch beams for machine commissioning and measurements (probe, Indiv) but also the standard physics beams with 50 ns and 25 ns bunch spacing and their high brightness variants using the Bunch Compression Merging and Splitting (BCMS) scheme. The required parameters and target performance of special beams like the doublet for electron cloud enhancement and the more exotic 8b$\\oplus$4e beam, compatible with some post-scrubbing scenarios are also described. The progress and plans for the LHC ion production beams during 2014-2015 are detailed. Highlights on the current progress of the setting up of the various beams are finally presented with special emphasis on potential performance issues across the proton and ion injector chain.

  4. A malacological survey in the Manso Power Plant, State of Mato Grosso, Brazil: new records of freshwater snails, including transmitters of schistosomiasis and exotic species

    Directory of Open Access Journals (Sweden)

    Monica Ammon Fernandez

    2014-07-01

    Full Text Available Introduction Schistosomiasis is a parasitic disease of public health concern in Brazil, and the construction of hydroelectric dams, in addition to increasing permanent human settlement and tourism, has created conditions suitable for the establishment of mollusks that can transmit schistosomiasis. Such areas require a number of actions to prevent the establishment of schistosomiasis. This paper reports on a freshwater malacological survey carried out in the geographical area of the Manso Power Plant. Methods Mollusks were collected in 18 municipalities in the State of Mato Grosso between February 2002 and February 2004 (qualitative study and from April 2009 to February 2011 (quantitative study. Results Thirty-one species of mollusks were collected, including newly recorded species (Antillorbis nordestensis and Burnupia ingae. In addition, the geographic distributions of known species, including Biomphalaria straminea, a snail vector of Schistosoma mansoni, were expanded. A total of 4,507 specimens were collected in the APM Manso reservoir (Usina Hidrelétrica de Aproveitamento Múltiplo de Manso during the quantitative study, and Biomphalaria amazonica was found in six of the 10 localities analyzed. The Afroasiatic species Melanoides tuberculata, introduced after February 2009, was the dominant species (relative abundance 94.96%. Conclusions The study area is epidemiologically important due to the occurrence of B. straminea and B. amazonica, which are vectors of schistosomiasis, and M. tuberculata, a snail host of Centrocestus formosanus, which is responsible for centrocestiasis transmission. Observations of M. tuberculata and the exotic freshwater clams Corbicula fluminea and Corbicula largillierti raise concerns about biodiversity.

  5. From the LHC to Future Colliders

    Energy Technology Data Exchange (ETDEWEB)

    De Roeck, A.; Ellis, J.; /CERN; Grojean, C.; Heinemeyer, S.; /Cantabria Inst. of Phys.; Jakobs, K.; /Freiburg U.; Weiglein, G.; /Durham U., IPPP; Azuelos, G.; /TRIUMF; Dawson, S.; /Brookhaven; Gripaios, B.; /CERN; Han, T.; /Wisconsin U., Madison; Hewett, J.; /SLAC; Lancaster, M.; /University Coll. London; Mariotti, C.; /INFN, Turin; Moortgat, F.; /Zurich, ETH; Moortgat-Pick, G.; /Durham U., IPPP; Polesello, G.; /INFN, Pavia; Riemann, S.; /DESY; Assamagan, K.; /Brookhaven; Bechtle, P.; /DESY; Carena, M.; /Fermilab; Chachamis, G.; /PSI, Villigen /Taiwan, Natl. Taiwan U. /INFN, Florence /Bonn U. /CERN /Bonn U. /Freiburg U. /Oxford U. /Louvain U., CP3 /Bangalore, Indian Inst. Sci. /INFN, Milan Bicocca /Munich, Max Planck Inst. /Taiwan, Natl. Taiwan U. /Frascati /Fermilab /Warsaw U. /Florida U. /Orsay, LAL /LPSC, Grenoble /Warsaw U. /Yale U. /Stockholm U., Math. Dept. /Durham U., IPPP /DESY /Rome U. /University Coll. London /UC, San Diego /Heidelberg U. /Florida State U. /SLAC /Durham U., IPPP /Southern Denmark U., CP3-Origins /McGill U. /Durham U., IPPP; /more authors..

    2010-06-11

    Discoveries at the LHC will soon set the physics agenda for future colliders. This report of a CERN Theory Institute includes the summaries of Working Groups that reviewed the physics goals and prospects of LHC running with 10 to 300 fb{sup -1} of integrated luminosity, of the proposed sLHC luminosity upgrade, of the ILC, of CLIC, of the LHeC and of a muon collider. The four Working Groups considered possible scenarios for the first 10 fb{sup -1} of data at the LHC in which (i) a state with properties that are compatible with a Higgs boson is discovered, (ii) no such state is discovered either because the Higgs properties are such that it is difficult to detect or because no Higgs boson exists, (iii) a missing-energy signal beyond the Standard Model is discovered as in some supersymmetric models, and (iv) some other exotic signature of new physics is discovered. In the contexts of these scenarios, theWorking Groups reviewed the capabilities of the future colliders to study in more detail whatever new physics may be discovered by the LHC. Their reports provide the particle physics community with some tools for reviewing the scientific priorities for future colliders after the LHC produces its first harvest of new physics from multi-TeV collisions.

  6. The LHC is safe

    CERN Document Server

    CERN. Geneva; Alvarez-Gaumé, Luís

    2008-01-01

    Concerns have been expressed from time to time about the safety of new high-energy colliders, and the LHC has been no exception. The LHC Safety Assessment Group (LSAG)(*) was asked last year by the CERN management to review previous LHC safety analyses in light of additional experimental results and theoretical understanding. LSAG confirms, updates and extends previous conclusions that there is no basis for any conceivable threat from the LHC. Indeed, recent theoretical and experimental developments reinforce this conclusion. In this Colloquium, the basic arguments presented by LSAG will be reviewed. Cosmic rays of much higher effective centre-of-mass energies have been bombarding the Earth and other astronomical objects for billions of years, and their continued existence shows that the Earth faces no dangers from exotic objects such as hypothetical microscopic black holes that might be produced by the LHC - as discussed in a detailed paper by Giddings and Mangano(**). Measurements of strange particle produc...

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

    International Nuclear Information System (INIS)

    Vernet, R.

    2006-02-01

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

  8. Exotic charmonium

    Energy Technology Data Exchange (ETDEWEB)

    Pakhlova, Galina V; Pakhlov, Pavel N [Alikhanov Institute for Theoretical and Experimental Physics, Russian Federation State Scientific Center, Moscow (Russian Federation); Eidel' man, Semen I [Budker Institute of Nuclear Physics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2010-06-07

    The most significant results on the spectroscopy, production, and decay of charmonium and charmonium-like states are reviewed. The surprise-filled physics of charmonium is currently attracting great experimental and theoretical attention. Unexpected properties exhibited by numerous discovered states fail to be explained by the theory, which instead suggests the existence in the spectra of charmonium-like particles of exotic systems different from usual bound states. (reviews of topical problems)

  9. NLO QCD effective field theory analysis of W+W- production at the LHC including fermionic operators

    Science.gov (United States)

    Baglio, Julien; Dawson, Sally; Lewis, Ian M.

    2017-10-01

    We study the impact of anomalous gauge boson and fermion couplings on the production of W+W- pairs at the LHC. Helicity amplitudes are presented separately to demonstrate the sources of new physics contributions and the impact of QCD and electroweak corrections. The QCD corrections have important effects on the fits to anomalous couplings, in particular when one W boson is longitudinally polarized and the other is transversely polarized. In effective field theory language, we demonstrate that the dimension-6 approximation to constraining new physics effects in W+W- pair production fails at pT˜500 - 1000 GeV .

  10. Bottomonium, charmonium and exotic states

    International Nuclear Information System (INIS)

    Nakao, M.

    2014-01-01

    Heavy quarkonia states have been extensively studied in the past decade by B-factories and other experiments, and have provided many surprises that suggest that our understanding of the meson is still incomplete. The recent BaBar and Belle data filled many of the missing seats in the bottomonium table such as η b or h b , while LHC experiments are also contributing, for example in the observation of χ b (3P) state by ATLAS. There are clear signs of exotic states, such as the charged Z b + and Z c + found by Belle, yet puzzling X(3872), and overpopulated Y state series. Recent progress on the bottomonium, charmonium and exotic states is discussed in this review. (author)

  11. Discovering uncolored naturalness in exotic Higgs decays

    International Nuclear Information System (INIS)

    Curtin, David; Verhaaren, Christopher B.

    2015-01-01

    Solutions to the hierarchy problem usually require top partners. In standard SUSY or composite Higgs theories, the partners carry SM color and are becoming increasingly constrained by LHC searches. However, theories like Folded SUSY (FS), Twin Higgs (TH) and Quirky Little Higgs (QLH) introduce uncolored top partners, which can be SM singlets or carry electroweak charge. Their small production cross section left doubt as to whether the LHC can effectively probe such scenarios. Typically, these partners are charged under their own mirror color gauge group. In FS and QLH, the absence of light mirror matter allows glueballs to form at the bottom of the mirror spectrum. This is also the case in some TH realizations. The Higgs can decay to these mirror glueballs, with the glueballs decaying into SM particles with potentially observable lifetimes. We undertake the first detailed study of this glueball signature and quantitatively demonstrate the discovery potential of uncolored naturalness via exotic Higgs decays at the LHC and a potential future 100 TeV collider. Our findings indicate that mirror glueballs are the smoking gun signature of natural FS and QLH type theories, in analogy to tree-level Higgs coupling shifts for the TH. We show that glueball masses in the ∼10–60 GeV mass range are theoretically preferred. Careful treatment of lifetime, mirror-hadronization and nonperturbative uncertainties is required to perform meaningful collider studies. We outline several new search strategies for exotic Higgs decays of the form h→XX→4f at the LHC, with X having lifetimes in the 10μm to km range. We find that FS stops can be probed with masses up to 600 (1100) GeV at the LHC with 300 (3000) fb −1 of data, and TH top partners could be accessible with masses up to 900 (1500) GeV. This makes exotic Higgs decays the prime discovery channel for uncolored naturalness at the LHC.

  12. LHC physics

    National Research Council Canada - National Science Library

    Binoth, T

    2012-01-01

    "Exploring the phenomenology of the Large Hadron Collider (LHC) at CERN, LHC Physics focuses on the first years of data collected at the LHC as well as the experimental and theoretical tools involved...

  13. Electroweak scale physics & exotic searches at LHCb

    CERN Document Server

    Lupton, Olli

    2018-01-01

    The LHCb detector is a single-arm forward spectrometer covering the pseudorapidity range 2–5 that is principally designed for the study of b- and c-hadrons, but which is well-suited to a wide variety of electroweak scale measurements and exotic searches that are highly complementary to other experiments at the LHC and elsewhere. Several features of the detector that are crucial for the core flavour physics programme, such as excellent vertex and momentum resolution, and a powerful trigger system, contribute to excellent jet tagging performance and sensitivity to low mass exotic states. LHCb operates at a substantially lower instantaneous luminosity than the general purpose detectors at the LHC, ATLAS and CMS, which results in a clean, low pile-up environment in which to search for physics beyond the Standard Model (SM).

  14. Doubly charmed exotic mesons: A gift of nature?

    Energy Technology Data Exchange (ETDEWEB)

    Carames, T.F. [Departamento de Fisica Fundamental, Universidad de Salamanca, E-37008 Salamanca (Spain); Valcarce, A., E-mail: valcarce@usal.e [Departamento de Fisica Fundamental, Universidad de Salamanca, E-37008 Salamanca (Spain); Vijande, J. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Valencia (UV) and IFIC (UV-CSIC), Valencia (Spain)

    2011-05-16

    We study doubly charmed exotic states by solving the scattering problem of two D mesons. Our results point to the existence of a stable isoscalar doubly charmed meson with quantum numbers (I)J{sup P}=(0)1{sup +}. We perform a thorough comparison to the results obtained within the hyperspherical harmonic formalism. Such exotic states could be measured at LHC and RHIC. Their experimental observation would, for the first time, confirm the contribution of multiquark structures to hadron spectroscopy.

  15. Non-SM Exotic Higgs: Beyond SM and MSSM

    Directory of Open Access Journals (Sweden)

    Lacaprara Stefano

    2013-05-01

    Full Text Available A review of the searches for exotic Higgs boson beyond standard model and minimal supersymmetric standard model (MSSM, from experiments at the Tevatron and LHC, is presented. Several different models have been considered, including extensions to standard model with fourth generation of fermions, fermiophobic Higgs, next-to-MSSM models, seesaw type-II, and rare decay of Higgs boson to hidden sector. For next-to- MSSM models several final states have been considered, including light pseudo-scalar Higgs decay into taus, muons, and photons, as well as charged Higgs boson. The searches has been performed with re-interpretation of results from standard model Higgs search as well as on new signatures.

  16. LHC physics results and prospects

    CERN Document Server

    Kono, Takanori; The ATLAS collaboration

    2018-01-01

    This talk presents the latest results from LHC Run-2 as of May 2018 which include Standard Model measurements, Higgs boson properties and beyond Standard Model search results. The prospects for future LHC runs are also shown.

  17. Exotic power and propulsion concepts

    International Nuclear Information System (INIS)

    Forward, R.L.

    1990-01-01

    The status of some exotic physical phenomena and unconventional spacecraft concepts that might produce breakthroughs in power and propulsion in the 21st Century are reviewed. The subjects covered include: electric, nuclear fission, nuclear fusion, antimatter, high energy density materials, metallic hydrogen, laser thermal, solar thermal, solar sail, magnetic sail, and tether propulsion

  18. Exotic Higgs and mh ≅ 125 GeV

    International Nuclear Information System (INIS)

    Englert, C.

    2014-01-01

    We review non-SM (Standard Model) Higgs signatures which are missed in standard analyses by both ATLAS and CMS and show how the strong bounds by recent measurements can be relaxed in strongly-interacting theories. We also review strategies how to measure or constrain exotic Higgs decay at the LHC and a future linear collider. (author)

  19. Energy exotic options

    International Nuclear Information System (INIS)

    Kaminski, V.; Gibner, S.; Pinnamaneni, K.

    1999-01-01

    This chapter with 88 references focuses on the use of exotic options to control exposure to energy prices. Exotic options are defined, and the conversion of a standard option into an exotic option and pricing models are examined. Pricing and hedging exotic options, path-dependent options, multi-commodity options, options on the minimum-or-maximum of two commodities, compound options, digital options, hybrid and complex structures, and natural gas daily options are described. Formulas for option pricing for vanilla, barrier, compound, options on minimum or maximum of two assets, and look back options are given in an appendix

  20. Nuclei with exotic constituents

    International Nuclear Information System (INIS)

    Yamazaki, Toshimitsu.

    1990-08-01

    We discuss various interesting features in the behavior of exotic constituents of nuclei such as hyperons and mesons, in particular, with emphases on the aspect of exotic halos which are formed in general by short-range repulsion and long-range attraction. Specifically, Λ and Σ hypernuclei and pionic nuclei are discussed. (author)

  1. From the LHC to future colliders. CERN Theory Institute summary report

    International Nuclear Information System (INIS)

    Roeck, A. de; Ellis, J.; Wells, J.; Gripaios, B.; Dittmar, M.; Grojean, C.; Heinemeyer, S.; Jakobs, K.; Schumacher, M.; Duehrssen, M.; Weiglein, G.; Moortgat-Pick, G.; Morton-Thurtle, V.; Rolbiecki, K.; Smillie, J.; Tattersall, J.; Azuelos, G.; Dawson, S.; Assamagan, K.; Gopalakrishna, S.; Han, T.; Hewett, J.; Rizzo, T.; Lancaster, M.; Ozcan, E.; Mariotti, C.; Moortgat, F.; Polesello, G.; Riemann, S.; Bechtle, P.; Carena, M.; Juste, A.; Chachamis, G.; Chen, K.F.; Hou, W.S.; Curtis, S. de; Desch, K.; Wienemann, P.; Dreiner, H.; Foster, B.; Frandsen, M.T.; Giammanco, A.; Godbole, R.; Govoni, P.; Gunion, J.; Hollik, W.; Isidori, G.; Kalinowski, J.; Krawczyk, M.; Korytov, A.; Kou, E.; Kraml, S.; Martin, A.; Milstead, D.; Moenig, K.; Mele, B.; Pieri, M.; Plehn, T.; Reina, L.; Richter-Was, E.; Sannino, F.; Schram, M.; Sultansoy, S.; Uwer, P.; Webber, B.

    2010-01-01

    Discoveries at the LHC will soon set the physics agenda for future colliders. This report of a CERN Theory Institute includes the summaries of Working Groups that reviewed the physics goals and prospects of LHC running with 10 to 300 fb -1 of integrated luminosity, of the proposed sLHC luminosity upgrade, of the ILC, of CLIC, of the LHeC and of a muon collider. The four Working Groups considered possible scenarios for the first 10 fb -1 of data at the LHC in which (i) a state with properties that are compatible with a Higgs boson is discovered, (ii) no such state is discovered either because the Higgs properties are such that it is difficult to detect or because no Higgs boson exists, (iii) a missing-energy signal beyond the Standard Model is discovered as in some supersymmetric models, and (iv) some other exotic signature of new physics is discovered. In the contexts of these scenarios, the Working Groups reviewed the capabilities of the future colliders to study in more detail whatever new physics may be discovered by the LHC. Their reports provide the particle physics community with some tools for reviewing the scientific priorities for future colliders after the LHC produces its first harvest of new physics from multi-TeV collisions. (orig.)

  2. CERN confirms LHC schedule

    CERN Document Server

    2003-01-01

    The CERN Council held its 125th session on 20 June. Highlights of the meeting included confirmation that the LHC is on schedule for a 2007 start-up, and the announcement of a new organizational structure in 2004.

  3. Exotic decays of the 125 GeV Higgs boson at future e+e- colliders

    Science.gov (United States)

    Liu, Zhen; Wang, Lian-Tao; Zhang, Hao

    2017-06-01

    The discovery of unexpected properties of the Higgs boson would offer an intriguing opportunity to shed light on some of the most profound puzzles in particle physics. Beyond Standard Model (BSM) decays of the Higgs boson could reveal new physics in a direct manner. Future electron-positron lepton colliders operating as Higgs factories, including CEPC, FCC-ee and ILC, with the advantages of a clean collider environment and large statistics, could greatly enhance sensitivity in searching for these BSM decays. In this work, we perform a general study of Higgs exotic decays at future e+e- lepton colliders, focusing on the Higgs decays with hadronic final states and/or missing energy, which are very challenging for the High-Luminosity program of the Large Hadron Collider (HL-LHC). We show that with simple selection cuts, (10-3-10-5) limits on the Higgs exotic decay branching fractions can be achieved using the leptonic decaying spectator Z boson in the associated production mode e+e-→ ZH. We further discuss the interplay between detector performance and Higgs exotic decays, and other possibilities of exotic decays. Our work is a first step in a comprehensive study of Higgs exotic decays at future lepton colliders, which is a key area of Higgs physics that deserves further investigation. Supported by Fermi Research Alliance, LLC (DE-AC02-07CH11359) with the U.S. Department of Energy, DOE (DE-SC0013642), IHEP(Y6515580U1), and IHEP Innovation (Y4545171Y2)

  4. On exotic fireballs

    International Nuclear Information System (INIS)

    Tati, T.

    1984-01-01

    Exotic fireballs found by Brazil-Japan Collaboration of Chacaltaya Emulsion Chamber Experiment are interpreted in terms of a model of hadronic matter (of which hadrons are made) based on the theory of finite degree of freedom. It is considered in our picture that exotic fireballs reveal the part left undefined in the renormalization theory of quantum field and nonappearance of exotic fireballs (of relatively small mass, i.e. Mini-Centauro and Geminion) in CERN SPS collider experiment is possibly due to the existence of universal time realized by the cutoff of momentum degree of freedom of the field of basic particles. (Author) [pt

  5. Exotic Small Mammals and Bartonella

    Centers for Disease Control (CDC) Podcasts

    In this podcast, Dr. Nina Marano discusses Bartonella, a bacterial agent that’s prevalent in many species, including cats, dogs, and cattle. Wild animals are normally thought to carry Bartonella, so when animals are caught in the wild for pet trade, the risk that humans can become infected with Bartonella increases. Bartonella is an identified risk associated with ownership of exotic animals and has serious health consequences.

  6. Exotic Nuclei and Yukawa's Forces

    International Nuclear Information System (INIS)

    Otsuka, Takaharu; Suzuki, Toshio; Utsuno, Yutaka

    2008-01-01

    In this plenary talk, we will overview the evolution of the shell structure in stable and exotic nuclei as a new paradigm of nuclear structure physics. This shell evolution is primarily due to the tensor force. The robust mechanism and some examples will be presented. Such examples include the disappearance of existing magic numbers and the appearance of new ones. The nuclear magic numbers have been believed, since Mayer and Jensen, to be constants as 2, 8, 20, 28, 50, ... This turned out to be changed, once we entered the regime of exotic nuclei. This shell evolution develops at many places on the nuclear chart in various forms. For example, superheavy magic numbers may be altered. Thus, we are led to a new paradigm as to how and where the nuclear shell evolves, and what consequences arise. The evolution of the shell affects weak process transitions, and plays a crucial role in deformation. The π and ρ mesons generate tensor forces, and are the fundamental elements of such intriguing phenomena. Thus, physics of exotic nuclei arises as a manifestation of Yukawa's forces

  7. E6 exotic quark production in ep collisions

    International Nuclear Information System (INIS)

    Hewett, J.L.

    1987-06-01

    We examine the possibility of producing exotic quarks from E 6 theories via flavor changing couplings in high energy ep collisions at HERA and the proposed LEP x LHC. We find that the rate is rather small and very mixing angle dependent. Assuming maximal mixing, the production rates are ≅10 to 30 events per year at HERA (for masses up to 100 GeV) and ≅200 events per year at LEP x LHC (for masses up to 300 GeV)

  8. The LHC

    CERN Multimedia

    2002-01-01

    The LHC will use the latest technologies on an enormous scale. 8000 superconducting magnets will keep the beams on track. The entire 27 km ring will be cooled by 700 000 litres of liquid helium to a temperature of -271 degrees Celsius , making the LHC the world's largest superconducting installation. Conventional superconducting wire will form the magnet coils, while high-temperature superconductors will carry a total of 2 300 000 amperes from the power supplies into the magnet cryostat

  9. LHC magnets

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Preparations for the LHC proton collider to be built in CERN's LEP tunnel continue to make good progress. In particular development work for the high field superconducting magnets to guide the almost 8 TeVproton beams through the 'tight' curve of the 27-kilometre ring are proceeding well, while the magnet designs and lattice configuration are evolving in the light of ongoing experience. At the Evian LHC Experiments meeting, this progress was covered by Giorgio Brianti

  10. Charge parity exotic mesons

    International Nuclear Information System (INIS)

    Burden, C.J.

    1998-01-01

    Full text: Evidence for a meson with exotic quantum numbers J PC 1 -+ , the ρ(1405), has been observed at the AGS at Brookhaven and Crystal Barrel at CERN. This meson is exotic to the extent that its quantum numbers are not consistent with the generalised Pauli exclusion principle applied to the naive constituent quark model. In a fully relativistic field theoretic treatment, however, there is nothing in principle to preclude the existence of charge parity exotics. Using our earlier covariant Bethe-Salpeter model of light-quark mesons with no new parameter fitting we demonstrate the existence of a q - q-bar bound state with the quantum numbers of the ρ

  11. Exotic snakes are not always found in exotic places: how poison centres can assist emergency departments.

    Science.gov (United States)

    Lubich, Carol; Krenzelok, Edward P

    2007-11-01

    Emergency departments throughout the USA may have some familiarity with the management of envenomation from indigenous snake species such as Crotalinae (rattlesnakes) and Micrurus (coral snakes). However, venomous species may include exotic reptiles whose bites pose substantial treatment challenges due to both a lack of experience and the difficulty in obtaining antivenoms. Two pet cobra envenomation incidents illustrate the challenges that face emergency departments, especially in urban settings, that are confronted with these exposures. It is important for emergency departments to be aware of the large underground presence of exotic venomous reptile pets and to utilise the expertise of regional poison centres that will also assist in the procurement of exotic antivenoms.

  12. Exotics searches in ATLAS

    CERN Document Server

    Wang, Renjie; The ATLAS collaboration

    2017-01-01

    Many theories beyond the Standard Model predict new physics accessible by the LHC. The ATLAS experiment all have rigorous search programs ongoing with the aim to find indications for new physics involving state of the art analysis techniques. This talk reports on new results obtained using the pp collision data sample collected in 2015 and 2016 at the LHC with a centre-of-mass energy of 13 TeV.

  13. LHC luminosity upgrade detector challenges

    CERN Multimedia

    CERN. Geneva; de Roeck, Albert; Bortoletto, Daniela; Wigmans, Richard; Riegler, Werner; Smith, Wesley H

    2006-01-01

    LHC luminosity upgrade: detector challenges The upgrade of the LHC machine towards higher luminosity (1035 cm -2s-1) has been studied over the last few years. These studies have investigated scenarios to achieve the increase in peak luminosity by an order of magnitude, as well as the physics potential of such an upgrade and the impact of a machine upgrade on the LHC DETECTORS. This series of lectures will cover the following topics: • Physics motivation and machine scenarios for an order of magnitude increase in the LHC peak luminosity (lecture 1) • Detector challenges including overview of ideas for R&D programs by the LHC experiments: tracking and calorimetry, other new detector developments (lectures 2-4) • Electronics, trigger and data acquisition challenges (lecture 5) Note: the much more ambitious LHC energy upgrade will not be covered

  14. Exotic invasive plants

    Science.gov (United States)

    Carolyn Hull Sieg; Barbara G. Phillips; Laura P. Moser

    2003-01-01

    Ecosystems worldwide are threatened by nonnative plant invasions that can cause undesirable, irreversible changes. They can displace native plants and animals, out-cross with native flora, alter nutrient cycling and other ecosystem functions, and even change an ecosystem's flammability (Walker and Smith 1997). After habitat loss, the spread of exotic species is...

  15. Exotic biological control agents

    NARCIS (Netherlands)

    Hajek, Ann E.; Hurley, Brett P.; Kenis, Marc; Garnas, Jeffrey R.; Bush, Samantha J.; Wingfield, Michael J.; Lenteren, van Joop C.; Cock, Matthew J.W.

    2016-01-01

    Biological control is a valuable and effective strategy for controlling arthropod pests and has been used extensively against invasive arthropods. As one approach for control of invasives, exotic natural enemies from the native range of a pest are introduced to areas where control is needed.

  16. Glueballs, Hybrids and Exotics

    Science.gov (United States)

    Reyes, M. A.; Moreno, G.

    2006-09-01

    We comment on the physics analysis carried out by the Experimental High Energy Physics (EHEP) group of the Instituto de Fisica of the University of Guanajuato (IFUG), Mexico. In particular, this group has been involved in analysis carried out to search for glueball, hybrid and exotic candidates.

  17. Glueballs, Hybrids and Exotics

    International Nuclear Information System (INIS)

    Reyes, M. A.; Moreno, G.

    2006-01-01

    We comment on the physics analysis carried out by the Experimental High Energy Physics (EHEP) group of the Instituto de Fisica of the University of Guanajuato (IFUG), Mexico. In particular, this group has been involved in analysis carried out to search for glueball, hybrid and exotic candidates

  18. Exotic baryonium exchanges

    International Nuclear Information System (INIS)

    Nicolescu, B.

    1978-05-01

    The prominent effects supposed to be associated with the exchange of exotic baryonium Regge trajectories are reviewed. The experimental presence of all expected effects leads to suggest that the baryonium exchange mechanism is a correct phenomenological picture and that mesons with isospin 2 or 3/2 or with strangeness 2, strongly coupled to the baryon-antibaryon channels, must be observed

  19. Exotic reptile bites.

    Science.gov (United States)

    Kelsey, J; Ehrlich, M; Henderson, S O

    1997-09-01

    Reptiles are a growing part of the exotic pet trade, and reptile bites have been considered innocuous in the emergency medicine literature. Two cases are reported of reptile bites, one from a green iguana and the other from a reticulated python. The treatment concerns associated with reptile bites are discussed.

  20. Exotic Signals of Vectorlike Quarks

    Energy Technology Data Exchange (ETDEWEB)

    Dobrescu, Bogdan A. [Fermilab; Yu, Felix [U. Mainz, PRISMA

    2016-12-06

    Vectorlike fermions are an important target for hadron collider searches. We show that the vectorlike quarks may predominantly decay via higher-dimensional operators into a quark plus a couple of other Standard Model fermions. Pair production of vectorlike quarks of charge 2/3 at the LHC would then lead to a variety of possible final states, including $t\\bar t + 4\\tau$, $t\\bar b\

  1. Exotic Small Mammals and Bartonella

    Centers for Disease Control (CDC) Podcasts

    2009-04-09

    In this podcast, Dr. Nina Marano discusses Bartonella, a bacterial agent that’s prevalent in many species, including cats, dogs, and cattle. Wild animals are normally thought to carry Bartonella, so when animals are caught in the wild for pet trade, the risk that humans can become infected with Bartonella increases. Bartonella is an identified risk associated with ownership of exotic animals and has serious health consequences.  Created: 4/9/2009 by Emerging Infectious Diseases.   Date Released: 4/9/2009.

  2. submitter Simulation of a quench event in the upgraded High-Luminosity LHC Main dipole circuit including the 11 T Nb$_{3}$Sn dipole magnets

    CERN Document Server

    Fernandez Navarro, Alejandro Manuel; Verweij, Arjan P; Bortot, Lorenzo; Mentink, Matthias; Prioli, Marco; Auchmann, Bernhard; Izquierdo Bermudez, Susana; Ravaioli, Emmanuele; Yammine, Samer

    2018-01-01

    To achieve the goal of increased luminosity, two out of eight main dipole circuits of the accelerator will be reconfigured in the coming LHC upgrade by replacing one standard 14.3-m long, Nb-Ti-based, 8.3 T dipole magnet by two 5.3-m long, Nb$_{3}$Sn-based, 11.2 T magnets (MBH). The modified dipole circuits will contain 153 Nb-Ti magnets and two MBH magnets. The latter will be connected to an additional trim power converter to compensate for the differences in the magnetic transfer functions. These modifications imply a number of challenges from the point of view of the circuit integrity, operation, and quench protection. In order to assess the circuit performance under different scenarios and to validate the circuit quench protection strategy, reliable and accurate numerical transient simulations have to be performed. We present the field/circuit coupling simulation of the reconfigured main dipole magnet chain following the introduction of the MBH magnets. 2-D distributed LEDET models of the MBH's have been ...

  3. Injuries, envenomations and stings from exotic pets.

    Science.gov (United States)

    Warwick, Clifford; Steedman, Catrina

    2012-07-01

    A variety of exotic vertebrate and invertebrate species are kept as 'pets' including fishes, amphibians (for example, frogs and toads), reptiles (turtles, crocodiles, lizards and snakes), birds, mammals (for example, primates, civets, and lions), and invertebrates (for example spiders, scorpions, and centipedes), and ownership of some of these animals is rising. Data for 2009-2011 suggest that the number of homes with reptiles rose by approximately 12.5%. Recent surveys, including only some of these animals, indicated that they might be present in around 18.6% of homes (equal to approximately 42 million animals of which around 40 million are indoor or outdoor fish). Many exotic 'pets' are capable of causing injury or poisoning to their keepers and some contacts prove fatal. We examined NHS Health Episode Statistics for England using selected formal categories for hospital admissions and bed days for 2004-2010 using the following categories of injury, envenomation or sting; bitten or struck by crocodile or alligator; bitten or crushed by other reptiles: contact with venomous snakes and lizards; contact with scorpions. Between 2004 and 2010 these data conservatively show a total of 760 full consultation episodes, 709 admissions and 2,121 hospital bed days were associated with injuries probably from exotic pets. Injuries, envenomations and stings from exotic pets constitute a small but important component of emerging medical problems. Greater awareness of relevant injuries and medical sequelae from exotic pet keeping may help medics formulate their clinical assessment and advice to patients.

  4. Electronics for LHC experiments

    International Nuclear Information System (INIS)

    Bourgeois, Francois

    1995-01-01

    Full text: A major effort is being mounted to prepare the way handling the high interaction rates expected from CERN's new LHC proton-proton collider (see, for example, November, page 6). September saw the First Workshop on Electronics for LHC Experiments, organized by Lisbon's Particle Physics Instrumentation Laboratory (LIP) on behalf of CERN's LHC Electronics Review Board (LERB - March, page 2). Its purpose was not only for the LERB to have a thorough review of ongoing activities, but also to promote cross fertilization in the engineering community involved in electronics design for LHC experiments. The Workshop gathered 187 physicists and engineers from 20 countries including USA and Japan. The meeting comprised six sessions and 82 talks, with special focus on radiation-hard microelectronic processes, electronics for tracking, calorimetry and muon detectors, optoelectronics, trigger and data acquisition systems. Each topic was introduced by an invited speaker who reviewed the requirements set by the particular detector technology at LHC. At the end of each session, panel discussions were chaired by each invited speaker. Representatives from four major integrated circuit manufacturers covered advanced radiation hard processes. Two talks highlighted the importance of obsolescence and quality systems in the long-lived and demanding environment of LHC. The Workshop identified areas and encouraged efforts for rationalization and common developments within and between the different detector groups. As a result, it will also help ensure the reliability and the long term maintainability of installed equipment. The proceedings of the Workshop are available from LIP Lisbon*. The LERB Workshop on Electronics for LHC Experiments will become a regular event, with the second taking place in Hungary, by Lake Balaton, from 23-27 September 1996. The Hungarian institutes KFKIRMKI have taken up the challenge of being as successful as LIP Lisbon in the organization

  5. From the LHC to Future Colliders

    DEFF Research Database (Denmark)

    De Roeck, A.; Ellis, J.; Grojean, C.

    2010-01-01

    Discoveries at the LHC will soon set the physics agenda for future colliders. This report of a CERN Theory Institute includes the summaries of Working Groups that reviewed the physics goals and prospects of LHC running with 10 to 300/fb of integrated luminosity, of the proposed sLHC luminosity up...

  6. LHC milestone

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    At the December meeting of CERN's Council, the Organization's Governing Body, the delegates from the 16 Member States unanimously agreed that the LHC proton-proton collider proposed for the 27-kilometre LEP tunnel is the 'right machine for the advance of the subject and of the future of CERN'

  7. LHC Create

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    LHC Create is an upcoming 2-day workshop held at IdeaSquare in November. Participants from CERN and IPAC school of design will compete to design an exhibit that explains why CERN does what it does. The winner will have their exhibit fully realised and made available to experiments, institutes, and tourism agencies around the world.

  8. LHC Supertable

    International Nuclear Information System (INIS)

    Pereira, M.; Lahey, T.E.; Lamont, M.; Mueller, G.J.; Teixeira, D.D.; McCrory, E.S.

    2012-01-01

    LHC operations generate enormous amounts of data. This data is being stored in many different databases. Hence, it is difficult for operators, physicists, engineers and management to have a clear view on the overall accelerator performance. Until recently the logging database, through its desktop interface TIMBER, was the only way of retrieving information on a fill-by-fill basis. The LHC Supertable has been developed to provide a summary of key LHC performance parameters in a clear, consistent and comprehensive format. The columns in this table represent main parameters that describe the collider operation such as luminosity, beam intensity, emittance, etc. The data is organized in a tabular fill-by-fill manner with different levels of detail. Particular emphasis was placed on data sharing by making data available in various open formats. Typically the contents are calculated for periods of time that map to the accelerator's states or beam modes such as Injection, Stable Beams, etc. Data retrieval and calculation is triggered automatically after the end of each fill. The LHC Supertable project currently publishes 80 columns of data on around 100 fills. (authors)

  9. Exotic Black Holes?

    OpenAIRE

    Brans, Carl H.

    1993-01-01

    Exotic smooth manifolds, ${\\bf R^2\\times_\\Theta S^2}$, are constructed and discussed as possible space-time models supporting the usual Kruskal presentation of the vacuum Schwarzschild metric locally, but {\\em not globally}. While having the same topology as the standard Kruskal model, none of these manifolds is diffeomorphic to standard Kruskal, although under certain conditions some global smooth Lorentz-signature metric can be continued from the local Kruskal form. Consequently, it can be ...

  10. Exotic composite vector boson

    International Nuclear Information System (INIS)

    Akama, K.; Hattori, T.; Yasue, M.

    1991-01-01

    An exotic composite vector boson V is introduced in two dynamical models of composite quarks, leptons, W, and Z. One is based on four-Fermi interactions, in which composite vector bosons are regarded as fermion-antifermion bound states and the other is based on the confining SU(2) L gauge model, in which they are given by scalar-antiscalar bound states. Both approaches describe the same effective interactions for the sector of composite quarks, leptons, W, Z, γ, and V

  11. Clusters and exotic processes

    International Nuclear Information System (INIS)

    Schiffer, J.P.

    1975-01-01

    An attempt is made to present some data which may be construed as indicating that perhaps clusters play a role in high energy and exotic pion or kaon interactions with complex (A much greater than 16) nuclei. Also an attempt is made to summarize some very recent experimental work on pion interactions with nuclei which may or may not in the end support a picture in which clusters play an important role. (U.S.)

  12. RF upgrade program in LHC injectors and LHC machine

    International Nuclear Information System (INIS)

    Jensen, E.

    2012-01-01

    The main themes of the RF upgrade program are: the Linac4 project, the LLRF-upgrade and the study of a tuning-free wide-band system for PSB, the upgrade of the SPS 800 MHz amplifiers and beam controls and the upgrade of the transverse dampers of the LHC. Whilst LHC Splice Consolidation is certainly the top priority for LS1, some necessary RF consolidation and upgrade is necessary to assure the LHC performance for the next 3- year run period. This includes: 1) necessary maintenance and consolidation work that could not fit the shorter technical stops during the last years, 2) the upgrade of the SPS 200 MHz system from presently 4 to 6 cavities and possibly 3) the replacement of one LHC cavity module. On the longer term, the LHC luminosity upgrade requires crab cavities, for which some preparatory work in SPS Coldex must be scheduled during LS1. (author)

  13. Exotic Phenomena Searches at Hadron Colliders

    CERN Document Server

    INSPIRE-00305407

    2013-01-01

    This review presents a selection of the final results of searches for various exotic physics phenomena in proton-proton collisions at $\\sqrt{s}=7$ and 8~TeV delivered by the LHC and collected with the ATLAS and CMS detectors in 2011 (5 $fb^{-1}$) and in the first part of 2012 (4 $fb^{-1}$). Searches for large extra dimensions, gravitons, microscopic black holes, long-lived particles, dark matter, and leptoquarks are presented in this report. No sign of new physics beyond the standard model has been observed so far. In the majority of the cases these searches set the most stringent limits to date on the aforementioned new physics phenomena.

  14. Exotic quarks in Twin Higgs models

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Hsin-Chia [Department of Physics, University of California, Davis,One Shields Avenue, Davis, CA 95616 (United States); Jung, Sunghoon [School of Physics, Korea Institute for Advanced Study,85 Hoegiro, Dongdaemun-gu, Seoul 130-722 (Korea, Republic of); SLAC National Accelerator Laboratory,2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Salvioni, Ennio [Department of Physics, University of California, Davis,One Shields Avenue, Davis, CA 95616 (United States); Tsai, Yuhsin [Department of Physics, University of California, Davis,One Shields Avenue, Davis, CA 95616 (United States); Maryland Center for Fundamental Physics,Department of Physics, University of Maryland,College Park, MD 20742 (United States)

    2016-03-14

    The Twin Higgs model provides a natural theory for the electroweak symmetry breaking without the need of new particles carrying the standard model gauge charges below a few TeV. In the low energy theory, the only probe comes from the mixing of the Higgs fields in the standard model and twin sectors. However, an ultraviolet completion is required below ∼ 10 TeV to remove residual logarithmic divergences. In non-supersymmetric completions, new exotic fermions charged under both the standard model and twin gauge symmetries have to be present to accompany the top quark, thus providing a high energy probe of the model. Some of them carry standard model color, and may therefore be copiously produced at current or future hadron colliders. Once produced, these exotic quarks can decay into a top together with twin sector particles. If the twin sector particles escape the detection, we have the irreducible stop-like signals. On the other hand, some twin sector particles may decay back into the standard model particles with long lifetimes, giving spectacular displaced vertex signals in combination with the prompt top quarks. This happens in the Fraternal Twin Higgs scenario with typical parameters, and sometimes is even necessary for cosmological reasons. We study the potential displaced vertex signals from the decays of the twin bottomonia, twin glueballs, and twin leptons in the Fraternal Twin Higgs scenario. Depending on the details of the twin sector, the exotic quarks may be probed up to ∼ 2.5 TeV at the LHC and beyond 10 TeV at a future 100 TeV collider, providing a strong test of this class of ultraviolet completions.

  15. Highlights from the ATLAS experiment at CERN LHC

    CERN Document Server

    Tsukerman, Ilya; The ATLAS collaboration

    2018-01-01

    Highlights from the ATLAS Experiment at the LHC are presented. Results shown are mostly based on the analysis of 2015-2016 year dataset which corresponds to the luminosity 36 inverse fb. Mainly recent measurements of Higgs boson production and decay are discussed while only summary of summaries is given for the SM processes, top production, SUSY and Exotics.

  16. Top 5 exotic clones for potato breeding

    Science.gov (United States)

    Wild and cultivated relatives of potato feature prominently in breeding programs. In this short article, I describe five exotic clones that have promising traits for the future of the US potato industry. They include M6, an inbred line of S. chacoense that provides a source of genes for self-compati...

  17. 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)

  18. LHC Supertable

    CERN Document Server

    Pereira, M; Lamont, M; Muller, GJ; Teixeira, D D; McCrory, ES

    2011-01-01

    LHC operations generate enormous amounts of data. This data is being stored in many different databases. Hence, it is difficult for operators, physicists, engineers and management to have a clear view on the overall accelerator performance. Until recently the logging database, through its desktop interface TIMBER, was the only way of retrieving information on a fill-by-fill basis. The LHC Supertable has been developed to provide a summary of key LHC performance parameters in a clear, consistent and comprehensive format. The columns in this table represent main parameters that describe the collider’s operation such as luminosity, beam intensity, emittance, etc. The data is organized in a tabular fill-by-fill manner with different levels of detail. Particular emphasis was placed on data sharing by making data available in various open formats. Typically the contents are calculated for periods of time that map to the accelerator’s states or beam modes such as Injection, Stable Beams, etc. Data retrieval and ...

  19. Exotic smoothness and particle physics

    International Nuclear Information System (INIS)

    Sladkowski, J.

    1996-01-01

    Short introduction to exotic differential structures on manifolds is given. The possible physical context of this mathematical curiosity is discussed. The topic is very interesting although speculative. (author)

  20. Exotic searches at lep

    International Nuclear Information System (INIS)

    Seager, P.

    2001-01-01

    The search for exotic processes at LEP is presented. The Standard Model Higgs has as yet not been observed. This provides freedom to search for processes beyond the Standard Model and even beyond the minimal version of the supersymmetric extension to the Standard Model. This paper outlines the searches for charged Higgs bosons, fermiophobic Higgs bosons, invisibly decaying Higgs bosons, technicolor, leptoquarks, unstable heavy leptons and excited leptons. The results presented are those from the LEP collaborations using data taken up to a centre-of-mass energy of √s = 202 GeV. (author)

  1. Euroschool on Exotic Beams

    CERN Document Server

    Pfützner, Marek

    2018-01-01

    This is the fifth volume in a series of Lecture Notes based on the highly successful Euro Summer School on Exotic Beams. The aim of these notes is to provide a thorough introduction to radioactive ion-beam physics at the level of graduate students and young postdocs starting out in the field. Each volume covers a range of topics from nuclear theory to experiment and applications. Vol I has been published as LNP 651, Vol II as LNP 700, Vol. III as LNP 764 and Vol. IV as LNP 879.

  2. LHC status report

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Following the great success of the first 3.5 TeV collisions in all four LHC experiments on 30 March, the focus of the LHC commissioning teams has turned to consolidating the beam injection and acceleration procedures.   During the last two weeks, the operators have adopted a cycle of beam commissioning studies by day and the preparation and delivery of collisions during the night shifts. The injection and acceleration processes for the beams are by now well established and almost all feedback systems, which are an essential ingredient for establishing reliable and safe machine operation, have been commissioned. Thanks to special current settings for the quadrupoles that are situated near the collision points, the LHC luminosity at high energy has been increased by a factor of 5 in three of the four experiments. Similar improvements are under way for the fourth experiment. The next steps include adjustments of the LHC machine protection and collimation devices, which will ensure 'stable beam' co...

  3. LHC Report: Ion Age

    CERN Multimedia

    John Jowett for the LHC team

    2013-01-01

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

  4. Diagnostic imaging of exotic pets

    International Nuclear Information System (INIS)

    Silverman, S.

    1993-01-01

    Radiographic, ultrasonographic, and computed tomographic (CT) imaging are important diagnostic modalities in exotic pets. The use of appropriate radiographic equipment, film-screen combinations, and radiographic projections enhances the information obtained from radiographs. Both normal findings and common radiographic abnormalities are discussed. The use of ultrasonography and CT scanning for exotic small mammals and reptiles is described

  5. Current Status of Exotic Hadrons

    International Nuclear Information System (INIS)

    Saeed, M.A.; Ahmed, Maqsood; Fazal-e-Aleem

    2005-01-01

    Physics of exotic hadrons is in the limelight these days. The models for these baryons are discussed as well as their production and decay processes and methods of their identification. The results of recent experiments in this field are presented, in which some unusual states are observed. These states are candidates for exotic hadrons

  6. LHCB : Exotic hadrons at LHCb

    CERN Multimedia

    Salazar De Paula, Leandro

    2015-01-01

    The latest years have seen a resurrection of interest in searches for exotic states motivated by tantalising observations by Belle and CDF. Using the data collected at pp collisions at 7 and 8 TeV by the LHCb experiment we present the unambiguous new observation of exotic charmonia hadrons produced in B decays.

  7. Exotic objects of atomic physics

    Science.gov (United States)

    Eletskii, A. V.

    2017-11-01

    There has been presented a short survey of physical properties, methods of production and exploration as well as directions of practical usage of the objects of atomic physics which are not yet described in detail in modern textbooks and manuals intended for students of technical universities. The family of these objects includes negative and multicharged ions, Rydberg atoms, excimer molecules, clusters. Besides of that, in recent decades this family was supplemented with new nanocarbon structures such as fullerenes, carbon nanotubes and graphene. The textbook “Exotic objects of atomic physics” [1] edited recently contains some information on the above-listed objects of the atomic physics. This textbook can be considered as a supplement to classic courses of atomic physics teaching in technical universities.

  8. LHC Startup

    CERN Document Server

    AUTHOR|(CDS)2067853

    2008-01-01

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

  9. PDF4LHC recommendations for LHC Run II

    CERN Document Server

    Butterworth, Jon; Cooper-Sarkar, Amanda; De Roeck, Albert; Feltesse, Joel; Forte, Stefano; Gao, Jun; Glazov, Sasha; Huston, Joey; Kassabov, Zahari; McNulty, Ronan; Morsch, Andreas; Nadolsky, Pavel; Radescu, Voica; Rojo, Juan; Thorne, Robert

    2016-01-01

    We provide an updated recommendation for the usage of sets of parton distribution functions (PDFs) and the assessment of PDF and PDF+$\\alpha_s$ uncertainties suitable for applications at the LHC Run II. We review developments since the previous PDF4LHC recommendation, and discuss and compare the new generation of PDFs, which include substantial information from experimental data from the Run I of the LHC. We then propose a new prescription for the combination of a suitable subset of the available PDF sets, which is presented in terms of a single combined PDF set. We finally discuss tools which allow for the delivery of this combined set in terms of optimized sets of Hessian eigenvectors or Monte Carlo replicas, and their usage, and provide some examples of their application to LHC phenomenology.

  10. Black Holes and Exotic Spinors

    Directory of Open Access Journals (Sweden)

    J. M. Hoff da Silva

    2016-05-01

    Full Text Available Exotic spin structures are non-trivial liftings, of the orthogonal bundle to the spin bundle, on orientable manifolds that admit spin structures according to the celebrated Geroch theorem. Exotic spin structures play a role of paramount importance in different areas of physics, from quantum field theory, in particular at Planck length scales, to gravity, and in cosmological scales. Here, we introduce an in-depth panorama in this field, providing black hole physics as the fount of spacetime exoticness. Black holes are then studied as the generators of a non-trivial topology that also can correspond to some inequivalent spin structure. Moreover, we investigate exotic spinor fields in this context and the way exotic spinor fields branch new physics. We also calculate the tunneling probability of exotic fermions across a Kerr-Sen black hole, showing that the exotic term does affect the tunneling probability, altering the black hole evaporation rate. Finally we show that it complies with the Hawking temperature universal law.

  11. MPI@LHC Talk.

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00392933; The ATLAS collaboration

    2016-01-01

    Draft version of talk for MPI@LHC, regarding the topic of "Monte Carlo Tuning @ ATLAS". The talk introduces the event generator chain, concepts of tuning, issues/problems with over tuning, and then proceeds to explain 3(4) tunes performed at ATLAS. A 4th tune known as A15-MG5aMC@NLO(-TTBAR) is also included, but is awaiting note approval.

  12. LHC Report

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    During last week the commissioning effort has been devoted to beam development work, required to accelerate beams with nominal bunch intensity to 3.5 TeV. Significant progress has been done with the commissioning of the systems required to control the beam size and bunch length during the ramp and accelerate the beam with reproducible characteristics. The setting-up of the collimation system for the operation with higher intensity is presently ongoing with the aim of delivering physics with nominal bunch intensity towards the end of next week. For more information about the LHC and a video of the presentation recently done by LHC operators, please visit: http://lpcc.web.cern.ch/LPCC/ http://indico.cern.ch/categoryDisplay.py?categId=2687

  13. The LHC superconducting cavities

    CERN Document Server

    Boussard, Daniel; Häbel, E; Kindermann, H P; Losito, R; Marque, S; Rödel, V; Stirbet, M

    1999-01-01

    The LHC RF system, which must handle high intensity (0.5 A d.c.) beams, makes use of superconducting single-cell cavities, best suited to minimizing the effects of periodic transient beam loading. There will be eight cavities per beam, each capable of delivering 2 MV (5 MV/m accelerating field) at 400 MHz. The cavities themselves are now being manufactured by industry, using niobium-on-copper technology which gives full satisfaction at LEP. A cavity unit includes a helium tank (4.5 K operating temperature) built around a cavity cell, RF and HOM couplers and a mechanical tuner, all housed in a modular cryostat. Four-unit modules are ultimately foreseen for the LHC (two per beam), while at present a prototype version with two complete units is being extensively tested. In addition to a detailed description of the cavity and its ancillary equipment, the first test results of the prototype will be reported.

  14. Cryogenics for LHC experiments

    CERN Multimedia

    2001-01-01

    Cryogenic systems will be used by LHC experiments to maximize their performance. Institutes around the world are collaborating with CERN in the construction of these very low temperature systems. The cryogenic test facility in hall 180 for ATLAS magnets. High Energy Physics experiments have frequently adopted cryogenic versions of their apparatus to achieve optimal performance, and those for the LHC will be no exception. The two largest experiments for CERN's new flagship accelerator, ATLAS and CMS, will both use large superconducting magnets operated at 4.5 Kelvin - almost 270 degrees below the freezing point of water. ATLAS also includes calorimeters filled with liquid argon at 87 Kelvin. For the magnets, the choice of a cryogenic version was dictated by a combination economy and transparency to emerging particles. For the calorimeters, liquid argon was selected as the fluid best suited to the experiment's physics requirements. High Energy Physics experiments are the result of worldwide collaborations and...

  15. MSSM interpretations of the LHC discovery. Light or heavy Higgs?

    Energy Technology Data Exchange (ETDEWEB)

    Bechtle, P.; Stefaniak, T. [Bonn Univ. (Germany). Physikalisches Inst.; Heinemeyer, S. [Instituto de Fisica de Cantabria (CSIC-UC), Santander (Spain); Staal, O. [Stockholm Univ. (Sweden). The Oskar Klein Centre; Weiglein, G.; Zeune, L. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2012-11-15

    A Higgs-like particle with a mass of about 126 GeV has been discovered at the LHC. Within the experimental uncertainties, the measured properties of this new state are compatible with those of the Higgs boson in the Standard Model (SM). While not statistically significant at present, the results show some interesting patterns of deviations from the SM predictions, in particular a higher rate in the {gamma}{gamma} decay mode observed by ATLAS and CMS, and a somewhat smaller rate in the {tau}{sup +}{tau}{sup -} mode. The LHC discovery is also compatible with the predictions of the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM), interpreting the new state as either the light or the heavy CP-even MSSM Higgs boson. Within the framework of the MSSM with seven free parameters (pMSSM-7), we fit the various rates of cross section times branching ratio as measured by the LHC and Tevatron experiments under the hypotheses of either the light or the heavy CP-even Higgs boson being the new state around 126 GeV, with and without the inclusion of further lowenergy observables. We find an overall good quality of the fits, with the best fit points exhibiting an enhancement of the {gamma}{gamma} rate, as well as a small suppression of the b anti b and {tau}{sup +}{tau}{sup -} channels with respect to their SM expectations, depending on the details of the fit. For the fits including the whole data set the light CP-even Higgs interpretation in the MSSM results in a higher relative fit probability than the SM fit. On the other hand, we find that the present data also permit the more exotic interpretation in terms of the heavy CP-even MSSM Higgs, which could give rise to experimental signatures of additional Higgs states in the near future.

  16. BROOKHAVEN: Glueballs, hybrids and exotics

    Energy Technology Data Exchange (ETDEWEB)

    Chung, S. -U.

    1988-12-15

    A workshop at Brookhaven from August 29 to September 1 looked at the current status of hadron spectroscopy beyond the realm of states conventionally built up from quarks and discussed future experimental effort to explore such exotic states.

  17. Constraints on fermion mixing with exotics

    International Nuclear Information System (INIS)

    Nardi, E.; Tommasini, D.

    1991-11-01

    We analyze the constraints on the mixing angles of the standard fermions with new heavy particles with exotic SU(2) x U(1) quantum number assignments (left-handed singlets or right-handed doublets), that appear in many extensions of the electroweak theory. The updated Charged Current and Neutral Current experimental data, including also the recent Z-peak measurements, are considered. The results of the global analysis of all these data are then presented

  18. Human salmonellosis associated with exotic pets.

    OpenAIRE

    Woodward, D L; Khakhria, R; Johnson, W M

    1997-01-01

    During the period from 1994 to 1996, an increase in the number of laboratory-confirmed cases of human salmonellosis associated with exposure to exotic pets including iguanas, pet turtles, sugar gliders, and hedgehogs was observed in Canada. Pet turtle-associated salmonellosis was recognized as a serious public health problem in the 1960s and 1970s, and in February 1975 legislation banning the importation of turtles into Canada was enacted by Agriculture Canada. Reptile-associated salmonellosi...

  19. New possibilities for exotic hadrons

    International Nuclear Information System (INIS)

    Lipkin, H.J.

    1987-01-01

    New theoretical ideas and experimental evidence for exotic hadrons are presented. A new exciting candidate is an anticharmed baryon; i.e., a bound state of a nucleon and an F (now called D 3 ). New experimental evidence for four-quark exotic mesons presented at this conference is discussed. The confusion in the E-iota region and the pseudoscalar spectrum still await further experimental clarification

  20. Exotic nuclei and radioactive beams

    International Nuclear Information System (INIS)

    Chomaz, P.

    1996-01-01

    The Nuclei called exotic are all the nuclei that it is necessary to recreate in laboratory to study them. Their life time is too short -in relation to earth age- for it remains enough on earth. The researchers are going to have at their s disposal at GANIL (Caen) with the S.P.I.R.A.L. project, exotic nuclei beams and will study new kinds of nuclear reactions to better understand the atom nucleus. (N.C.). 2 refs., 9 figs

  1. Future energy, exotic energy

    Energy Technology Data Exchange (ETDEWEB)

    Dumon, R

    1974-01-01

    The Detroit Energy Conference has highlighted the declining oil reserves, estimated worldwide at 95 billion tons vs. an annual rate of consumption of over 3 billion tons. The present problem is one of price; also, petroleum seems too valuable to be simply burned. New sources must come into action before 1985. The most abundant is coal, with 600 billion tons of easily recoverable reserves; then comes oil shale with a potential of 400 billion tons of oil. Exploitation at the rate of 55 go 140 million tons/yr is planned in the U.S. after 1985. More exotic and impossible to estimate quantitatively are such sources as wind, tides, and the thermal energy of the oceans--these are probably far in the future. The same is true of solar and geothermal energy in large amounts. The only other realistic energy source is nuclear energy: the European Economic Community looks forward to covering 60% of its energy needs from nuclear energy in the year 2000. Even today, from 400 mw upward, a nuclear generating plant is more economical than a fossil fueled one. Conservation will become the byword, and profound changes in society are to be expected.

  2. Production of exotic and conventional quarkonia and open beauty/open charm at ATLAS

    CERN Document Server

    C. Bini; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at LHC is carrying on a wide programme to study the production properties of conventional and exotic quarkonium, beauty, and charm bound states. The latest results on J/$\\psi$, $\\psi$(2s) and X(3872) production at 7, 8, and 13 TeV, together with D meson production with Run-1 are presented. Studies of associated production of charmonium with vector bosons, searches for exotic states in the bottomonium sector and a new measurement of the ratio of b-quark fragmentation functions are also briefly presented.

  3. Diphoton and diboson probes of fermiophobic Higgs bosons at the LHC

    International Nuclear Information System (INIS)

    Delgado, Antonio; Garcia-Pepin, Mateo; Quirós, Mariano; Santiago, José; Vega-Morales, Roberto

    2016-01-01

    Extensions of the Standard Model Higgs sector with electroweak charged scalars can possess exotic ‘Higgs’ bosons with vanishing or suppressed couplings to Standard Model fermions. These ‘fermiophobic’ scalars, which cannot be produced via gluon fusion, are constrained by LHC measurements of the 125 GeV Higgs boson to have a small vacuum expectation value. This implies that vector boson fusion and associated vector boson production are in general suppressed rendering conventional Higgs searches insensitive. However, Drell-Yan Higgs pair production, which is not present in the SM, can be sizeable even in the limit of vanishing exotic Higgs vacuum expectation value. We utilize this to show that diphoton searches at 8 TeV LHC already rule out a large class of neutral fermiophobic Higgs bosons below ∼110 GeV. This includes fermiophobic scalars found in two Higgs doublet as well as Higgs triplet and Georgi-Machacek type models. Our results extend the only relevant limit on fermiophobic Higgs bosons obtained by a recent CDF analysis of 4γ+X Tevatron data. Furthermore, diphoton limits are independent of the decay of the second Higgs boson and thus apply even for degenerate masses in contrast to the CDF search. We also find that if the fermiophobic Higgs has very enhanced couplings to photons, masses as large as ∼150 GeV can be ruled out while if these couplings are somehow highly suppressed, masses below ∼90 GeV can still be ruled out. Finally, we show that WW and ZZ diboson searches may serve as complementary probes for masses above the diphoton limit up to ∼250 GeV and discuss prospects at 13 TeV LHC.

  4. LHC Report: Beam on

    CERN Multimedia

    Rossano Giachino for the LHC Team

    2012-01-01

    The powering tests described in the last edition of the Bulletin were successfully finished at the end of the first week of March opening the way for 4 TeV operations this year. The beam was back in the machine on Wednesday 14 March. The first collisions at 4 TeV are scheduled for the first week of April.   The first beam of 2012 is dumped after making a few rounds in the LHC. The magnet powering tests were followed by the machine checkout phase. Here the operations team in collaboration with the equipment groups performs a sequence of tests to ensure the readiness of the LHC for beam. The tests include driving all the LHC systems – beam dump, injection, collimation, RF, power converters, magnet circuits, vacuum, interlocks, controls, timing and synchronization – through the operational cycle. The “checkout phase” is really a massive de-bugging exercise, which is performed with the objective of ensuring the proper functioning of the whole machine and t...

  5. Human salmonellosis associated with exotic pets.

    Science.gov (United States)

    Woodward, D L; Khakhria, R; Johnson, W M

    1997-11-01

    During the period from 1994 to 1996, an increase in the number of laboratory-confirmed cases of human salmonellosis associated with exposure to exotic pets including iguanas, pet turtles, sugar gliders, and hedgehogs was observed in Canada. Pet turtle-associated salmonellosis was recognized as a serious public health problem in the 1960s and 1970s, and in February 1975 legislation banning the importation of turtles into Canada was enacted by Agriculture Canada. Reptile-associated salmonellosis is once again being recognized as a resurgent disease. From 1993 to 1995, there were more than 20,000 laboratory-confirmed human cases of salmonellosis in Canada. The major source of Salmonella infection is food; however, an estimated 3 to 5% of all cases of salmonellosis in humans are associated with exposure to exotic pets. Among the isolates from these patients with salmonellosis, a variety of Salmonella serotypes were also associated with exotic pets and included the following: S. java, S. stanley, S. poona, S. jangwani, S. tilene, S. litchfield, S. manhattan, S. pomona, S. miami, S. rubislaw, S. marina subsp. IV, and S. wassenaar subsp. IV.

  6. Abort Gap Cleaning for LHC Run 2

    Energy Technology Data Exchange (ETDEWEB)

    Uythoven, Jan [CERN; Boccardi, Andrea [CERN; Bravin, Enrico [CERN; Goddard, Brennan [CERN; Hemelsoet, Georges-Henry [CERN; Höfle, Wolfgang [CERN; Jacquet, Delphine [CERN; Kain, Verena [CERN; Mazzoni, Stefano [CERN; Meddahi, Malika [CERN; Valuch, Daniel [CERN; Gianfelice-Wendt, Eliana [Fermilab

    2014-07-01

    To minimize the beam losses at the moment of an LHC beam dump the 3 μs long abort gap should contain as few particles as possible. Its population can be minimised by abort gap cleaning using the LHC transverse damper system. The LHC Run 1 experience is briefly recalled; changes foreseen for the LHC Run 2 are presented. They include improvements in the observation of the abort gap population and the mechanism to decide if cleaning is required, changes to the hardware of the transverse dampers to reduce the detrimental effect on the luminosity lifetime and proposed changes to the applied cleaning algorithms.

  7. Physics possibilities at LHC/SSC

    International Nuclear Information System (INIS)

    Hinchliffe, I.

    1991-01-01

    This document reviews some recent work on physics simulations for SSC/LHC. Included are reviews of some of the recent developments in physics simulations for the SSC/LHC and comments upon the requirements that are placed upon detectors by the need to extract specific physics signatures. The material in the various EOI/LOI documents submitted to the SCC Laboratory and the work done at the Aachen LHC workshop are discussed. In the following discussion 1 SSC (LHC) year corresponds to an integrated luminosity of 10 (100) fb -1 . 41 refs., 14 figs

  8. Abort Gap Cleaning for LHC Run 2

    CERN Document Server

    Uythoven, J; Bravin, E; Goddard, B; Hemelsoet, GH; Höfle, W; Jacquet, D; Kain, V; Mazzoni, S; Meddahi, M; Valuch, D

    2015-01-01

    To minimise the beam losses at the moment of an LHC beam dump the 3 μs long abort gap should contain as few particles as possible. Its population can be minimised by abort gap cleaning using the LHC transverse damper system. The LHC Run 1 experience is briefly recalled; changes foreseen for the LHC Run 2 are presented. They include improvements in the observation of the abort gap population and the mechanism to decide if cleaning is required, changes to the hardware of the transverse dampers to reduce the detrimental effect on the luminosity lifetime and proposed changes to the applied cleaning algorithms.

  9. Parton distributions with LHC data

    DEFF Research Database (Denmark)

    Ball, R.D.; Deans, C.S.; Del Debbio, L.

    2013-01-01

    We present the first determination of parton distributions of the nucleon at NLO and NNLO based on a global data set which includes LHC data: NNPDF2.3. Our data set includes, besides the deep inelastic, Drell-Yan, gauge boson production and jet data already used in previous global PDF determinati......We present the first determination of parton distributions of the nucleon at NLO and NNLO based on a global data set which includes LHC data: NNPDF2.3. Our data set includes, besides the deep inelastic, Drell-Yan, gauge boson production and jet data already used in previous global PDF...... fraction of the proton. We also present collider PDF sets, constructed using only data from HERA, the Tevatron and the LHC, but find that this data set is neither precise nor complete enough for a competitive PDF determination....

  10. Exotic helium molecules

    International Nuclear Information System (INIS)

    Portier, M.

    2007-12-01

    We study the photo-association of an ultracold cloud of magnetically trapped helium atoms: pairs of colliding atoms interact with one or two laser fields to produce a purely long range 4 He 2 (2 3 S 1 -2 3 P 0 ) molecule, or a 4 He 2 (2 3 S 1 -2 3 S 1 ) long range molecule. Light shifts in one photon photo-association spectra are measured and studied as a function of the laser polarization and intensity, and the vibrational state of the excited molecule. They result from the light-induced coupling between the excited molecule, and bound and scattering states of the interaction between two metastable atoms. Their analysis leads to the determination of the scattering length a = (7.2 ± 0.6) ruling collisions between spin polarized atoms. The two photon photo-association spectra show evidence of the production of polarized, long-range 4 He 2 (2 3 S 1 -2 3 S 1 ) molecules. They are said to be exotic as they are made of two metastable atoms, each one carrying a enough energy to ionize the other. The corresponding lineshapes are calculated and decomposed in sums and products of Breit-Wigner and Fano profiles associated to one and two photon processes. The experimental spectra are fit, and an intrinsic lifetime τ = (1.4 ± 0.3) μs is deduced. It is checked whether this lifetime could be limited by spin-dipole induced Penning autoionization. This interpretation requires that there is a quasi-bound state close to the dissociation threshold in the singlet interaction potential between metastable helium atoms for the theory to match the experiment. (author)

  11. Effects of exotic species on Yellowstone's grizzly bears

    Science.gov (United States)

    Reinhart, Daniel P.; Haroldson, Mark A.; Mattson, D.J.; Gunther, Kerry A.

    2001-01-01

    Humans have affected grizzly bears (Ursus arctos horribilis) by direct mortality, competition for space and resources, and introduction of exotic species. Exotic organisms that have affected grizzly bears in the Greater Yellowstone Area include common dandelion (Taraxacum officinale), nonnative clovers (Trifolium spp.), domesticated livestock, bovine brucellosis (Brucella abortus), lake trout (Salvelinus namaycush), and white pine blister rust (Cronartium ribicola). Some bears consume substantial amounts of dandelion and clover. However, these exotic foods provide little digested energy compared to higher-quality bear foods. Domestic livestock are of greater energetic value, but use of this food by bears often leads to conflicts with humans and subsequent increases in bear mortality. Lake trout, blister rust, and brucellosis diminish grizzly bears foods. Lake trout prey on native cutthroat trout (Oncorhynchus clarkii) in Yellowstone Lake; white pine blister rust has the potential to destroy native whitebark pine (Pinus albicaulis) stands; and management response to bovine brucellosis, a disease found in the Yellowstone bison (Bison bison) and elk (Cervus elaphus), could reduce populations of these 2 species. Exotic species will likely cause more harm than good for Yellowstone grizzly bears. Managers have few options to mitigate or contain the impacts of exotics on Yellowstone's grizzly bears. Moreover, their potential negative impacts have only begun to unfold. Exotic species may lead to the loss of substantial highquality grizzly bear foods, including much of the bison, trout, and pine seeds that Yellowstone grizzly bears currently depend upon.

  12. LHC goes global

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1995-09-15

    As CERN's major project for the future, the LHC sets a new scale in world-wide scientific collaboration. As well as researchers and engineers from CERN's 19 European Member States, preparations for the LHC now include scientists from several continents. Some 50 per cent of the researchers involved in one way or another with preparations for the LHC experimental programme now come from countries which are not CERN Member States. Underlining this enlarged international involvement is the recent decision by the Japanese Ministry of Education, Science and Culture ('Monbusho') to accord CERN a generous contribution of five billion yen (about 65 million Swiss francs) to help finance the construction of the LHC. This money will be held in a special fund earmarked for construction of specific LHC components and related activities. To take account of the new situation, CERN is proposing to set up a totally new 'Associate State' status. This is foreseen as a flexible bilateral framework which will be set up on a case-by-case basis to adapt to different circumstances. This proposal was introduced to CERN Council in June, and will be further discussed later this year. These developments reflect CERN's new role as a focus of world science, constituting a first step towards a wider level of international collaboration. At the June Council session, as a first step, Japan was unanimously elected as a CERN Observer State, giving them the right to attend Council meetings. Introducing the topic at the Council session, Director General Chris Llewellyn Smith sketched the history of Japanese involvement in CERN research. This began in 1957 and has gone on to include an important experiment at the LEAR low energy antiproton ring using laser spectroscopy of antiprotonic helium atoms, the new Chorus neutrino experiment using an emulsion target, and a major contribution to the Opal experiment at the LEP electronpositron collider. In welcoming the development, many Council delegates looked

  13. LHC goes global

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    As CERN's major project for the future, the LHC sets a new scale in world-wide scientific collaboration. As well as researchers and engineers from CERN's 19 European Member States, preparations for the LHC now include scientists from several continents. Some 50 per cent of the researchers involved in one way or another with preparations for the LHC experimental programme now come from countries which are not CERN Member States. Underlining this enlarged international involvement is the recent decision by the Japanese Ministry of Education, Science and Culture ('Monbusho') to accord CERN a generous contribution of five billion yen (about 65 million Swiss francs) to help finance the construction of the LHC. This money will be held in a special fund earmarked for construction of specific LHC components and related activities. To take account of the new situation, CERN is proposing to set up a totally new 'Associate State' status. This is foreseen as a flexible bilateral framework which will be set up on a case-by-case basis to adapt to different circumstances. This proposal was introduced to CERN Council in June, and will be further discussed later this year. These developments reflect CERN's new role as a focus of world science, constituting a first step towards a wider level of international collaboration. At the June Council session, as a first step, Japan was unanimously elected as a CERN Observer State, giving them the right to attend Council meetings. Introducing the topic at the Council session, Director General Chris Llewellyn Smith sketched the history of Japanese involvement in CERN research. This began in 1957 and has gone on to include an important experiment at the LEAR low energy antiproton ring using laser spectroscopy of antiprotonic helium atoms, the new Chorus neutrino experiment using an emulsion target, and a major contribution to the Opal experiment at the LEP electronpositron collider. In welcoming the

  14. Everyday and Exotic Foodborne Parasites

    Directory of Open Access Journals (Sweden)

    Marilyn B Lee

    2000-01-01

    Full Text Available Everyday foodborne parasites, which are endemic in Canada, include the protozoans Entamoeba histolytica, Giardia lamblia and Cryptosporidium parvum. However, these parasites are most frequently acquired through unfiltered drinking water, homosexual activity or close personal contact such as in daycare centres and occasionally via a food vehicle. It is likely that many foodborne outbreaks from these protozoa go undetected. Transmission of helminth infections, such as tapeworms, is rare in Canada because of effective sewage treatment. However, a common foodborne parasite of significance is Toxoplasma gondii. Although infection can be acquired from accidental ingestion of oocysts from cat feces, infection can also result from consumption of tissue cysts in undercooked meat, such as pork or lamb. Congenital transmission poses an immense financial burden, costing Canada an estimated $240 million annually. Also of concern is toxoplasmosis in AIDS patients, which may lead to toxoplasmosis encephalitis, the second most common AIDS-related opportunistic infection of the central nervous system. Exotic parasites (ie, those acquired from abroad or from imported food are of growing concern because more Canadians are travelling and the number of Canada?s trading partners is increasing. Since 1996, over 3000 cases of Cyclospora infection reported in the United States and Canada were epidemiologically associated with importation of Guatemalan raspberries. Unlike toxoplasmosis, where strategies for control largely rest with individual practices, control of cyclosporiasis rests with government policy, which should prohibit the importation of foods at high risk.

  15. P fluxes and exotic branes

    Energy Technology Data Exchange (ETDEWEB)

    Lombardo, Davide M. [Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy); Riccioni, Fabio [INFN - Sezione di Roma, Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy); Risoli, Stefano [Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy); INFN - Sezione di Roma, Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy)

    2016-12-21

    We consider the N=1 superpotential generated in type-II orientifold models by non-geometric fluxes. In particular, we focus on the family of P fluxes, that are related by T-duality transformations to the S-dual of the Q flux. We determine the general rule that transforms a given flux in this family under a single T-duality transformation. This rule allows to derive a complete expression for the superpotential for both the IIA and the IIB theory for the particular case of a T{sup 6}/[ℤ{sub 2}×ℤ{sub 2}] orientifold. We then consider how these fluxes modify the generalised Bianchi identities. In particular, we derive a fully consistent set of quadratic constraints coming from the NS-NS Bianchi identities. On the other hand, the P flux Bianchi identities induce tadpoles, and we determine a set of exotic branes that can be consistently included in order to cancel them. This is achieved by determining a universal transformation rule under T-duality satisfied by all the branes in string theory.

  16. P fluxes and exotic branes

    International Nuclear Information System (INIS)

    Lombardo, Davide M.; Riccioni, Fabio; Risoli, Stefano

    2016-01-01

    We consider the N=1 superpotential generated in type-II orientifold models by non-geometric fluxes. In particular, we focus on the family of P fluxes, that are related by T-duality transformations to the S-dual of the Q flux. We determine the general rule that transforms a given flux in this family under a single T-duality transformation. This rule allows to derive a complete expression for the superpotential for both the IIA and the IIB theory for the particular case of a T 6 /[ℤ 2 ×ℤ 2 ] orientifold. We then consider how these fluxes modify the generalised Bianchi identities. In particular, we derive a fully consistent set of quadratic constraints coming from the NS-NS Bianchi identities. On the other hand, the P flux Bianchi identities induce tadpoles, and we determine a set of exotic branes that can be consistently included in order to cancel them. This is achieved by determining a universal transformation rule under T-duality satisfied by all the branes in string theory.

  17. Infectious threats from exotic pets: dermatological implications.

    Science.gov (United States)

    Rosen, Ted; Jablon, Jennifer

    2003-04-01

    Zoonoses are diseases that can be transmitted from animals to humans. More than 250 distinct zoonoses have been described in the literature. It is estimated that 56% of United States households contain at least one pet, and although considerable research has been performed regarding the more common household animals including dogs, cats, small birds, and rodents, surprisingly little is known about the zoonotic hazards of owning the more exotic pets. According to the 1997 USPHS/IDSA Report on the Prevention of Opportunistic Infections in Persons Infected with Human Immunodeficiency Virus, the immunocompromised patient should avoid contact with feces-laden soil, litter boxes, reptiles, most pet birds, and any animal less than 6 months old . It has also been documented that because of their inquisitive nature, children are at even higher risk for infection from animals than adolescents or immunocompetent adults. In this article the authors have reviewed the available data regarding hazards associated with the hedgehog, flying squirrel, iguana, chinchilla, and cockatoo. With the growing popularity of such exotic pets, further observation and research is warranted. Physicians need to be aware of the possibility of zoonotic disease related to exotic pet ownership, and they should address this issue when obtaining a history and formulating a differential diagnosis of cutaneous lesions suggestive of such illnesses.

  18. Exotic quarkonium states in CMS experiment

    CERN Document Server

    Chen, Kai-Feng

    2013-01-01

    Using large data samples of di-muon events, CMS can perform detailed measurements and searches for new states in the field of exotic quarkonium. We present our results on the production of prompt and non-prompt $\\rm X(3872)$, detected in the ${\\rm J}/\\psi \\pi^+\\pi^-$ decay channel, which extend to higher $p_{\\rm T}$ values than in any previous measurement. The cross-section ratio with respect to the $\\psi(2S)$ is given differentially in $p_{\\rm T}$, as well as $p_{\\rm T}$ integrated. For the first time at the LHC, the fraction of $\\rm X(3872)$ coming from B hadron decays has been measured. After these studies of the charmonium $\\rm X$, we present a new search for its bottomonium counterpart, denoted as $\\rm X_b$, based on a data sample of pp collisions at 8 TeV collected by CMS in 2012. In analogy to the $\\rm X(3872)$ studies, the analysis uses the ${\\rm X_b} \\to \\Upsilon(1S) \\pi \\pi$ exclusive decay channel, with the $\\Upsilon(1S)$ decaying to $\\mu^+ \\mu^-$ pairs. No evidence for $\\rm X_b$ is observed and up...

  19. Parton distributions with LHC data

    NARCIS (Netherlands)

    Ball, Richard D.; Bertone, Valerio; Carrazza, Stefano; Deans, Christopher S.; Debbio, Luigi Del; Forte, Stefano; Guffanti, Alberto; Hartland, Nathan P.; Latorre, Jose I.; Rojo, Juan; Ubiali, Maria

    2013-01-01

    We present the first determination of parton distributions of the nucleon at NLO and NNLO based on a global data set which includes LHC data: NNPDF2.3. Our data set includes, besides the deep inelastic, Drell-Yan, gauge boson production and jet data already used in previous global PDF

  20. The LHC and its successors

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    Not too long before the first long technical stop of the LHC, engineers and physicists are already working on the next generation of accelerators: HL-LHC and LHeC. The first would push proton-proton collisions to an unprecedented luminosity rate; the second would give a second wind to electron-proton collisions.   The ring-ring configuration of the LHeC would need this type of magnets, currently being studied for possible future use. In one year, the LHC will begin to change. During the first long shutdown, from December 2012 to late 2014, the machine will go through a first phase of major upgrades, with the objective of running at 7 TeV per beam at the beginning of 2015. With this long technical stop and the two others that will follow (in 2018 and 2022), a new project will see the light of day. Current plans include the study of something that looks more like a new machine rather than a simple upgrade: the High Luminosity LHC (HL-LHC). Much more powerful than the current machine, the HL-...

  1. Higgs exotic decays in general NMSSM with self-interacting dark matter

    Science.gov (United States)

    Wang, Wenyu; Zhang, Mengchao; Zhao, Jun

    2018-04-01

    Under current LHC and dark matter constraints, the general NMSSM can have self-interacting dark matter to explain the cosmological small structure. In this scenario, the dark matter is the light singlino-like neutralino (χ) which self-interacts through exchanging the light singlet-like scalars (h1,a1). These light scalars and neutralinos inevitably interact with the 125 GeV SM-like Higgs boson (hSM), which cause the Higgs exotic decays hSM → h1h1, a1a1, χχ. We first demonstrate the parameter space required by the explanation of the cosmological small structure and then display the Higgs exotic decays. We find that in such a parameter space the Higgs exotic decays can have branching ratios of a few percent, which should be accessible in the future e+e‑ colliders.

  2. Shell model calculations for exotic nuclei

    International Nuclear Information System (INIS)

    Brown, B.A.; Wildenthal, B.H.

    1991-01-01

    A review of the shell-model approach to understanding the properties of light exotic nuclei is given. Binding energies including p and p-sd model spaces and sd and sd-pf model spaces; cross-shell excitations around 32 Mg, including weak-coupling aspects and mechanisms for lowering the ntw excitations; beta decay properties of neutron-rich sd model, of p-sd and sd-pf model spaces, of proton-rich sd model space; coulomb break-up cross sections are discussed. (G.P.) 76 refs.; 12 figs

  3. Hadronic interaction and structure of exotic nuclei

    International Nuclear Information System (INIS)

    Otsuka, Takaharu

    2009-01-01

    I will overview recent studies on the evolution of the shell structure in stable and exotic nuclei, and will show its relevance to hadronic interaction, including nuclear forces. This shell evolution is primarily due to the tensor force. The robust mechanism and some examples will be presented. Such examples include the disappearance of existing magic numbers and the appearance of new ones. The shell structure and existing limit of nuclei depend also on the three-body interaction in a specific way. I will sketch how the Δ-hole excitation induced three-body force (Fujita-Miyazawa force) modifies them. (author)

  4. HL-LHC Accelerator

    CERN Document Server

    Zimmermann, F

    2013-01-01

    The tentative schedule, key ingredients, as well as progress of pertinent R&D and component prototypes for the LHC luminosity upgrade, "HL-LHC," are reviewed. Also alternative scenarios based on performance-improving consolidations (PICs) instead of a full upgrade are discussed. Tentative time schedules and expected luminosity evolutions for the different scenarios are sketched. The important role of HL-LHC development as a step towards a future HE-LHC or VHE-LHC is finally highlighted. Presented at "Higgs & Beyond" Conference Tohoku University, Sendai 7 June 2013.

  5. Safe LHC beam commissioning

    International Nuclear Information System (INIS)

    Uythoven, J.; Schmidt, R.

    2007-01-01

    Due to the large amount of energy stored in magnets and beams, safety operation of the LHC is essential. The commissioning of the LHC machine protection system will be an integral part of the general LHC commissioning program. A brief overview of the LHC Machine Protection System will be given, identifying the main components: the Beam Interlock System, the Beam Dumping System, the Collimation System, the Beam Loss Monitoring System and the Quench Protection System. An outline is given of the commissioning strategy of these systems during the different commissioning phases of the LHC: without beam, injection and the different phases with stored beam depending on beam intensity and energy. (author)

  6. The LHC inauguration in pictures

    CERN Multimedia

    2008-01-01

    The LHC inauguration ceremony was a memorable experience for everyone who attended. On Tuesday 21 October the ceremony hall, SMA18, was filled with over 1500 invited guests, VIPs included Swiss President Pascal Couchepin, French Prime Minister François Fillon and several ministers from CERN’s Member States and around the world. You can watch a video of the highlights of the ceremony at http://cds.cern.ch/record/1136012 The Heads of Delegations from all the Member and Observer States pose with the Director-General. "The LHC is a marvel of modern technology, which would not have been possible without the continuous support of our Member States," said the Director-General in his opening speech. "This is an opportunity for me to thank them on behalf of the world’s particle physics community." The LHC inauguration ceremony officially marked the end of 24 years of conception, development, constru...

  7. Searching dark matter at LHC

    International Nuclear Information System (INIS)

    Nojiri, Mihoko M.

    2007-01-01

    We now believe that the dark matter in our Universe must be an unknown elementary particle, which is charge neutral and weakly interacting. The standard model must be extended to include it. The dark matter was likely produced in the early universe from the high energy collisions of the particles. Now LHC experiment starting from 2008 will create such high energy collision to explore the nature of the dark matter. In this article we explain how dark matter and LHC physics will be connected in detail. (author)

  8. Multiquark exotics (baryonium, dibaryons etc)

    International Nuclear Information System (INIS)

    Kondratyuk, L.A.

    1987-01-01

    The multiquark exotic resonant states q 2 -(anti q) 2 , q 3 -(anti q) 3 , q 6 and q 9 are discussed as systems composed of the few colour clusters. Special attention is devoted to the problem of narrow resonances in channels anti NN, Δanti p+pions, πNN and NN. 42 refs.; 2 figs.; 5 tabs

  9. Exotic meson studies at LHCb

    Directory of Open Access Journals (Sweden)

    Kreps Michal

    2014-01-01

    Full Text Available The latest years have seen a resurrection of interest in searches for exotic states motivated by tantalising observations of several states. Using the pp collisions data collected at 7 and 8 TeV by the LHCb experiment, we performed studies of the X(3872 decay rate to ψ (2Sγ final state, as well as confirmation the Z(4430+ state.

  10. Exotic decay in cerium isotopes

    Indian Academy of Sciences (India)

    Geiger–Nuttall plots were studied for different clusters and are found to be linear. Inclusion of proximity potential will not produce much deviation to linear nature of Geiger–Nuttall plots. It is observed that neutron excess in the parent nuclei slow down the exotic decay process. These findings support the earlier observations ...

  11. Exotic snakes are not always found in exotic places: how poison centres can assist emergency departments

    OpenAIRE

    Lubich, Carol; Krenzelok, Edward P

    2009-01-01

    Emergency departments throughout the USA may have some familiarity with the management of envenomation from indigenous snake species such as Crotalinae (rattlesnakes) and Micrurus (coral snakes). However, venomous species may include exotic reptiles whose bites pose substantial treatment challenges due to both a lack of experience and the difficulty in obtaining antivenoms. Two pet cobra envenomation incidents illustrate the challenges that face emergency departments, especially in urban sett...

  12. Exotic snakes are not always found in exotic places: how poison centres can assist emergency departments

    OpenAIRE

    Lubich, Carol; Krenzelok, Edward P

    2007-01-01

    Emergency departments throughout the USA may have some familiarity with the management of envenomation from indigenous snake species such as Crotalinae (rattlesnakes) and Micrurus (coral snakes). However, venomous species may include exotic reptiles whose bites pose substantial treatment challenges due to both a lack of experience and the difficulty in obtaining antivenoms. Two pet cobra envenomation incidents illustrate the challenges that face emergency departments, especially in urban sett...

  13. Searching for doubly charged vector bileptons in the golden channel at the LHC

    International Nuclear Information System (INIS)

    Meirose, B.; Nepomuceno, A. A.

    2011-01-01

    In this paper we investigate the LHC potential for discovering doubly charged vector bileptons considering the measurable process p, p→e ± e ± μ ± μ ± X. We perform the study using four different bilepton masses and three different exotics quark masses. Minimal LHC integrated luminosities needed for discovering and for setting limits on bilepton masses are obtained for both 7 and 14 TeV center-of-mass energies. We find that these spectacular signatures can be observed at the LHC in the next years up to a bilepton mass of order of 1 TeV.

  14. BSM searches (SUSY and Exotic) from ATLAS

    CERN Document Server

    ATLAS Collaboration; The ATLAS collaboration

    2015-01-01

    Searches for new physics beyond the Standard Model (SM) at the LHC are mainly driven by two approaches: a signature-based search where one looks for a deviation from the SM prediction in event yield or kinematic properties, and a more theory-oriented approach where the search is designed to look for specific signatures/topologies predicted by certain beyond standard model (BSM ) scenarios. Typical examples for the latter are searches for Supersymmetry and other BSM theories with extended symmetries. Supersymmetry predicts a new partner for every SM particle. An extension to the SM by introducing new gauge or global symmetries (including in Hidden Sector) usually leads to the presence of new heavy gauge bosons. Extensive searches for such particles have been performed in ATLAS at LHC in the context of Supersymmetry, Extended Gauge models, Technicolor, Little Higgs, Extra Dimensions, Left-Right symmetric models, and many other BSM scenarios. Highlights from these searches are presented.

  15. Fourteenth Exotic Beam Summer School EBSS 2015

    International Nuclear Information System (INIS)

    Wiedenhoever, Ingo

    2016-01-01

    The Fourteenth Annual Exotic Beam Summer School EBSS 2015 was held August 2nd - August 7th, 2015, and belongs to the series of summer programs aimed at educating future workforce in nuclear physics-related areas, mostly about the challenges of radioactive ion beam physics. Through these schools the research community will be able to exploit fully the opportunities created by the exotic beam facilities. These facilities in the US include CARIBU at ANL, the NSCL and the future FRIB laboratory as well as smaller-scale university laboratories. The skill set needed by the future workforce is very diverse and a fundamental understanding of theoretical, technical, computational and applied fields are all important. Therefore, the Exotic Beam Summer Schools follow a unique approach, in which the students not only receive lectures but also participate in hands-on activities. The lectures covered broad topics in both the experimental and theoretical physics of nuclei far from stability as well as radioactive ions production and applications. The afternoons provided opportunities for 'hands-on' projects with experimental equipment and techniques useful in FRIB research. Five activities were performed in groups of eight students, rotating through the activities over the five afternoons of the school. The center of the activities was an experiment at the FSU tandem accelerator, measuring the angular distribution and cross section of the "1"2C(d,p)"1"3C transfer reaction, measured with a silicon telescope in a scattering chamber. The experimental data were analyzed by performing a DWBA calculation with the program DWUCK, and the resulting spectroscopic factors were compared to a shell model calculation. The other activities included target preparation, digital gamma-spectroscopy and modern neutron detection methods.

  16. Fourteenth Exotic Beam Summer School EBSS 2015

    Energy Technology Data Exchange (ETDEWEB)

    Wiedenhoever, Ingo [Florida State Univ., Tallahassee, FL (United States). Dept. of Physics

    2016-07-11

    The Fourteenth Annual Exotic Beam Summer School EBSS 2015 was held August 2nd - August 7th, 2015, and belongs to the series of summer programs aimed at educating future workforce in nuclear physics-related areas, mostly about the challenges of radioactive ion beam physics. Through these schools the research community will be able to exploit fully the opportunities created by the exotic beam facilities. These facilities in the US include CARIBU at ANL, the NSCL and the future FRIB laboratory as well as smaller-scale university laboratories. The skill set needed by the future workforce is very diverse and a fundamental understanding of theoretical, technical, computational and applied fields are all important. Therefore, the Exotic Beam Summer Schools follow a unique approach, in which the students not only receive lectures but also participate in hands-on activities. The lectures covered broad topics in both the experimental and theoretical physics of nuclei far from stability as well as radioactive ions production and applications. The afternoons provided opportunities for "hands-on" projects with experimental equipment and techniques useful in FRIB research. Five activities were performed in groups of eight students, rotating through the activities over the five afternoons of the school. The center of the activities was an experiment at the FSU tandem accelerator, measuring the angular distribution and cross section of the 12C(d,p)13C transfer reaction, measured with a silicon telescope in a scattering chamber. The experimental data were analyzed by performing a DWBA calculation with the program DWUCK, and the resulting spectroscopic factors were compared to a shell model calculation. The other activities included target preparation, digital gamma-spectroscopy and modern neutron detection methods.

  17. Parton distributions with LHC data

    CERN Document Server

    Ball, Richard D.; Carrazza, Stefano; Deans, Christopher S.; Del Debbio, Luigi; Forte, Stefano; Guffanti, Alberto; Hartland, Nathan P.; Latorre, Jose I.; Rojo, Juan; Ubiali, Maria

    2013-01-01

    We present the first determination of parton distributions of the nucleon at NLO and NNLO based on a global data set which includes LHC data: NNPDF2.3. Our data set includes, besides the deep inelastic, Drell-Yan, gauge boson production and jet data already used in previous global PDF determinations, all the relevant LHC data for which experimental systematic uncertainties are currently available: ATLAS and LHCb W and Z lepton rapidity distributions from the 2010 run, CMS W electron asymmetry data from the 2011 run, and ATLAS inclusive jet cross-sections from the 2010 run. We introduce an improved implementation of the FastKernel method which allows us to fit to this extended data set, and also to adopt a more effective minimization methodology. We present the NNPDF2.3 PDF sets, and compare them to the NNPDF2.1 sets to assess the impact of the LHC data. We find that all the LHC data are broadly consistent with each other and with all the older data sets included in the fit. We present predictions for various ...

  18. Section of LHC beampipe

    CERN Multimedia

    2009-01-01

    A short section of the LHC beampipe including beam screen. Particle beams circulate for around 10 hours in the Large Hadron Collider (LHC). During this time, the particles make four hundred million revolutions of the machine, travelling a distance equivalent to the diameter of the solar system. The beams must travel in a pipe which is emptied of air, to avoid collisions between the particles and air molecules (which are considerably bigger than protons). The beam pipes are pumped down to an air pressure similar to that on the surface of the moon. Emptying the air from the two 27 km long Large Hadron Collider beam-pipes is equivalent in volume to emptying the nave of the Notre Dame cathedral in Paris. Initially, the air pressure is reduced by pumping. Then, cold sections of the beam-pipe are further emptied using the temperature gradient across special beam-screens inside the tube where particles travel. The warm sections are emptied using a coating called a getter that works like molecular fly-paper. This va...

  19. LHC beampipe section

    CERN Multimedia

    A short section of the LHC beam-pipe including beam screen. In the LHC, particles circulate under vacuum. The vacuum chamber can be at room temperature (for example, in the experimental areas), or at cryogenic temperature, in the superconductive magnets. This piece is located in the superconductive magnets. The outer pipe is the vacuum chamber, which is in contact with the magnets, at cryogenic temperature (1.9K). It is called the “cold bore”. The inner tube is the beam screen. Its main goal is to protect the magnets from the heat load coming from the synchrotron radiation. Indeed, when high energy protons’ trajectory is bent, photons are emitted by the beam. They are intercepted by the beam screen. The temperature of the beam screen is kept between 5 and 20K by a circulation of gaseous helium in the small pipes on both sides of the beam screen. As those surfaces are at cryogenic temperature. The residual gas present in the accelerator is sticking on the surfaces. This phenomenon called “adsorption”...

  20. LHC Report: Rocky Recovery

    CERN Multimedia

    Mike Lamont for the LHC Team

    2011-01-01

    The last technical stop finished on Friday 8 July, but the machine returned to its pre-stop performance level over a week later.   Efficiency of LHC fills between 16 July and 20 July, 2011. The cryogenics team had the entire ring cold by Saturday morning and the usual post-technical stop tests with circulating beams started soon after. Unfortunately, they were interrupted by a major perturbation to CERN’s electrical network caused by an impressive thunderstorm that swept over the Pays de Gex. There were major knock-on effects, including the loss of cooling to the cryogenics and an inevitable recovery period once normal service had been re-established. The beams were circulating again by Tuesday afternoon and the post-technical stop checks continued, beefed up with further tests to address a number of issues related to the power cut.  Before the stop, the LHC had managed to get 1380 bunches per beam into collisions and the plan was to ramp back up relatively quickly to this leve...

  1. Highlights on searches for supersymmetry and exotic models

    International Nuclear Information System (INIS)

    Clerbaux, B.

    2015-01-01

    In this review, we present highlight results of the first three years of the LHC running on searches for new physics beyond the Standard Model (BSM). The excellent performance of the LHC machine and detectors has provided a large, high-quality dataset, mainly proton-proton interactions at a centre of mass energy of 7 TeV (collected in 2010 and 2011) and 8 TeV (collected in 2012). This allowed the experiments to test the Standard Model (SM) at the highest available energy and to search for new phenomena in a considerably enlarged phase space compared to previous colliders. The present review is organised as follows. Section 2 gives motivations to search for new physics beyond the SM, and a brief description of the main classes of BSM theory candidates is reported in Section 3. Section 4 summarises the characteristics of the 3-year LHC dataset, called in the following the Run 1 dataset. Precise tests of the SM are reported in Section 5. The following next sections are the core of the review and present a selection of results from the ATLAS and CMS experiments on BSM searches, gathered in four parts: the search for new physics in the scalar sector in Section 6, the search for supersymmetric particles in Section 7, the search for dark matter candidates in Section 8, and a non-exhaustive list of other exotics BSM (heavy resonances, excited fermions, leptoquarks and vector-like quarks) searches in Section 9. Future plans of the LHC running are reported in Section 10

  2. LHC synchronization test successful

    CERN Multimedia

    The synchronization of the LHC's clockwise beam transfer system and the rest of CERN's accelerator chain was successfully achieved last weekend. Tests began on Friday 8 August when a single bunch of a few particles was taken down the transfer line from the SPS accelerator to the LHC. After a period of optimization, one bunch was kicked up from the transfer line into the LHC beam pipe and steered about 3 kilometres around the LHC itself on the first attempt. On Saturday, the test was repeated several times to optimize the transfer before the operations group handed the machine back for hardware commissioning to resume on Sunday. The anti-clockwise synchronization systems will be tested over the weekend of 22 August.Picture:http://lhc-injection-test.web.cern.ch/lhc-injection-test/

  3. Some LHC milestones...

    CERN Multimedia

    2008-01-01

    October 1995 The LHC technical design report is published. This document details the operation and the architecture of the future accelerator. November 2000 The first of the 1232 main dipole magnets for the LHC are delivered. May 2005 The first interconnection between two magnets of the accelerator is made. To carry out the 1700 interconnections of the LHC, 123 000 operations are necessary. February 2006 The new CERN Control Centre, which combines all the control rooms for the accelerators, the cryogenics and the technical infrastructure, starts operation. The LHC will be controlled from here. October 2006 Construction of the largest refrigerator in the world is complete. The 27 km cryogenic distribution line inside the LHC tunnel will circulate helium in liquid and gas phases to provide cryogenic conditions for the superconducting magnets of the accelerator. November 2006 Magnet production for the LHC is complete. The last of t...

  4. Search for Multi-quark Exotic States with Heavy Flavor at D0 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Popov, Alexei [Serpukhov, IHEP

    2017-12-20

    We present the results for multi-quark exotic states search from D0 Collaboration at the FNAL Tevatron. This includes an evidence for a state (X(5568)) with hadronic decays of Bs meson, a confirmation of the X(5568) state with semileptonic decays of Bs meson, and a search for exotic baryons decaying to J/ψΛ pairs.

  5. Towards LHC experiments

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    As plans for the LHC proton collider to be built in CERN's 27-kilometre LEP tunnel take shape, interest widens to bring in the experiments exploiting the big machine. The first public presentations of 'expressions of interest' for LHC experiments featured from 5-8 March at Evian-les-Bains on the shore of Lake Geneva, some 50 kilometres from CERN, at the special Towards the LHC Experimental Programme' meeting

  6. LHC Report: The beam is back at the LHC

    CERN Multimedia

    Reyes Alemany

    2015-01-01

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

  7. An exotic composite vector boson

    International Nuclear Information System (INIS)

    Akama, Keiichi; Hattori, Takashi; Yasue, Masaki.

    1990-08-01

    An exotic composite vector boson, V, is introduced in two dynamical models of composite quarks, leptons, W and Z. One is based on four Fermi interactions, in which composite vector bosons are regarded as fermion-antifermion bound states and the other is based on the confining SU(2) L gauge model, in which they are given by scalar-antiscalar bound states. Both approaches describe the same effective interactions for the sector of composite quarks, leptons, W, Z, γ and V. (author)

  8. Exotic phases in neutron stars

    International Nuclear Information System (INIS)

    Li, A.; Burgio, G.F.; Lombardo, U.; Peng, G.X.

    2008-01-01

    The appearance of exotic phases in neutron stars is studied. The possible transition from hadron to quark phase is studied within the density dependent mass quark model, and the kaon condensation within the Nelson and Kaplan model. In both cases a microscopic approach is adopted for dense hadron matter. From the study of the possible coexistence between the two phases it is found that the hybrid phase may strongly hinder the onset of kaon condensation. (author)

  9. Hands on exotics

    Science.gov (United States)

    Sandy. Bivens

    1998-01-01

    To lead, teach, rear, bring up, instruct, train, show, inform, guide, direct, inspire, and foster expansion of knowledge-that is education. Environmental education has been defined as the interdisciplinary process of developing a citizenry that is knowledgeable about the total environment, including both its natural and built aspects, that has the capacity and the...

  10. LHC Report: Back in operation

    CERN Multimedia

    2016-01-01

    With the machine back in their hands since Friday, 4 March, the LHC operators are now performing the powering tests on the magnets. This is a crucial step before receiving the first beams and restarting Run 2 for physics.   A Distribution Feed-Box (DFB) brings power to the LHC magnets and maintains the stability of the current in the superconducting circuits. The LHC was the last machine to be handed back to operators after the completion of maintenance work carried out during the Year-End Technical Stop (YETS) that had started on 14 December 2015. During the eleven weeks of scheduled maintenance activities, several operations took place in all the accelerators and beam lines. They included the maintenance in several points of the cryogenic system, the replacement of 18 magnets in the Super Proton Synchrotron; an extensive campaign to identify and remove thousands of obsolete cables; the replacement of the LHC beam absorbers for injection (TDIs) that are used to absorb the SPS b...

  11. Keeping the LHC in power

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    The critical safety equipment around the LHC, including the machine protection systems, is connected to Uninterruptible Power Supplies (UPS).  In case of mains failure, the UPS systems continue to power, for a limited time, these critical systems and ensure a safe shutdown of the accelerator. This week, work began to upgrade and replace over 100 UPS systems in the LHC.   The new UPS installations. For the LHC, even a perturbation on the mains is more than just an inconvenience: it often results in beam dumps and, in some cases, requires an energy extraction from superconducting circuits. When this occurs, machine protection systems, and in particular the Quench Protection System, must remain active to correctly carry out the shutdown procedure. With the UPS systems, 10 minutes of crucial power can be provided to the protection systems during this critical phase. There are currently two UPS systems in place in each one of the 32 LHC UPS zones. Originally one was used as a backup if ...

  12. Scintillating Fibre Calorimetry at the LHC

    CERN Multimedia

    2002-01-01

    Good electromagnetic and hadronic calorimetry will play a central role in an LHC detector. The lead/scintillating fibre calorimeter technique provides a fast signal response well matched to the LHC rate requirements. It can be made to give equal response for electrons and hadrons (compensation) with good electromagnetic and hadronic energy resolutions.\\\\ \\\\ The aim of this R&D proposal is to study in detail the aspects that are relevant for application of this type of calorimeter in an LHC environment, including its integration in a larger system of detectors, e.g.~projective geometry, radiation hardness, light detection, calibration and stability monitoring, electron/hadron separation.....

  13. Slice through an LHC bending magnet

    CERN Multimedia

    Slice through an LHC superconducting dipole (bending) magnet. The slice includes a cut through the magnet wiring (niobium titanium), the beampipe and the steel magnet yokes. Particle beams in the Large Hadron Collider (LHC) have the same energy as a high-speed train, squeezed ready for collision into a space narrower than a human hair. Huge forces are needed to control them. Dipole magnets (2 poles) are used to bend the paths of the protons around the 27 km ring. Quadrupole magnets (4 poles) focus the proton beams and squeeze them so that more particles collide when the beams’ paths cross. There are 1232 15m long dipole magnets in the LHC.

  14. Exotic nuclear excitations

    CERN Document Server

    Pancholi, S C

    2011-01-01

    By providing the reader with a foundational background in high spin nuclear structure physics and exploring exciting current discoveries in the field, this book presents new phenomena in a clear and compelling way. The quest for achieving the highest spin states has resulted in some remarkable successes which this monograph will address in comprehensive detail. The text covers an array of pertinent subject matter, including the rotational alignment and bandcrossings, magnetic rotation, triaxial strong deformation and wobbling motion and chirality in nuclei. Dr. Pancholi offers his readers a clearly-written and up-to-date treatment of the topics covered. The prerequisites for a proper appreciation are courses in nuclear physics and nuclear models and measurement techniques of observables like gamma-ray energies, intensities, multi-fold coincidences, angular correlations or distributions, linear polarization, internal conversion coefficients, short lifetime (pico-second range) of excited states etc. and instrum...

  15. Exotic nuclei and astrophysics

    Directory of Open Access Journals (Sweden)

    Penionzhkevich Yu.

    2012-12-01

    Full Text Available In recent years, nuclear physics investigations of the laws of the microscopic world contributed significantly to extension of our knowledge of phenomena occurring in the macroscopic world (Universe and made a formidable contribution to the development of astrophysical and cosmological theories. First of all, this concerns the expanding universe model, the evolution of stars, and the abundances of elements, as well as the properties of various stars and cosmic objects, including “cold” and neutron stars, black holes, and pulsars. Without claiming to give a full account of all cosmological problems, we will dwell upon those of them that, in my opinion, have much in common with nuclear-matter properties manifesting themselves in nuclear interactions.

  16. HL-LHC updates in Japan

    CERN Multimedia

    Antonella Del Rosso

    2014-01-01

    At a recent meeting in Japan, updates on the High Luminosity LHC (HL-LHC) project were presented, including the progress made so far and the deadlines still to be met for the upgraded machine to be operational from 2020.   New magnets made with advanced superconductor Nb3Sn in the framework of the HL-LHC project. These magnets are currently under construction at CERN by the TE-MSC group. The LHC is the world’s most powerful particle accelerator, and in 2015 it will reach yet another new record for the energy of its colliding beams. One key factor of its discovery potential is its ability to produce collisions described in mathematical terms by the parameter known as “luminosity”. In 2025, the HL-LHC project will allow the total number of collisions in the LHC to increase by a factor of 10. The first step in this rich upgrade programme is the delivery of the Preliminary Design Report (PDR), which is also a key milestone of the HiLumi LHC Design Study partly fund...

  17. The whole world behind the LHC

    CERN Multimedia

    2001-01-01

    The LHC Board, which includes representatives of the non-Member State organisations directly involved in the construction of the LHC accelerator and representatives of CERN, held its fourth meeting on Monday 21 May 2001. From left to right: 1st row, A. Yamamoto (KEK, Japan), P. Pfund (FNAL, United States), L. Maiani (CERN Director-General), L. Evans (LHC Project Leader), F. Dupont (IN2P3, France), D.D. Bhawalkar (CAT, India) ; 2nd row, P. Brossier (CEA, France), N. Tyurin (IHEP, Russia), A. Skrinsky (BINP, Russia), A. Astbury (TRIUMF, Canada), P. Lebrun (LHC Division Leader, CERN); 3rd row, T. Taylor (Deputy Division Leader LHC Division, CERN), A. Shotter (TRIUMF, Canada), P. Bryant (LHC, CERN), K. Hübner (Director for Accelerators, CERN), J. van der Boon (Director of Administration, CERN). Although Canada, the United States, India, Japan and the Russian Federation are not members of CERN, they are all playing an active part in the construction of the LHC through important technical and financial co...

  18. LHC superconducting strand

    CERN Multimedia

    Patrice Loiez

    1999-01-01

    This cross-section through a strand of superconducting matieral as used in the LHC shows the 8000 Niobium-Titanium filaments embedded like a honeycomb in copper. When cooled to 1.9 degrees above absolute zero in the LHC accelerator, these filaments will have zero resistance and so will carry a high electric current with no energy loss.

  19. The physics behind LHC

    CERN Multimedia

    CERN. Geneva

    2006-01-01

    What do physicists want to discover with experiments at the LHC? What is the Higgs boson? What are the new phenomena that could be observed at the LHC?I will try to answer these questions using language accessible also to non-experts. Organiser(s): L. Alvarez-Gaume / PH-THNote: * Tea & coffee will be served at 16:00.

  20. Characterization of Indian and exotic quality protein maize (QPM ...

    African Journals Online (AJOL)

    Polymorphism analysis and genetic diversity of normal maize and quality protein maize (QPM) inbreds among locally well adapted germplasm is a prerequisite for hybrid maize breeding program. The diversity analyses of 48 maize accessions including Indian and exotic germplasm using 75 simple sequence repeat (SSR) ...

  1. Backward exotic meson production in π-n→px--

    International Nuclear Information System (INIS)

    Mantell, D.

    1978-01-01

    A discussion is given of some of the theory and theoretical techniques as well as actual previous experiments for the study of π - + n → p + X -- interactions. Included are the forces, classification, inclusive reactions, quark diagrams, properties of the unobserved X, cross sections, exotic mesons, duality and crossing, the working and normalization of some actual rexperiments, and analysis. 10 references

  2. Exotics. Heavy pentaquarks and tetraquarks

    International Nuclear Information System (INIS)

    Ali, Ahmed; Lange, Jens Soeren; Stone, Sheldon

    2017-07-01

    For many decades after the invention of the quark model in 1964 there was no evidence that hadrons are formed from anything other than the simplest pairings of quarks and antiquarks, mesons being formed of a quark-antiquark pair and baryons from three quarks. In the last decade, however, in an explosion of data from both e"+e"- and hadron colliders, there are many recently observed states that do not fit into this picture. These new particles are called generically ''exotics''. They can be either mesons or baryons. Remarkably, they all decay into at least one meson formed of either a c anti c or b anti b pair. In this review, after the introduction, we explore each of these new discoveries in detail first from an experimental point of view, then subsequently give a theoretical discussion. These exotics can be explained if the new mesons contain two-quarks and two antiquarks (tetraquarks), while the baryons contain four-quarks plus an antiquark (pentaquarks). The theoretical explanations for these states take three divergent tracks: tightly bound objects, just as in the case of normal hadrons, but with more constituents, or loosely bound ''molecules'' similar to the deuteron, but formed from two mesons, or a meson or baryon, or more wistfully, they are not multiquark states but appear due to kinematic effects caused by different rescatterings of virtual particles; most of these models have all been post-dictions. Both the tightly and loosely bound models predict the masses and related quantum numbers of new, as yet undiscovered states. Thus, future experimental discoveries are needed along with theoretical advances to elucidate the structure of these new exotic states.

  3. Exotics. Heavy pentaquarks and tetraquarks

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Ahmed [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Lange, Jens Soeren [Giessen Univ. (Germany). II. Physikalisches Inst.; Stone, Sheldon [Syracuse Univ., Syracuse, NY (United States). Physics Dept.

    2017-07-15

    For many decades after the invention of the quark model in 1964 there was no evidence that hadrons are formed from anything other than the simplest pairings of quarks and antiquarks, mesons being formed of a quark-antiquark pair and baryons from three quarks. In the last decade, however, in an explosion of data from both e{sup +}e{sup -} and hadron colliders, there are many recently observed states that do not fit into this picture. These new particles are called generically ''exotics''. They can be either mesons or baryons. Remarkably, they all decay into at least one meson formed of either a c anti c or b anti b pair. In this review, after the introduction, we explore each of these new discoveries in detail first from an experimental point of view, then subsequently give a theoretical discussion. These exotics can be explained if the new mesons contain two-quarks and two antiquarks (tetraquarks), while the baryons contain four-quarks plus an antiquark (pentaquarks). The theoretical explanations for these states take three divergent tracks: tightly bound objects, just as in the case of normal hadrons, but with more constituents, or loosely bound ''molecules'' similar to the deuteron, but formed from two mesons, or a meson or baryon, or more wistfully, they are not multiquark states but appear due to kinematic effects caused by different rescatterings of virtual particles; most of these models have all been post-dictions. Both the tightly and loosely bound models predict the masses and related quantum numbers of new, as yet undiscovered states. Thus, future experimental discoveries are needed along with theoretical advances to elucidate the structure of these new exotic states.

  4. Design of superconducting corrector magnets for LHC

    International Nuclear Information System (INIS)

    Baynham, D.E.; Coombs, R.C.; Ijspeert, A.; Perin, R.

    1994-01-01

    The Large Hadron Collider (LHC) will require a range of superconducting corrector magnets. This paper presents the design of sextupole and decapole corrector coils which will be included as spool pieces adjacent to reach main ring dipole. The paper gives detailed 3D field computations of the coil configurations to meet LHC beam dynamics requirements. Coil protection within a long string environment is addressed and mechanical design outlines are presented

  5. Design of superconducting corrector magnets for LHC

    Science.gov (United States)

    Baynham, D. E.; Coombs, R. C.; Ijspeert, A.; Perin, R.

    1994-07-01

    The Large Hadron Collider (LHC) will require a range of superconducting corrector magnets. This paper presents the design of sextupole and decapole corrector coils which will be included as spool pieces adjacent to each main ring dipole. The paper gives detailed 3D field computations of the coil configurations to meet LHC beam dynamics requirements. Coil protection within a long string environment is addressed and mechanical design outlines are presented.

  6. Exotic Nuclei Arena in JHP

    International Nuclear Information System (INIS)

    Nomura, T.

    1991-12-01

    The Exotic Nuclei Arena planned in Japanese Hadron Project aims to accelerate various unstable nuclei produced in 1-GeV proton-induced reactions up to 6.5 MeV/u by means of heavy-ion linacs. The present status of research and development for the Earena is briefly reported. The construction of the prototype facility to accelerate unstable beams up to 0.8 MeV/u is planned in 1992-94, in which the existing cyclotron in INS is used as the primary accelerator. (author)

  7. Mitigating exotic impacts: restoring native deer mouse populations elevated by an exotic food subsidy

    Science.gov (United States)

    Dean E. Pearson; Robert J. Fletcher

    2008-01-01

    The threat posed by exotic organisms to native systems has led to extensive research on exotic invaders, yet management of invasives has progressed relatively slowly. This is partly due to poor understanding of how exotic species management influences native organisms. To address this shortfall, we experimentally evaluated the efficacy of an invasives management tool...

  8. LHC Report: LHC hit the target!

    CERN Multimedia

    Enrico Bravin for the LHC team

    2016-01-01

    Last week, the accumulated integrated luminosity reached the target value for 2016 of 25 fb-1 in both ATLAS and CMS.   The integrated luminosity delivered to ATLAS and CMS reached (and already passed!) 25 fb-1– the target for the whole year! Tuesday, 30 August was just a regular day for the 2016 LHC run. However,  on that day, the integrated luminosity delivered to ATLAS and CMS reached 25 fb-1 – the target for the whole year! How did we get here? A large group of committed scientists and technical experts work behind the scenes at the LHC, ready to adapt to the quirks of this truly impressive machine. After the push to produce as many proton-proton collisions as possible before the summer conferences, several new ideas and production techniques (such as Bunch Compression Multiple Splitting, BCMS) have been incorporated in the operation of LHC in order to boost its performance even further. Thanks to these improvements, the LHC was routinely operated with peak luminos...

  9. Exotic Higgs decay h → φφ → 4b at the LHeC

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shang; Zhang, Chen [Peking University, Institute of Theoretical Physics and State Key Laboratory of Nuclear Physics and Technology, Beijing (China); Tang, Yi-Lei [Peking University, Center for High Energy Physics, Beijing (China); Zhu, Shou-hua [Peking University, Institute of Theoretical Physics and State Key Laboratory of Nuclear Physics and Technology, Beijing (China); Peking University, Center for High Energy Physics, Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China)

    2017-07-15

    We study the exotic decay of the 125 GeV Higgs boson (h) into a pair of light spin-0 particles (φ) which subsequently decay and result in a 4b final state. This channel is well motivated in models with an extended Higgs sector. Instead of searching at the Large Hadron Collider (LHC) and the high luminosity LHC (HL-LHC) which are beset by large standard model (SM) backgrounds, we investigate this decay channel at the much cleaner Large Hadron Electron Collider (LHeC). With some simple selection cuts this channel becomes nearly free of background at this ep machine, in sharp contrast to the situation at the (HL-)LHC. With a parton level analysis we show that for the φ mass range [20,60] GeV, with 100 fb{sup -1} luminosity the LHeC is generally capable of constraining C{sub 4b}{sup 2} ≡ κ{sub V}{sup 2} x Br(h → φφ) x Br{sup 2}(φ → b anti b) (κ{sub V} denotes the hVV(V = W, Z) coupling strength relative to the SM value) to a few percent level (95% CLs). With 1 ab{sup -1} luminosity C{sub 4b}{sup 2} at a few per mille level can be probed. These sensitivities are much better than the HL-LHC performance and demonstrate the important role expected to be played by the LHeC in probing exotic Higgs decay processes, in addition to the already proposed invisible Higgs decay channel. (orig.)

  10. The LHC babies

    CERN Multimedia

    Laëtitia Pedroso

    2011-01-01

    With the machine restart and first collisions at 3.5 TeV, 2009 and 2010 were two action-packed years at the LHC. The events were a real media success, but one important result that remained well hidden was the ten births in the LHC team over the same period. The mothers – engineers, cryogenics experts and administrative assistants working for the LHC – confirm that it is possible to maintain a reasonable work-life balance. Two of them tell us more…   Verena Kain (left) and Reyes Alemany (right) in the CERN Control Centre. With the LHC running around the clock, LHC operations engineers have high-pressure jobs with unsociable working hours. These past two years, which will undoubtedly go down in the annals of CERN history, the LHC team had their work cut out, but despite their high-octane professional lives, several female members of the team took up no less of a challenge in their private lives, creating a mini-baby-boom by which the LHC start-up will also be remembe...

  11. Literature in Focus Perspectives on LHC Physics

    CERN Multimedia

    2008-01-01

    The CERN Library invites you to a book presentation, a Literature in Focus event. The Large Hadron Collider (LHC) will be the world’s largest, highest energy and highest intensity particle accelerator. This is a timely book with several perspectives on the hoped-for discoveries from the LHC. This book provides an overview of the techniques that will be crucial for finding new physics at the LHC, as well as perspectives on the importance and implications of the discoveries. Among the accomplished contributors to this book are leaders and visionaries in the field of particle physics beyond the Standard Model, including two Nobel Laureates (Steven Weinberg and Frank Wilczek). With its blend of popular and technical contents, the book will have wide appeal, not only to physical scientists but also to those in related fields. Perspectives on LHC Physics (World Scientific Publishing) Gordon Kane and Aaron Pierce (eds.) Tuesday 12 August, 4.30pm Council Chamber Refresh...

  12. LHC preparations change gear

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

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

  13. Conference: STANDARD MODEL @ LHC

    CERN Multimedia

    2012-01-01

    HCØ institute Universitetsparken 5 DK-2100 Copenhagen Ø Denmark Room: Auditorium 2 STANDARD MODEL @ LHC Niels Bohr International Academy and Discovery Center 10-13 April 2012 This four day meeting will bring together both experimental and theoretical aspects of Standard Model phenomenology at the LHC. The very latest results from the LHC experiments will be under discussion. Topics covered will be split into the following categories:     * QCD (Hard,Soft & PDFs)     * Vector Boson production     * Higgs searches     * Top Quark Physics     * Flavour physics

  14. HL-LHC alternatives

    CERN Document Server

    Tomás, R; White, S

    2014-01-01

    The HL-LHC parameters assume unexplored regimes for hadron colliders in various aspects of accelerator beam dynamics and technology. This paper reviews three alternatives that could potentially improve the LHC performance: (i) the alternative filling scheme 8b+4e, (ii) the use of a 200 MHz RF system in the LHC and (iii) the use of proton cooling methods to reduce the beam emittance (at top energy and at injection). The alternatives are assessed in terms of feasibility, pros and cons, risks versus benefits and the impact on beam availability.

  15. The Lhc beam commissioning

    International Nuclear Information System (INIS)

    Redarelli, S.; Bailey, R.

    2008-01-01

    The plans for the Lhc proton beam commissioning are presented. A staged commissioning approach is proposed to satisfy the request of the Lhc experiments while minimizing the machine complexity in early commissioning phases. Machine protection and collimation aspects will be tackled progressively as the performance will be pushed to higher beam intensities. The key parameters are the number of bunches, k b , the proton intensity pe bunch, N, and the β in the various interaction points. All together these parameters determine the total beam power and the complexity of the machine. We will present the proposed trade off between the evolution of these parameters and the Lhc luminosity performance.

  16. The super-LHC

    CERN Document Server

    Mangano, Michelangelo L

    2010-01-01

    We review here the prospects of a long-term upgrade programme for the Large Hadron Collider (LHC), CERN laboratory's new proton-proton collider. The super-LHC, which is currently under evaluation and design, is expected to deliver of the order of ten times the statistics of the LHC. In addition to a non-technical summary of the principal physics arguments for the upgrade, I present a pedagogical introduction to the technological challenges on the accelerator and experimental fronts, and a review of the current status of the planning.

  17. Experimental evidence for hadroproduction of exotic mesons

    International Nuclear Information System (INIS)

    G. S. Adams; T. Adams; Z. Bar-Yam; J. M. Bishop; V. A. Bodyagin; B. B. Brabson; D. S. Brown; N. M. Cason; S. U. Chung; R. R. Crittenden; J. P. Cummings; K. Danyo; S. Denisov; V. Dorofeev; J. P. Dowd; A. R. Dzierba; P. Eugenio; J. Gunter; R. W. Hackenburg; M. Hayek; E. I. Ivanov; I. Kachaev; W. Kern; E. King; O. L. Kodolova; V. L. Korotkikh; M. A. Kostin; J. Kuhn; R. Lindenbusch; V. Lipaev; J. M. LoSecco; J. J. Manak; J. Napolitano; M. Nozar; C. Olchanski; A. I. Ostrovidov; T. K. Pedlar; A. Popov; D. R. Rust; D. Ryabchikov; A. H. Sanjari; L. I. Sarycheva; E. Scott; K. K. Seth; N. Shenhav; W. D. Shephard; N. B. Sinev; J. A. Smith; P. T. Smith; D. L. Stienike; T. Sulanke; S. A. Taegar; S. Teige; D. R. Thompson; I. N. Vardanyan; D. P. Weygand; D. White; H. J. Willutzki; J. Wise; M. Witkowski; A. A. Yershov; D. Zhao

    2001-01-01

    New measurements of peripheral meson production are presented. The data confirm the existence of exotic mesons at 1.4 and 1.6 GeV/c2. The latter state dominates the eta'pi- decay spectrum. The data on eta pi+pi-pi- decay show large strength in several exotic (Jpc = 1- +) waves as well

  18. The mass and radius of exotic fragment

    International Nuclear Information System (INIS)

    Schutz, Y.

    1989-01-01

    Recent developments in the study of exotic nuclei are presented. A method to measure the ground-state mass is presented and the results are compared with standard models. Total reaction cross section measurements for exotic nuclei are also presented and interpreted in terms of matter distribution in the nucleus

  19. Domestic exotics and the perception of invasibility

    Science.gov (United States)

    Qinfeng Guo; Robert Ricklefs

    2010-01-01

    Susceptibility of an area to invasion by exotic species is often judged by the fraction of introduced species in the local biota. However, the degree of invasion, particularly in mainland areas, has often been underestimated because of the exclusion of ‘domestic exotics’ (those introduced to internal units from within the national border) in calculations. Because all...

  20. Search for exotic mesons at SLAC

    International Nuclear Information System (INIS)

    Bonamy, P.; Baggett, N.; Fieguth, T.

    1975-01-01

    The theoretical justification and results from recent experimental searches for backward-produced exotic mesons including two experiments carried out by the collaboration at SLAC are reviewed. The first experiment put upper limits of about 1 to 2 μb for X ++ → (2π, 4π, 6π) ++ and anti ppπ + π + in the reaction π + + p → X ++ + n/sub forward/ at 8.4 GeV/c studied with the SLAC 14 inch rapid cycling bubble chamber triggered by a downstream neutron detector. Also the important features of the recently completed second experiment with the SLAC streamer chamber to study the reaction π - + p → X -- + p/sub forward/ at 14 GeV/c are discussed

  1. Probing exotic physics with cosmic neutrinos

    International Nuclear Information System (INIS)

    Hooper, Dan; Fermilab

    2005-01-01

    Traditionally, collider experiments have been the primary tool used in searching for particle physics beyond the Standard Model. In this talk, I will discuss alternative approaches for exploring exotic physics scenarios using high energy and ultra-high energy cosmic neutrinos. Such neutrinos can be used to study interactions at energies higher, and over baselines longer, than those accessible to colliders. In this way, neutrino astronomy can provide a window into fundamental physics which is highly complementary to collider techniques. I will discuss the role of neutrino astronomy in fundamental physics, considering the use of such techniques in studying several specific scenarios including low scale gravity models, Standard Model electroweak instanton induced interactions, decaying neutrinos and quantum decoherence

  2. LHC beam energy in 2012

    International Nuclear Information System (INIS)

    Siemko, A.; Charifouline, Z.; Dahlerup-Petersen, K.; Denz, R.; Ravaioli, E.; Schmidt, R.; Verweij, A.

    2012-01-01

    The interconnections between the LHC main magnets are made of soldered joints (splices) of two superconducting cables stabilized by a copper bus bar. The measurements performed in 2009 in the whole machine, in particular in sector 3-4 during the repair after the 2008 accident, demonstrated that there is a significant fraction of defective copper bus bar joints in the machine. In this paper, the limiting factors for operating the LHC at higher energies with defective 13 kA bus bar joints are briefly reviewed. The experience gained during the 2011 run, including the quench statistics and dedicated quench propagation tests impacting on maximum safe energy are presented. The impact of the by-pass diode contact resistance issue is also addressed. Finally, a proposal for running at the highest possible safe energy compatible with the pre-defined risk level is presented. (authors)

  3. LHC Beam Energy in 2012

    CERN Document Server

    Siemko, A; Dahlerup-Petersen, K; Denz, R; Ravaioli, E; Schmidt, R; Verweij, A

    2012-01-01

    The interconnections between the LHC main magnets are made of soldered joints (splices) of two superconducting cables stabilized by a copper bus bar. The measurements performed in 2009 in the whole machine, in particular in sector 3-4 during the repair after the 2008 accident, demonstrated that there is a significant fraction of defective copper bus bar joints in the machine. In this paper, the limiting factors for operating the LHC at higher energies with defective 13 kA bus bar joints are briefly reviewed. The experience gained during the 2011 run, including the quench statistics and dedicated quench propagation tests impacting on maximum safe energy are presented. The impact of the by-pass diode contact resistance issue is also addressed. Finally, a proposal for running at the highest possible safe energy compatible with the pre-defined risk level is presented.

  4. Present and Future Experiments with Stored Exotic Nuclei at GSI

    International Nuclear Information System (INIS)

    Geissel, H.

    2009-01-01

    Recent results and perspectives of experiments with stored exotic nuclei at GSI-FAIR will presented. An overview on the planned NUSTAR experiments will also presented. Relativistic exotic nuclei produced via projectile fragmentation and fission were separated in flight by the fragment separator FRS and injected into the storage-cooler ring ESR for accurate mass- and lifetime measurements. Direct mass measurements of electron-cooled exotic nuclei were performed using time-resolved Schottky spectrometry. Fragments with half-lives shorter than the time required for electron cooling have been investigated by time-of-flight measurements with the ESR being operated in the isochronous mode. This novel experimental technique gives access to all nuclei with half-lives down to the microsecond range and has been successfully applied. Lifetimes of stored bare and few-electron ions have been measured with the goal to study the beta-decay under ionization conditions prevailing in stellar plasma. For the first time the direct observation of bound-state beta decay has been achieved with 2 07T l fragments. The future project FAIR includes a new large-acceptance in-flight separator (Super-FRS) in combination with a new storage ring system (CR, NESR) which will be ideal tools to study exotic nuclei far from stability.(author)

  5. Confirmation of the Z(4430)- resonance and other exotic meson results from the LHCb experiment

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    The LHCb experiment at CERN has recently confirmed the existence of the exotic Z(4430)- state first observed by the Belle experiment in 2008. Its quantum numbers have been measured and the resonant nature of this state has been demonstrated for the first time. As it is charged, the Z(4430)- cannot be classified as a conventional charmonium (ccbar) state, making it a candidate for an exotic resonance composed of four quarks (ccbar udbar). This talk will outline the history of the Z(4430)-, its possible interpretations and describe how the signature of this exotic state can be extracted from the large sample of B0 -> psi(2S) K+pi- decays that LHCb has collected during Run-1 of the LHC. I will also describe recent LHCb results that probe the nature of the exotic X(3872) particle and help to clarify our understanding of the f0(500) and f0(980) scalar mesons that have long thought to be four quark states.

  6. Single top quark production cross-section measurements using the ATLAS and CMS detectors at the LHC

    CERN Document Server

    Finelli, Kevin Daniel; The ATLAS collaboration

    2015-01-01

    Measurements of single top quark production in proton--proton collisions at 7 and 8 TeV using the ATLAS and CMS detectors at the LHC are presented. In the leading order process, a $W$ boson is exchanged in the $t$-channel. The single top quark and anti-top total production cross-sections ratio, as well as a measurement of the inclusive and fiducial production cross-sections are presented. In addition, a measurement of the production cross-section of a single top quark in association with a $W$ boson is presented. All measurements are compared to state-of-the-art theoretical calculations and the CKM matrix element $|V_{tb}|$ is determined. The $s$-channel production is also explored and limits on exotic production in single top quark processes are discussed. This includes the search for additional $W’$ bosons and a search for monotops.

  7. LHC brochure (Italian version)

    CERN Multimedia

    Lefevre, Christiane

    2011-01-01

    A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

  8. LHC brochure (German version)

    CERN Multimedia

    Lefevre, Christiane

    2011-01-01

    A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which will start-up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

  9. LHC brochure (French version)

    CERN Multimedia

    Lefevre, C

    2010-01-01

    A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

  10. LHC brochure (Danish version)

    CERN Multimedia

    Lefevre, C

    2010-01-01

    A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

  11. LHC brochure (English version)

    CERN Multimedia

    Lefevre, C

    2010-01-01

    A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

  12. LHC brochure (French version)

    CERN Multimedia

    Marcastel, Fabienne

    2014-01-01

    A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

  13. LHC brochure (English version)

    CERN Multimedia

    AUTHOR|(CDS)2070305

    2014-01-01

    A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

  14. LHC Brochure (german version)

    CERN Multimedia

    Vanoli, C.

    2006-01-01

    A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which will start-up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

  15. LHC brochure (German version)

    CERN Multimedia

    Lefevre, C

    2008-01-01

    A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which will start-up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

  16. CERN recognises LHC suppliers

    CERN Multimedia

    2002-01-01

    CERN has just presented the first awards recognising LHC suppliers. The Russian institute BINP, the Belgian firm Cockerill-Sambre and the US company Wah-Chang are the recipients of the first 'Golden Hadrons'.

  17. LHC Luminosity Performance

    CERN Document Server

    AUTHOR|(CDS)2091107; Fuchsberger, Kajetan; Papotti, Giulia

    This thesis adresses several approaches with the common goal of assessing, understanding and improving the luminosity of the Large Hadron Collider (LHC). To better exploit existing margins for maximum luminosity while fulfilling the requirements of the LHC experiments, new techniques for luminosity levelling are studied and developed to an operational state, such as changing the crossing angle or $\\beta^*$ (beam size) at the interaction points with the beams in collisions. In 2017 LHC operation, the crossing angle reduction in collisions improved the integrated luminosity by $\\mathrm{\\sim} 2\\,\\mathrm{fb^{-1}}$ ($\\mathrm{\\sim} 4\\,\\mathrm{\\%}$ of the yearly production). For additional diagnostics, a new method for measuring beam sizes and orbits for each circulating bunch using the luminosity measurement during beam separation scans is shown. The results of these Emittance Scans improved the understanding of the LHC luminosity reach and of the orbit offsets introduced by beam-beam long-range effects.

  18. LHC brochure (German version)

    CERN Multimedia

    Marcastel, Fabienne

    2014-01-01

    A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

  19. LHC brochure (Spanish version)

    CERN Multimedia

    Lefevre, C

    2008-01-01

    A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which will start-up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

  20. LHC: seven golden suppliers

    CERN Multimedia

    2005-01-01

    The fourth CERN Golden Hadron awards saw seven of the LHC's best suppliers receive recognition for the high quality of their work, compliance with delivery deadlines, flexibility and adaptability to the demanding working conditions of the project. The representatives of the seven companies which received awards during the Golden Hadron ceremony, standing with Lyn Evans, LHC Project Leader. 'The Golden Hadron awards are a symbol of our appreciation of not only the quality and timely delivery of components but also the collaborative and flexible way the firms have contributed to this very difficult project,' said Lyn Evans, head of the LHC project. The awards went to Kemppi-Kempower (Finland), Metso Powdermet (Finland), Transtechnik (Germany), Babcock Noell Nuclear (Germany), Iniziative Industriali (Italy), ZTS VVU Kosice (Slovakia), and Jehier (France). Babock Noell Nuclear (BNN) successfully produced one-third (416 cold dipole masses) of the LHC's superconducting dipole magnets, one of the most critical an...

  1. The Large Hadron Collider (LHC): The Energy Frontier

    Science.gov (United States)

    Brianti, Giorgio; Jenni, Peter

    The following sections are included: * Introduction * Superconducting Magnets: Powerful, Precise, Plentiful * LHC Cryogenics: Quantum Fluids at Work * Current Leads: High Temperature Superconductors to the Fore * A Pumping Vacuum Chamber: Ultimate Simplicity * Vertex Detectors at LHC: In Search of Beauty * Large Silicon Trackers: Fast, Precise, Efficient * Two Approaches to High Resolution Electromagnetic Calorimetry * Multigap Resistive Plate Chamber: Chronometry of Particles * The LHCb RICH: The Lord of the Cherenkov Rings * Signal Processing: Taming the LHC Data Avalanche * Giant Magnets for Giant Detectors

  2. LHC First Beam 2008

    CERN Multimedia

    Tuura, L

    2008-01-01

    The CMS Centre played a major part in the LHC First Beam Event on September 10th 2008: it was a central point for CMS, hosting journalists from all over the world and providing live link-ups to collaborating institutes as well as, of course, monitoring events as they happened at Point 5. It was also a venue for celebration as the beam completed circuits of the LHC in both directions, passing successfully through the detector (Courtesy of Lassi Tuura)

  3. submitter LHC experiments

    CERN Document Server

    Tanaka, Shuji

    2001-01-01

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

  4. Future of LHC

    CERN Document Server

    Dova, Maria-Teresa; The ATLAS collaboration

    2018-01-01

    The High-Luminosity LHC aims to provide a total integrated luminosity of 3000 fb-1 from p-p collisions at  14 TeV over the course of 10 years. The upgraded ATLAS detector must be able to cope well with increased occupancies and data rates. The large data samples at the High-Luminosity LHC will enable precise measurements of the Higgs boson and other Standard Model particles, as well as searches for new phenomena BSM.

  5. Considerations on Energy Frontier Colliders after LHC

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir [Fermilab

    2016-11-15

    Since 1960’s, particle colliders have been in the forefront of particle physics, 29 total have been built and operated, 7 are in operation now. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). The future of the world-wide HEP community critically depends on the feasibility of possible post-LHC colliders. The concept of the feasibility is complex and includes at least three factors: feasibility of energy, feasibility of luminosity and feasibility of cost. Here we overview all current options for post-LHC colliders from such perspective (ILC, CLIC, Muon Collider, plasma colliders, CEPC, FCC, HE-LHC) and discuss major challenges and accelerator R&D required to demonstrate feasibility of an energy frontier accelerator facility following the LHC. We conclude by taking a look into ultimate energy reach accelerators based on plasmas and crystals, and discussion on the perspectives for the far future of the accelerator-based particle physics. This paper largely follows previous study [1] and the presenta ion given at the ICHEP’2016 conference in Chicago [2].

  6. LHC Report: astounding availability

    CERN Multimedia

    Andrea Apollonio for the LHC team

    2016-01-01

    The LHC is off to an excellent start in 2016, having already produced triple the luminosity of 2015. An important factor in the impressive performance so far this year is the unprecedented machine availability.   LHC integrated luminosity in 2011, 2012, 2015 and 2016 and the prediction of the 2016 performance foreseen at the start of the year. Following the 2015-2016 end of year shutdown, the LHC restarted beam operation in March 2016. Between the restart and the first technical stop (TS1) in June, the LHC's beam intensity was successively increased, achieving operation with 2040 bunches per beam. The technical stop on 7-8 June was shortened to maximise the time available for luminosity production for the LHC experiments before the summer conferences. Following the technical stop, operation resumed and quickly returned to the performance levels previously achieved. Since then, the LHC has been running steadily with up to 2076 bunches per beam. Since the technical stop, a...

  7. LHC INAUGURATION, LHC Fest highlights: exhibition time!

    CERN Multimedia

    2008-01-01

    David Gross, one of the twenty-one Nobel Laureates who have participated in the project.Tuesday 21 October 2008 Accelerating Nobels Colliding Charm, Atomic Cuisine, The Good Anomaly, A Quark Somewhere on the White Paper, Wire Proliferation, A Tale of Two Liquids … these are just some of the titles given to artworks by Physics Nobel Laureates who agreed to make drawings of their prize-winning discoveries (more or less reluctantly) during a special photo session. Science photographer Volker Steger made portraits of Physics Nobel Laureates and before the photo sessions he asked them to make a drawing of their most important discovery. The result is "Accelerating Nobels", an exhibition that combines unusual portraits of and original drawings by twenty-one Nobel laureates in physics whose work is closely related to CERN and the LHC. This exhibition will be one of the highlights of the LHC celebrations on 21 October in the SM18 hall b...

  8. Exotic RG flows from holography

    Energy Technology Data Exchange (ETDEWEB)

    Kiritsis, Elias [APC, Universite Paris 7, CNRS/IN2P3, CEA/IRFU, Obs. de Paris, Sorbonne Paris Cite (France); Crete Center for Theoretical Physics, Institute for Theoretical and Computational Physics, Department of Physics, University of Crete, Heraklion (Greece); Crete Center for Quantum Complexity and Nanotechnology, Department of Physics, University of Crete, Heraklion (Greece); Nitti, Francesco; Silva Pimenta, Leandro [APC, Universite Paris 7, CNRS/IN2P3, CEA/IRFU, Obs. de Paris, Sorbonne Paris Cite (France)

    2017-02-15

    Holographic RG flows are studied in an Einstein-dilaton theory with a general potential. The superpotential formalism is utilized in order to characterize and classify all solutions that are associated with asymptotically AdS space-times. Such solutions correspond to holographic RG flows and are characterized by their holographic β-functions. Novel solutions are found that have exotic properties from a RG point-of view. Some have β-functions that are defined patch-wise and lead to flows where the β-function changes sign without the flow stopping. Others describe flows that end in non-neighboring extrema in field space. Finally others describe regular flows between two minima of the potential and correspond holographically to flows driven by the VEV of an irrelevant operator in the UV CFT. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. LHC detectors trigger/DAQ at LHC

    CERN Document Server

    Sphicas, Paris

    1998-01-01

    At its design luminosity, the LHC will deliver hundreds of millions of proton-proton interactions per second. Storage and computing limitations limit the number of physics events that can be recorded to about 100 per second. The selection will be carried out by the Trigger and data acquisition systems of the experiments. This lecture will review the requirements, architectures and various designs currently considered.

  10. LHC Report: LHC smashes collision records

    CERN Multimedia

    Sarah Charley

    2016-01-01

    The Large Hadron Collider is now producing more than a billion proton-proton collisions per second.   The LHC is colliding protons at a faster rate than ever before: approximately 1 billion times per second. Since April 2016, the LHC has delivered more than 30 inverse femtobarns (fb-1) to both ATLAS and CMS. This means that around 2.4 quadrillion (2.4 million billion) collisions have been seen by each of the experiments this year. The inverse femtobarn is the unit of measurement for integrated luminosity, indicating the cumulative number of potential collisions. This compares with the total of 33.2 fb-1 produced between 2010 and 2015. The unprecedented performance this year is the result of both the incremental increases in collision rate and the sheer amount of time the LHC has been up and running. This comes after a slow start-up in 2015, when scientists and engineers still needed to learn how to operate the machine at a much higher energy. “With more energy, the machine is much more sen...

  11. Latest news from the LHC

    CERN Document Server

    CERN Bulletin

    2010-01-01

    Last week the LHC passed the threshold of 3 pb-1 total integrated luminosity delivered to the experiments, of which about half was delivered in just one week. These excellent results were achieved by operating the machine with up to 50 nominal bunches per beam.   After a very successful week that saw intense beams circulating for long periods (a total of 76.5 hours of stable beams, corresponding to about 40% of the time), there has been a technical stop this week. Over the coming days, experts will work on bunch trains with 150 ns spacing between bunches (the current minimum spacing is 1000 ns). This will involve making the necessary changes throughout the injector chain, as well as in the LHC itself. In the LHC, bunch trains imply working with a crossing angle throughout the machine cycle, in order to avoid unwanted parasitic collisions, which means that the whole process of injection, ramp and squeeze will have to be re-commissioned. The task also includes re-commissioning all the protection syste...

  12. Cryogenics for HL-LHC

    Science.gov (United States)

    Tavian, L.; Brodzinski, K.; Claudet, S.; Ferlin, G.; Wagner, U.; van Weelderen, R.

    The discovery of a Higgs boson at CERN in 2012 is the start of a major program of work to measure this particle's properties with the highest possible precision for testing the validity of the Standard Model and to search for further new physics at the energy frontier. The LHC is in a unique position to pursue this program. Europe's top priority is the exploitation of the full potential of the LHC, including the high-luminosity upgrade of the machine and detectors with an objective to collect ten times more data than in the initial design, by around 2030. To reach this objective, the LHC cryogenic system must be upgraded to withstand higher beam current and higher luminosity at top energy while keeping the same operation availability by improving the collimation system and the protection of electronics sensitive to radiation. This chapter will present the conceptual design of the cryogenic system upgrade with recent updates in performance requirements, the corresponding layout and architecture of the system as well as the main technical challenges which have to be met in the coming years.

  13. LHC Report: a brief deceleration

    CERN Multimedia

    Rossano Giachino & Markus Albert

    2015-01-01

    The LHC has now transitioned from powering tests to the machine checkout phase. This phase involves the full-scale tests of all systems in preparation for beam. Early last Saturday morning, during the ramp-down, an earth fault developed in the main dipole circuit. Full evaluation of the situation is ongoing.   The various systems are put through their operational paces from the CCC. This includes important tests of the beam dump system and full-scale tests of the beam interlock system (BIS) and its many inputs from other systems around the ring. All magnetic circuits are driven through the ramp, squeeze, ramp-down, and pre-cycle along with the collimators and RF. Instrumentation, feedbacks, and the control system are also stress tested. Inevitably there is some final frantic debugging but, up to now, things seem to be in reasonable shape. The machine checkout is an important coming together of all LHC systems. During this final phase before beam, the operations team tests all of the LHC subsystem...

  14. The latest from the LHC

    CERN Multimedia

    2009-01-01

    Work on closing up sectors in the LHC tunnel. The foreseen shutdown work on the LHC is proceeding well, including the powering tests with the new quench protection system. However, during the past week vacuum leaks have been found in two "cold" sectors of the LHC. The leaks were found in Sectors 8-1 and 2-3 while they were being prepared for the electrical tests on the copper stabilizers at around 80 K. In both cases the leak is at one end of the sector, where the electrical feedbox, DFBA, joins Q7, the final magnet in the sector. Unfortunately, the repair necessitates a partial warm-up of both sectors. This involves the end sub-sector being warmed to room temperature, while the adjacent sub-sector "floats" in temperature and the remainder of the sector is kept at 80 K. As the leak is from the helium circuit to the insulating vacuum, the repair work will have no impact on the vacuum in the beam pipe. However the intervention wil...

  15. Exotic quarkonium states in CMS

    CERN Document Server

    Cristella, Leonardo

    2017-01-01

    The studies of the production of the $X(3872)$, either prompt or from B hadron decays, and of the $J/\\psi \\phi$ mass spectrum in B hadron decays have been carried out by using $pp$ collisions at $\\sqrt{s}=7$ TeV collected with the CMS detector at the LHC. %The production of the $X(3872)$ is studied in $pp$ collisions at $\\sqrt{s} = 7$ TeV with the CMS detector at LHC, using decays to $J/\\psi\\pi^{+}\\pi^{-}$ where the $J/\\psi$ decays to two muons. The cross-section ratio of the $X(3872)$ with respect to the $\\psi(2S)$ in the $J/\\psi\\pi^{+}\\pi^{-}$ decay channel and the fraction of $X(3872)$ coming from B-hadron decays are measured as a function of transverse momentum ($p\\mathrm{_T}$), covering unprecedentedly high values of $p\\mathrm{_T}$. For the first time, the prompt production cross section for the $X(3872)$ times the unknown branching fraction for the decay of $X(3872) \\rightarrow J/\\psi\\pi^{+}\\pi^{-}$ is extracted differentially in $p\\mathrm{_T}$ and compared to theoretical predictions based on the Non-R...

  16. Experiment Dashboard for Monitoring of the LHC Distributed Computing Systems

    International Nuclear Information System (INIS)

    Andreeva, J; Campos, M Devesas; Cros, J Tarragon; Gaidioz, B; Karavakis, E; Kokoszkiewicz, L; Lanciotti, E; Maier, G; Ollivier, W; Nowotka, M; Rocha, R; Sadykov, T; Saiz, P; Sargsyan, L; Sidorova, I; Tuckett, D

    2011-01-01

    LHC experiments are currently taking collisions data. A distributed computing model chosen by the four main LHC experiments allows physicists to benefit from resources spread all over the world. The distributed model and the scale of LHC computing activities increase the level of complexity of middleware, and also the chances of possible failures or inefficiencies in involved components. In order to ensure the required performance and functionality of the LHC computing system, monitoring the status of the distributed sites and services as well as monitoring LHC computing activities are among the key factors. Over the last years, the Experiment Dashboard team has been working on a number of applications that facilitate the monitoring of different activities: including following up jobs, transfers, and also site and service availabilities. This presentation describes Experiment Dashboard applications used by the LHC experiments and experience gained during the first months of data taking.

  17. Marine exotic isopods from the Iberian Peninsula and nearby waters.

    Science.gov (United States)

    Martínez-Laiz, Gemma; Ros, Macarena; Guerra-García, José M

    2018-01-01

    Effective management of marine bioinvasions starts with prevention, communication among the scientific community and comprehensive updated data on the distribution ranges of exotic species. Despite being a hotspot for introduction due to numerous shipping routes converging at the Strait of Gibraltar, knowledge of marine exotics in the Iberian Peninsula is scarce, especially of abundant but small-sized and taxonomically challenging taxa such as the Order Isopoda. To fill this gap, we conducted several sampling surveys in 44 marinas and provide the first comprehensive study of marine exotic isopods from the Iberian Peninsula, the southern side of the Strait of Gibraltar (northern Africa) and the Balearic Islands. Exotic species included Ianiropsis serricaudis (first record for the Iberian Peninsula and Lusitanian marine province), Paracerceis sculpta (first record for the Alboran Sea ecoregion), Paradella dianae , Paranthura japonica (earliest record for the Iberian Peninsula) and Sphaeroma walkeri . Photographs with morphological details for identification for non-taxonomic experts are provided, their worldwide distribution is updated and patterns of invasion are discussed. We report an expansion in the distribution range of all species, especially at the Strait of Gibraltar and nearby areas. Ianiropsis serricaudis and Paranthura japonica are polyvectic, with shellfish trade and recreational boating being most probable vectors for their introduction and secondary spread. The subsequent finding of the studied species in additional marinas over the years points at recreational boating as a vector and indicates a future spread. We call for attention to reduce lags in the detection and reporting of small-size exotics, which usually remain overlooked or underestimated until the invasion process is at an advanced stage.

  18. Search for exotic Higgs boson decays to pairs of light pseudoscalars with the CMS detector

    CERN Document Server

    Caillol, Cecile

    2018-01-01

    Searches for exotic Higgs boson decays to pairs of light pseudoscalars are performed using the data collected by the CMS experiment at center-of-mass energies of 8 and 13 TeV. The results are interpreted in different scenarios of two Higgs doublet models extended by a scalar singlet. Particular emphasis is given to the recent $\\textrm{h}\\to \\textrm{aa}\\to 2\\textrm{b}2\\tau$ analysis, which is the first to target this decay chain at the LHC.

  19. LHC Abort Gap Cleaning with the Transverse Damper

    CERN Document Server

    Gianfelice-Wendt, E; Höfle, Wolfgang; Kain, V; Meddahi, M; Shaposhnikova, E; Koschik, A

    2010-01-01

    In the Large Hadron Collider, LHC, particles not captured by the RF system at injection or leaking out of the RF bucket may quench the superconducting magnets during beam abort. The problem, common to other superconducting machines, is particularly serious for the LHC due to the very large stored energy in the beam. For the LHC a way of removing the unbunched beam has been studied and it uses the existing damper kickers to excite resonantly the particles travelling along the abort gap. In this paper we describe the results of simulations performed with MAD X for various LHC optics configurations, including the estimated multipolar errors.

  20. Higher representations and multijet resonances at the LHC

    International Nuclear Information System (INIS)

    Kumar, Jason; Thomas, Brooks; Rajaraman, Arvind

    2011-01-01

    The CMS Collaboration has recently conducted a search for trijet resonances in multijet events at the LHC. Motivated in part by this analysis, we examine the phenomenology of exotic particles transforming under higher representations of SU(3) color, focusing on those representations which intrinsically prohibit decays to fewer than three jets. We determine the LHC discovery reach for a particle transforming in a representation of this sort and discuss several additional theoretical and phenomenological constraints which apply to such a particle. Furthermore, we demonstrate that such a particle can provide a consistent explanation for a trijet excess (an invariant-mass peak of roughly 375 GeV) observed in the recent CMS study.

  1. Testing ATLAS diboson excess with dark matter searches at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Liew, Seng Pei [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Shirai, Satoshi [Deutsches Elektronen-Synchrotron (DESY), 22607 Hamburg (Germany)

    2015-11-27

    The ATLAS collaboration has recently reported a 2.6σ excess in the search for a heavy resonance decaying into a pair of weak gauge bosons. Only fully hadronic final states are being looked for in the analysis. If the observed excess really originates from the gauge bosons’ decays, other decay modes of the gauge bosons would inevitably leave a trace on other exotic searches. In this paper, we propose the use of the Z boson decay into a pair of neutrinos to test the excess. This decay leads to a very large missing energy and can be probed with conventional dark matter searches at the LHC. We discuss the current constraints from the dark matter searches and the prospects. We find that optimizing these searches may give a very robust probe of the resonance, even with the currently available data of the 8 TeV LHC.

  2. Testing ATLAS diboson excess with dark matter searches at LHC

    International Nuclear Information System (INIS)

    Liew, Seng Pei; Shirai, Satoshi

    2015-01-01

    The ATLAS collaboration has recently reported a 2.6σ excess in the search for a heavy resonance decaying into a pair of weak gauge bosons. Only fully hadronic final states are being looked for in the analysis. If the observed excess really originates from the gauge bosons’ decays, other decay modes of the gauge bosons would inevitably leave a trace on other exotic searches. In this paper, we propose the use of the Z boson decay into a pair of neutrinos to test the excess. This decay leads to a very large missing energy and can be probed with conventional dark matter searches at the LHC. We discuss the current constraints from the dark matter searches and the prospects. We find that optimizing these searches may give a very robust probe of the resonance, even with the currently available data of the 8 TeV LHC.

  3. Testing ATLAS diboson excess with dark matter searches at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Liew, Seng Pei [Tokyo Univ. (Japan). Dept. of Physics; Shirai, Satoshi [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2015-08-15

    The ATLAS collaboration has recently reported a 2.6σ excess in the search for a heavy resonance decaying into a pair of weak gauge bosons. Only fully hadronic final states are being looked for in the analysis. If the observed excess really originates from the gauge bosons' decays, other decay modes of the gauge bosons would inevitably leave a trace on other exotic searches. In this paper, we propose the use of the Z boson into a pair of neutrinos to test the excess. This decay leads to a very large missing energy and can be probed with conventional dark matter searches at the LHC. We discuss the current constraints from the dark matter searches and the prospects. We find that optimizing these searches may give a very robust probe of the resonance, even with the currently available data of the 8 TeV LHC.

  4. Young and Exotic Stellar Zoo

    Science.gov (United States)

    2005-03-01

    Universe. Westerlund 1 will certainly provide new opportunities in the long-standing quest for more and finer details about how stars, and especially massive ones, do form. ... and the Most Dense The large number of stars in Westerlund 1 was not the only surprise awaiting Clark and his colleagues. From their observations, the team members also found that all these stars are packed into an amazingly small volume of space, indeed less than 6 light-years across. In fact, this is more or less comparable to the 4 light-year distance to the star nearest to the Sun, Proxima Centauri! It is incredible: the concentration in Westerlund 1 is so high that the mean separation between stars is quite similar to the extent of the Solar System. "With so many stars in such a small volume, some of them may collide", envisages Simon Clark. "This could lead to the formation of an intermediate-mass black hole more massive than 100 solar masses. It may well be that such a monster has already formed at the core of Westerlund 1." The huge population of massive stars in Westerlund 1 suggests that it will have a very significant impact on its surroundings. The cluster contains so many massive stars that in a time span of less than 40 million years, it will be the site of more than 1,500 supernovae. A gigantic firework that may drive a fountain of galactic material! Because Westerlund 1 is at a distance of only about 10,000 light-years, high-resolution cameras such as NAOS/CONICA on ESO's Very Large Telescope can resolve its individual stars. Such observations are now starting to reveal smaller stars in Westerlund 1, including some that are less massive than the Sun. Astronomers will thus soon be able to study this exotic galactic zoo in great depth. More information The research presented in this ESO Press Release will soon appear in the leading research journal Astronomy and Astrophysics ("On the massive stellar population of the Super Star Cluster Westerlund 1" by J.S. Clark and colleagues). The

  5. LHC Report: Take Five

    CERN Multimedia

    Mike Lamont for the LHC Team

    2011-01-01

    The LHC is continuing to perform well and an integrated luminosity of over 5fb-1 has now been delivered to ATLAS and CMS. While keeping a close eye on beam induced heating and vacuum quality, the bunch current has been gently raised to over 1.4x1011 protons per bunch. This has given a peak luminosity of 3.6x1033 cm-2s-1. Some long fills have helped production and recent high points include 120pb-1 delivered in one fill and 580pb-1 delivered in one week.   Time has also been devoted to some special physics runs for TOTEM and ALFA. In these runs, the beam is de-squeezed to a ß* of 90 m in ATLAS and CMS. This is instead of the usual 1m ß*, and gives a larger beam size at interaction points. The increased beam size results in a reduced beam divergence at the interaction points. This permits TOTEM and ALFA to probe low-angle scattering and allows them to measure the total cross section of proton-proton interactions and the absolute luminosity cal...

  6. Exotic mammals disperse exotic fungi that promote invasion by exotic trees.

    Science.gov (United States)

    Nuñez, Martin A; Hayward, Jeremy; Horton, Thomas R; Amico, Guillermo C; Dimarco, Romina D; Barrios-Garcia, M Noelia; Simberloff, Daniel

    2013-01-01

    Biological invasions are often complex phenomena because many factors influence their outcome. One key aspect is how non-natives interact with the local biota. Interaction with local species may be especially important for exotic species that require an obligatory mutualist, such as Pinaceae species that need ectomycorrhizal (EM) fungi. EM fungi and seeds of Pinaceae disperse independently, so they may use different vectors. We studied the role of exotic mammals as dispersal agents of EM fungi on Isla Victoria, Argentina, where many Pinaceae species have been introduced. Only a few of these tree species have become invasive, and they are found in high densities only near plantations, partly because these Pinaceae trees lack proper EM fungi when their seeds land far from plantations. Native mammals (a dwarf deer and rodents) are rare around plantations and do not appear to play a role in these invasions. With greenhouse experiments using animal feces as inoculum, plus observational and molecular studies, we found that wild boar and deer, both non-native, are dispersing EM fungi. Approximately 30% of the Pinaceae seedlings growing with feces of wild boar and 15% of the seedlings growing with deer feces were colonized by non-native EM fungi. Seedlings growing in control pots were not colonized by EM fungi. We found a low diversity of fungi colonizing the seedlings, with the hypogeous Rhizopogon as the most abundant genus. Wild boar, a recent introduction to the island, appear to be the main animal dispersing the fungi and may be playing a key role in facilitating the invasion of pine trees and even triggering their spread. These results show that interactions among non-natives help explain pine invasions in our study area.

  7. The top quark as a probe for searching new physics at the LHC using the ATLAS detector

    International Nuclear Information System (INIS)

    Kukla, Romain

    2016-01-01

    The work of this thesis focuses on the search for new physics beyond the Standard Model in the compositeness framework, which postulates strongly coupled sectors at the TeV-scale consisting of exotic particles. Their existence can be tested at the CERN proton-proton collider, the LHC, using the ATLAS detector. The production of an heavy quark, such as the T5/3 predicted in those models, can be inferred from an enhancement of the cross-section of a given signature. Some final states, such as the one studied in this thesis involving 2 same-sign leptons, are very rare and have an excellent sensitivity. Searches for T5/3 production at the LHC using 8 and 13 TeV ATLAS data are presented. A small excess is seen at 8 TeV. Preliminary results of the 13 TeV analysis are presented and do not show any excess. The inferior limits put on the T5/3 mass is 745 GeV at 8 TeV and 990 GeV at 13 TeV. Composite models include also heavy bosons such as top-philic Z' coupled only to the top quark whose production in association to a top quark pair gives a final state similar to those from 4 tops events. A phenomenological study on the discovery potential of those exotic (Z' and effective theory) or standard (tttt) processes at 13 and 14 TeV is done and gives the minimal luminosities needed to observe deviations from the Standard Model. An instrumental study for the conception of the new LTDB card, part of the electromagnetic calorimeter's level 1 trigger system is described in the context of the ATLAS upgrade program. (author) [fr

  8. Trends in exotic-atom research

    International Nuclear Information System (INIS)

    Lambrecht, R.M.; Horvath, D.

    1983-01-01

    An attempt was made to analyze the trends in the development of exotic-atom research on the basis of a recently compiled bibliography. The analysis of nearly 4000 publications demonstrated that: (1) exotic atoms are nuclear probes used in every field of physics, from the test of quantum electrodynamics (QED) to chemical physics, to materials sciences; (2) the role of nuclear and atomic physics in exotic atom research is decreasing (although it is still significant), while that of materials sciences and chemial physics is exponentially increasing; and (3) prior to 1980 most investigators were mainly interested in atoms with negative muons, while during the last few years the positive muon (μSR) studies have dominated exotic atom research

  9. Probabilistic methods in exotic option pricing

    NARCIS (Netherlands)

    Anderluh, J.H.M.

    2007-01-01

    The thesis presents three ways of calculating the Parisian option price as an illustration of probabilistic methods in exotic option pricing. Moreover options on commidities are considered and double-sided barrier options in a compound Poisson framework.

  10. A comprehensive method for exotic option pricing

    OpenAIRE

    Rossella Agliardi

    2010-01-01

    This work illustrates how several new pricing formulas for exotic options can be derived within a Levy framework by employing a unique pricing expression. Many existing pricing formulas of the traditional Gaussian model are obtained as a by-product.

  11. Commissioning of the LHC

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    The LHC construction is now approaching the end and it is now time to prepare for commissioning with beam. The behavior of a proton storage ring is much different to that of LEP, which profited from strong radiation damping to keep the beam stable. Our last experience with a hadron collider at CERN goes back more than 15 years when the proton-antiproton collider last operated. Ppbar taught us a lot about the machine physics of bunched beam proton storage rings and was essential input for the design of the LHC. After a short presentation of where we stand today with machine installation and hardware commissioning, I will discuss the main machine physics issues that will have to be dealt with in the LHC.

  12. Electronics at LHC

    CERN Document Server

    Hall, Geoffrey

    1998-01-01

    An overview of the electronic readout systems planned for use in the CMS and ATLAS experiments at the LHC will be given, with an emphasis on the motivations for the designs adopted and major technologies to be employed, specially those which are specific to LHC. At its design luminosity, the LHC will deliver hundreds of millions of proton-proton interactions per second. Storage and computing limitations limit the number of physics events that can be recorded to about 100 per second. The selection will be carried out by the Trigger and data acquisition systems of the experiments. This lecture will review the requirements, architectures and various designs currently considered. Introduction. Structure of gauge theories. The QED and QCD examples. Chiral theories. The electroweak theory. Spontaneous symmetry breaking. The Higgs machanism.Gauge boson and fermion masses. Yukawa coupling. Charges current couplings. The Cabibbo-Kobayashi-Maskawa matrix and CP violation. neutral current couplings. the Clashow-Iliopoul...

  13. LHC bending magnet coil

    CERN Multimedia

    A short test version of coil of wire used for the LHC dipole magnets. The high magnetic fields needed for guiding particles around the Large Hadron Collider (LHC) ring are created by passing 12’500 amps of current through coils of superconducting wiring. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC is the largest superconducting installation ever built. The magnetic field must also be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. Indeed, nowhere before has such precision been achieved at such high currents. Magnet coils are made of copper-clad niobium–titanium cables — each wire in the cable consists of 9’000 niobium–titanium filaments ten times finer than a hair.

  14. Lectures on LHC physics

    CERN Document Server

    Plehn, Tilman

    2015-01-01

    With the discovery of the Higgs boson, the LHC experiments have closed the most important gap in our understanding of fundamental interactions, confirming that such interactions between elementary particles can be described by quantum field theory, more specifically by a renormalizable gauge theory. This theory is a priori valid for arbitrarily high energy scales and does not require an ultraviolet completion. Yet, when trying to apply the concrete knowledge of quantum field theory to actual LHC physics - in particular to the Higgs sector and certain regimes of QCD - one inevitably encounters an intricate maze of phenomenological know-how, common lore and other, often historically developed intuitions about what works and what doesn’t. These lectures cover three aspects to help understand LHC results in the Higgs sector and in searches for physics beyond the Standard Model: they discuss the many facets of Higgs physics, which is at the core of this significantly expanded second edition; then QCD, to the deg...

  15. The LHC in numbers

    CERN Multimedia

    Alizée Dauvergne

    2010-01-01

    What makes the LHC the biggest particle accelerator in the world? Here are some of the numbers that characterise the LHC, and their equivalents in terms that are easier for us to imagine.   Feature Number Equivalent Circumference ~ 27 km   Distance covered by beam in 10 hours ~ 10 billion km a round trip to Neptune Number of times a single proton travels around the ring each second 11 245   Speed of protons first entering the LHC 299 732 500 m/s 99.9998 % of the speed of light Speed of protons when they collide 299 789 760 m/s 99.9999991 % of the speed of light Collision temperature ~ 1016 °C ove...

  16. UFOs in the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Grob, Laura [CERN, Geneva (Switzerland); Technische Universitaet Darmstadt (Germany)

    2016-07-01

    In the Large Hadron Collider (LHC) localized and recurring beam losses have been observed, which usually persist for several hundred microseconds. With increasing beam energy these losses were found to pose a serious risk to the machine availability, as some of these events can cause quenches in the superconducting magnets. The current understanding is that these losses are caused by falling microparticles that interact with the proton beam. To describe these so-called UFOs (unidentified falling objects) and their dynamics, a model was developed starting from the approach that only gravitational and electrostatic forces act on a neutrally charged particle. However, the model's results cannot reproduce the actual data from the LHC's beam loss monitors (BLMs), which indicates a more complex UFO dynamic. Experimental studies and further analysis of the BLM data are planned to investigate the UFO dynamics in greater detail and to understand origins and release mechanisms for microparticles in the LHC beam pipe.

  17. Meteors, space aliens, and other exotic encounters

    Science.gov (United States)

    Tom. Hofacker

    1998-01-01

    Exotics have had a big impact on our environment. If you do not think so, just look at how many people believe that humans would not exist on this planet were it not for exotics. This belief centers on two main theories: (1) that humans could not have evolved were it not for a huge meteor from outer space striking the earth resulting in extinction of the dinasours, the...

  18. Exotic hadron and string junction model

    International Nuclear Information System (INIS)

    Imachi, Masahiro

    1978-01-01

    Hadron structure is investigated adopting string junction model as a realization of confinement. Besides exotic hadrons (M 4 , B 5 etc.), unconventional hadrons appear. A mass formula for these hadrons is proposed. New selection rule is introduced which requires the covalence of constituent line at hadron vertex. New duality appears due to the freedom of junction, especially in anti BB→anti BB reaction. A possible assignment of exotic and unconventional hadrons to recently observed narrow meson states is presented. (auth.)

  19. Deep electroproduction of exotic hybrid mesons

    International Nuclear Information System (INIS)

    Anikin, I.V.; Pire, B.; Szymanowski, L.; Teryaev, O.V.; Wallon, S.

    2004-01-01

    We evaluate the leading order amplitude for the deep exclusive electroproduction of an exotic hybrid meson in the Bjorken regime. We show that, contrarily to naive expectation, this amplitude factorizes at the twist 2 level and thus scales like usual meson electroproduction when the virtual photon and the hybrid meson are longitudinally polarized. Exotic hybrid mesons may thus be studied in electroproduction experiments at JLAB, HERA (HERMES) or CERN (Compass)

  20. CARBONIFEROUS CORALS AND CHAETETIDS FROM EXOTIC LIMESTONE BLOCK OF THE CRIMEA

    OpenAIRE

    OGAR, VICTOR; KLEVTSOVSKYI, ANDREY

    2015-01-01

    A chaetetid sponge and coral fauna from a Carboniferous exotic limestone block in the Lower Jurassic Esciorda olistostrome on the Bodrak River (Crimean Mountains) are described for the first time. The Bodrak exotic block is composed of massive limestone. It contains the chaetetid Chaetetes (Boswellia) sp., the tabulate coral Multithecopora sp., and poorly preserved rugose corals, including Dibunophyllum? sp., Cordibia? sp. and gen. et sp. indet. Only the fasciculate colonies of the rugose cor...

  1. Cryogenics will cool LHC

    International Nuclear Information System (INIS)

    Anon.

    2001-01-01

    Results of the investigation into the cryogenic regulating line (QRL) performed by the LHC laboratory are presented. It is projected that eight cryogenic units located in five places around the LHC ring will provide superconducting magnets by liquid helium through eight cryogenic regulating lines of 3.2 km each. All QRL zones remain to be independent. CERN uses three test units with the aim of the certification of chosen constructions and verification of their thermal and mechanical efficiency before starting full-scale production [ru

  2. LHC-ILC synergy

    CERN Document Server

    Godbole, Rohini M

    2006-01-01

    I will begin by making a few general comments on the synergy between the Large Hadron Collider (LHC) which will go in action in 2007 and the International Linear Collider (ILC) which is under planning. I will then focus on the synergy between the LHC and the PLC option at the ILC, which is expected to be realised in the later stages of the ILC program. In this I will cover the possible synergy in the Higgs sector (with and without CP violation), in the determination of the anomalous vector boson couplings and last but not the least, in the search for extra dimensions and radions.

  3. The LHC detector challenge

    CERN Document Server

    Virdee, Tejinder S

    2004-01-01

    The Large Hadron Collider (LHC) from CERN, scheduled to come online in 2007, is a multi-TeV proton-proton collider with vast detectors. Two of the more significant detectors for LHC are ATLAS and CMS. Currently, both detectors are more than 65% complete in terms of financial commitment, and the experiments are being assembled at an increasing pace. ATLAS is being built directly in its underground cavern, whereas CMS is being assembled above ground. When completed, both detectors will aid researchers in determining what lies at the high-energy frontier, in particular the mechanism by which particles attain mass. (Edited abstract).

  4. LHC beampipe interconnection

    CERN Document Server

    Particle beams circulate for around 10 hours in the Large Hadron Collider (LHC). During this time, the particles make four hundred million revolutions of the machine, travelling a distance equivalent to the diameter of the solar system. The beams must travel in a pipe which is emptied of air, to avoid collisions between the particles and air molecules (which are considerably bigger than protons). The beam pipes are pumped down to an air pressure similar to that on the surface of the moon. Much of the LHC runs at 1.9 degrees above absolute zero. When material is cooled, it contracts. The interconnections must absorb this contraction whilst maintaining electrical connectivity.

  5. Electron scattering and reactions from exotic nuclei

    International Nuclear Information System (INIS)

    Karataglidis, S.

    2017-01-01

    The SCRIT and FAIR/ELISe experiments are the first to attempt to measure directly electron scattering form factors from nuclei far from stability. This will give direct information for the (one-body) charge densities of those systems, about which there is little information available. The SCRIT experiment will be taking data for medium-mass exotic nuclei, while the electron-ion collider at ELISe, when constructed, will be able to measure form factors for a wide range of exotic nuclei, as available from the radioactive ion beams produced by the FAIR experiment. Other facilities are now being proposed, which will also consider electron scattering from exotic nuclei at higher energies, to study short-range correlations in exclusive reactions. This review will consider all available information concerning the current status (largely theoretical) of electron scattering from exotic nuclei and, where possible, complement such information with equivalent information concerning the neutron densities of those exotic systems, as obtained from intermediate energy proton scattering. The issue of long- and short-range correlations will be discussed, and whether extending such studies to the exotic sector will elicit new information. (orig.)

  6. EXOTIC: Development of ceramic tritium breeding materials

    International Nuclear Information System (INIS)

    Flipot, A.J.; Kennedy, P.; Conrad, R.

    1989-03-01

    As part of the joint European Programme on fusion blanket technology three laboratories, Northern Research Laboratories (NRL), Springfields in the UK, SCK/CEN-Mol in Belgium and ECN-Petten in conjunction with JRC-Petten in the Netherlands have worked closely together since 1983 on the development of ceramic breeder materials, the programme being codenamed EXOTIC. Lithium oxides, aluminates, silicates and zirconates have been produced, characterised and irradiated in the HFR-Petten in experiments EXOTIC-1, -2 and -3. EXOTIC-4 is in preparation. In this fourth annual progress report the work achieved in 1987 is reported. For EXOTIC-1 to -3 mainly post irradiation examinations have been carried out like: visual inspection, puncturing of closed capsules, tritium retention measurements and material characterisation. Moreover, tritium release experiments on small specimens have started. SCK/CEN performed a general study on lithium silicates, in particular on the thermal stability. Finally, the fabrication and the characterisation of the materials to be irradiated in experiment EXOTIC-4 are presented. The eight capsules of EXOTIC-4 will be loaed with samples of Li 2 SiO 3 , Li 2 O, Li 2 ZrO 3 , Li 6 Zr 2 O 7 and Li 8 ZrO 6 . The irradiation will last 4 reactor cycles or about 100, Full Power Day, FPD. The main objective is to determine the tritium residence time of the various lithium zirconates. 18 figs., 8 refs., 15 tabs

  7. Electron scattering and reactions from exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Karataglidis, S. [University of Johannesburg, Department of Physics, Auckland Park (South Africa); University of Melbourne, School of Physics, Victoria (Australia)

    2017-04-15

    The SCRIT and FAIR/ELISe experiments are the first to attempt to measure directly electron scattering form factors from nuclei far from stability. This will give direct information for the (one-body) charge densities of those systems, about which there is little information available. The SCRIT experiment will be taking data for medium-mass exotic nuclei, while the electron-ion collider at ELISe, when constructed, will be able to measure form factors for a wide range of exotic nuclei, as available from the radioactive ion beams produced by the FAIR experiment. Other facilities are now being proposed, which will also consider electron scattering from exotic nuclei at higher energies, to study short-range correlations in exclusive reactions. This review will consider all available information concerning the current status (largely theoretical) of electron scattering from exotic nuclei and, where possible, complement such information with equivalent information concerning the neutron densities of those exotic systems, as obtained from intermediate energy proton scattering. The issue of long- and short-range correlations will be discussed, and whether extending such studies to the exotic sector will elicit new information. (orig.)

  8. LHC Commissioning and First Operation

    OpenAIRE

    Myers, S

    2010-01-01

    A description is given of the repair of the LHC after the accident of September 2008. The LHC hardware and beam commissioning and initial operation are reviewed both in terms of beam and hardware performance. The implemented machine protection measures and their impact on LHC operation are presented.

  9. LHC challenges and upgrade options

    Energy Technology Data Exchange (ETDEWEB)

    Bruning, O [CERN AB/ABP, Y03600, 1211 Geneva 23 (Switzerland)], E-mail: Oliver.Bruning@cern.ch

    2008-05-15

    The presentation summarizes the key parameters of the LHC collider. Following a discussion of the main challenges for reaching the nominal machine performance the presentation identifies options for increasing the operation tolerances and the potential performance reach of the LHC by means of future hardware upgrades of the LHC and its injector complex.

  10. LHC challenges and upgrade options

    International Nuclear Information System (INIS)

    Bruning, O

    2008-01-01

    The presentation summarizes the key parameters of the LHC collider. Following a discussion of the main challenges for reaching the nominal machine performance the presentation identifies options for increasing the operation tolerances and the potential performance reach of the LHC by means of future hardware upgrades of the LHC and its injector complex

  11. Single top quark production cross-section and properties using the ATLAS detector at the LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00358737; The ATLAS collaboration

    2015-01-01

    ATLAS measurements of single top-quark processes are summarized. Measurements using data at 7 and 8 TeV collisions from the LHC are presented. The measurements are performed using the semi-leptonic decay mode of the top-quark. Production cross-sections and the $\\left|V_{tb}\\right|$ CKM matrix element extraction are shown. All measurements are compared to theoretical calculations. In addition, the $s$-channel production mode is explored along with limits on exotic production modes.

  12. LHC Report: Summer temperatures in the LHC

    CERN Multimedia

    Jan Uythoven for the LHC Team

    2012-01-01

    The LHC experiments have finished their data-taking period before the summer conferences. The machine has already delivered substantially more collisions to the experiments this year than in the whole of 2011. The LHC has now started a six-day Machine Development period, which will be followed by the second Technical Stop of the year.   The number of collisions delivered to the experiments is expressed in integrated luminosity. In 2011, the integrated luminosity delivered to both ATLAS and CMS was around 5.6 fb-1. On Monday 18 June, experiments finished taking data before the summer conferences and the integrated luminosity for 2012 so far is about 6.6 fb-1, well above the unofficial target of 5 fb-1. The LHC’s performance over the last week of running was so efficient that the injection kicker magnets – which heat up due to the circulating beam – did not have time to cool down between the subsequent fills. As the time constants for warming up and cooli...

  13. LHC Status and Upgrade Challenges

    Science.gov (United States)

    Smith, Jeffrey

    2009-11-01

    The Large Hadron Collider has had a trying start-up and a challenging operational future lays ahead. Critical to the machine's performance is controlling a beam of particles whose stored energy is equivalent to 80 kg of TNT. Unavoidable beam losses result in energy deposition throughout the machine and without adequate protection this power would result in quenching of the superconducting magnets. A brief overview of the machine layout and principles of operation will be reviewed including a summary of the September 2008 accident. The current status of the LHC, startup schedule and upgrade options to achieve the target luminosity will be presented.

  14. Exotic superconducting states in the extended attractive Hubbard model.

    Science.gov (United States)

    Nayak, Swagatam; Kumar, Sanjeev

    2018-04-04

    We show that the extended attractive Hubbard model on a square lattice allows for a variety of superconducting phases, including exotic mixed-symmetry phases with [Formula: see text] and [Formula: see text] symmetries, and a novel [Formula: see text] state. The calculations are performed within the Hartree-Fock Bardeen-Cooper-Schrieffer framework. The ground states of the mean-field Hamiltonian are obtained via a minimization scheme that relaxes the symmetry constraints on the superconducting solutions, hence allowing for a mixing of s-, p- and d-wave order parameters. The results are obtained within the assumption of uniform-density states. Our results show that extended attractive Hubbard model can serve as an effective model for investigating properties of exotic superconductors.

  15. Nuclear shapes: From the mundane to the exotic

    International Nuclear Information System (INIS)

    Yates, S.W.

    1994-01-01

    The collection of protons and neutrons that forms an atomic nucleus can be characterized as having a shape. Surprisingly, the nuclei of most atoms are not spherical but exhibit shapes that are football-like, pear-like, etc. Following a brief review of the characteristics of these open-quotes mundaneclose quotes nuclear shapes, recent observations of nuclei that are superdeformed or even hyperdeformed are presented. In addition, the evidence for more exotic nuclei that can be described as exhibiting halos, forming a nuclear sausage, or undergoing a scissors-like motion are examined. The discussion concludes with some speculation about additional exotic shapes, such as the nuclear banana. Since nuclear shapes cannot be observed directly, one must rely on knowledge from indirect sources. Some of the details about these sources of information, including excitation spectra and nuclear lifetimes, are presented

  16. Electrical Quality Assurance of the Superconducting Circuits during LHC Machine Assembly

    CERN Document Server

    Bozzini, D; Desebe, O; Mess, K H; Russenschuck, Stephan; Bednarek, M; Dworak, D; Górnicki, E; Jurkiewicz, P; Kapusta, P; Kotarba, A; Ludwin, J; Olek, S; Talach, M; Zieblinski, M; Klisch, M; Prochal, B

    2008-01-01

    Based on the LHC powering reference database, all-together 1750 superconducting circuits were connected in the various cryogenic transfer lines of the LHC machine. Testing the continuity, magnet polarity, and the quality of the electrical insulation were the main tasks of the Electrical Quality Assurance (ELQA) activities during the LHC machine assembly. With the assembly of the LHC now complete, the paper reviews the work flow, resources, and the qualification results including the different types of electrical non-conformities.

  17. HL-LHC kicker magnet (MKI)

    CERN Multimedia

    Brice, Maximilien

    2018-01-01

    HL-LHC kicker magnet (MKI): last vacuum test, preparation for transport to LHC transfer line in underground tunnel.The LHC injection kicker systems (MKIs) generate fast field pulses to inject the clockwise rotating beam at Point 2 and the anti-clockwise rotating beam at Point 8: there are eight MKI magnets installed in total. Each MKI magnet contains a high purity alumina tube: if an MKI magnet is replaced this tube requires conditioning with LHC beam: until it is properly conditioned, there can be high vacuum pressure due to the beam. This high pressure can also cause electrical breakdowns in the MKI magnets. A special coating (Cr2O3) has been applied to the inside of the alumina tube of an upgraded MKI magnet – this is expected to greatly reduce the pressure rise with beam. In addition, HL-LHC beam would result in excessive heating of the MKI magnets: the upgraded design includes modifications that will reduce heating, and move the power deposition to parts that will be easier to cool. Experience during 2...

  18. Academic Training: The LHC machine /experiment interface

    CERN Multimedia

    Françoise Benz

    2005-01-01

    2004-2005 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 18, 19, 20, 21 & 22 April from 11.00 to 12.00 hrs - Main Auditorium, bldg. 500 The LHC machine /experiment interface S. TAPPROGGE, Univ. of Mainz, D, R. ASSMANN, CERN-AB E. TSESMELIS and D. MACINA, CERN-TS This series of lectures will cover some of the major issues at the boundary between the LHC machine and the experiments: 1) The physics motivation and expectations of the experiments regarding the machine operation. This will include an overview of the LHC physics programme (in pp and PbPb collisions), of the experimental signatures (from high pT objects to leading nucleons) and of the expected trigger rates as well as the data sets needed for specific measurements. Furthermore, issues related to various modes of operation of the machine (e.g. bunch spacings of 25 ns. vs. 75 ns.) and special requirements of the detectors for their commissioning will be described. 2) The LHC machine aspects: introduction of the main LHC parameters and discu...

  19. High Luminosity LHC: challenges and plans

    Science.gov (United States)

    Arduini, G.; Barranco, J.; Bertarelli, A.; Biancacci, N.; Bruce, R.; Brüning, O.; Buffat, X.; Cai, Y.; Carver, L. R.; Fartoukh, S.; Giovannozzi, M.; Iadarola, G.; Li, K.; Lechner, A.; Medina Medrano, L.; Métral, E.; Nosochkov, Y.; Papaphilippou, Y.; Pellegrini, D.; Pieloni, T.; Qiang, J.; Redaelli, S.; Romano, A.; Rossi, L.; Rumolo, G.; Salvant, B.; Schenk, M.; Tambasco, C.; Tomás, R.; Valishev, S.; Van der Veken, F. F.

    2016-12-01

    The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a new energy frontier for exploration in 2010, it has gathered a global user community working in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. To sustain and extend its discovery potential, the LHC will undergo a major upgrade in the 2020s. This will increase its rate of collisions by a factor of five beyond the original design value and the integrated luminosity by a factor ten. The new configuration, known as High Luminosity LHC (HL-LHC), will rely on a number of key innovations that push accelerator technology beyond its present limits. Among these are cutting-edge 11-12 T superconducting magnets, including Nb3Sn-based magnets never used in accelerators before, compact superconducting cavities for longitudinal beam rotation, new technology and physical processes for beam collimation. The dynamics of the HL-LHC beams will be also particularly challenging and this aspect is the main focus of this paper.

  20. Academic Training: The LHC machine /experiment interface

    CERN Multimedia

    Françoise Benz

    2005-01-01

    2004-2005 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 18, 19, 20, 21 & 22 April from 11.00 to 12.00 hrs - Main Auditorium, bldg. 500 The LHC machine /experiment interface S. TAPPROGGE, Univ. of Mainz, D, R. ASSMANN, CERN-AB E. TSESMELIS and D. MACINA, CERN-TS This series of lectures will cover some of the major issues at the boundary between the LHC machine and the experiments: 1) The physics motivation and expectations of the experiments regarding the machine operation. This will include an overview of the LHC physics programme (in pp and PbPb collisions), of the experimental signatures (from high pT objects to leading nucleons) and of the expected trigger rates as well as the data sets needed for specific measurements. Furthermore, issues related to various modes of operation of the machine (e.g. bunch spacings of 25 ns. vs. 75 ns.) and special requirements of the detectors for their commissioning will be described. 2) The LHC machine aspects: introduction of the main LHC parameters and disc...

  1. Academic Training - LHC luminosity upgrade: detector challenges

    CERN Multimedia

    Françoise Benz

    2006-01-01

    ACADEMIC TRAINING LECTURE SERIES 13, 14, 15, March, from 11:00 to 12:00 - 16 March from 10:00 to 12:00 Main Auditorium, bldg. 500 on 14, 15 March, Council Room on 13, 16 March LHC luminosity upgrade: detector challenges A. De Roeck / CERN-PH, D. Bortoletto / Purdue Univ. USA, R. Wigmans / Texas, Tech Univ. USA, W. Riegler / CERN-PH, W. Smith / Wisconsin Univ. USA The upgrade of the LHC machine towards higher luminosity (1035 cm-2s-1) has been studied over the last few years. These studies have investigated scenarios to achieve the increase in peak luminosity by an order of magnitude, as well as the physics potential of such an upgrade and the impact of a machine upgrade on the LHC DETECTORS. This series of lectures will cover the following topics: Physics motivation and machine scenarios for an order of magnitude increase in the LHC peak luminosity (lecture 1) Detector challenges including overview of ideas for R&D programs by the LHC experiments: tracking and calorimetry, other new detector ...

  2. High Luminosity LHC: Challenges and plans

    International Nuclear Information System (INIS)

    Arduini, G.; Barranco, J.; Bertarelli, A.; Biancacci, N.; Bruce, R.

    2016-01-01

    The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a new energy frontier for exploration in 2010, it has gathered a global user community working in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. To sustain and extend its discovery potential, the LHC will undergo a major upgrade in the 2020s. This will increase its rate of collisions by a factor of five beyond the original design value and the integrated luminosity by a factor ten. The new configuration, known as High Luminosity LHC (HL-LHC), will rely on a number of key innovations that push accelerator technology beyond its present limits. Among these are cutting-edge 11–12 T superconducting magnets, including Nb 3 Sn-based magnets never used in accelerators before, compact superconducting cavities for longitudinal beam rotation, new technology and physical processes for beam collimation. As a result, the dynamics of the HL-LHC beams will be also particularly challenging and this aspect is the main focus of this paper.

  3. Camel as a transboundary vector for emerging exotic Salmonella serovars.

    Science.gov (United States)

    Ghoneim, Nahed H; Abdel-Moein, Khaled A; Zaher, Hala

    2017-05-01

    The current study was conducted to shed light on the role of imported camels as a transboundary vector for emerging exotic Salmonella serovars. Fecal samples were collected from 206 camels directly after slaughtering including 25 local camels and 181 imported ones as well as stool specimens were obtained from 50 slaughterhouse workers at the same abattoir. The obtained samples were cultured while Salmonella serovars were identified through Gram's stain films, biochemical tests and serotyping with antisera kit. Moreover, the obtained Salmonella serovars were examined by PCR for the presence of invA and stn genes. The overall prevalence of Salmonella serovars among the examined camels was 8.3%. Stn gene was detected in the vast majority of exotic strains (11/14) 78.6% including emerging serovars such as Salmonella Saintpaul, S. Chester, S. Typhimurium whereas only one isolate from local camels carried stn gene (1/3) 33.3%. On the other hand, none of the examined humans yielded positive result. Our findings highlight the potential role of imported camels as a transboundary vector for exotic emerging Salomenella serovars.

  4. CERN: LHC magnets

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    With test magnets for CERN's LHC proton-proton collider regularly attaining field strengths which show that 10 Tesla is not forbidden territory, attention turns to why and where quenches happen. If 'training' can be reduced, superconducting magnets become easier to commission

  5. Fully transparent LHC

    CERN Multimedia

    2008-01-01

    Thanks to the first real signals received from the LHC while in operation before the incident, the experiments are now set to make the best use of the data they have collected. Report from the LHCC open session.The September open session of the LHCC (LHC Experiments Committee) came just a few days after the incident that occurred at the LHC. The packed auditorium was a testament to the huge interest raised by Lyn Evans’ talk about the status of the machine and the plans for the future. After being told that the actual consequences of the incident will be clear only once Sector 3-4 has been warmed up, the audience focussed on the reports from the experiments. For the first time, the reports showed performance results of the various detectors with particles coming from the machine and not just from cosmic rays or tests and simulations. "The first days of LHC beam exceeded all expectations and the experiments made extensive and rapid use of the data they collected", says ...

  6. Higgs physics at LHC

    OpenAIRE

    Unal, G

    2006-01-01

    This is a review of Higgs physics at LHC. The topics covered are the search of the Standard Model Higgs boson (with emphasis on the low mass region), the measurements of the Higgs boson properties (mass, width, spin, CP and couplings) and the Higgs sector of the MSSM.

  7. Mobilizing for the LHC

    CERN Multimedia

    2008-01-01

    A follow-up report on the incident that occurred in LHC Sector 3-4 was published on 5 December. It confirms that the accelerator will be restarted in the summer of 2009. From now until then, the teams will be pulling out all the stops to repair the sector and enhance the operational safety of the machine.

  8. LHC: forwards and onwards

    CERN Multimedia

    2008-01-01

    Following the recent incident in Sector 3-4, which has brought the start-up of the LHC to a halt, the various teams are working hard to establish the cause, evaluate the situation and plan the necessary repairs. The LHC will be started up again in spring 2009 following the winter shutdown for the maintenance of all the CERN installations. The LHC teams are at work on warming up Sector 3-4 and establishing the cause of the serious incident that occurred on Friday, 19 September. Preliminary investigations suggest that the likely cause of the problem was a faulty electrical connection between two magnets. The connections probably melted, leading to a mechanical failure and a large leak of helium into the tunnel. However, the teams will not be able to carry out a full evaluation and assess the repairs needed until the sector has been warmed up again and inspected. "We are not worried about repairing the magnets as spare parts are available", said Lyn Evans, the LHC Project Leade...

  9. Higgs physics at LHC

    Indian Academy of Sciences (India)

    The large hadron collider (LHC) and its detectors, ATLAS and CMS, are being built to study TeV scale physics, and to fully understand the electroweak symmetry breaking mechanism. The Monte-Carlo simulation results for the standard model and minimal super symmetric standard model Higgs boson searches and ...

  10. Electronics for LHC Experiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This document gathers the abstracts of most presentations made at this workshop on electronics for the large hadron collider (LHC) experiments. The presentations were arranged into 6 sessions: 1) electronics for tracker, 2) trigger electronics, 3) detector control systems, 4) data acquisition, 5) electronics for calorimeters and electronics for muons, and 6) links, power systems, grounding and shielding, testing and quality assurance.

  11. CERN: LHC magnets

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1992-08-15

    With test magnets for CERN's LHC proton-proton collider regularly attaining field strengths which show that 10 Tesla is not forbidden territory, attention turns to why and where quenches happen. If 'training' can be reduced, superconducting magnets become easier to commission.

  12. Electronics for LHC Experiments

    International Nuclear Information System (INIS)

    2004-01-01

    This document gathers the abstracts of most presentations made at this workshop on electronics for the large hadron collider (LHC) experiments. The presentations were arranged into 6 sessions: 1) electronics for tracker, 2) trigger electronics, 3) detector control systems, 4) data acquisition, 5) electronics for calorimeters and electronics for muons, and 6) links, power systems, grounding and shielding, testing and quality assurance

  13. ATLAS. LHC experiments

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    In Greek mythology, Atlas was a Titan who had to hold up the heavens with his hands as a punishment for having taken part in a revolt against the Olympians. For LHC, the ATLAS detector will also have an onerous physics burden to bear, but this is seen as a golden opportunity rather than a punishment. The major physics goal of CERN's LHC proton-proton collider is the quest for the long-awaited£higgs' mechanism which drives the spontaneous symmetry breaking of the electroweak Standard Model picture. The large ATLAS collaboration proposes a large general-purpose detector to exploit the full discovery potential of LHC's proton collisions. LHC will provide proton-proton collision luminosities at the aweinspiring level of 1034 cm2 s~1, with initial running in at 1033. The ATLAS philosophy is to handle as many signatures as possible at all luminosity levels, with the initial running providing more complex possibilities. The ATLAS concept was first presented as a Letter of Intent to the LHC Committee in November 1992. Following initial presentations at the Evian meeting (Towards the LHC Experimental Programme') in March of that year, two ideas for generalpurpose detectors, the ASCOT and EAGLE schemes, merged, with Friedrich Dydak (MPI Munich) and Peter Jenni (CERN) as ATLAS cospokesmen. Since the initial Letter of Intent presentation, the ATLAS design has been optimized and developed, guided by physics performance studies and the LHC-oriented detector R&D programme (April/May, page 3). The overall detector concept is characterized by an inner superconducting solenoid (for inner tracking) and large superconducting air-core toroids outside the calorimetry. This solution avoids constraining the calorimetry while providing a high resolution, large acceptance and robust detector. The outer magnet will extend over a length of 26 metres, with an outer diameter of almost 20 metres. The total weight of the detector is 7,000 tonnes. Fitted with its end

  14. New EU project supports LHC theorists

    CERN Multimedia

    Katarina Anthony

    2011-01-01

    LHCPhenonet, a new EU-funded research network aimed at improving the theoretical predictions that guide the LHC experiments, has begun its 4-year run as a Marie Curie Initial Training Network. CERN joins the network as an associate partner, along with almost 30 multinational institutions and computing companies.   Theorists from around the world gathered in Valencia to attend LHCPhenonet's kick-off meeting. LHCPhenonet will create research opportunities for young, talented European theorists, providing funding for both doctoral and post-doctoral positions across the various participating institutions – including the University of Durham, DESY, and the Istituto Nazionale di Fisica Nucleare (INFN). LHCPhenoNet aims to improve the Quantum Field Theory calculations that set the parameters of the LHC experiments, focusing on the LHC phenomenology that gave it its name. The 4.5 million euro project is funded by the EU's 7th Research Framework Programme and will be coordinated through the Span...

  15. Demineralised water cooling in the LHC accelerator

    CERN Document Server

    Peón-Hernández, G

    2002-01-01

    In spite of the LHC accelerator being a cryogenic machine, it remains nevertheless a not negligible heat load to be removed by conventional water-cooling. About 24MW will be taken away by demineralised water cooled directly by primary water from the LHC cooling towers placed at the even points. This paper describes the demineralised water network in the LHC tunnel including pipe diameters, lengths, water speed, estimated friction factor, head losses and available supply and return pressures for each point. It lists all water cooled equipment, highlights the water cooled cables as the most demanding equipment followed by the radio frequency racks and cavities, and by the power converters. Their main cooling requirements and their positions in the tunnel are also presented.

  16. Distinctive exotic flavor and aroma compounds of some exotic tropical fruits and berries: a review.

    Science.gov (United States)

    Lasekan, Ola; Abbas, Kassim A

    2012-01-01

    The characteristic flavor of exotic tropical fruits is one of their most attractive attributes to consumers. In this article, the enormous diversity of exotic fruit flavors is reviewed. Classifying some of the exotic fruits into two classes on the basis of whether esters or terpenes predominate in the aroma was also attempted. Indeed, as far as exotic tropical fruits are concerned, the majority of fruits have terpenes predominating in their aroma profile. Some of the fruits in this group are the Amazonian fruits such as pitanga, umbu-caja, camu-camu, garcinia, and bacuri. The ester group is made up of rambutan, durians, star fruit, snake fruit, acerola, tamarind, sapodilla, genipap, soursop, cashew, melon, jackfruit, and cupuacu respectively. Also, the role of sulphur-volatiles in some of the exotic fruits is detailed.

  17. Exotic nuclear structures and decays: new nuclear collective phenomena

    International Nuclear Information System (INIS)

    Hamilton, J.H.

    1986-01-01

    Studies of the properties of exotic nuclei have revealed a surprising richness and diversity in their shapes, structures, and decay modes far exceeding our understandings and expectations of even a decay ago. From studies of far-off-stability exotic nuclei have come evidence for the coexistence of different nuclear shapes in the same nucleus, new regions of unusually large deformation, new ground-state phase transitions from one shape to another, new magic numbers but now for deformed shapes, and for the importance of reinforcing shell gaps. New exotic decay modes include a wide variety of beta delayed particle emission and heavy cluster emissions such as 14 C and 24 Ne. The new deformed magic numbers of 38 and 60 seen far off stability clearly support that there are likely other ''magic'' numbers for protons and neutrons which give stability to different deformed shapes. Perhaps these other new magic shell gap numbers at large deformation could influence the sticking of two very heavy nuclei in collisions such as U on Cm. Finally, another area which could have a bearing on the formation, motions, and structures of giant nuclear systems involves the recent observation of very energetic, light particle (proton, alpha) emission with up to 50% and more of the total incoming energy in a collision, for example in 300 MeV 32 S on Ta. 43 refs., 11 figs., 2 tabs

  18. Search for signatures with top, bottom, tau and exotics

    CERN Document Server

    Andrea Favareto; Luigi Longo

    2016-01-01

    The Standard Model (SM) of particle physics is a sensational success, especially since the discov- ery of the 125 GeV Higgs boson. However, there are still several open questions that the Standard Model doesnâ??t address, like the nature of dark matter and dark energy, the matter-antimatter asym- metry, the neutrino oscillations, the inconsistency with the general relativity and the hierarchy problem. Theories Beyond the Standard Model (BSM), such as Supersymmetry, Little and Com- posite Higgs, Extra-Dimensions, Extended Gauge models, Technicolor, Left-Right symmetric models, and many other BSM scenarios are trying to answer these questions. In these proceed- ings we present the most recent results for searches Beyond the Standard Model at the LHC by the ATLAS and CMS experiments, focusing on signatures with top, bottom, tau and exotics. The data are found to be consistent with the Standard Model. The non-observation of a signal permits to set limits at the 95pct confidence level on the production cross sect...

  19. The LHC Low Level RF

    CERN Document Server

    Baudrenghien, Philippe; Molendijk, John Cornelis; Olsen, Ragnar; Rohlev, Anton; Rossi, Vittorio; Stellfeld, Donat; Valuch, Daniel; Wehrle, Urs

    2006-01-01

    The LHC RF consists of eight 400 MHz superconducting cavities per ring, with each cavity independently powered by a 300 kW klystron, via a circulator. The challenge for the Low Level is to cope with very high beam current (more than 1 A RF component) and achieve excellent beam lifetime (emittance growth time in excess of 25 hours). Each cavity has an associated Cavity Controller rack consisting of two VME crates which implement high gain RF Feedback, a Tuner Loop with a new algorithm, a Klystron Ripple Loop and a Conditioning system. In addition each ring has a Beam Control system (four VME crates) which includes a Frequency Program, Phase Loop, Radial Loop and Synchronization Loop. A Longitudinal Damper (dipole and quadrupole mode) acting via the 400 MHz cavities is included to reduce emittance blow-up due to filamentation from phase and energy errors at injection. Finally an RF Synchronization system implements the bunch into bucket transfer from the SPS into each LHC ring. When fully installed in 2007, the...

  20. Human land use promotes the abundance and diversity of exotic species on caribbean islands.

    Science.gov (United States)

    Jesse, Wendy A M; Behm, Jocelyn E; Helmus, Matthew R; Ellers, Jacintha

    2018-05-31

    Human land use causes major changes in species abundance and composition, yet native and exotic species can exhibit different responses to land use change. Native populations generally decline in human-impacted habitats while exotic species often benefit. In this study, we assessed the effects of human land use on exotic and native reptile diversity, including functional diversity, which relates to the range of habitat use strategies in biotic communities. We surveyed 114 reptile communities from localities that varied in habitat structure and human impact level on two Caribbean islands, and calculated species richness, overall abundance and evenness for every plot. Functional diversity indices were calculated using published trait data, which enabled us to detect signs of trait filtering associated with impacted habitats. Our results show that environmental variation among sampling plots was explained by two PCA ordination axes related to habitat structure (i.e. forest or non-forest) and human impact level (i.e. addition of man-made constructions such as roads and buildings). Several diversity indices were significantly correlated with the two PCA axes, but exotic and native species showed opposing responses. Native species reached the highest abundance in forests, while exotic species were absent in this habitat. Human impact was associated with an increase in exotic abundance and species richness, while native species showed no significant associations. Functional diversity was highest in non-forested environments on both islands, and further increased on St. Martin with the establishment of functionally unique exotic species in non-forested habitat. Habitat structure, rather than human impact, proved to be an important agent for environmental filtering of traits, causing divergent functional trait values across forested and non-forested environments. Our results illustrate the importance of considering various elements of land use when studying its impact on

  1. Hunting, Exotic Carnivores, and Habitat Loss: Anthropogenic Effects on a Native Carnivore Community, Madagascar.

    Directory of Open Access Journals (Sweden)

    Zach J Farris

    Full Text Available The wide-ranging, cumulative, negative effects of anthropogenic disturbance, including habitat degradation, exotic species, and hunting, on native wildlife has been well documented across a range of habitats worldwide with carnivores potentially being the most vulnerable due to their more extinction prone characteristics. Investigating the effects of anthropogenic pressures on sympatric carnivores is needed to improve our ability to develop targeted, effective management plans for carnivore conservation worldwide. Utilizing photographic, line-transect, and habitat sampling, as well as landscape analyses and village-based bushmeat hunting surveys, we provide the first investigation of how multiple forms of habitat degradation (fragmentation, exotic carnivores, human encroachment, and hunting affect carnivore occupancy across Madagascar's largest protected area: the Masoala-Makira landscape. We found that as degradation increased, native carnivore occupancy and encounter rates decreased while exotic carnivore occupancy and encounter rates increased. Feral cats (Felis species and domestic dogs (Canis familiaris had higher occupancy than half of the native carnivore species across Madagascar's largest protected landscape. Bird and small mammal encounter rates were negatively associated with exotic carnivore occupancy, but positively associated with the occupancy of four native carnivore species. Spotted fanaloka (Fossa fossana occupancy was constrained by the presence of exotic feral cats and exotic small Indian civet (Viverricula indica. Hunting was intense across the four study sites where hunting was studied, with the highest rates for the small Indian civet (mean=90 individuals consumed/year, the ring-tailed vontsira (Galidia elegans (mean=58 consumed/year, and the fosa (Cryptoprocta ferox (mean=31 consumed/year. Our modeling results suggest hunters target intact forest where carnivore occupancy, abundance, and species richness, are highest

  2. Hunting, Exotic Carnivores, and Habitat Loss: Anthropogenic Effects on a Native Carnivore Community, Madagascar.

    Science.gov (United States)

    Farris, Zach J; Golden, Christopher D; Karpanty, Sarah; Murphy, Asia; Stauffer, Dean; Ratelolahy, Felix; Andrianjakarivelo, Vonjy; Holmes, Christopher M; Kelly, Marcella J

    2015-01-01

    The wide-ranging, cumulative, negative effects of anthropogenic disturbance, including habitat degradation, exotic species, and hunting, on native wildlife has been well documented across a range of habitats worldwide with carnivores potentially being the most vulnerable due to their more extinction prone characteristics. Investigating the effects of anthropogenic pressures on sympatric carnivores is needed to improve our ability to develop targeted, effective management plans for carnivore conservation worldwide. Utilizing photographic, line-transect, and habitat sampling, as well as landscape analyses and village-based bushmeat hunting surveys, we provide the first investigation of how multiple forms of habitat degradation (fragmentation, exotic carnivores, human encroachment, and hunting) affect carnivore occupancy across Madagascar's largest protected area: the Masoala-Makira landscape. We found that as degradation increased, native carnivore occupancy and encounter rates decreased while exotic carnivore occupancy and encounter rates increased. Feral cats (Felis species) and domestic dogs (Canis familiaris) had higher occupancy than half of the native carnivore species across Madagascar's largest protected landscape. Bird and small mammal encounter rates were negatively associated with exotic carnivore occupancy, but positively associated with the occupancy of four native carnivore species. Spotted fanaloka (Fossa fossana) occupancy was constrained by the presence of exotic feral cats and exotic small Indian civet (Viverricula indica). Hunting was intense across the four study sites where hunting was studied, with the highest rates for the small Indian civet (mean=90 individuals consumed/year), the ring-tailed vontsira (Galidia elegans) (mean=58 consumed/year), and the fosa (Cryptoprocta ferox) (mean=31 consumed/year). Our modeling results suggest hunters target intact forest where carnivore occupancy, abundance, and species richness, are highest. These various

  3. Acceleration of exotic plant invasion in a forested ecosystem by a generalist herbivore.

    Science.gov (United States)

    Eschtruth, Anne K; Battles, John J

    2009-04-01

    The successful invasion of exotic plants is often attributed to the absence of coevolved enemies in the introduced range (i.e., the enemy release hypothesis). Nevertheless, several components of this hypothesis, including the role of generalist herbivores, remain relatively unexplored. We used repeated censuses of exclosures and paired controls to investigate the role of a generalist herbivore, white-tailed deer (Odocoileus virginianus), in the invasion of 3 exotic plant species (Microstegium vimineum, Alliaria petiolata, and Berberis thunbergii) in eastern hemlock (Tsuga canadensis) forests in New Jersey and Pennsylvania (U.S.A.). This work was conducted in 10 eastern hemlock (T. canadensis) forests that spanned gradients in deer density and in the severity of canopy disturbance caused by an introduced insect pest, the hemlock woolly adelgid (Adelges tsugae). We used maximum likelihood estimation and information theoretics to quantify the strength of evidence for alternative models of the influence of deer density and its interaction with the severity of canopy disturbance on exotic plant abundance. Our results were consistent with the enemy release hypothesis in that exotic plants gained a competitive advantage in the presence of generalist herbivores in the introduced range. The abundance of all 3 exotic plants increased significantly more in the control plots than in the paired exclosures. For all species, the inclusion of canopy disturbance parameters resulted in models with substantially greater support than the deer density only models. Our results suggest that white-tailed deer herbivory can accelerate the invasion of exotic plants and that canopy disturbance can interact with herbivory to magnify the impact. In addition, our results provide compelling evidence of nonlinear relationships between deer density and the impact of herbivory on exotic species abundance. These findings highlight the important role of herbivore density in determining impacts on

  4. Behind the scenes at the LHC inauguration

    CERN Document Server

    2008-01-01

    On 21 October the LHC inauguration ceremony will take place and people from all over CERN have been busy preparing. With delegations from 38 countries attending, including ministers and heads of state, the Bulletin has gone behind the scenes to see what it takes to put together an event of this scale.

  5. US-LHC Magnet Database and conventions

    CERN Document Server

    Wei, J; Jain, A; Peggs, S; Pilat, F; Bottura, L; Sabbi, G L; MacKay, W W

    1999-01-01

    The US-LHC Magnet Database is designed for production-magnet quality assurance, field and alignment error impact analysis, cryostat assembly assistance, and ring installation assistance. The database consists of tables designed to store magnet field and alignment measurements data and quench data. This information will also be essential for future machine operations including local IR corrections. (7 refs).

  6. US-LHC Magnet Database and Conventions

    International Nuclear Information System (INIS)

    Wei, J.; McChesney, D.; Jain, A.; Peggs, S.; Pilat, F.; Bottura, L.; Sabbi, G.

    1999-01-01

    The US-LHC Magnet Database is designed for production-magnet quality assurance, field and alignment error impact analysis, cryostat assembly assistance, and ring installation assistance. The database consists of tables designed to store magnet field and alignment measurements data and quench data. This information will also be essential for future machine operations including local IR corrections

  7. Exotic plant species attack revegetation plants in post-coal mining areas

    Science.gov (United States)

    Yusuf, Muhammad; Arisoesilaningsih, Endang

    2017-11-01

    This study aimed to explore some invasive exotic plant species that have the potential to disrupt the growth of revegetation plants in post-coal mining areas. This research was conducted in a revegetation area of PT, Amanah Anugerah Adi Mulia (A3M) Kintap site, South Borneo. Direct observation was carried out on some revegetation areas by observing the growth of revegetation plants disturbed by exotic plant species and the spread of exotic plant species. Based on observation, several invasive exotic plant species were identified including Mikania cordata, Centrosema pubescence, Calopogonium mucunoides, Mimosa pudica, Ageratum conyzoides, and Chromolaena odorata. These five plant species grew wild in the revegetation area and showed ability to disrupt the growth of other plants. In some tree species, such as Acacia mangium, Paraserianthes falcataria, M. cordata could inhibit the growth and even kill the trees through covering the tree canopy. So, the trees could not receive optimum sun light for photosynthesis processes. M. cordata was also observed to have the most widespread distribution. Several exotic plant species such as C. mucunoides, M. pudica, and A. conyzoides were observed to have deep root systems compared with plant species used for revegetation. This growth characteristic allowed exotic plant species to win the competition for nutrient absorption with other plant species.

  8. LHC Nobel Symposium Proceedings

    Science.gov (United States)

    Ekelöf, Tord

    2013-12-01

    In the summer of 2012, a great discovery emerged at the Large Hadron Collider (LHC) at CERN in Geneva. A plethora of new precision data had already by then been collected by the ATLAS and CMS experiments at LHC, providing further extensive support for the validity of the Standard Model of particle physics. But what now appeared was the first evidence for what was not only the last unverified prediction of the Standard Model, but also perhaps the most decisive one: the prediction made already in 1964 of a unique scalar boson required by the theory of François Englert and Peter Higgs on how fundamental particles acquire mass. At that moment in 2012, it seemed particularly appropriate to start planning a gathering of world experts in particle physics to take stock of the situation and try to answer the challenging question: what next? By May 2013, when the LHC Nobel Symposium was held at the Krusenberg Mansion outside Uppsala in Sweden, the first signs of a great discovery had already turned into fully convincing experimental evidence for the existence of a scalar boson of mass about 125 GeV, having properties compatible with the 50-year-old prediction. And in October 2013, the evidence was deemed so convincing that the Swedish Royal Academy of Sciences awarded the Nobel Prize in Physics to Englert and Higgs for their pioneering work. At the same time the search at the LHC for other particles, beyond those predicted by the Standard Model, with heavier masses up to—and in some cases beyond—1 TeV, had provided no positive result. The triumph of the Standard Model seems resounding, in particular because the mass of the discovered scalar boson is such that, when identified with the Higgs boson, the Standard Model is able to provide predictions at energies as high as the Planck mass, although at the price of accepting that the vacuum would be metastable. However, even if there were some feelings of triumph, the ambience at the LHC Nobel Symposium was more one of

  9. Searches for Extra Dimensions, Leptoquarks, and Technicolor at the LHC : proceedings for the Rencontres de Blois on "Particle Physics and Cosmology"

    CERN Document Server

    Grancagnolo, S; The ATLAS collaboration

    2013-01-01

    A review of the last results with the data collected by the ATLAS and CMS experiments during 2011-2012 runs at the LHC is presented. The focus is on exotic searches for Extra Dimensions, Leptoquarks and Technicolor, with various reconstruction and analysis techniques.

  10. Long-lived staus and displaced leptons at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Jared A.; Shelton, Jessie [Department of Physics, University of Illinois at Urbana-Champaign,Urbana, IL 61801 (United States)

    2016-04-11

    As the majority of LHC searches are focused on prompt signatures, specific long-lived particles have the potential to be overlooked by the otherwise systematic new physics programs at ATLAS and CMS. While in many cases long-lived superparticles are now stringently constrained by existing exotic searches, we point out that the highly motivated model of gauge mediation with staus as the next-to-lightest superparticle (NLSP) is relatively far less tested. We recast LHC searches for heavy stable charged particles, disappearing tracks, and opposite-flavor leptons with large impact parameters to assess current constraints on a variety of spectra that contain an NLSP stau, and find that portions of the parameter space motivated by naturalness are still experimentally unexplored. We additionally note a gap in the current experimental search program: same-flavor leptons with large impact parameters evade the suite of existing searches for long-lived objects. This gap is especially noteworthy as vetoes on displaced leptons in prompt new physics searches could be systematically discarding such events. We discuss several motivated models that can exhibit same-flavor displaced leptons: gauge mediation with co-NLSP sleptons, extended gauge mediation, R-parity violation, and lepton-flavored dark matter that freezes in during a matter-dominated era of the early universe. To address this gap, we propose a straightforward extension of the CMS search for leptons with large impact parameters, and project sensitivity to these scenarios at 13 TeV. Throughout this analysis, we highlight several methods whereby LHC searches for exotic long-lived objects could potentially improve their sensitivity to the displaced leptons originating from gauge mediation and beyond.

  11. 2008 LHC Open Days LHC magnets on display

    CERN Multimedia

    2008-01-01

    Over the last few years you’ve probably seen many of the 15 m long blue LHC dipole magnets being ferried around the site. Most of them are underground now, but on the LHC Open Days on 5 and 6 April the magnets will also play a central role on the surface. Installation of one of the LHC dipole magnets on the Saint-Genis roundabout on 7 March. The LHC dipole testing facility with several magnets at various stages of testing. The 27 km ring of the LHC consists of 1232 double-aperture superconducting dipole magnets, 360 short straight sections (SSS) and 114 special SSS for the insertion regions. On the Open Day, you will be able to "Follow the LHC magnets" through different stages around the site, culminating in their descent into the tunnel. Discover all the many components that have to be precisely integrated in the magnet casings, and talk to the engine...

  12. Exotic nuclei: another aspect of nuclear structure

    International Nuclear Information System (INIS)

    Dobaczewski, J.; Blumenfeld, Y.; Flocard, H.; Garcia Borge, M.J.; Nowacki, F.; Rombouts, S.; Theisen, Ch.; Marques, F.M.; Lacroix, D.; Dessagne, P.; Gaeggeler, H.

    2002-01-01

    This document gathers the lectures made at the Joliot Curie international summer school in 2002 whose theme that year was exotic nuclei. There were 11 contributions whose titles are: 1) interactions, symmetry breaking and effective fields from quarks to nuclei; 2) status and perspectives for the study of exotic nuclei: experimental aspects; 3) the pairing interaction and the N = Z nuclei; 4) borders of stability region and exotic decays; 5) shell structure of nuclei: from stability to decay; 6) variational approach of system with a few nucleons; 7) from heavy to super-heavy nuclei; 8) halos, molecules and multi-neutrons; 9) macroscopic approaches for fusion reactions; 10) beta decay: a tool for spectroscopy; 11) the gas phase chemistry of super-heavy elements

  13. Quasi-exotic open-flavor mesons

    Energy Technology Data Exchange (ETDEWEB)

    Hilger, T.; Krassnigg, A. [University of Graz, NAWI Graz, Institute of Physics, Graz (Austria)

    2017-06-15

    Meson states with exotic quantum numbers arise naturally in a covariant bound-state framework in QCD. We investigate the consequences of shifting quark masses such that the states are no longer restricted to certain C-parities, but only by J{sup P}. Then, a priori, one can no longer distinguish exotic or conventional states. In order to identify signatures of the different states to look for experimentally, we provide the behavior of masses, leptonic decay constants, and orbital-angular-momentum decomposition of such mesons, as well as the constellations in which they could be found. Most prominently, we consider the case of charged quasi-exotic excitations of the pion. (orig.)

  14. X-ray spectroscopy from exotic atoms

    International Nuclear Information System (INIS)

    Hartmann, F.J.

    1994-01-01

    Why do experimentalists study exotic atoms, in particular antiprotonic atoms? The answer is simple: the information about electromagnetic, weak, and strong interactions that can be obtained by doing X-ray spectroscopy from exotic atoms is really worth the effort. It is possible to (1) enlarge the knowledge about the properties of exotic particles (such as mass and magnetic moment); (2) open a possibility to test quantum electrodynamics; (3) get detailed insight into the shape of nuclei (characterized by the nuclear radium and higher momenta) and even into the neutron distribution in the nucleus (neutron halo); and (4) use it as a powerful tool to learn about the strong interaction at very low relative hadron-nucleon velocities

  15. LHC forward physics

    Energy Technology Data Exchange (ETDEWEB)

    Cartiglia, N. [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Royon, C. [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States). et al.

    2015-10-02

    The goal of this report is to give a comprehensive overview of the rich field of forward physics, with a special attention to the topics that can be studied at the LHC. The report starts presenting a selection of the Monte Carlo simulation tools currently available, chapter 2, then enters the rich phenomenology of QCD at low, chapter 3, and high, chapter 4, momentum transfer, while the unique scattering conditions of central exclusive production are analyzed in chapter 5. The last two experimental topics, Cosmic Ray and Heavy Ion physics are presented in the chapter 6 and 7 respectively. Chapter 8 is dedicated to the BFKL dynamics, multiparton interactions, and saturation. The report ends with an overview of the forward detectors at LHC. Each chapter is correlated with a comprehensive bibliography, attempting to provide to the interested reader with a wide opportunity for further studies.

  16. LHC Forward Physics

    CERN Document Server

    Akiba, K.

    2016-10-17

    The goal of this report is to give a comprehensive overview of the rich field of forward physics, with a special attention to the topics that can be studied at the LHC. The report starts presenting a selection of the Monte Carlo simulation tools currently available, chapter 2, then enters the rich phenomenology of QCD at low, chapter 3, and high, chapter 4, momentum transfer, while the unique scattering conditions of central exclusive production are analyzed in chapter 5. The last two experimental topics, Cosmic Ray and Heavy Ion physics are presented in the chapter 6 and 7 respectively. Chapter 8 is dedicated to the BFKL dynamics, multiparton interactions, and saturation. The report ends with an overview of the forward detectors at LHC. Each chapter is correlated with a comprehensive bibliography, attempting to provide to the interested reader with a wide opportunity for further studies.

  17. LHC Report: machine development

    CERN Multimedia

    Rogelio Tomás García for the LHC team

    2015-01-01

    Machine development weeks are carefully planned in the LHC operation schedule to optimise and further study the performance of the machine. The first machine development session of Run 2 ended on Saturday, 25 July. Despite various hiccoughs, it allowed the operators to make great strides towards improving the long-term performance of the LHC.   The main goals of this first machine development (MD) week were to determine the minimum beam-spot size at the interaction points given existing optics and collimation constraints; to test new beam instrumentation; to evaluate the effectiveness of performing part of the beam-squeezing process during the energy ramp; and to explore the limits on the number of protons per bunch arising from the electromagnetic interactions with the accelerator environment and the other beam. Unfortunately, a series of events reduced the machine availability for studies to about 50%. The most critical issue was the recurrent trip of a sextupolar corrector circuit –...

  18. LHC, Astrophysics and Cosmology

    Directory of Open Access Journals (Sweden)

    Giulio Auriemma

    2014-12-01

    Full Text Available In this paper we discuss the impact on cosmology of recent results obtained by the LHC (Large Hadron Collider experiments in the 2011-2012 runs, respectively at √s = 7 and 8 TeV. The capital achievement of LHC in this period has been the discovery of a spin-0 particle with mass 126 GeV/c2, very similar to the Higgs boson of the Standard Model of Particle Physics. Less exciting, but not less important, negative results of searches for Supersymmetric particles or other exotica in direct production or rare decays are discussed in connection with particles and V.H.E. astronomy searches for Dark Matter.

  19. The Latest from the LHC

    CERN Multimedia

    In SM18 six magnets have been cold tested with good results. It has also been a good week for cyostating with five more magnets completed. In sector 3-4 interconnection work and welding has started in the area damaged on 19 September last year. Interconnection work is also ongoing on the replacement magnet for the faulty dipole removed from sector 1-2. Three separate teams are now working in the three sectors to install the new DN200 pressure release nozzles. In total 27 magnets have been completed so far, with 34 nozzles welded. A new study is also underway to include a similar pressure release system for both the stand-alone magnets (SAMs) and the triplet magnets. All about Chamonix At the public session of the LHCC (the LHC experiments committee) held Wednesday, 18 February Steve Myers, Director for Accelerators and Technology, reviewed the discussions on the LHC at the Chamonix workshop. He explained the scenarios being studied to implement the machine consolidation measures and resume operation. The ...

  20. Forward Physics at the LHC

    CERN Document Server

    Martin, A D; Khoze, V A

    2009-01-01

    We review two inter-related topics. First, we consider the behaviour of "soft" scattering observables, such as sigma_{tot}, dsigma_{el}/dt, dsigma_{SD}/dtdM^2, particle multiplicities etc., at high-energy proton-(anti)proton colliders. We emphasize the sizeable effects of absorption on high-energy `soft' processes, and, hence, the necessity to include multi-Pomeron-Pomeron interactions in the usual multi-channel eikonal description. We describe a multi-component model which has been tuned to the available data for soft processes in the CERN-ISR to Tevatron energy range, and which therefore allows predictions to be made for `soft' observables at the LHC. The second topic concerns the calculation of the rate of exclusive processes of the form pp --> p+A+p at high energy colliders, where A is a heavy system. In particular, we discuss the survival probability of the rapidity gaps (denoted by the + signs) to both eikonal and enhanced soft rescattering effects. At the LHC energy, the most topical case is when A is ...

  1. The LHC Lead Injector Chain

    CERN Document Server

    Beuret, A; Blas, A; Burkhardt, H; Carli, Christian; Chanel, M; Fowler, A; Gourber-Pace, M; Hancock, S; Hourican, M; Hill, C E; Jowett, John M; Kahle, K; Küchler, D; Lombardi, A M; Mahner, E; Manglunki, Django; Martini, M; Maury, S; Pedersen, F; Raich, U; Rossi, C; Royer, J P; Schindl, Karlheinz; Scrivens, R; Sermeus, L; Shaposhnikova, Elena; Tranquille, G; Vretenar, Maurizio; Zickler, T

    2004-01-01

    A sizeable part of the LHC physics programme foresees lead-lead collisions with a design luminosity of 1027 cm-2 s-1. This will be achieved after an upgrade of the ion injector chain comprising Linac3, LEIR, PS and SPS machines [1,2]. Each LHC ring will be filled in 10 min by almost 600 bunches, each of 7×107 lead ions. Central to the scheme is the Low Energy Ion Ring (LEIR) [3,4], which transforms long pulses from Linac3 into high-brilliance bunches by means of multi-turn injection, electron cooling and accumulation. Major limitations along the chain, including space charge, intrabeam scattering, vacuum issues and emittance preservation are highlighted. The conversion from LEAR (Low Energy Antiproton Ring) to LEIR involves new magnets and power converters, high-current electron cooling, broadband RF cavities, and a UHV vacuum system with getter (NEG) coatings to achieve a few 10-12 mbar. Major hardware changes in Linac3 and the PS are also covered. An early ion scheme with fewer bunches (but each at nominal...

  2. The LHC Computing Grid Project

    CERN Multimedia

    Åkesson, T

    In the last ATLAS eNews I reported on the preparations for the LHC Computing Grid Project (LCGP). Significant LCGP resources were mobilized during the summer, and there have been numerous iterations on the formal paper to put forward to the CERN Council to establish the LCGP. ATLAS, and also the other LHC-experiments, has been very active in this process to maximally influence the outcome. Our main priorities were to ensure that the global aspects are properly taken into account, that the CERN non-member states are also included in the structure, that the experiments are properly involved in the LCGP execution and that the LCGP takes operative responsibility during the data challenges. A Project Launch Board (PLB) was active from the end of July until the 10th of September. It was chaired by Hans Hoffmann and had the IT division leader as secretary. Each experiment had a representative (me for ATLAS), and the large CERN member states were each represented while the smaller were represented as clusters ac...

  3. LHC signals of radiatively-induced neutrino masses and implications for the Zee-Babu model

    Science.gov (United States)

    Alcaide, Julien; Chala, Mikael; Santamaria, Arcadi

    2018-04-01

    Contrary to the see-saw models, extended Higgs sectors leading to radiatively-induced neutrino masses do require the extra particles to be at the TeV scale. However, these new states have often exotic decays, to which experimental LHC searches performed so far, focused on scalars decaying into pairs of same-sign leptons, are not sensitive. In this paper we show that their experimental signatures can start to be tested with current LHC data if dedicated multi-region analyses correlating different observables are used. We also provide high-accuracy estimations of the complicated Standard Model backgrounds involved. For the case of the Zee-Babu model, we show that regions not yet constrained by neutrino data and low-energy experiments can be already probed, while most of the parameter space could be excluded at the 95% C.L. in a high-luminosity phase of the LHC.

  4. The ATLAS Tau Trigger Performance during LHC Run 1 and Prospects for Run 2

    CERN Document Server

    Mitani, T; The ATLAS collaboration

    2016-01-01

    The ATLAS tau trigger is designed to select hadronic decays of the tau leptons. Tau lepton plays an important role in Standard Model (SM) physics, such as in Higgs boson decays. Tau lepton is also important in beyond the SM (BSM) scenarios, such as supersymmetry and exotic particles, as they are often produced preferentially in these models. During the 2010-2012 LHC run (Run1), the tau trigger was accomplished successfully, which leads several rewarding results such as evidence for $H\\rightarrow \\tau\\tau$. From the 2015 LHC run (Run2), LHC will be upgraded and overlapping interactions per bunch crossing (pile-up) are expected to increase by a factor two. It will be challenging to control trigger rates while keeping interesting physics events. This paper summarized the tau trigger performance in Run1 and its prospects for Run2.

  5. LHC Magnet test failure

    CERN Multimedia

    2007-01-01

    "On Tueday, March 22, a Fermilab-built quadrupole magnet, one of an "inner triplet" of three focusing magnets, failed a high-pressure test at Point 5 in the tunnel of the LHC accelerator at CERN. Since Tuesday, teams at CERN and Fermilab have worked closely together to address the problem and have identified the cause of the failure. Now they are at work on a solution.:" (1 page)

  6. The LHC on Google

    CERN Multimedia

    2009-01-01

    Where in the world could the LHC outdo Barack Obama in the popularity stakes? On Google, of course! The famous search engine has just published its Top Ten "most popular" and "fastest rising" searches for 2008 in each of 34 countries. Surprise, surprise, the term "Large Hadron Collider" was the 6th fastest rising topic in the United Kingdom and the 10th fastest in New Zealand. In the UK, "Large Hadron Collider" even beat "Obama" into 7th place!

  7. Lectures on LHC physics

    CERN Document Server

    Plehn, Tilman

    2012-01-01

    When we try to advance from a solid knowledge of field theory to LHC physics we usually encounter a frustrating problem: in particular Higgs physics and QCD techniques appear as a impenetrable granite block of phenomenological know-how, common lores, and historically grown intuition what works and what does not. I hope this lecture can drill a few holes into the rock and put you into a position to digest advanced writeups as well as some first research papers on the topic.

  8. The LHC project

    CERN Multimedia

    CERN. Geneva

    2002-01-01

    At the halfway point in the construction of the LHC, the project is now moving from the design and procurement phase to the installation phase, which officially started on 1st March. An overview of the progress of the project is given and the final schedule for installation and commissioning is discussed. The talk will be given in English but questions can be taken in French.

  9. Handbook of LHC Higgs Cross Sections: 4. Deciphering the Nature of the Higgs Sector

    Energy Technology Data Exchange (ETDEWEB)

    de Florian, D. [National Univ. of San Martin, Buenos Aires (Argentina); et al.

    2016-10-25

    This Report summarizes the results of the activities of the LHC Higgs Cross Section Working Group in the period 2014-2016. The main goal of the working group was to present the state-of-the-art of Higgs physics at the LHC, integrating all new results that have appeared in the last few years. The first part compiles the most up-to-date predictions of Higgs boson production cross sections and decay branching ratios, parton distribution functions, and off-shell Higgs boson production and interference effects. The second part discusses the recent progress in Higgs effective field theory predictions, followed by the third part on pseudo-observables, simplified template cross section and fiducial cross section measurements, which give the baseline framework for Higgs boson property measurements. The fourth part deals with the beyond the Standard Model predictions of various benchmark scenarios of Minimal Supersymmetric Standard Model, extended scalar sector, Next-to-Minimal Supersymmetric Standard Model and exotic Higgs boson decays. This report follows three previous working-group reports: Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables (CERN-2011-002), Handbook of LHC Higgs Cross Sections: 2. Differential Distributions (CERN-2012-002), and Handbook of LHC Higgs Cross Sections: 3. Higgs properties (CERN-2013-004). The current report serves as the baseline reference for Higgs physics in LHC Run 2 and beyond.

  10. Status of exotic states at ATLAS

    CERN Document Server

    Yeletskikh, Ivan; The ATLAS collaboration

    2017-01-01

    We review the status of searches and measurements of exotic hadron states at ATLAS. Among them: the search for the beauty partner of X(3872) charmonium state, the measurement of differential cross-section of the prompt and non-prompt production of X(3872) in the J/psi pi pi final states, the search for the structure in the B_s pi invariant mass, reported by D0 experiment, search for exotic states in B-hadron decays: pentaquarks in Lambda_b decays and tetraquarks in B-meson decays. ATLAS results and ongoing analyses perspectives are highlighted together with CMS and LHCb results.

  11. LHC Report: imaginative injectors

    CERN Multimedia

    Pierre Freyermuth for the LHC team

    2016-01-01

    A new bunch injection scheme from the PS to the SPS allowed the LHC to achieve a new peak luminosity record.   Figure 1: PSB multi-turn injection principle: to vary the parameters during injection with the aim of putting the newly injected beam in a different region of the transverse phase-space plan. The LHC relies on the injector complex to deliver beam with well-defined bunch populations and the necessary transverse and longitudinal characteristics – all of which fold directly into luminosity performance. There are several processes taking place in the PS Booster (PSB) and the Proton Synchrotron (PS) acting on the beam structure in order to obtain the LHC beam characteristics. Two processes are mainly responsible for the beam brightness: the PSB multi-turn injection and the PS radio-frequency (RF) gymnastics. The total number of protons in a bunch and the transverse emittances are mostly determined by the multi-turn Booster injection, while the number of bunches and their time spacin...

  12. LHC Report: Rocky XIV

    CERN Multimedia

    Mike Lamont for the LHC Team

    2012-01-01

    The LHC has been in luminosity production mode for the last couple of weeks. Peak luminosities have ranged between 6 and a record 7.74 x 1033 cm -2 s-1. Integrated luminosities per fill have been healthy, with 170 inverse picobarn per fill reached on five occasions in the last two weeks.  The total integrated luminosity for the year has passed 14 inverse femtobarns.   Injected bunch currents have peaked at an average of  1.69 x 1011 protons per bunch on average - a remarkable achievement for both the injectors and the LHC: the injectors to be able to produce good quality beam at these intensities; the LHC for being able to cope with these intensities without excessive losses. Peak performance from day to day depends strongly on the beam sizes and bunch intensities delivered by the injectors. It is a continual challenge to keep the Booster, PS and SPS optimally tuned while they deliver beams to their other wide range of users. Despite the excel...

  13. LHC Dipoles Accelerate

    CERN Multimedia

    2001-01-01

    Andrezej Siemko (left), Peter Sievers (centre), and Lucio Rossi (right), have the exciting challenge of preparing and testing 2000 magnets for the LHC. The LHC is going to require a lot of powerful magnets by the time it begins operation in 2006. More specifically, it is going to need 130 special magnets, 400 quadrupoles, and a whopping 1250 dipoles! Preparing and testing these magnets for the conditions they will encounter in the LHC is not an easy task. But evaluation of the most recently received magnet, from the German company Noell, is showing that while the monumental task of receiving and testing nearly 2000 magnets is going to be exhausting, the goals are definitely attainable. At the moment and over the next year, pre-series magnets (the magnets that CERN uses to fine tune performance) are arriving slowly (90 in total will arrive), but by 2003 the rate of series magnet arrival will accelerate to 9 per week, that's over 450 in a single year! And working with these magnets when they arrive is tough. ...

  14. US-LHC IR magnet error analysis and compensation

    International Nuclear Information System (INIS)

    Wei, J.; Ptitsin, V.; Pilat, F.; Tepikian, S.; Gelfand, N.; Wan, W.; Holt, J.

    1998-01-01

    This paper studies the impact of the insertion-region (IR) magnet field errors on LHC collision performance. Compensation schemes including magnet orientation optimization, body-end compensation, tuning shims, and local nonlinear correction are shown to be highly effective

  15. Results from searches for exotic phenomena

    CERN Document Server

    Martyniuk, Alex; The ATLAS collaboration

    2017-01-01

    This talk will review the current state of experimental searches for "exotic" physics beyond the standard model of particle physics. The talk will cover a wide range of searches from ATLAS and CMS, in a (hopefully) jargon free pedagogical fashion, showing the big picture of the field at this time.

  16. Mean-field models and exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Bender, M; Buervenich, T; Maruhn, J A; Greiner, W [Inst. fuer Theoretische Physik, Univ. Frankfurt (Germany); Rutz, K [Inst. fuer Theoretische Physik, Univ. Frankfurt (Germany); [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Reinhard, P G [Inst. fuer Theoretische Physik, Univ. Erlangen (Germany)

    1998-06-01

    We discuss two widely used nuclear mean-field models, the relativistic mean-field model and the (nonrelativistic) Skyrme-Hartree-Fock model, and their capability to describe exotic nuclei. Test cases are superheavy nuclei and neutron-rich Sn isotopes. New information in this regime helps to fix hitherto loosely determined aspects of the models. (orig.)

  17. Microscopic Cluster Theory for Exotic Nuclei

    International Nuclear Information System (INIS)

    Tomaselli, M; Kuehl, T; Ursescu, D; Fritzsche, S

    2006-01-01

    For a better understanding of the dynamics of complex exotic nuclei it is of crucial importance to develop a practical microscopic theory easy to be applied to a wide range of masses. In this paper we propose to calculate the structure of neutron-rich nuclei within a dynamic model based on the EoM theory

  18. Biodiversity and the exotic species threat

    Science.gov (United States)

    Peter S. White

    1998-01-01

    Exotic species invasions, called by one conservation biologist the "least reversible" of all human impacts, cause harm to economies (e.g., fisheries, wildlife populations, tourism), the environment (e.g., in the form of broadcast of pesticides and herbicides), human health and wellbeing (e.g., allergic responses and the increase in fire severity in some...

  19. EXOTIC: Development of ceramic tritium breeding materials

    International Nuclear Information System (INIS)

    Kwast, H.; Conrad, R.

    1989-09-01

    In this fifth EXOTIC annual progress report the work carried out in 1988 is reported. For EXOTIC-1, -2 and -3 the post-irradiation examinations have been continued with tritium retention measurements, annealng experiments, determination of physical and mechanical properties and X-ray diffraction analysis. Irradiation of EXOTIC-4 has been performde and the post-irradiation examination has started. Transient tritium release curves are given and analysed. The resulting tritium residence times show that for the Li-zirconates a residence time of less than one day can be achieved in the temperature region of 350-600 C. The loading scheme, the objectives and some fabrication data of EXOTIC-5 are give. Moreover, the fabrication of laboratory scale batches has started to investigate the effect of microstructural parameters on tritium release. Finally, an investigation was started on the system Li 2 O-ZrO 2 , with emphasis on the lithia-rich compositions. 40 figs., 9 refs., 10 tabs

  20. Mean-field models and exotic nuclei

    International Nuclear Information System (INIS)

    Bender, M.; Buervenich, T.; Maruhn, J.A.; Greiner, W.; Rutz, K.; Reinhard, P.G.

    1998-01-01

    We discuss two widely used nuclear mean-field models, the relativistic mean-field model and the (nonrelativistic) Skyrme-Hartree-Fock model, and their capability to describe exotic nuclei. Test cases are superheavy nuclei and neutron-rich Sn isotopes. New information in this regime helps to fix hitherto loosely determined aspects of the models. (orig.)

  1. Overview of Exotic Physics at ATLAS

    CERN Document Server

    Li, Shu; The ATLAS collaboration

    2016-01-01

    Proceeding for the conference plenary talk at HEPMAD16, Madagascar on the topic of "Overview of Exotic Physics at ATLAS" (ATL-PHYS-SLIDE-2016-807 https://cds.cern.ch/record/2225222) Deadline: 16/12/2016 (could be postponed for some days later upon request as recently suggested by the conference organizer)

  2. Summary of exotic collider concepts group

    International Nuclear Information System (INIS)

    Pellegrini, C.

    1995-01-01

    We present a summary of the discussions in the Exotic Collider Concepts Group. Most of the discussions were centered around the status and open problems for muon-muon and gamma-gamma colliders. In addition the group discussed some general problems and new results of accelerator physics. copyright 1995 American Institute of Physics

  3. Gaugephobic Higgs Signals at the LHC

    CERN Document Server

    Galloway, Jamison; McRaven, John; Terning, John

    2009-01-01

    The Gaugephobic Higgs model provides an interpolation between three different models of electroweak symmetry breaking: Higgsless models, Randall-Sundrum models, and the Standard Model. At parameter points between the extremes, Standard Model Higgs signals are present at reduced rates, and Higgsless Kaluza-Klein excitations are present with shifted masses and couplings, as well as signals from exotic quarks necessary to protect the Zbb coupling. Using a new implementation of the model in SHERPA, we show the LHC signals which differentiate the generic Gaugephobic Higgs model from its limiting cases. These are all signals involving a Higgs coupling to a Kaluza-Klein gauge boson or quark. We identify the clean signal $p p \\to W^(i) \\to W H$ mediated by a Kaluza-Klein W, which can be present at large rates and is enhanced for even Kaluza-Klein numbers. Due to the very hard lepton coming from the W decay, this signature has little background, and provides a better discovery channel for the Higgs than any of the Sta...

  4. Ticks imported to Europe with exotic reptiles.

    Science.gov (United States)

    Mihalca, Andrei Daniel

    2015-09-30

    It is known that traded exotic animals carry with them an immense number of associated symbionts, including parasites. Reptiles are no exception. Most of the imported reptiles originate from tropical countries and their possibility to carry potentially dangerous pathogens is high. According to CITES, Europe is currently the main reptile importer in the world. Despite this, there is no review or analysis available for the risk related to the importation of tick-borne diseases with traded reptile to the EU. The main aim of the manuscript is to provide a review on the available literature on ticks introduced to and exchanged between European countries via the live reptile trade. So far, the published reports of ticks imported on reptiles are limited to few European countries: Italy, Poland, Spain, Netherlands, Belgium, Slovenia and UK. The following species have been reported: Hyalomma aegyptium, Amblyomma dissimile, Amblyomma exornatum, Amblyomma flavomaculatum, Amblyomma fuscolineatum, Amblyomma latum, Amblyomma quadricavum, Amblyomma marmoreum, Amblyomma nuttalli, Amblyomma sparsum, Amblyomma sphenodonti, Amblyomma transversale and Amblyomma varanense. The majority of species are of African origin, followed by American and Asian species. All groups of reptiles (chelonians, snakes, lizards, crocodiles, tuataras) were involved. However, it seems that certain groups (i.e. tortoises of genus Testudo, monitor lizards of genus Varanus, snakes of genus Python) are more important as host for imported ticks, but this may be related to higher levels of international trade. Even fewer are the reports of tick-borne pathogens associated with imported reptile ticks. Despite the diversity of tick species reported on imported reptiles, the situations of truly invasive species are atypical and are limited in natural environments to maximum two cases where H. aegyptium was involved. Otherwise, the risk associated with reptile trade for introduction of invasive tick to Europe is low

  5. LHC Injectors Upgrade (LIU) Project at CERN

    CERN Document Server

    Shaposhnikova, Elena; Damerau, Heiko; Funken, Anne; Gilardoni, Simone; Goddard, Brennan; Hanke, Klaus; Kobzeva, Lelyzaveta; Lombardi, Alessandra; Manglunki, Django; Mataguez, Simon; Meddahi, Malika; Mikulec, Bettina; Rumolo, Giovanni; Scrivens, Richard; Vretenar, Maurizio

    2016-01-01

    A massive improvement program of the LHC injector chain is presently being conducted under the LIU project. For the proton chain, this includes the replacement of Linac2 with Linac4 as well as all necessary upgrades to the Proton Synchrotron Booster (PSB), the Proton Synchrotron (PS) and Super Proton Synchrotron (SPS), aimed at producing beams with the challenging High Luminosity LHC (HL-LHC) parameters. Regarding the heavy ions, plans to improve the performance of Linac3 and the Low Energy Ion Ring (LEIR) are also pursued under the general LIU program. The full LHC injection chain returned to operation after Long Shutdown 1, with extended beam studies taking place in Run 2. A general project Cost and Schedule Review also took place in March 2015, and several dedicated LIU project reviews were held to address issues awaiting pending decisions. In view of these developments, 2014 and 2015 have been key years to define a number of important aspects of the final LIU path. This paper will describe the reviewed LI...

  6. Electron cloud buildup studies for the LHC

    CERN Document Server

    AUTHOR|(CDS)2160803; Boine-Frankenheim, Oliver

    Electron clouds can develop in accelerators operating with positively charged particles. The con- sequences of e-cloud related effects are very important for the operation of the Large Hadron Collider (LHC) at CERN, and for the design of future accelerators including the LHC luminosity upgrade (HL-LHC). High electron densities are generated by an interaction between the beam and the confining chamber. Primary electrons, that can be generated through various mecha- nisms, are accelerated by the beam and impinge on the chamber walls, thereby extracting more electrons from the material. Furthermore they also deposit their kinetic energy in the process, which has to be compensated by the cooling system. Especially in cryogenic environments, as it is the case for a large part of the LHC, high heat loads can pose a serious problem. In order to improve the understanding of the electron cloud, simulation studies are performed with the code PyECLOUD, developed at CERN. The work of the first half of the project is desc...

  7. PDF4LHC recommendations for LHC Run II

    NARCIS (Netherlands)

    Butterworth, Jon; Carrazza, Stefano; Cooper-Sarkar, Amanda; Roeck, Albert de; Feltesse, Joel; Forte, Stefano; Gao, Jun; Glazov, Sasha; Huston, Joey; Kassabov, Zahari; McNulty, Ronan; Morsch, Andreas; Nadolsky, Pavel; Radescu, Voica; Rojo, Juan; Thorne, Robert S.

    2015-01-01

    We provide an updated recommendation for the usage of sets of parton distribution functions (PDFs) and the assessment of PDF and PDF+$\\alpha_s$ uncertainties suitable for applications at the LHC Run II. We review developments since the previous PDF4LHC recommendation, and discuss and compare the new

  8. Long term estimates for sorting strategies of the LHC dipoles

    CERN Document Server

    Scandale, Walter; Giovannozzi, Massimo; Todesco, Ezio

    1998-01-01

    Sorting strategies are investigated in view of improving the dynamic aperture of the CERN-LHC. Local and quasi-local compensation of the random field shape imperfections are discussed and applied to simplified model of the LHC lattice. The most promising strategies are further investigated on a realistic LHC model with particular emphasis on the analysis of the robustness of the dynamic aperture improvements including long term effects. First results on the application of the recently developed extrapolation law for the prediction of the dynamic aperture to the sorting problem are presented.

  9. Conceptual Design of the LHC Interaction Region Upgrade Phase-I

    CERN Document Server

    Ostojic, R; Baglin, V; Ballarino, A; Cerutti, F; Denz, R; Fartoukh, S; Fessia, P; Foraz, K; Fürstner, M; Herr, Werner; Karppinen, M; Kos, N; Mainaud-Durand, H; Mereghetti, A; Muttoni, Y; Nisbet, D; Prin, H; Tock, J P; Van Weelderen, R; Wildner, E

    2008-01-01

    The LHC is starting operation with beam. The primary goal of CERN and the LHC community is to ensure that the collider is operated efficiently and that it achieves nominal performance in the shortest term. Since several years the community has been discussing the directions for maximizing the physics reach of the LHC by upgrading the experiments, in particular ATLAS and CMS, the LHC machine and the CERN proton injector complex, in a phased approach. The first phase of the LHC interaction region upgrade was approved by Council in December 2007. This phase relies on the mature Nb-Ti superconducting magnet technology with the target of increasing the LHC luminosity to 2 to 3 10^34 cm^-2s^-1, while maximising the use of the existing infrastructure. In this report, we present the goals and the proposed conceptual solutions for the LHC IR Upgrade Phase-I which include the recommendations of the conceptual design review.

  10. LNV Higgses at LHC

    Science.gov (United States)

    Maiezza, Alessio; Nemevšek, Miha; Nesti, Fabrizio

    2016-06-01

    Lepton number is a fundamental symmetry that can be probed at the LHC. Here, we study the Higgs sector of theories responsible for neutrino mass generation. After a brief discussion of simple see-saw scenarios, we turn to theories where heavy Majorana neutrino mass is protected by a gauge symmetry and focus on the Left-Right symmetric theory. There, the SM-like Higgs boson can decay to a pair of heavy neutrinos and provide enough information to establish the origin of neutrino mass.

  11. Thermometry for the LHC

    International Nuclear Information System (INIS)

    Buhler, S.; Junquera, T.; Thermeau, J.P.

    1999-01-01

    The LHC project will use about 8000 thermometers to control the temperature of magnets. These thermometers will be operated at a temperature ranging from 1.6 K to 300 K and their calibration should be better than 0.25%. A small cryogenic thermometer calibration facility has been designed and tested. To select the cryogenic temperature sensors, an irradiation program is being performed to expose at high neutron fluences (>10 15 n/cm 2 ) the following thermometers: carbon resistors, Ge, thin film, RhFe and Pt. The resistance shifts under radiation of the different sensors at liquid helium are presented. (authors)

  12. QCD probes at LHC

    CERN Document Server

    Da Silveira, G. Gil

    2018-01-01

    The LHC experiments have reported new results with respect to the dynamics of the strong interactions in $pp$, $p$A, and AA collisions over the past years. In proton-proton collisions, the data analyses have focused in exploring the nature of underlying events and double parton scattering at high energies. For large systems, the heavy-ion collisions have provided new insights on physics aspects related to azimuthal correlations, jet quenching, and particle production, such as antiprotons. This Letter reports the recent results from the ATLAS, CMS, and LHCb Collaborations on these various topics and highlights its relevant findings for the high-energy community.

  13. Optical data transmission ASICs for the high-luminosity LHC (HL-LHC) experiments

    International Nuclear Information System (INIS)

    Li, X; Huang, G; Sun, X; Liu, G; Deng, B; Gong, D; Guo, D; Liu, C; Liu, T; Xiang, A C; Ye, J; Zhao, X; Chen, J; You, Y; He, M; Hou, S; Teng, P-K; Jin, G; Liang, H; Liang, F

    2014-01-01

    We present the design and test results of two optical data transmission ASICs for the High-Luminosity LHC (HL-LHC) experiments. These ASICs include a two-channel serializer (LOCs2) and a single-channel Vertical Cavity Surface Emitting Laser (VCSEL) driver (LOCld1V2). Both ASICs are fabricated in a commercial 0.25-μm Silicon-on-Sapphire (SoS) CMOS technology and operate at a data rate up to 8 Gbps per channel. The power consumption of LOCs2 and LOCld1V2 are 1.25 W and 0.27 W at 8-Gbps data rate, respectively. LOCld1V2 has been verified meeting the radiation-tolerance requirements for HL-LHC experiments

  14. A Global Computing Grid for LHC; Una red global de computacion para LHC

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Calama, J. M.; Colino Arriero, N.

    2013-06-01

    An innovative computing infrastructure has played an instrumental role in the recent discovery of the Higgs boson in the LHC and has enabled scientists all over the world to store, process and analyze enormous amounts of data in record time. The Grid computing technology has made it possible to integrate computing center resources spread around the planet, including the CIEMAT, into a distributed system where these resources can be shared and accessed via Internet on a transparent, uniform basis. A global supercomputer for the LHC experiments. (Author)

  15. Post LHC8 SUSY benchmark points for ILC physics

    International Nuclear Information System (INIS)

    Baer, Howard; List, Jenny

    2013-07-01

    We re-evaluate prospects for supersymmetry at the proposed International Linear e + e - Collider (ILC) in light of the first two years of serious data taking at LHC: LHC7 with ∝5 fb -1 of pp collisions at √(s)=7 TeV and LHC8 with ∝20 fb -1 at √(s)=8 TeV. Strong new limits from LHC8 SUSY searches, along with the discovery of a Higgs boson with m h ≅125 GeV, suggest a paradigm shift from previously popular models to ones with new and compelling signatures. After a review of the current status of supersymmetry, we present a variety of new ILC benchmark models, including: natural SUSY, radiatively-driven natural SUSY (RNS), NUHM2 with low m A , a focus point case from mSUGRA/CMSSM, non-universal gaugino mass (NUGM) model, τ-coannihilation, Kallosh-Linde/spread SUSY model, mixed gauge-gravity mediation, normal scalar mass hierarchy (NMH), and one example with the recently discovered Higgs boson being the heavy CP-even state H. While all these models at present elude the latest LHC8 limits, they do offer intriguing case study possibilities for ILC operating at √(s)≅ 0.25-1 TeV. The benchmark points also present a view of the widely diverse SUSY phenomena which might still be expected in the post LHC8 era at both LHC and ILC.

  16. Greater soil carbon accumulation in deeper soils in native- than in exotic-dominated grassland plantings in the southern Plains

    Science.gov (United States)

    Wilsey, B. J.; Xu, X.; Polley, H. W.; Hofmockel, K. S.

    2017-12-01

    Global change includes invasion by non-native plant species, and invasion may affect carbon cycling and storage. We tested predictions in central Texas in an experiment that compares mixtures of all exotic or all native species under two summer irrigation treatments (128 or 0 mm) that varies the amount of summer drought stress. At the end of the eighth growing season after establishment, soils were sampled in 10 cm increments to 100 cm depth to determine if soil C differed among treatments, and if treatments differentially affected soil C in deeper soils. Soil C content was significantly (5%) higher under native plantings than under exotic species plantings (P plantings increased with depth, and native plantings had higher soil C in deeper soil layers than in surface layers (native-exotic x depth, P plantings had decreasing soil C with depth. Soil C:N ratio and δ13C/12C were also significantly affected by native-exotic status, with soils in exotic plots having a significantly greater C4 contribution than native soils. Soil C was unaffected by summer irrigation treatments. Our results suggest that a significant amount of carbon could be sequestered by replacing exotic plant species with native species in the southern Plains, and that more work should be conducted at deeper soil depths. If we had restricted our analyses to surface soil layers (e.g. top 30 cm), we would have failed to detect depth differences between natives and exotics.

  17. First LHC beam in 2017

    CERN Multimedia

    ATLAS Collaboration

    2017-01-01

    Impressions from the ATLAS control room while waiting for the very first 2017 LHC beams, from the traditional croissants in the morning to the "beam splashes" in the evening. The shift crew, online experts, run coordinators and management are looking forward to the next steps of the LHC restart.

  18. Status of the LHC machine

    International Nuclear Information System (INIS)

    Faugeras, P.

    1997-01-01

    The report represents itself a set of diagrams, characterizing: the LHC main parameters for proton-proton collisions and lead ion collisions, parameters of SC dipole and quadrupole magnets and outlines of their designs, LHC cryogenic systems, injection complex and detectors [ru

  19. Le futur du project LHC

    CERN Multimedia

    Heyoka

    2007-01-01

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

  20. LHC Cryogenics on the mend

    CERN Multimedia

    2004-01-01

    On 29 September, repairs began on the LHC cryogenic distribution line, or QRL, to replace a faulty part that occurs in the hundreds of elements of the line that are already on-site. The Accelerator Technology Department is designing a work programme to finish the repairs as soon as possible and minimize delays to the rest of the LHC project.

  1. First LHC beam in 2017

    CERN Multimedia

    ATLAS Collaboration

    2017-01-01

    Impressions from the ATLAS control room while waiting for the very first 2017 LHC beams, from the traditional croissants in the morning to the "beam splashes" in the evening. The shift crew, online experts, run coordinators and management are looking forward the next steps of the LHC restart.

  2. Support for the LHC experiments

    CERN Document Server

    Butin, François; Gastal, M; Lacarrère, D; Macina, D; Perrot, A L; Tsesmelis, E; Wilhelmsson, M; CERN. Geneva. TS Department

    2008-01-01

    Experimental Area Teams have been put in place and charged with the general co-ordination and management of the LHC experimental areas and of the zones in the LHC tunnel hosting near-beam detectors of the experiments. This organization is responsible for the in situ co-ordination of work with the aim of providing a structure that enables the experiment collaborations and accelerator groups to carry out their work effectively and safely. This presentation will review some key elements in the support given to the LHC experimental areas and, given the track record and successful implementation during the LHC installation and commissioning phase, will argue that such an organization structure will be required also for the period of LHC exploitation for physics.

  3. CERN: LHC progress

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The push for CERN's next major project, the LHC proton collider to be built in the 27-kilometre LEP tunnel, is advancing on a wide front. For the machine itself, there has been considerable progress in the detailed design. While the main thrust is for proton-proton collisions, heavy ions are also on the LHC collision menu. On the experimental side, proposals are coming into sharper focus. For the machine, the main aim is for the highest possible proton collision energies and collision rates in the confines of the existing LEP tunnel, and the original base design looked to achieve these goals in three collision regions. Early discussions on the experimental programme quickly established that the most probable configuration would have two collision regions rather than three. This, combined with hints that the electronics of several detectors would have to handle several bunch crossings at a time, raised the question whether the originally specified bunch spacing of 15 ns was still optimal

  4. LHC Power Distribution

    CERN Document Server

    Pedersen, J

    1999-01-01

    The power distribution for the LHC machine and its experiments will be realised making extensive use of the existing infrastructure for the LEP. The overall power requirement is approximately the same, about 125 MW. The load distribution will however change. The even points will loose in importance and the points 1 and 5 will, due to the installation of ATLAS and CMS, gain. A thorough reorganisation of the 18 kV distribution will thus be necessary. Due to the important cryogenic installations required for the LHC, the 3.3 kV distribution system, supplying mainly cryogenic compressors, will be extended with a number of new substations. The important number of new surface buildings, underground caverns and other underground structures all will receive general service installations: Lighting and power. The new injection tunnels will require complete installations: A.C. supplies for the power converters and for general service, and D.C. cabling for the magnets of the beam line. Special safe power installations ar...

  5. Vacuum system for LHC

    International Nuclear Information System (INIS)

    Groebner, O.

    1995-01-01

    The Large Hadron Collider (LHC) which is planned at CERN will be housed in the tunnel of the Large Electron Positron collider (LEP) and will store two counter-rotating proton beams with energies of up to 7 TeV in a 27 km accelerator/storage ring with superconducting magnets. The vacuum system for the LHC will be at cryogenic temperatures (between 1.9 and 20 K) and will be exposed to synchrotron radiation emitted by the protons. A stringent limitation on the vacuum is given by the energy deposition in the superconducting coils of the magnets due to nuclear scattering of the protons on residual gas molecules because this may provoke a quench. This effect imposes an upper limit to a local region of increased gas density (e.g. a leak), while considerations of beam lifetime (100 h) will determine more stringent requirements on the average gas density. The proton beam creates ions from the residual gas which may strike the vacuum chamber with sufficient energy to lead to a pressure 'run-away' when the net ion induced desorption yield exceeds a stable limit. These dynamic pressure effects will be limited to an acceptable level by installing a perforated 'beam screen' which shields the cryopumped gas molecules at 1.9 K from synchrotron radiation and which also absorbs the synchrotron radiation power at a higher and, therefore, thermodynamically more efficient temperature. (author)

  6. LHC progress report

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Last weekend saw a record physics fill with a tenfold increase in instantaneous luminosity (event rate from collisions), marking an important milestone for the LHC. This physics fill did not only establish luminosities above 1.1 x 1028 cm-2 s-1 in all four experiments but was also kept in "stable beam" mode for a new record length of 30 hours. The particle physics experiments were able to more than double the total number of events so far recorded at 3.5 TeV.   The LHC screen indicating that squeezed stable beams have been achieved for the first time. The very successful weekend had been preceded by hard work on the accelerator side. A factor 5 improvement in luminosity was achieved by "squeezing" (reducing) the beam sizes at all four interaction points. This process, one of the most complex stages in the operation of the accelerator, was finalised the week before. Once the machine is "squeezed", the experimental insertions become aperture bot...

  7. LHC Capabilities for Quarkonia

    CERN Document Server

    Petrushanko, Sergey

    2008-01-01

    The measurement of the charmonium and bottomonium resonances in nucleus-nucleus collisions provides crucial information on high-density QCD matter. First, the suppression of quarkonia production is generally agreed to be one of the most direct probes of quark-gluon plasma formation. The observation of anomalous J/$\\psi$ suppression at the CERN-SPS and at RHIC is well established but the clarification of some important remaining questions requires equivalent studies of the $\\Upsilon$ family, only possible at the LHC energies. Second, the production of heavy-quarks proceeds mainly via gluon-gluon fusion processes and, as such, is sensitive to saturation of the gluon density at low-x in the nucleus. Measured departures from the expected vacuum quarkonia cross-sections in Pb+Pb collisions at the LHC will thus provide valuable information not only on the thermodynamical state of the produced partonic medium, but also on the initial-state modifications of the nuclear parton distribution functions. The capabilities ...

  8. Strongly coupled models at the LHC

    International Nuclear Information System (INIS)

    Vries, Maikel de

    2014-10-01

    In this thesis strongly coupled models where the Higgs boson is composite are discussed. These models provide an explanation for the origin of electroweak symmetry breaking including a solution for the hierarchy problem. Strongly coupled models provide an alternative to the weakly coupled supersymmetric extensions of the Standard Model and lead to different and interesting phenomenology at the Large Hadron Collider (LHC). This thesis discusses two particular strongly coupled models, a composite Higgs model with partial compositeness and the Littlest Higgs model with T-parity - a composite model with collective symmetry breaking. The phenomenology relevant for the LHC is covered and the applicability of effective operators for these types of strongly coupled models is explored. First, a composite Higgs model with partial compositeness is discussed. In this model right-handed light quarks could be significantly composite, yet compatible with experimental searches at the LHC and precision tests on Standard Model couplings. In these scenarios, which are motivated by flavour physics, large cross sections for the production of new resonances coupling to light quarks are expected. Experimental signatures of right-handed compositeness at the LHC are studied, and constraints on the parameter space of these models are derived using recent results by ATLAS and CMS. Furthermore, dedicated searches for multi-jet signals at the LHC are proposed which could significantly improve the sensitivity to signatures of right-handed compositeness. The Littlest Higgs model with T-parity, providing an attractive solution to the fine-tuning problem, is discussed next. This solution is only natural if its intrinsic symmetry breaking scale f is relatively close to the electroweak scale. The constraints from the latest results of the 8 TeV run at the LHC are examined. The model's parameter space is being excluded based on a combination of electroweak precision observables, Higgs precision

  9. LHC Injection Beam Quality During LHC Run I

    CERN Document Server

    AUTHOR|(CDS)2079186; Kain, Verena; Stapnes, Steinar

    The LHC at CERN was designed to accelerate proton beams from 450 GeV to 7 TeV and collide them in four large experiments. The 450 GeV beam is extracted from the last pre-accelerator, the SPS, and injected into the LHC via two 3 km long transfer lines, TI 2 and TI 8. The injection process is critical in terms of preservation of beam quality and machine protection. During LHC Run I (2009-2013) the LHC was filled with twelve high intensity injections per ring, in batches of up to 144 bunches of 1.7*10^11 protons per bunch. The stored beam energy of such a batch is already an order of magnitude above the damage level of accelerator equipment. Strict quality and machine protection requirements at injection have a significant impact on operational efficiency. During the first years of LHC operation, the injection phase was identified as one of the limiting factors for fast LHC turnaround time. The LHC Injection Quality Check (IQC) software framework was developed as a part of this thesis to monitor the beam quality...

  10. Thermal and prompt photons at RHIC and the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Paquet, Jean-François [Department of Physics & Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States); Department of Physics, McGill University, 3600 University Street, Montreal, Quebec, H3A2T8 (Canada); Shen, Chun [Department of Physics, McGill University, 3600 University Street, Montreal, Quebec, H3A2T8 (Canada); Denicol, Gabriel [Department of Physics, McGill University, 3600 University Street, Montreal, Quebec, H3A2T8 (Canada); Physics Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Luzum, Matthew [Universidade de Santiago de Compostela, E-15706 Santiago de Compostela, Galicia-Spain (Spain); Universidade de São Paulo, Rua do Matão Travessa R, no. 187, 05508-090, Cidade Universitária, São Paulo (Brazil); Schenke, Björn [Physics Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Jeon, Sangyong; Gale, Charles [Department of Physics, McGill University, 3600 University Street, Montreal, Quebec, H3A2T8 (Canada)

    2016-12-15

    Thermal and prompt photon production in heavy ion collisions is evaluated and compared with measurements from both RHIC and the LHC. An event-by-event hydrodynamical model of heavy ion collisions that includes shear and bulk viscosities is used, along with up-to-date photon emission rates. Larger tension with measurements is observed at RHIC than at the LHC. The center-of-mass energy and centrality dependence of thermal and prompt photons is investigated.

  11. Review of 2011 LHC run from the experiments perspective

    Energy Technology Data Exchange (ETDEWEB)

    Ferro-Luzzi, M [European Organization for Nuclear Research, Geneva (Switzerland)

    2012-07-01

    The 2011 LHC run is reviewed from the experiments' perspective. The LHC achievements directly related to physics production are summarized. This includes high luminosity p-p and Pb-Pb running, special activities (such as intermediate energy p-p physics, 90 m optics, luminosity calibrations) and other experiments (for example satellite-main bunch collisions in IP2, 25 ns stable beams tests, etc.). (author)

  12. Tracking detectors for the sLHC, the LHC upgrade

    CERN Document Server

    Sadrozinski, Hartmut F W

    2005-01-01

    The plans for an upgrade of the Large Hadron Collider (LHC) to the Super-LHC (sLHC) are reviewed with special consideration of the environment for the inner tracking system. A straw-man detector upgrade for ATLAS is presented, which is motivated by the varying radiation levels as a function of radius, and choices for detector geometries and technologies are proposed, based on the environmental constraints. A few promising technologies for detectors are discussed, both for sensors and for the associated front-end electronics. On-going research in silicon detectors and in ASIC technologies will be crucial for the success of the upgrade.

  13. LHC-B: a dedicated LHC collider beauty experiment

    International Nuclear Information System (INIS)

    Erhan, S.

    1995-01-01

    LHC-B is a forward detector optimized for the study of CP-violation and other rare phenomena in the decays of beauty particles at the LHC. An open geometry forward detector design, with good mass, vertex resolution and particle identification, will facilitate the collection of a large numbers of event samples in diverse B decay channels and allow for a thorough understanding of the systematic uncertainties. With the expected large event statistics, LHC-B will be able to test the closure of the unitarity triangle and make sensitive tests of the Standard Model description of CP-violation. Here we describe the experiment and summarize its anticipated performance. (orig.)

  14. Exotic Material as Interactions Between Scalar Fields

    Directory of Open Access Journals (Sweden)

    Robertson G. A.

    2015-10-01

    Full Text Available Many theoretical papers refer to the need to create exotic materials with average negative energies for the formation of space propulsion anomalies such as “wormholes” and “warp drives”. However, little hope is given for the existence of such material to resolve its creation for such use. From the standpoint that non-minimally coupled scalar fields to gravity appear to be the current direction mathematically. It is proposed that exotic material is really scalar field interactions. Within this paper the Ginzburg- Landau (GL scalar fields associated with superconductor junctions is investigated as a source for negative vacuum energy fluctuations, which could be used to study the interactions among energy fluctuations, cosmological scalar (i. e., Higgs fields, and gravity.

  15. Electron microscopy of some exotic materials

    International Nuclear Information System (INIS)

    Mitchell, T.E.

    1998-01-01

    Just about every material has been looked at under the microscope, either out of pure inquisitiveness or the need to relate the microstructure to its properties. Some of these materials are mundane, like steels or glass or polyethylene; others are so-called advanced, such as intermetallics, silicon nitride or zirconia; yet others might be called exotic whether they be martian rocks, high temperature superconductors, fullerenes, diamonds, or the latest thin film device. Many exotic materials are important in Los Alamos, not only weapons materials such as actinides, tritium and explosives, but also civilian materials for energy applications. Here the author will report briefly on plutonium and uranium, on rhenium disilicide, and on Cu-Nb nanolayered composites

  16. Exotic Material as Interactions Between Scalar Fields

    Directory of Open Access Journals (Sweden)

    Robertson G. A.

    2006-04-01

    Full Text Available Many theoretical papers refer to the need to create exotic materials with average negative energies for the formation of space propulsion anomalies such as "wormholes" and "warp drives". However, little hope is given for the existence of such material to resolve its creation for such use. From the standpoint that non-minimally coupled scalar fields to gravity appear to be the current direction mathematically. It is proposed that exotic material is really scalar field interactions. Within this paper the Ginzburg-Landau (GL scalar fields associated with superconductor junctions isinvestigated as a source for negative vacuum energy fluctuations, which could be used to study the interactions among energyfluctuations, cosmological scalar (i.e., Higgs fields, and gravity.

  17. Kulit ikan kakap tersamak: Exotic dan prospektif

    Directory of Open Access Journals (Sweden)

    Emiliana Kasmudjiastuti

    2005-01-01

    Full Text Available Kakap fish skins are waste products of fillet industry. Up to now they have been wasted, of course accumulatively will cause environmental pollution. They are classified as the type of non conventional leather and exotic ones for the reasons of having special, beautiful, unique, typical, and attractive grain. Kakap fish skin have relatively small dimentions, there fore the tanning process can be done by home industry because simple equipments are possible to be used to process the fish skins into leather. In addition, Kakap fish leather have physical property of good tensile strength that may be used as material for leather goods. Although small however the exotic leather of kakap fish skins are prospective to be developed as material to manufacture exclusive leather goods, especially for niche markets. They also can be used as an alternative to substitute conventional leather.

  18. Exotic nuclei: production, properties and specificity

    International Nuclear Information System (INIS)

    Van Duppen, Piet

    1998-01-01

    In this paper we will put the production of energetic radioactive ion beams of exotic nuclei in perspective and describe the two complementary production processes that are used nowadays: Isotope Separation On-Line (ISOL) followed by post-acceleration, and In-Flight Separation (IFS). After a general description of the process we will focus on recent technical developments in the field. In the subsequent section we give some 'typical' examples of physics cases that are addressed with exotic beams. The examples are chosen not only because their physics importance but also to demonstrate the complementary aspects in the production process and the detection systems. This overview will not be complete and the reader is referred to literature for further information, nor is the lecture intended to give an overview of all the efforts that are taking place in the field by mentioning every project separately. (author)

  19. Lecture 7: Worldwide LHC Computing Grid Overview

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    This presentation will introduce in an informal, but technically correct way the challenges that are linked to the needs of massively distributed computing architectures in the context of the LHC offline computing. The topics include technological and organizational aspects touching many aspects of LHC computing, from data access, to maintenance of large databases and huge collections of files, to the organization of computing farms and monitoring. Fabrizio Furano holds a Ph.D in Computer Science and has worked in the field of Computing for High Energy Physics for many years. Some of his preferred topics include application architectures, system design and project management, with focus on performance and scalability of data access. Fabrizio has experience in a wide variety of environments, from private companies to academic research in particular in object oriented methodologies, mainly using C++. He has also teaching experience at university level in Software Engineering and C++ Programming.

  20. Accurate predictions for the LHC made easy

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    The data recorded by the LHC experiments is of a very high quality. To get the most out of the data, precise theory predictions, including uncertainty estimates, are needed to reduce as much as possible theoretical bias in the experimental analyses. Recently, significant progress has been made in computing Next-to-Leading Order (NLO) computations, including matching to the parton shower, that allow for these accurate, hadron-level predictions. I shall discuss one of these efforts, the MadGraph5_aMC@NLO program, that aims at the complete automation of predictions at the NLO accuracy within the SM as well as New Physics theories. I’ll illustrate some of the theoretical ideas behind this program, show some selected applications to LHC physics, as well as describe the future plans.

  1. 2d orbifolds with exotic supersymmetry

    Science.gov (United States)

    Florakis, Ioannis; García-Etxebarria, Iñaki; Lüst, Dieter; Regalado, Diego

    2018-02-01

    We analyse various two dimensional theories arising from compactification of type II and heterotic string theory on asymmetric orbifolds. We find extra supersymmetry generators arising from twisted sectors, giving rise to exotic supersymmetry algebras. Among others we discover new cases with a large number of supercharges, such as N=(20,8), N=(24,8), N=(32,0), N=(24,24) and N=(48,0).

  2. From heavy ions to exotic atoms

    OpenAIRE

    Indelicato, Paul; Trassinelli, Martino

    2005-01-01

    We review a number of experiments and theoretical calculations on heavy ions and exotic atoms, which aim at providing informations on fundamental interactions. Among those are propositions of experiments for parity violation measurements in heavy ions and high-precision mesurements of He-like transition energies in highly charged ions. We also describe recent experiments on pionic atoms, that make use of highly-charged ion transitions to obtain accurate measurements of strong interaction shif...

  3. Remarks on the exotic U-meson

    International Nuclear Information System (INIS)

    Chan Hongmo; Tsou Sheungtsun

    1991-12-01

    In expectation of imminent results from the new hyperon beam experiment at CERN concerning the exotic U-meson at 3.1 GeV, we propose a detailed program of experimental tests to check the suggestion that U is a qqq-barq-bar ''M-diquonium'' state. Apart from some very characteristic decay modes, the U is expected to occur together with several analogous states with various quantum numbers to which it is intimately related. (author)

  4. Exotic rotational correlations in quantum geometry

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, Craig

    2017-05-01

    It is argued by extrapolation of general relativity and quantum mechanics that a classical inertial frame corresponds to a statistically defined observable that rotationally fluctuates due to Planck scale indeterminacy. Physical effects of exotic nonlocal rotational correlations on large scale field states are estimated. Their entanglement with the strong interaction vacuum is estimated to produce a universal, statistical centrifugal acceleration that resembles the observed cosmological constant.

  5. Strange exotic states and compact stars

    International Nuclear Information System (INIS)

    Sagert, Irina; Wietoska, Mirjam; Schaffner-Bielich, Juergen

    2006-01-01

    We discuss the possible appearance of strange exotic multi-quark states in the interiors of neutron stars and signals for the existence of strange quark matter in the cores of compact stars. We show how the in-medium properties of possible pentaquark states are constrained by pulsar mass measurements. The possibility of generating the observed large pulsar kick velocities by asymmetric emission of neutrinos from strange quark matter in magnetic fields is outlined

  6. Production and identification of very exotic nuclei

    International Nuclear Information System (INIS)

    Pougheon, F.

    1986-01-01

    New very exotic nuclei have been produced by fragmentation of the projectile at intermediate energy at GANIL. They have been identified through time of flight and ΔE-E measurements after a magnetic separation with the 0 0 LISE spectrometer. New neutron rich isotopes have been identified up to Z = 26 and evidence for the stability of the new series Tz = -5/2 has been shown. These results improve the knowledge of the neutron and proton drip lines

  7. Exploring exotic states with twisted boundary conditions

    International Nuclear Information System (INIS)

    Agadjanov, Dimitri

    2017-01-01

    he goal of this thesis is to develop methods to study the nature and properties of exotic hadrons from lattice simulations. The main focus lies in the application of twisted boundary conditions. The thesis consists of a general introduction and the collection of three papers, represented respectively in three chapters. The introduction of the thesis reviews the theoretical background, which is further used in the rest of the thesis. Further implementing partially twisted boundary conditions in the scalar sector of lattice QCD is studied. Then we develop a method to study the content of the exotic hadrons by determining the wave function renormalization constant from lattice simulations, exploiting the dependence of the spectrum on the twisted boundary conditions. The final chapter deals with a novel method to study the multi-channel scattering problem in a finite volume, which is relevant for exotic states. Its key idea is to extract the complex hadron-hadron optical potential, avoiding the difficulties, associated with the solution of the multi-channel Luescher equation.

  8. Exploring exotic states with twisted boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Agadjanov, Dimitri

    2017-09-11

    he goal of this thesis is to develop methods to study the nature and properties of exotic hadrons from lattice simulations. The main focus lies in the application of twisted boundary conditions. The thesis consists of a general introduction and the collection of three papers, represented respectively in three chapters. The introduction of the thesis reviews the theoretical background, which is further used in the rest of the thesis. Further implementing partially twisted boundary conditions in the scalar sector of lattice QCD is studied. Then we develop a method to study the content of the exotic hadrons by determining the wave function renormalization constant from lattice simulations, exploiting the dependence of the spectrum on the twisted boundary conditions. The final chapter deals with a novel method to study the multi-channel scattering problem in a finite volume, which is relevant for exotic states. Its key idea is to extract the complex hadron-hadron optical potential, avoiding the difficulties, associated with the solution of the multi-channel Luescher equation.

  9. Production LHC HTS power lead test results

    CERN Document Server

    Tartaglia, M; Fehér, S; Huang, Y; Orris, D F; Pischalnikov, Y; Rabehl, Roger Jon; Sylvester, C D; Zbasnik, J

    2005-01-01

    The Fermilab Magnet test facility has built and operated a test stand to characterize the performance of HTS power leads. We report here the results of production tests of 20 pairs of 7.5 kA HTS power leads manufactured by industry for installation in feed boxes for the LHC Interaction Region quadrupole strings. Included are discussions of the thermal, electrical, and quench characteristics under "standard" and "extreme" operating conditions, and the stability of performance across thermal cycles.

  10. Production LHC HTS power lead test results

    International Nuclear Information System (INIS)

    Tartaglia, M.A.; Carcagno, R.H.; Feher, S.; Huang, Y.; Orris, D.F.; Pischalnikov, Y.; Rabehl, R.J.; Sylvester, C.; Zbasnik, J.

    2004-01-01

    The Fermilab Magnet test facility has built and operated a test stand to characterize the performance of HTS power leads. We report here the results of production tests of 20 pairs of 7.5 kA HTS power leads manufactured by industry for installation in feed boxes for the LHC Interaction Region quadrupole strings. Included are discussions of the thermal, electrical, and quench characteristics under ''standard'' and ''extreme'' operating conditions, and the stability of performance across thermal cycles

  11. Dedication of Fermilab's LHC Remote Operations Center

    CERN Multimedia

    Claudia Marcelloni

    2007-01-01

    Fermilab's Remote Operations Center will be dedicated simultaneously at Fermilab in the U.S. and from CMS (Point 5) in Cessy, France. Speakers will include: from the U.S. DOE Undersecretary for Science Raymond Orbach and Fermilab Director Pier Oddone (U.S.); and from CERN Director General Robert Aymar, CMS Spokesperson Jim Virdee, LHC Project Leader Lyn Evans and US CMS Project Manager Joel Butler.

  12. Keeping HL-LHC accountable

    CERN Multimedia

    2015-01-01

    This week saw the cost and schedule of the High Luminosity LHC (HL-LHC) and LHC Injectors Upgrade (LIU) projects come under close scrutiny from the external review committee set up for the purpose.    HL-LHC, whose implementation requires an upgrade to the CERN injector complex, responds directly to one of the key recommendations of the updated European Strategy for Particle Physics, which urges CERN to prepare for a ‘major luminosity upgrade’, a recommendation that is also perfectly in line with the P5 report on the US strategy for the field. Responding to this recommendation, CERN set up the HL-LHC project in 2013, partially supported by FP7 funding through the HiLumi LHC Design Study (2011-2015), and coordinated with the American LARP project, which oversees the US contribution to the upgrade. A key element of HL-LHC planning is a mechanism for receiving independent expert advice on all aspects of the project.  To this end, several technical reviews h...

  13. Use of exotic species in afforestation and facilitation for the establishment of biological invasion

    Directory of Open Access Journals (Sweden)

    Juliano Ricardo Fabricante

    2017-02-01

    Full Text Available This study aimed to inventory the species used in landscaping the Campus of Agricultural Sciences of the Federal University of Paraíba, Areia, PB, Brazil and to rank them according to their origin and their invasive potential. Through walks throughout the study area (active search, we cataloged all the species used in local afforestation and classified them as native or exotic. Exotic plants were also classified as to their invasive potential. Altogether, we identified 76 species belonging to 67 genera and 25 families. Of these, only 26 species were native. The results of this study are worrisome because of the large number of exotic species used for planting at the study site (50 species, including known aggressive species: Artocarpus heterophyllus Lam., Azadirachta indica A. Juss. and Leucaena leucocephala (Lam. de Wit.

  14. Anisotropic harmonic oscillator, non-commutative Landau problem and exotic Newton-Hooke symmetry

    International Nuclear Information System (INIS)

    Alvarez, Pedro D.; Gomis, Joaquim; Kamimura, Kiyoshi; Plyushchay, Mikhail S.

    2008-01-01

    We investigate the planar anisotropic harmonic oscillator with explicit rotational symmetry as a particle model with non-commutative coordinates. It includes the exotic Newton-Hooke particle and the non-commutative Landau problem as special, isotropic and maximally anisotropic, cases. The system is described by the same (2+1)-dimensional exotic Newton-Hooke symmetry as in the isotropic case, and develops three different phases depending on the values of the two central charges. The special cases of the exotic Newton-Hooke particle and non-commutative Landau problem are shown to be characterized by additional, so(3) or so(2,1) Lie symmetry, which reflects their peculiar spectral properties

  15. Timing, Trigger and Control Systems for LHC Detectors

    CERN Multimedia

    2002-01-01

    \\\\ \\\\At the LHC, precise bunch-crossing clock and machine orbit signals must be broadcast over distances of several km from the Prevessin Control Room to the four experiment areas and other destinations. At the LHC experiments themselves, quite extensive distribution systems are also required for the transmission of timing, trigger and control (TTC) signals to large numbers of front-end electronics controllers from a single location in the vicinity of the central trigger processor. The systems must control the detector synchronization and deliver the necessary fast signals and messages that are phased with the LHC clock, orbit or bunch structure. These include the bunch-crossing clock, level-1 trigger decisions, bunch and event numbers, as well as test signals and broadcast commands. A common solution to this TTC system requirement is expected to result in important economies of scale and permit a rationalization of the development, operational and support efforts required. LHC Common Project RD12 is developi...

  16. Operating the worldwide LHC computing grid: current and future challenges

    International Nuclear Information System (INIS)

    Molina, J Flix; Forti, A; Girone, M; Sciaba, A

    2014-01-01

    The Wordwide LHC Computing Grid project (WLCG) provides the computing and storage resources required by the LHC collaborations to store, process and analyse their data. It includes almost 200,000 CPU cores, 200 PB of disk storage and 200 PB of tape storage distributed among more than 150 sites. The WLCG operations team is responsible for several essential tasks, such as the coordination of testing and deployment of Grid middleware and services, communication with the experiments and the sites, followup and resolution of operational issues and medium/long term planning. In 2012 WLCG critically reviewed all operational procedures and restructured the organisation of the operations team as a more coherent effort in order to improve its efficiency. In this paper we describe how the new organisation works, its recent successes and the changes to be implemented during the long LHC shutdown in preparation for the LHC Run 2.

  17. Large Hadron Collider (LHC) phenomenology, operational challenges and theoretical predictions

    CERN Document Server

    Gilles, Abelin R

    2013-01-01

    The Large Hadron Collider (LHC) is the highest-energy particle collider ever constructed and is considered "one of the great engineering milestones of mankind." It was built by the European Organization for Nuclear Research (CERN) from 1998 to 2008, with the aim of allowing physicists to test the predictions of different theories of particle physics and high-energy physics, and particularly prove or disprove the existence of the theorized Higgs boson and of the large family of new particles predicted by supersymmetric theories. In this book, the authors study the phenomenology, operational challenges and theoretical predictions of LHC. Topics discussed include neutral and charged black hole remnants at the LHC; the modified statistics approach for the thermodynamical model of multiparticle production; and astroparticle physics and cosmology in the LHC era.

  18. Physics Validation of the LHC Software

    CERN Multimedia

    CERN. Geneva

    2004-01-01

    The LHC Software will be confronted to unprecedented challenges as soon as the LHC will turn on. We summarize the main Software requirements coming from the LHC detectors, triggers and physics, and we discuss several examples of Software components developed by the experiments and the LCG project (simulation, reconstruction, etc.), their validation, and their adequacy for LHC physics.

  19. The ALICE experiment at the CERN LHC

    Energy Technology Data Exchange (ETDEWEB)

    Aamodt, K [Department of Physics, University of Oslo, Oslo (Norway); Abrahantes Quintana, A [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear (CEADEN), Madrid/Havana, Spain (Cuba); Achenbach, R [Kirchhoff-Institut fuer Physik, Ruprecht-Karls-Universitaet Heidelberg, Heidelberg, Germany BMBF (Germany); Acounis, S [SUBATECH, Ecole des Mines de Nantes, Universite de Nantes, CNRS/IN2P3, Nantes (France); Adamova, D [Academy of Sciences of the Czech Republic, Nuclear Physics Institute, Rez/Prague (Czech Republic); Adler, C [Physikalisches Institut, Ruprecht-Karls-Universitaet Heidelberg, Heidelberg, Germany BMBF (Germany); Aggarwal, M [Physics Department, Panjab University, Chandigarh (India); Agnese, F [IPHC, Universite Louis Pasteur, CNRS/IN2P3, Strasbourg (France); Rinella, G Aglieri [CERN, European Organization for Nuclear Reasearch, Geneva (Switzerland); Ahammed, Z [Variable Energy Cyclotron Centre, Kolkata (India); Ahmad, A; Ahmad, N; Ahmad, S [Department of Physics Aligarh Muslim University, Aligarh (India); Akindinov, A [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Akishin, P [JINR, Joint Institute for Nuclear Research, Dubna, (Russian Federation); Aleksandrov, D [Russian Research Center Kurchatov Institute, Moscow (Russian Federation); Alessandro, B; Alfarone, G [Sezione INFN, Torino (Italy); Alfaro, R [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Mexico City (Mexico); Alici, A [Dipartimento di Fisica dell' Universita and Sezione INFN, Bologna (Italy)], E-mail: Hans-Ake.Gustafsson@hep.lu.se (and others)

    2008-08-15

    ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries. Its overall dimensions are 16 x 16 x 26 m{sup 3} with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010

  20. Dissecting an LHC dipole

    CERN Multimedia

    2004-01-01

    The cold mass of a 15-metre main dipole magnet has some fifteen different components. All the main components are manufactured under CERN's direct responsibility. Four of them transit through CERN before being shipped to the dipole assembly contractors, namely the cable, which constitutes the magnet's superconducting core (see Bulletin 14/2004), the beam screens, the heat exchanger tubes and the cold bore beam tubes. The two latter components transit via Building 927 where they undergo part of the production process. The 58-mm diameter heat exchanger tubes will remove heat from the magnets using superfluid helium. The 53-mm diameter cold bore tubes will be placed under vacuum to allow the twin beams to circulate around the LHC.

  1. CARBONIFEROUS CORALS AND CHAETETIDS FROM EXOTIC LIMESTONE BLOCK OF THE CRIMEA

    Directory of Open Access Journals (Sweden)

    VICTOR OGAR

    2015-11-01

    Full Text Available A chaetetid sponge and coral fauna from a Carboniferous exotic limestone block in the Lower Jurassic Esciorda olistostrome on the Bodrak River (Crimean Mountains are described for the first time. The Bodrak exotic block is composed of massive limestone. It contains the chaetetid Chaetetes (Boswellia sp., the tabulate coral Multithecopora sp., and poorly preserved rugose corals, including Dibunophyllum? sp., Cordibia? sp. and gen. et sp. indet. Only the fasciculate colonies of the rugose coral Lytvophyllum askynensis (Kossovaya, 2009 are confidently identified. The studied association of fossils is similar to that of the Donets Basin and the Urals and confirms the Lower Bashkirian age of the Bodrak limestone block. 

  2. Beam Scraping for LHC Injection

    CERN Document Server

    Burkhardt, H; Fischer, C; Gras, J-J; Koschik, A; Kramer, Daniel; Pedersen, S; Redaelli, S

    2007-01-01

    Operation of the LHC will require injection of very high intensity beams from the SPS to the LHC. Fast scrapers have been installed and will be used in the SPS to detect and remove any existing halo before beams are extracted, to minimize the probability for quenching of superconducting magnets at injection in the LHC. We briefly review the functionality of the scraper system and report about measurements that have recently been performed in the SPS on halo scraping and re-population of tails.

  3. CERN LHC dipole prototype success

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    In a crash programme, the first prototype superconducting dipole magnet for CERN's LHC protonproton collider was successfully powered for the first time at CERN on 14 April, eventually sailing to 9T, above the 8.65T nominal LHC field, before quenching for the third time. The next stage is to install the delicate measuring system for making comprehensive magnetic field maps in the 10 m long, 50 mm diameter twin-apertures of the magnet. These measurements will check that the required LHC field quality has been achieved at both the nominal and injection fields

  4. Electron scattering for exotic nuclei

    International Nuclear Information System (INIS)

    Suda, T.

    2013-01-01

    An electron scattering facility is under construction in RIKEN RI Beam Factory, Japan, which is dedicated to the structure studies of short-lived nuclei. This is the world's first and currently only facility of its type. The construction is nearly completed, and the first electron scattering experiment off short-lived nuclei will be carried out in the beginning of next year. The charge density distributions of short-lived nuclei will be precisely determined by elastic electron scattering for the first time. Physics pursued at this facility including future perspectives are explained

  5. Exotic atoms - a new scope

    International Nuclear Information System (INIS)

    Kuehl, T.

    1993-01-01

    Heavy ion cooler rings have been installed in a number of laboratories around the world. They allow for a new generation of experiments using the products of high energy heavy ion collisions, i.e. highly charged and possibly radioactive ions. The first series of investigations at the SIS-ESR facility at the GSI, reviewed here, includes the observation of beta decay into a bound state of a highly charged ion and precision spectroscopy of inner-shell levels by means of X-ray spectroscopy, laser spectroscopy and resonant di-electronic recombination. (orig.)

  6. The PDF4LHC report on PDFs and LHC data: results from Run I and preparation for Run II

    International Nuclear Information System (INIS)

    Rojo, Juan; Accardi, Alberto; Ball, Richard D; Cooper-Sarkar, Amanda; Gwenlan, Claire; Roeck, Albert de; Mangano, Michelangelo; Farry, Stephen; Ferrando, James; Forte, Stefano; Gao, Jun; Harland-Lang, Lucian; Huston, Joey; Glazov, Alexander; Lipka, Katerina; Gouzevitch, Maxime; Lisovyi, Mykhailo; Nadolsky, Pavel

    2015-01-01

    The accurate determination of the parton distribution functions (PDFs) of the proton is an essential ingredient of the Large Hadron Collider (LHC) program. PDF uncertainties impact a wide range of processes, from Higgs boson characterization and precision Standard Model measurements to new physics searches. A major recent development in modern PDF analyses has been to exploit the wealth of new information contained in precision measurements from the LHC Run I, as well as progress in tools and methods to include these data in PDF fits. In this report we summarize the information that PDF-sensitive measurements at the LHC have provided so far, and review the prospects for further constraining PDFs with data from the recently started Run II. This document aims to provide useful input to the LHC collaborations to prioritize their PDF-sensitive measurements at Run II, as well as a comprehensive reference for the PDF-fitting collaborations. (topical review)

  7. The PDF4LHC report on PDFs and LHC data. Results from Run I and preparation for Run II

    International Nuclear Information System (INIS)

    Rojo, Juan; Ball, Richard D.; CERN, Geneva

    2015-07-01

    The accurate determination of the Parton Distribution Functions (PDFs) of the proton is an essential ingredient of the Large Hadron Collider (LHC) program. PDF uncertainties impact a wide range of processes, from Higgs boson characterisation and precision Standard Model measurements to New Physics searches. A major recent development in modern PDF analyses has been to exploit the wealth of new information contained in precision measurements from the LHC Run I, as well as progress in tools and methods to include these data in PDF fits. In this report we summarise the information that PDF-sensitive measurements at the LHC have provided so far, and review the prospects for further constraining PDFs with data from the recently started Run II. This document aims to provide useful input to the LHC collaborations to prioritise their PDF-sensitive measurements at Run II, as well as a comprehensive reference for the PDF-fitting collaborations.

  8. The PDF4LHC report on PDFs and LHC data: Results from Run I and preparation for Run II

    CERN Document Server

    Rojo, Juan; Ball, Richard D; Cooper-Sarkar, Amanda; de Roeck, Albert; Farry, Stephen; Ferrando, James; Forte, Stefano; Gao, Jun; Harland-Lang, Lucian; Huston, Joey; Glazov, Alexander; Gouzevitch, Maxime; Gwenlan, Claire; Lipka, Katerina; Lisovyi, Mykhailo; Mangano, Michelangelo; Nadolsky, Pavel; Perrozzi, Luca; Placakyte, Ringaile; Radescu, Voica; Salam, Gavin P; Thorne, Robert

    2015-01-01

    The accurate determination of the Parton Distribution Functions (PDFs) of the proton is an essential ingredient of the Large Hadron Collider (LHC) program. PDF uncertainties impact a wide range of processes, from Higgs boson characterisation and precision Standard Model measurements to New Physics searches. A major recent development in modern PDF analyses has been to exploit the wealth of new information contained in precision measurements from the LHC Run I, as well as progress in tools and methods to include these data in PDF fits. In this report we summarise the information that PDF-sensitive measurements at the LHC have provided so far, and review the prospects for further constraining PDFs with data from the recently started Run II. This document aims to provide useful input to the LHC collaborations to prioritise their PDF-sensitive measurements at Run II, as well as a comprehensive reference for the PDF-fitting collaborations.

  9. Searches for Physics Beyond Standard Model at LHC with ATLAS

    CERN Document Server

    Soni, N; The ATLAS collaboration

    2013-01-01

    This contribution summarises some of the recent results on the searches for physics beyond the Standard Model using the pp-collision data collected at Large Hadron Collider (LHC) with ATLAS detector at centre-of-mass energy of sqrt{s} = 8 TeV. The search for supersymmetry (SUSY) is carried out in a large variety of production modes such as strong production of squarks and gluinos, weak production of sleptons and gauginos os production of massive long-lived particles through R-parity violation. No excess above the Standard Model background expectation is observed and exclusion limits are derived on the production of new physics. The results are interpreted as lower limits on sparticle masses in SUSY breaking scenarios. Searches for new exotic phenomena such as dark matter, large extra dimensions and black holes are also performed at ATLAS. As in the case of SUSY searches, no new exotic phenomena is observed and results are presented as upper limits on event yields from non-Standard-Model processes in a model i...

  10. LHC Report: Tests of new LHC running modes

    CERN Document Server

    Verena Kain for the LHC team

    2012-01-01

    On 13 September, the LHC collided lead ions with protons for the first time. This outstanding achievement was key preparation for the planned 2013 operation in this mode. Outside of two special physics runs, the LHC has continued productive proton-proton luminosity operation.   Celebrating proton-ion collisions. The first week of September added another 1 fb-1 of integrated luminosity to ATLAS’s and CMS’s proton-proton data set. It was a week of good and steady production mixed with the usual collection of minor equipment faults. The peak performance was slightly degraded at the start of the week but thanks to the work of the teams in the LHC injectors the beam brightness – and thus the LHC peak performance – were restored to previous levels by the weekend. The LHC then switched to new running modes and spectacularly proved its potential as a multi-purpose machine. This is due in large part to the LHC equipment and controls, which have been designed wi...

  11. Yukawa Bound States and Their LHC Phenomenology

    Directory of Open Access Journals (Sweden)

    Enkhbat Tsedenbaljir

    2013-01-01

    Full Text Available We present the current status on the possible bound states of extra generation quarks. These include phenomenology and search strategy at the LHC. If chiral fourth-generation quarks do exist their strong Yukawa couplings, implied by current experimental lower bound on their masses, may lead to formation of bound states. Due to nearly degenerate 4G masses suggested by Precision Electroweak Test one can employ “heavy isospin” symmetry to classify possible spectrum. Among these states, the color-octet isosinglet vector ω 8 is the easiest to be produced at the LHC. The discovery potential and corresponding decay channels are covered in this paper. With possible light Higgs at ~125 GeV two-Higgs doublet version is briefly discussed.

  12. Slice through an LHC focusing magnet

    CERN Multimedia

    Slice through an LHC superconducting quadrupole (focusing) magnet. The slice includes a cut through the magnet wiring (niobium titanium), the beampipe and the steel magnet yokes. Particle beams in the Large Hadron Collider (LHC) have the same energy as a high-speed train, squeezed ready for collision into a space narrower than a human hair. Huge forces are needed to control them. Dipole magnets (2 poles) are used to bend the paths of the protons around the 27 km ring. Quadrupole magnets (4 poles) focus the proton beams and squeeze them so that more particles collide when the beams’ paths cross. Bringing beams into collision requires a precision comparable to making two knitting needles collide, launched from either side of the Atlantic Ocean.

  13. Scientific Opportunity: the Tevatron and the LHC

    CERN Multimedia

    2010-01-01

    The press makes much of the competition between CERN’s LHC and Fermilab’s Tevatron in the search for the Higgs boson. This competitive aspect is real, and probably adds spice to the scientific exploration, but for us such reporting often feels like spilling the entire pepper shaker over a fine meal. The media’s emphasis on competition obscures the more important substance of our long-standing collaboration in scientific discovery.   Our laboratories and our communities have worked together for decades. Europeans have contributed greatly to the Tevatron’s many successes, including the discovery of the top quark, the discovery of fast oscillations in the decay of strange B mesons and the many searches for new phenomena. Americans have contributed to many programs at CERN, notably the extraordinary precision measurements of LEP, and more recently construction of the LHC accelerator and detectors. Fermilab scientists played a vital role throughout 2009 in...

  14. QCD-instantons at LHC. Theoretical aspects

    International Nuclear Information System (INIS)

    Petermann, M.

    2007-06-01

    Instantons are nonperturbative, topologically nontrivial field configurations, which occur in every nonabelian gauge theory. They can be understood as tunneling processes between topologically distinct vacua. Although being a basic theoretical aspect of the Standard Model, a direct experimental verification of instanton processes is still lacking. In this thesis the general discovery potential for QCD-instantons at the LHC is studied in detail by means of instanton perturbation theory. In this context the close correspondence between the leading instanton induced processes at HERA and at LHC becomes important. Essential aspects and differences to deep inelastic scattering can already be revealed by studying the simplest process. Based on these results inclusive cross sections are calculated including the emission of final state gluons. Compared to deep inelastic scattering, a large enhancement of the cross section is found. (orig.)

  15. LHC Report: No beams but still busy

    CERN Multimedia

    Mike Lamont for the LHC Team

    2012-01-01

    The LHC finished with beams for 2011 on Wednesday 7 December after a pretty good year of operation. The cryogenics team has emptied the magnets of helium for the winter technical stop and a full maintenance programme has started. The LHC is running long operational years at present with only a few short technical stops during operation with beam. This leaves very little time for much-needed maintenance and upgrades. Thus, the hardware teams involved have to take full advantage of the time available during the winter stop.   The Engineering Department is planning and coordinating the maintenance and repair activities for the whole accelerator complex. The list of planned interventions is truly impressive! There is a lot of work that involves the essential technical infrastructure systems (electricity, cooling, ventilation). Cryogenics have established a full programme aimed at maintaining and improving their already good level of availability. Other systems undergoing maintenance include: vacu...

  16. LHC Report: No beams but still busy

    CERN Multimedia

    Mike Lamont for the LHC Team

    2011-01-01

    The LHC finished with beams for 2011 on Wednesday 7 December after a pretty good year of operation. The cryogenics team has emptied the magnets of helium for the winter technical stop and a full maintenance programme has started. The LHC is running long operational years at present with only a few short technical stops during operation with beam. This leaves very little time for much-needed maintenance and upgrades. Thus, the hardware teams involved have to take full advantage of the time available during the winter stop.   The Engineering Department is planning and coordinating the maintenance and repair activities for the whole accelerator complex. The list of planned interventions is truly impressive! There is a lot of work that involves the essential technical infrastructure systems (electricity, cooling, ventilation). Cryogenics have established a full programme aimed at maintaining and improving their already good level of availability. Other systems undergoing maintenance include: vacu...

  17. To the LHC and beyond

    CERN Document Server

    Rodgers, Peter

    2004-01-01

    CERN was conceived in 1949 as a new European laboratory to halt the exodus of physics talent from Europe to North America. In 1954, the new lab formally came into existence upon ratification of the resolution by the first 12 European member states. To further strengthen its position as the top particle-physics laboratory in the world, the CERN council agreed a new seven-point strategy. Completing the Large Hadron Collider (LHC) on schedule in 2007 is the top priority, followed by consolidating the lab's infrastructure to guarantee reliable operation of the LHC; examining the lab's experimental program apart from the LHC; coordinating research in Europe; building a new injector for the LHC in 2006; increasing R&D on the Compact Linear Collider (CLIC); and working on a long-term strategy for the lab. CERN expects to complete half of these at the end of 2008. (Edited abstract).

  18. High Luminosity LHC Project Description

    CERN Document Server

    Apollinari, Giorgio; Rossi, Lucio

    2014-01-01

    The High Luminosity LHC (HL-LHC) is a novel configuration of the Large Hadron Collider, aiming at increasing the luminosity by a factor five or more above the nominal LHC design, to allow increasing the integrated luminosity, in the high luminosity experiments ATLAS and CMS, from the 300 fb-1 of the LHC original design up to 3000 fb-1 or more. This paper contains a short description of the main machine parameters and of the main equipment that need to be developed and installed. The preliminary cost evaluation and the time plan are presented, too. Finally, the international collaboration that is supporting the project, the governance and the project structure are discussed, too.

  19. Coming Soon: LHC's Big Chill

    CERN Multimedia

    2003-01-01

    Installation of the LHC cryogenic distribution line has begun. The line is crucial to the project, as it is to be used to distribute the liquid helium for cooling the superconducting magnets down to 1.8 K.

  20. The Workflow of LHC Papers

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Finally, the talk will focus on how the institutional repository (CDS) is being linked to the HEP disciplinary archive (INSPIRE) in order to provide users with a central access point to reach LHC results.

  1. Exotic atoms. Technical progress report

    International Nuclear Information System (INIS)

    Kunselman, R.

    1994-01-01

    The experiments use a variety of hydrogen isotopic mixtures to form solid targets for muons to produce muonic hydrogen isotope atoms that escape into vacuum. The method relies on transfer of the muon from a proton to either a deuteron or a triton. The resulting muonic deuterium or muonic tritium will not immediately thermalize because of the very low elastic cross sections (RT effect), and are emitted from the surface of the layer. A second solid hydrogen isotopic target is produced downstream on which the muonic hydrogen atom can react. Measurements which detect decay electrons, muonic x-rays, and fusion products have been used to study the processes of energy dependence of transfer, production rates, and muon molecular formation. The processes include muon catalyzed fusion of muonic tritium with deuterium which is the most possible candidate for energy production fusion. Our interest is the nuclear physics reaction rates and to use the muonic hydrogen isotopes in vacuum for energy level measurements. The method uses time of flight and is reminiscent of double scattering experiments. Two other experiments are in the development stages. First to measure the energy dependence of the Ramsauer-Townsend cross section in tritium where it has not been measured. The measurements would be compared to deuterium and calculations. Second, kaonic atoms, hypernuclei, and kaon-nucleon scattering at DAPHNE

  2. Search for new light gauge bosons in Higgs boson decays to four-lepton final states in pp collisions at √s = 8 TeV with the ATLAS detector at the LHC

    Czech Academy of Sciences Publication Activity Database

    Aad, G.; Abbott, B.; Abdallah, J.; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Němeček, Stanislav; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav

    2015-01-01

    Roč. 92, č. 9 (2015), "092001-1"-"092001-30" ISSN 1550-7998 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : CERN LHC Coll * ATLAS * boson * exotic * experimental results * 8000 GeV-cms Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.643, year: 2014

  3. Static super-replicating strategies for a class of exotic options

    NARCIS (Netherlands)

    Chen, X.; Deelstra, G.; Dhaene, J.; Vanmaele, M.

    2008-01-01

    In this paper, we investigate static super-replicating strategies for European-type call options written on a weighted sum of asset prices. This class of exotic options includes Asian options and basket options among others. We assume that there exists a market where the plain vanilla options on the

  4. NNLO corrections for LHC processes

    CERN Document Server

    Caola, Fabrizio

    2015-01-01

    To fully profit from the remarkable achievements of the experimental program at the LHC, very precise theoretical predictions for signal and background processes are required. In this contribution, I will review some of the recent progress in fully exclusive next-to-next-toleading-order (NNLO) QCD computations. As an example of the phenomenological relevance of these results, I will present LHC predictions for t-channel single-top production and Higgs boson production in association with one hard jet.

  5. The LHC personnel safety system

    International Nuclear Information System (INIS)

    Ninin, P.; Valentini, F.; Ladzinski, T.

    2011-01-01

    Large particle physics installations such as the CERN Large Hadron Collider require specific Personnel Safety Systems (PSS) to protect the personnel against the radiological and industrial hazards. In order to fulfill the French regulation in matter of nuclear installations, the principles of IEC 61508 and IEC 61513 standard are used as a methodology framework to evaluate the criticality of the installation, to design and to implement the PSS.The LHC PSS deals with the implementation of all physical barriers, access controls and interlock devices around the 27 km of underground tunnel, service zones and experimental caverns of the LHC. The system shall guarantee the absence of personnel in the LHC controlled areas during the machine operations and, on the other hand, ensure the automatic accelerator shutdown in case of any safety condition violation, such as an intrusion during beam circulation. The LHC PSS has been conceived as two separate and independent systems: the LHC Access Control System (LACS) and the LHC Access Safety System (LASS). The LACS, using off the shelf technologies, realizes all physical barriers and regulates all accesses to the underground areas by identifying users and checking their authorizations.The LASS has been designed according to the principles of the IEC 61508 and 61513 standards, starting from a risk analysis conducted on the LHC facility equipped with a standard access control system. It consists in a set of safety functions realized by a dedicated fail-safe and redundant hardware guaranteed to be of SIL3 class. The integration of various technologies combining electronics, sensors, video and operational procedures adopted to establish an efficient personnel safety system for the CERN LHC accelerator is presented in this paper. (authors)

  6. LHC magnet string in 1994

    CERN Multimedia

    1994-01-01

    On 6-7 December 1994, a string of powerful superconducting magnets for CERN's next particle accelerator, the Large Hadron Collider (LHC), ran successfully at 8.36 tesla for 24 hours. This magnetic field is 100 000 times that of the Earth and is required to keep beams of protons travelling on the correct circular path over 27 km at 7 TeV in the new LHC accelerator.

  7. LHC: from hot to cold

    CERN Multimedia

    2006-01-01

    The first cryogenic feedbox designed to supply electricity to the superconducting magnets of one arc has just been installed at Point 8 of the LHC. This latest milestone is the reward for the joint efforts of the AT and TS Departments at CERN, the IHEP Institute in Moscow and CERN’s industrial partners who collaborated in its manufacture, and is a precursor to the forthcoming cool down of the first 3.3 km sector of the LHC.

  8. LHC Results Highlights (CLASHEP 2013)

    CERN Document Server

    Gonzalez, O.

    2015-05-22

    The good performance of the LHC provided enough data at 7 TeV and 8 TeV to allow the experiments to perform very competitive measurements and to expand the knowledge about the fundamental interaction far beyond that from previous colliders. This report summarizes the highlights of the results obtained with these data samples by the four large experiments, covering all the topics of the physics program and focusing on those exploiting the possibilities of the LHC.

  9. Search for the exotic decay of the Higgs boson to a pair of light pseudoscalars in the final state with two b quarks and two $\\tau$ leptons

    CERN Document Server

    CMS Collaboration

    2018-01-01

    A search for the exotic decay of the Higgs boson to a pair of light pseudoscalar bosons is performed in the final state with two b jets and two $\\tau$ leptons. The motivation lies in models beyond the standard model (SM), such as two-Higgs-doublet models extended with a complex scalar singlet, which include the next-to-minimal supersymmetric SM (NMSSM). The results are based on an integrated luminosity of $35.9~\\mathrm{fb}^{-1}$, accumulated by the CMS experiment at the LHC in 2016 at 13 TeV center-of-mass energy. Masses of the pseudoscalar boson between 15 and 60 GeV are probed, and upper limits as low as $23\\%$ are set on the branching fraction of the Higgs boson to two light pseudoscalar bosons in the NMSSM, assuming that the production cross section of the Higgs boson is the one predicted in the SM. No mass constraint is set on the b jet pair, making this search sensitive to Higgs boson decays to two scalars with different masses.

  10. The role of exotic tree species in Nordic forestry

    DEFF Research Database (Denmark)

    Kjær, Erik Dahl; Lobo, Albin; Myking, Tor

    2014-01-01

    the vegetation and forest history and its implications for the interest in using exotic species. We review to what extent exotic species can contribute to increased economic returns from forest plantings and the potential negative ecological effects associated with introduction of new species. Considering...... the expected climate changes, we discuss whether and how the increased use of exotic species can contribute to sustained and increased health and productivity of Nordic forests without jeopardising ecological and social values....

  11. Commissioning the cryogenic system of the first LHC sector

    International Nuclear Information System (INIS)

    Millet, F.; Claudet, S.; Ferlin, G.; Perin, A.; Riddone, G.; Serio, L.; Soubiran, M.; Tavian, L.; CERN; Ronayette, L.; GHMFL, Grenoble; Rabehl, R.; Fermilab

    2007-01-01

    The LHC machine, composed of eight sectors with superconducting magnets and accelerating cavities, requires a complex cryogenic system providing high cooling capacities (18 kW equivalent at 4.5 K and 2.4 W at 1.8 K per sector produced in large cold boxes and distributed via 3.3-km cryogenic transfer lines). After individual reception tests of the cryogenic subsystems (cryogen storages, refrigerators, cryogenic transfer lines and distribution boxes) performed since 2000, the commissioning of the cryogenic system of the first LHC sector has been under way since November 2006. After a brief introduction to the LHC cryogenic system and its specificities, the commissioning is reported detailing the preparation phase (pressure and leak tests, circuit conditioning and flushing), the cool-down sequences including the handling of cryogenic fluids, the magnet powering phase and finally the warm-up. Preliminary conclusions on the commissioning of the first LHC sector will be drawn with the review of the critical points already solved or still pending. The last part of the paper reports on the first operational experience of the LHC cryogenic system in the perspective of the commissioning of the remaining LHC sectors and the beam injection test

  12. Post LHC7 SUSY benchmark points for ILC physics

    Energy Technology Data Exchange (ETDEWEB)

    Baer, Howard [Oklahoma Univ., Norman, OK (United States); List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2012-05-15

    We re-evaluate prospects for supersymmetry at the proposed International Linear e{sup +}e{sup -} Collider (ILC) in light of the first year of serious data taking at LHC with {radical}(s)=7 TeV and {proportional_to}5 fb{sup -1} of pp collisions (LHC7). Strong new limits from LHC SUSY searches, along with a hint of a Higgs boson signal around m{sub h}{proportional_to}125 GeV, suggest a paradigm shift from previously popular models to ones with new and compelling signatures. We present a variety of new ILC benchmark models, including: natural SUSY, hidden SUSY, NUHM2 with low m{sub A}, non-universal gaugino mass (NUGM) model, pMSSM, Kallosh-Linde model, Bruemmer-Buchmueller model, normal scalar mass hierarchy (NMH) plus one surviving case from mSUGRA/CMSSM in the far focus point region. While all these models at present elude the latest LHC limits, they do offer intriguing case study possibilities for ILC operating at {radical}(s){proportional_to}0.25-1 TeV, and present a view of some of the diverse SUSY phenomena which might be expected at both LHC and ILC in the post LHC7 era.

  13. Post LHC7 SUSY benchmark points for ILC physics

    International Nuclear Information System (INIS)

    Baer, Howard; List, Jenny

    2012-05-01

    We re-evaluate prospects for supersymmetry at the proposed International Linear e + e - Collider (ILC) in light of the first year of serious data taking at LHC with √(s)=7 TeV and ∝5 fb -1 of pp collisions (LHC7). Strong new limits from LHC SUSY searches, along with a hint of a Higgs boson signal around m h ∝125 GeV, suggest a paradigm shift from previously popular models to ones with new and compelling signatures. We present a variety of new ILC benchmark models, including: natural SUSY, hidden SUSY, NUHM2 with low m A , non-universal gaugino mass (NUGM) model, pMSSM, Kallosh-Linde model, Bruemmer-Buchmueller model, normal scalar mass hierarchy (NMH) plus one surviving case from mSUGRA/CMSSM in the far focus point region. While all these models at present elude the latest LHC limits, they do offer intriguing case study possibilities for ILC operating at √(s)∝0.25-1 TeV, and present a view of some of the diverse SUSY phenomena which might be expected at both LHC and ILC in the post LHC7 era.

  14. New U.S. LHC Web site launched

    CERN Multimedia

    Katie Yurkewicz

    2007-01-01

    On September 12, the U.S. Department of Energy's Office of Science launched a new Web site, www.uslhc.us, to tell the story of the U.S. role in the LHC. The site provides general information for the public about the LHC and its six experiments, as well as detailed information about the participation of physicists, engineers and students from the United States. The U.S. site joins the UK's LHC site in providing information for a national audience, with sites from several more countries expected to launch within the next year. The US LHC site features news and information about the LHC, along with high-resolution images and resources for students and educators. The site also features blogs by four particle physicists, including ATLAS collaborators Monica Dunford from the University of Chicago and Peter Steinberg from Brookhaven National Laboratory. More than 1,300 scientists from over 90 U.S. institutions participate in the LHC and its experiments, representing universities and national laboratories from...

  15. LHC an unprecedented technological challenge

    International Nuclear Information System (INIS)

    Baruch, J.O.

    2002-01-01

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

  16. LHC Olympics flex physicists' brains

    CERN Multimedia

    2006-01-01

    Physicists from around the world met at CERN to strengthen their data-deciphering skills at the second LHC Olympics workshop. Physicists gather for the second LHC Olympics workshop. Coinciding with the kick-off of the winter Olympics in Turin, more than 70 physicists gathered at CERN from across the globe for the second LHC Olympics workshop on 9-10 February. Their challenge, however, involved brains rather than brawn. As the switch-on date for the LHC draws near, scientists excited by the project want to test and improve their ability to decipher the unprecedented amount of data that the world's biggest and most powerful particle accelerator is expected to generate. The LHC Olympics is a coordinated effort to do just that, minus the gold, silver and bronze of the athletics competition. 'In some ways, the LHC is not a precision instrument. It gives you the information that something is there but it's hard to untangle and interpret what it is,' said University of Michigan physicist Gordy Kane, who organiz...

  17. The LHC at level best

    CERN Multimedia

    Katarina Anthony

    2013-01-01

    On 10 March, a team of CERN surveyors descended into the LHC tunnel. Their aim: to take measurements of the height of the LHC magnets to see how geological shifts might be affecting the machine and to take reference positions of the machine before the interconnects are opened.    CERN surveyors take levelling measurements of the LHC magnets during LS1. The LHC tunnel is renowned for its geological stability: set between layers of sandstone and molasse, it has allowed the alignment of the world’s largest accelerators to be within sub-millimetre precision. But even the most stable of tunnels can be affected by geological events. To ensure the precise alignment of the LHC, the CERN survey team performs regular measurements of the vertical position of the magnets (a process known as “levelling”). Over the past month, the team has been taking measurements of the LHC before the temperature of the magnets reaches 100 K, beyond which there may be some mechanic...

  18. Last cast for the LHC

    CERN Multimedia

    2005-01-01

    The first major contract signed for the LHC is drawing to a close. Belgian firm Cockerill Sambre (a member of the Arcelor Group) has just completed production of 50,000 tonnes of steel sheets for the accelerator's superconducting magnet yokes, in what has proved to be an exemplary partnership with CERN. Philippe Lebrun, Head of the AT Department, Lyn Evans, LHC Project Leader, and Lucio Rossi, Head of the AT-MAS Group, in front of the last batch of steel for the LHC at Cockerill Sambre. It was a bright red-letter day at the end of May, when Belgian firm Cockerill Sambre of the Arcelor Group marked the completion of one of the largest contracts for the LHC machine by casting the last batch of steel sheets for the LHC superconducting magnet yokes in the presence of LHC Project Leader Lyn Evans, AT Department Head Philippe Lebrun, Magnets and Superconductors (AT-MAS) Group Leader Lucio Rossi and Head of the AT-MAS Group's components centre Francesco Bertinelli. The yokes constitute approximately 80% of the acc...

  19. The LHC on the table

    CERN Multimedia

    2002-01-01

    How many dipoles have been manufactured so far? How many have been delivered? To find out, you can now consult the LHC Progress Dashboard on the web. The dashboard tracks progress with regard to manufacture and delivery of thirty different types of LHC components. Do you want to know everything about progress on LHC construction? The LHC's engineers have recently acquired a very useful tracking tool precisely for that purpose. This is the LHC Progress Dashboard which makes it possible to track work progress in graph form. In the interests of transparency, the LHC Project Management has decided to make it accessible to the public on the web. You can now consult normalized graphs for each of the thirty different types of components that form part of machine construction, such as the cold masses of the dipole magnets, the vacuum chambers and the octupoles, etc. The graphs show: in blue: the contractual delivery curves, i.e. the delivery schedules to which the suppliers have committed themselves in their contra...

  20. The High Luminosity LHC Project

    Science.gov (United States)

    Rossi, Lucio

    The High Luminosity LHC is one of the major scientific project of the next decade. It aims at increasing the luminosity reach of LHC by a factor five for peak luminosity and a factor ten in integrated luminosity. The project, now fully approved and funded, will be finished in ten years and will prolong the life of LHC until 2035-2040. It implies deep modifications of the LHC for about 1.2 km around the high luminosity insertions of ATLAS and CMS and relies on new cutting edge technologies. We are developing new advanced superconducting magnets capable of reaching 12 T field; superconducting RF crab cavities capable to rotate the beams with great accuracy; 100 kA and hundred meter long superconducting links for removing the power converter out of the tunnel; new collimator concepts, etc... Beside the important physics goals, the High Luminosity LHC project is an ideal test bed for new technologies for the next hadron collider for the post-LHC era.

  1. The latest from the LHC

    CERN Document Server

    2009-01-01

    On 26 August, the first two fully tested crates for the new quench protection system (QPS) were installed in Sector 1-2. These are the first of 436 crates that will be installed around the ring. The two crates include detectors for both the enhanced busbar protection and the symmetric quench protection (more details). To test the crates before installation, a dedicated test bed has been created, capable of simulating all the conditions in the LHC, from a symmetric quench to an increase in busbar resistance. The teams are working two shifts a day, including weekends, to test the new crates. Two more test benches are also being built to increase the production rate. The whole task is on target for completion in mid October. Another important new task for the QPS team is to try and speed up the energy extraction from the magnets. The quicker the energy can be extracted the lower the risk of dangerously high temperatures should a quench occur. The time constant for the dipoles...

  2. R-parity violation at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Dercks, Daniel [Universitaet Bonn, Physikalisches Institut, Bethe Center for Theoretical Physics, Bonn (Germany); Universitaet Hamburg, II. Institut fuer Theoretische Physik, Hamburg (Germany); Dreiner, Herbi; Krauss, Manuel E.; Opferkuch, Toby; Reinert, Annika [Universitaet Bonn, Physikalisches Institut, Bethe Center for Theoretical Physics, Bonn (Germany)

    2017-12-15

    We investigate the phenomenology of the MSSM extended by a single R-parity-violating coupling at the unification scale. For all R-parity-violating couplings, we discuss the evolution of the particle spectra through the renormalization group equations and the nature of the lightest supersymmetric particle (LSP) within the CMSSM, as an example of a specific complete supersymmetric model. We use the nature of the LSP to classify the possible signatures. For each possible scenario we present in detail the current LHC bounds on the supersymmetric particle masses, typically obtained using simplified models. From this we determine the present coverage of R-parity-violating models at the LHC. We find several gaps, in particular for a stau-LSP, which is easily obtained in R-parity-violating models. Using the program CheckMATE we recast existing LHC searches to set limits on the parameters of all R-parity-violating CMSSMs. We find that virtually all of them are either more strongly constrained or similarly constrained in comparison to the R-parity-conserving CMSSM, including the anti U anti D anti D models. For each R-parity-violating CMSSM we then give the explicit lower mass bounds on all relevant supersymmetric particles. (orig.)

  3. LHC interaction region quadrupole cryostat design

    International Nuclear Information System (INIS)

    Nicol, T.H.; Darve, Ch.; Huang, Y.; Page, T.M.

    2002-01-01

    The cryostat of a Large Hadron Collider (LHC) Interaction Region (IR) quadrupole magnet consists of all components of the inner triplet except the magnet assembly itself. It serves to support the magnet accurately and reliably within the vacuum vessel, to house all required cryogenic piping, and to insulate the cold mass from heat radiated and conducted from the environment. It must function reliably during storage, shipping and handling, normal magnet operation, quenches, and seismic excitations, and must be able to be manufactured at low cost. The major components of the cryostat are the vacuum vessel, thermal shield, multi-layer insulation system, cryogenic piping, and suspension system. The overall design of a cryostat for superconducting accelerator magnets requires consideration of fluid flow, proper selection of materials for their thermal and structural performance at both ambient and operating temperature, and knowledge of the environment to which the magnets will be subjected over the course of their expected operating lifetime. This paper describes the current LHC IR inner triplet quadrupole magnet cryostats being designed and manufactured at Fermilab as part of the US-LHC collaboration, and includes discussions on the structural and thermal considerations involved in the development of each of the major systems

  4. The LHC's suppliers come up trumps

    CERN Multimedia

    2006-01-01

    Four of the LHC Project's most exceptional suppliers have just been honoured in the fifth Golden Hadron awards ceremony. For the first time, a CERN team was among the prize-winners. The CERN main workshop (Mechanical and Materials Engineering group, TS/MME) received the Golden Hadron Award at the prize-giving ceremony held at the Globe. From left to right, Saïd Atieh (TS/MME), Vincent Vuillemin (TS/MME group leader), Michel Caccioppoli (TS/MME), Lyn Evans (LHC Project Leader), Marc Polini (TS/MME-MS section leader), Jean-Luc Gayraud (Cegelec), Jean-Paul Bacher (TS/MME-AS section leader) and Paolo Ciriani (head of the TS Department). Flexible, responsive, committed... all fitting adjectives to describe the recipients of the fifth Golden Hadron awards. The prizes, designed to honour the LHC Project's best suppliers, were awarded to a total of four suppliers, including two that are involved in the final accelerator assembly work: proof, if it were needed, that the project has now entered its final phase. Drak...

  5. The BRAN luminosity detectors for the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Matis, H.S.; Placidi, M.; Ratti, A.; Turner, W.C. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Bravin, E. [CERN, 1211 Geneva 23 (Switzerland); Miyamoto, R. [European Spallation Source, ESS AB, P.O. Box 176, SE-221 00 Lund (Sweden)

    2017-03-11

    This paper describes the several phases which led, from the conceptual design, prototyping, construction and tests with beam, to the installation and operation of the BRAN (Beam RAte of Neutrals) relative luminosity monitors for the LHC. The detectors have been operating since 2009 to contribute, optimize and maintain the accelerator performance in the two high luminosity interaction regions (IR), the IR1 (ATLAS) and the IR5 (CMS). The devices are gas ionization chambers installed inside a neutral particle absorber 140 m away from the Interaction Points in IR1 and IR5 and monitor the energy deposited by electromagnetic showers produced by high-energy neutral particles from the collisions. The detectors have the capability to resolve the bunch-by-bunch luminosity at the 40 MHz bunch rate, as well as to survive the extreme level of radiation during the nominal LHC operation. The devices have operated since the early commissioning phase of the accelerator over a broad range of luminosities reaching 1.4×10{sup 34} cm{sup −2} s{sup −1} with a peak pileup of 45 events per bunch crossing. Even though the nominal design luminosity of the LHC has been exceeded, the BRAN is operating well. After describing how the BRAN can be used to monitor the luminosity of the collider, we discuss the technical choices that led to its construction and the different tests performed prior to the installation in two IRs of the LHC. Performance simulations are presented together with operational results obtained during p-p operations, including runs at 40 MHz bunch rate, Pb-Pb operations and p-Pb operations.

  6. Hunting, Exotic Carnivores, and Habitat Loss: Anthropogenic Effects on a Native Carnivore Community, Madagascar

    Science.gov (United States)

    Farris, Zach J.; Golden, Christopher D.; Karpanty, Sarah; Murphy, Asia; Stauffer, Dean; Ratelolahy, Felix; Andrianjakarivelo, Vonjy; Holmes, Christopher M.; Kelly, Marcella J.

    2015-01-01

    The wide-ranging, cumulative, negative effects of anthropogenic disturbance, including habitat degradation, exotic species, and hunting, on native wildlife has been well documented across a range of habitats worldwide with carnivores potentially being the most vulnerable due to their more extinction prone characteristics. Investigating the effects of anthropogenic pressures on sympatric carnivores is needed to improve our ability to develop targeted, effective management plans for carnivore conservation worldwide. Utilizing photographic, line-transect, and habitat sampling, as well as landscape analyses and village-based bushmeat hunting surveys, we provide the first investigation of how multiple forms of habitat degradation (fragmentation, exotic carnivores, human encroachment, and hunting) affect carnivore occupancy across Madagascar’s largest protected area: the Masoala-Makira landscape. We found that as degradation increased, native carnivore occupancy and encounter rates decreased while exotic carnivore occupancy and encounter rates increased. Feral cats (Felis species) and domestic dogs (Canis familiaris) had higher occupancy than half of the native carnivore species across Madagascar’s largest protected landscape. Bird and small mammal encounter rates were negatively associated with exotic carnivore occupancy, but positively associated with the occupancy of four native carnivore species. Spotted fanaloka (Fossa fossana) occupancy was constrained by the presence of exotic feral cats and exotic small Indian civet (Viverricula indica). Hunting was intense across the four study sites where hunting was studied, with the highest rates for the small Indian civet (x¯ = 90 individuals consumed/year), the ring-tailed vontsira (Galidia elegans) (x¯ = 58 consumed/year), and the fosa (Cryptoprocta ferox) (x¯ = 31 consumed/year). Our modeling results suggest hunters target intact forest where carnivore occupancy, abundance, and species richness, are

  7. Exotic nuclei from a theoretical perspective

    International Nuclear Information System (INIS)

    Nazarewicz, W.; Oak Ridge National Lab., TN; Univ. of Warsaw

    1998-01-01

    One of the main frontiers of nuclear structure today is the physics of radioactive nuclear beams. Experiments with radioactive beams will make it possible to look closely into many aspects of the nuclear many-body problem. What makes this subject both exciting and difficult is: (i) the weak binding and corresponding closeness of the particle continuum, implying a large diffuseness of the nuclear surface and extreme spatial dimensions characterizing the outermost nucleons, and (ii) access to the exotic combinations of proton and neutron numbers which offer prospects for completely new structural phenomena

  8. Exotic woody plant invaders of the Transvaal

    Directory of Open Access Journals (Sweden)

    L. Henderson

    1984-12-01

    Full Text Available The frequency and abundance o ;f exotic, woody plant invaders were recorded in 60% of the quarter degree squares in the study area. Sixty-one invaders were encountered o f which the most important and aggressive were Acacia dealbaia, Populus spp.,  Melia azedarach, Opuntia ficus-indica, Salix babylonica and  Acacia mearnsii. Invasion patterns are discussed and an attempt is made to correlate distribution with environmental factors. Attention is drawn to the areas of greatest invasion and the areas that are liable to show the greatest expansion in the future.

  9. Hard production of exotic hybrid mesons

    Energy Technology Data Exchange (ETDEWEB)

    Anikin, I.; Teryaev, O.V. [Bogoliubov Lab. of Theoretical Physics, JINR, Dubna (Russian Federation); Pire, B.; Anikin, I. [Ecole Polytechnique, CPHT, 91 - Palaiseau (France); Szymanowski, I. [Soltan Institute for Nuclear Studies, Warsaw (Poland); Liege Univ. (Belgium); Anikin, I.; Wallon, S. [Paris-11 Univ., Lab. de Physique Theorique, 91 - Orsay (France)

    2005-07-01

    Exotic hybrid mesons H, with quantum numbers J{sup PC} = 1{sup -+} may be copiously produced in the hard exclusive processes {gamma}{sup *}(Q{sup 2}){gamma} {yields} H and {gamma}{sup *}(Q{sup 2})P(p) {yields} HP(p') because they have a leading twist distribution amplitude with a sizable coupling constant f{sub H}, which may be estimated through QCD sum rules. The reaction rates scale in the same way as the corresponding rates for usual mesons. (authors)

  10. Supersymmetric exotic decays of the 125 GeV Higgs boson.

    Science.gov (United States)

    Huang, Jinrui; Liu, Tao; Wang, Lian-Tao; Yu, Felix

    2014-06-06

    We reveal a set of novel decay topologies for the 125 GeV Higgs boson in supersymmetry which are initiated by its decay into a pair of neutralinos, and discuss their collider search strategies. This category of exotic Higgs decays is characterized by the collider signature: visible objects+E_{T}, with E_{T} dominantly arising from escaping dark matter particles. Their benchmark arises naturally in the Peccei-Quinn symmetry limit of the minimal supersymmetric standard model singlet extensions, which is typified by the coexistence of three light particles: singletlike scalar h_{1} and pseudoscalar a_{1}, and singlinolike neutralino χ_{1}, all with masses of ≲10  GeV, and the generic suppression of the exotic decays of the 125 GeV Higgs boson h_{2}→h_{1}h_{1}, a_{1}a_{1} and χ_{1}χ_{1}, however. As an illustration, we study the decay topology: h_{2}→χ_{1}χ_{2}, where the binolike χ_{2} decays to h_{1}χ_{1} or a_{1}χ_{1}, and h_{1}/a_{1}→ff[over ¯], with ff[over ¯]=μ^{+}μ^{-}, bb[over ¯]. In the dimuon case (m_{h_{1}/a_{1}}∼1  GeV), a statistical sensitivity of S/sqrt[B]>6σ can be achieved easily at the 8 TeV LHC, assuming σ(pp→Wh_{2})/σ(pp→Wh_{SM})Br(h_{2}→μ^{+}μ^{-}χ_{1}χ_{1})=0.1. In the bb[over ¯] case (m_{h_{1}/a_{1}}∼45  GeV), 600  fb^{-1} data at the 14 TeV LHC can lead to a statistical sensitivity of S/sqrt[B]>5σ, assuming σ(pp→Zh_{2})/σ(pp→Zh_{SM})Br(h_{2}→bb[over ¯]χ_{1}χ_{1})=0.5. These exotic decays open a new avenue for exploring new physics couplings with the 125 GeV Higgs boson at colliders.

  11. Tracking the LHC halo

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    In the LHC, beams of 25-ns-spaced proton bunches travel at almost the speed of light and pass through many different devices installed along the ring that monitor their properties. During their whirling motion, beam particles might interact with the collimation instrumentation or with residual gas in the vacuum chambers and this creates the beam halo – an annoying source of background for the physics data. Newly installed CMS sub-detectors are now able to monitor it.   The Beam Halo Monitors (BHM) are installed around the CMS rotating shielding. The BHM are designed and built by University of Minnesota, CERN, Princeton University, INFN Bologna and the National Technical University of Athens. (Image: Andrea Manna). The Beam Halo Monitor (BHM) is a set of 20 Cherenkov radiators – 10-cm-long quartz crystals – installed at each end of the huge CMS detector. Their design goal is to measure the particles that can cause the so-called “machine-induced...

  12. LHC magnet support post

    CERN Multimedia

    1995-01-01

    A prototype magnet support for the Large Hadron Collider (LHC). The magnet supports have to bridge a difference in temperature of 300 degrees. Electrical connections, instrumentation and the posts on which the magnets stand are the only points where heat transfer can happen through conduction. They are all carefully designed to draw off heat progressively. The posts are made of 4 mm thick glass-fibre– epoxy composite material. Each post supports 10 000 kg of magnet and leaks just 0.1 W of heat. This piece required a long development period which started in the early ’90s and continued until the end of the decade. The wires next to the support post are wires from strain gauges, which are employed to measure the stress level in the material when the support is mechanically loaded. These supports are mechanically optimized to withstand a weight of up to 100Kn (10 tons) while being as thin as possible to minimize conduction heat to magnets. This is the reason why the stress measurement was extensively done...

  13. LHC on the bus

    CERN Multimedia

    Laëtitia Pedroso

    2010-01-01

    On 15 December, an airport bus will be transformed in the image of CERN. The bus will be seen by the thousands of travellers arriving in Geneva, informing them of the possibility to visit CERN.   Sketch of the bus. The good relationship between Geneva International Airport and CERN started several years ago. In 2004 the airport put advertising space in the arrivals area at CERN's disposal free of charge. Now, starting on 15 December, a 40-foot long bus will display a giant sticker advertisement depicting CERN as it takes passengers over the airport tarmac to their planes. This is no ordinary sticker, and it was no mean task to attach it to the bus. The task of producing and attaching it was entrusted to Geneva-based specialists Mathys SA. With the ski season opening on 15 December, there will be many travellers arriving at the airport, and the bus will be ready to receive them. When one thinks of CERN, the subjects that naturally come to mind are the LHC, the mysteries of the Universe...

  14. Power to the LHC

    CERN Multimedia

    2016-01-01

    It’s March already, and time for the LHC to wake up from its short winter break. The first of 7000 powering tests began on 4 March: the first step on the way to the first beams of 2016. It’s a tight schedule, with the powering tests scheduled for just 12 days before moving on to machine checkout and then commissioning with beam around Easter.   Last year marked a great start to Run 2. The objective for the year was to establish proton-proton collisions at 13 TeV with 25 ns bunch spacing, and in that we were successful, delivering four inverse femtobarns (4 fb-1) of data to the experiments. This was a great result but, to put it into context, the goal for the whole of Run 2 is to deliver 100 fb-1 by the end of 2018, so we still have a long way to go. 2015 was a learning year, and by the time we switched off for the end-of-year break, we had learned a great deal about how to operate this superb machine at the new higher energy, with shorter bunch spacing allowing us to get many ...

  15. LHC Report: Ticking over

    CERN Multimedia

    Mike Lamont for the LHC Team

    2012-01-01

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

  16. Illuminating the LHC

    CERN Multimedia

    2004-01-01

    For the first time ever, on 29 September the LHC ring will be visible above ground. Spotlights aimed at the sky will light up the 27 km path of the ring to celebrate CERN's 50th anniversary. Also, everyone born in 1954 is invited to come to blow out birthday candles on a cake. To see the display, you can come to departure station for the gondola at Crozet*, France, starting at 18:30. There will be music, official speeches and food stands. At 20:00 the ring will light up, and to wrap it up at 21:15 there will be the cake and videoconferences with Robert Aymar, the Director-General of CERN, and the inventor of the Web, Tim Berners-Lee. The event is organized by the Department of Justice, Police and Security of the Canton of Geneva, Switzerland, in collaboration with communes of the Canton of Geneva, the Communauté des communes du Pays de Gex and the Préfecture de l'Ain. More information on the schedule for the night. * The event initially planned at Divonne has been moved to Crozet.

  17. LHC vacuum system

    CERN Document Server

    Gröbner, Oswald

    1999-01-01

    The Large Hadron Collider (LHC) project, now in the advanced construction phase at CERN, comprises two proton storage rings with colliding beams of 7-TeV energy. The machine is housed in the existing LEP tunnel with a circumference of 26.7 km and requires a bending magnetic field of 8.4 T with 14-m long superconducting magnets. The beam vacuum chambers comprise the inner 'cold bore' walls of the magnets. These magnets operate at 1.9 K, and thus serve as very good cryo-pumps. In order to reduce the cryogenic power consumption, both the heat load from synchrotron radiation emitted by the proton beams and the resistive power dissipation by the beam image currents have to be absorbed on a 'beam screen', which operates between 5 and 20 K and is inserted inside the vacuum chamber. The design of this beam screen represents a technological challenge in view of the numerous and often conflicting requirements and the very tight mechanical tolerances imposed. The synchrotron radiation produces strong outgassing from the...

  18. Crystals in the LHC

    CERN Multimedia

    Antonella Del Rosso

    2012-01-01

    Bent crystals can be used to deflect charged particle beams. Their use in high-energy accelerators has been investigated for almost 40 years. Recently, a bent crystal was irradiated for the first time in the HiRadMat facility with an extreme particle flux, which crystals would have to withstand in the LHC. The results were very encouraging and confirmed that this technology could play a major role in increasing the beam collimation performance in future upgrades of the machine.   UA9 bent crystal tested with a laser. Charged particles interacting with a bent crystal can be trapped in channelling states and deflected by the atomic planes of the crystal lattice (see box). The use of bent crystals for beam manipulation in particle accelerators is a concept that has been well-assessed. Over the last three decades, a large number of experimental findings have contributed to furthering our knowledge and improving our ability to control crystal-particle interactions. In modern hadron colliders, su...

  19. The LHC collimators

    CERN Document Server

    Bertarelli, A

    2004-01-01

    In the framework of the LHC Collimator project, TS department has been assigned the task to design the series collimators and to manufacture prototypes to be tested in summer 2004. Their concept must comply with a very demanding specification, entailing a temperature on the collimating jaws not exceeding 50ºC in steady conditions and an unparalleled overall geometrical stability of 25 micro m on a 1200 mm span, meeting, at the same time, the challenging deadlines required by the project schedule. To respond to these tough and sometimes conflicting constraints, the chosen design appeals to a mixture of traditional and innovative technologies, largely drawing from LEP collimator experience. The specification imposes a low-Z material for the collimator jaws, directing the design towards graphite or such novel materials as 2-D and 3-D Carbon/Carbon composites. An accurate mechanical design has allowed to considerably reduce the mechanical play and to optimize the geometrical stability. The mechanical lay-out a...

  20. LHC Report: Level best

    CERN Multimedia

    Mike Lamont for the LHC team

    2012-01-01

    The LHCb experiment is special: there is a limit to the number of the events the detector can handle per bunch crossing. Consequently the maximum luminosity provided in 2012 has been around 4 x1032 cm-2s-1 (compared to the maximum of 7.7 x1033 cm-2s-1 seen by ATLAS and CMS). Nonetheless LHCb still wants to integrate as much luminosity as possible.    To meet LHCb's requirements a luminosity leveling technique is used. A machine setup is chosen that would give a peak luminosity well above the required maximum if the beams are collided head-on at LHCb's interaction point. This peak luminosity is then reduced to the required maximum by moving the two beams transversely apart at the interaction point. As the beam current goes down during a fill, the beams can be moved together in small increments to keep the collision rate constant throughout the fill. In practice, when the LHC goes into collisions in LHCb, the initial luminosity is safely below LHCb's demanded le...

  1. LHC Report: a record start for LHC ion operation

    CERN Multimedia

    Jan Uythoven for the LHC Team

    2011-01-01

    After the technical stop, the LHC switched over to ion operation, colliding lead-ions on lead-ions. The recovery from the technical stop was very smooth, and records for ion luminosity were set during the first days of ion operation.   The LHC technical stop ended on the evening of Friday, 11 November. The recovery from the technical stop was extremely smooth, and already that same evening ion beams were circulating in the LHC. ‘Stable beams’ were declared the same night, with 2 x 2 bunches of ions circulating in the LHC, allowing the experiments to have their first look at ion collisions this year. However, the next step-up in intensity – colliding 170 x 170 bunches – was postponed due to a vacuum problem in the PS accelerator, so the collisions on Sunday, 13 November were confined to 9 x 9 bunches. The vacuum problem was solved, and on the night of Monday, 14 November, trains of 24 lead bunches were injected into the LHC and 170 x 170 bunches were brough...

  2. LHC Report: playing with angles

    CERN Multimedia

    Mike Lamont for the LHC team

    2016-01-01

    Ready (after a machine development period), steady (running), go (for a special run)!   The crossing angles are an essential feature of the machine set-up. They have to be big enough to reduce the long-range beam-beam effect. The LHC has recently enjoyed a period of steady running and managed to set a new record for “Maximum Stable Luminosity Delivered in 7 days” of 3.29 fb-1 between 29 August and 4 September. The number of bunches per beam remains pegged at 2220 because of the limitations imposed by the SPS beam dump. The bunch population is also somewhat reduced due to outgassing near one of the injection kickers at point 8. Both limitations will be addressed during the year-end technical stop, opening the way for increased performance in 2017. On 10 and 11 September, a two day machine development (MD) period took place. The MD programme included a look at the possibility of reducing the crossing angle at the high-luminosity interaction points. The crossing angles are an ess...

  3. RF Power Generation in LHC

    CERN Document Server

    Brunner, O C; Valuch, D

    2003-01-01

    The counter-rotating proton beams in the Large Hadron Collider (LHC) will be captured and then accelerated to their final energies of 2 x 7 TeV by two identical 400 MHz RF systems. The RF power source required for each beam comprises eight 300 kW klystrons. The output power of each klystron is fed via a circulator and a waveguide line to the input coupler of a single-cell super-conducting (SC) cavity. Four klystrons are powered by a 100 kV, 40A AC/DC power converter, previously used for the operation of the LEP klystrons. A five-gap thyratron crowbar protects the four klystrons in each of these units. The technical specification and measured performance of the various high-power elements are discussed. These include the 400MHz/300kW klystrons with emphasis on their group delay and the three-port circulators, which have to cope with peak reflected power levels up to twice the simultaneously applied incident power of 300 kW. In addition, a novel ferrite loaded waveguide absorber, used as termination for port No...

  4. The latest from the LHC

    CERN Multimedia

    2009-01-01

    The consolidation campaign, managed by the Quench Protection team, is advancing well. Phase 1 of the campaign is focused on the new protection system designed to monitor the superconducting busbars. This system will be able to detect tiny electrical resistances on these busbars, similar to the one that caused the incident in Sector 3-4. Following completion of the design of the two principal electronics boards, the first order for 2500 and 500 such boards will be placed this week. The manufacture of the cable segments for the first three LHC sectors is going ahead, and the installation programme has already begun in Sector 4-5. In total, more than 230 km of various types of cables will have to be laid. The complete system will consist of a network of 2132 detectors housed in 436 crates around the machine. These will monitor the interconnections of the main dipoles and quadrupoles in the three major circuits. The detectors will precisely measure the electrical resistance of each busbar segment, including the ...

  5. LHC rap: a global phenomenon

    CERN Multimedia

    2008-01-01

    Do you think the LHC is super duper fly? Does it make you want to compose some slick rhymes and bust out some killer beats? It did for one CERN rapper, and the results have become a YouTube smash hit! Katie McAlpine will sing for the CMS party on 24 September, and for the ATLAS Fest on 4 October.The Large Hadron Rap, to give it its full name, is the brainchild of AlpineKat, AKA Katie McAlpine, who is currently working for ATLAS e-News and outreach. To date, the YouTube video rap has been viewed more than 2.5 million times, to say nothing of the media coverage. Featured in newspapers around the world, including the New York Times in the US, The Telegraph in the UK and Geneva’s very own Matin Bleu, the rap is officially a sensation! Katie wrote the inspired (and pretty accurate) physics lyrics during her commute on the number 56 bus between Geneva and CERN. After obtaining permission to film in the experiment caverns and tunnel,...

  6. LHC Report: First collisions soon

    CERN Multimedia

    Jan Uythoven for the LHC team

    2012-01-01

    On the evening of Friday 16 March beams were accelerated in the LHC at 4 TeV for the first time: a new world record! According to the schedule for the machine restart it will take another three weeks before the stable beams mode – the requirement for the detectors to start taking data – is achieved.   During the beam commissioning period the equipment teams make sure that their systems – beam instrumentation, radio frequency, beam interlock, feedback on orbit and tune, etc. – are working flawlessly with beam. Confidence in the correct functioning of all the magnets, their settings and their alignment is obtained by detailed measurements of the optics and the physical aperture. The optics measurements include the beta* of the squeezed beam at the centre of the experiments where the collisions will soon take place. This year the aim is to have a smaller beta* of 60 cm for the ATLAS and CMS experiments. As a reminder, smaller values of beta* mean thinner and m...

  7. MSSM Forecast for the LHC

    CERN Document Server

    Cabrera, Maria Eugenia; de Austri, Roberto Ruiz

    2009-01-01

    We perform a forecast of the MSSM with universal soft terms (CMSSM) for the LHC, based on an improved Bayesian analysis. We do not incorporate ad hoc measures of the fine-tuning to penalize unnatural possibilities: such penalization arises from the Bayesian analysis itself when the experimental value of $M_Z$ is considered. This allows to scan the whole parameter space, allowing arbitrarily large soft terms. Still the low-energy region is statistically favoured (even before including dark matter or g-2 constraints). Contrary to other studies, the results are almost unaffected by changing the upper limits taken for the soft terms. The results are also remarkable stable when using flat or logarithmic priors, a fact that arises from the larger statistical weight of the low-energy region in both cases. Then we incorporate all the important experimental constrains to the analysis, obtaining a map of the probability density of the MSSM parameter space, i.e. the forecast of the MSSM. Since not all the experimental i...

  8. LHC Report: a Roman potpourri

    CERN Multimedia

    Mike Lamont for the LHC Team

    2012-01-01

    The last couple of weeks of operation have been a mixed bag, with time dedicated to TOTEM and ALFA, a floating machine development period and luminosity calibration runs. These special running periods were interleaved with some standard proton running where we’ve struggled a little to recover previous highs. The LHC has now returned to more routine operation.   The TOTEM and ALFA run required the development of special optics to produce large beam sizes and smaller angular spread at the interaction points in ATLAS and CMS. These special optics produce shallower angled proton-proton collisions than normal and thus allow experiments to probe the very small angle scattering regime. (For more information visit the TOTEM and ALFA websites.) The qualification of the new set-up at 4 TeV went well, paving the way for a 13-hour physics run for both TOTEM and ALFA with their Roman pots in position. Highlights from the 48-hour machine development period included the injection of high intensity bun...

  9. LHC Report: Omnium-gatherum

    CERN Multimedia

    Mike Lamont for the LHC team

    2012-01-01

    The last couple of weeks have seen a mixed bag of special runs, luminosity production, machine development and down-time.   Van der Meer scans were performed for ATLAS, CMS and ALICE. These scans step the beams transversely across each other and aim at a measurement of the absolute luminosity. A precise determination of the luminosity uncertainty is beneficial for many physics analyses and, indeed, measurements of important physics processes (such as top quark pair production) can be limited by luminosity errors. The scans were ultimately successful but the set-up and execution were affected by a number of technical problems. One of the main down-times was due to the replacement of an SPS dipole magnet which had developed a vacuum leak. A SPS magnet exchange is a well-practiced intervention. In this case, the whole exercise, including the pump down of the vacuum, took around 24 hours. There were also re-occuring problems with the fast switches of the SPS beam dump system. The LHC, as always, dep...

  10. Experiments with stored relativistic exotic nuclei

    International Nuclear Information System (INIS)

    Klepper, O.; Attallah, F.; Beckert, K.; Bosch, F.; Dolinskiy, A.; Eickhoff, H.; Franczak, B.; Franzke, B.; Geissel, H.; Hausmann, M.; Hellstroem, M.; Herfurth, F.; Kluge, H.-J.; Kozhuharov, C.; Muenzenberg, G.; Nolden, F.; Quint, W.; Tradon, T.; Reich, H.; Scheidenberger, C.; Schlitt, B.; Steck, M.; Suemmerer, K.; Vermeeren, L.; Winkler, M.; Winkler, Th.; Falch, M.; Kerscher, Th.; Loebner, K.E.G.; Fujita, Y.; Novikov, Yu.; Patyk, Z.; Stadlmann, J.; Wollnik, H.

    1999-01-01

    Beams of relativistic exotic nuclei were produced, separated and investigated with the combination of the fragment separator FRS and the storage ring ESR. The following experiments are presented: 1) Direct mass measurements of relativistic nickel and bismuth projectile fragments were performed using Schottky spectrometry. Applying electron cooling, the relative velocity spread of the circulating secondary nuclear beams of low intensity was reduced to below 10 -6 . The achieved mass resolving power of m/Δm = 6.5·10 5 (FWHM) in recent measurements represents an improvement by a factor of two compared to authors' previous experiments. The previously unknown masses of more than 100 proton-rich isotopes have been measured in the range of 54≤Z≤84. The results are compared with mass models and estimated values based on extrapolations of experimental values. 2) Exotic nuclei with half-lives shorter than the time required for electron cooling can be investigated by time-of-flight measurements with the ESR being operated in the isochronous mode. This novel experimental technique has been successfully applied in a first measurement with nickel fragments. A mass resolving power of m/Δm = 1.5·10 5 (FWHM) was achieved in this mode of operation. 3) Nuclear half-lives of stored and cooled bare projectile fragments have been measured to study the influence of the ionic charge state on the beta-decay probability

  11. Exotic hybrid mesons in hard electroproduction

    International Nuclear Information System (INIS)

    Anikin, I.V.; Pire, B.; Szymanowski, L.; Teryaev, O.V.; Wallon, S.

    2005-01-01

    We estimate the sizeable cross section for deep exclusive electroproduction of an exotic J PC =1 -+ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e., as 1/Q 2 . This is due to the nonvanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy-momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in α S and we explore the consequences of fixing the renormalization scale ambiguity through the Brodsky-Lepage-Mackenzie (BLM) procedure. We study the particular case where the hybrid meson decays through a πη meson pair. We discuss the πη generalized distribution amplitude and then calculate the production amplitude for this process. We propose a forward-backward asymmetry in the production of π and η mesons as a signal for the hybrid meson production. We briefly comment on hybrid electroproduction at very high energy, in the diffractive limit where a QCD Odderon exchange mechanism should dominate. The conclusion of our study is that hard electroproduction is a promising way to study exotic hybrid mesons, in particular, at JLAB, HERA (HERMES), or CERN (Compass)

  12. LHC collimator controls for a safe LHC operation

    International Nuclear Information System (INIS)

    Redaelli, S.; Assmann, R.; Losito, R.; Donze, M.; Masi, A.

    2012-01-01

    The Large Hadron Collider (LHC) collimation system is designed to protect the machine against beam losses and consists of 108 collimators, 100 of which are movable, located along the 27 km long ring and in the transfer lines. The cleaning performance and machine protection role of the system depend critically on accurate jaw positioning. A fully redundant control system has been developed to ensure that the collimators dynamically follow optimum settings in all phases of the LHC operational cycle. Jaw positions and collimator gaps are interlocked against dump limits defined redundantly as functions of time, beam energy and the β functions, which describe the focusing property of the beams. In this paper, the architectural choices that guarantee a safe LHC operation are presented. Hardware and software implementations that ensure the required performance are described. (authors)

  13. Le LHC, un tunnel cosmique

    CERN Multimedia

    CERN. Geneva

    2009-01-01

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

  14. Scenarios for the LHC Upgrade

    CERN Document Server

    Scandale, Walter

    2008-01-01

    The projected lifetime of the LHC low-beta quadrupoles, the evolution of the statistical error halving time, and the physics potential all call for an LHC luminosity upgrade by the middle of the coming decade. In the framework of the CARE-HHH network three principal scenarios have been developed for increasing the LHC peak luminosity by more than a factor of 10, to values above 1035 cm−2s−1. All scenarios imply a rebuilding of the high-luminosity interaction regions (IRs) in combination with a consistent change of beam parameters. However, their respective features, bunch structures, IR layouts, merits and challenges, and luminosity variation with β∗ differ substantially. In all scenarios luminosity leveling during a store would be advantageous for the physics experiments. An injector upgrade must complement the upgrade measures in the LHC proper in order to provide the beam intensity and brightness needed as well as to reduce the LHC turnaround time for higher integrated luminosity.

  15. Physics at LHC and beyond

    CERN Document Server

    2014-01-01

    The topics addressed during this Conference are as follows. ---An overview of the legacy results of the LHC experiments with 7 and 8 TeV data on Standard Model physics, Scalar sector and searches for New Physics. ---A discussion of the readiness of the CMS, ATLAS, and LHCb experiments for the forthcoming high-energy run and status of the detector upgrades ---A review of the most up-to-date theory outcome on cross-sections and uncertainties, phenomenology of the scalar sector, constraints and portals for new physics. ---The presentation of the improvements and of the expected sensibilities for the Run 2 of the LHC at 13 TeV and beyond. ---A comparison of the relative scientific merits of the future projects for hadron and e+e- colliders (HL-LHC, HE-LHC, ILC, CLIC, TLEP, VHE-LHC) towards precision measurements of the Scalar boson properties and of the Electroweak-Symmetry-Breaking parameters, and towards direct searches for New Physics.

  16. Heavy feet for the LHC

    CERN Document Server

    2003-01-01

    The first 800 jacks (adjustable supports) for one sector of the LHC have arrived from India in recent weeks. After the final acceptance of the preseries jacks at the end of October, they can now be used to support the LHC cryo-magnets. How do you move the weight of eight adult Indian elephants by the breadth of a human hair? If you are a surveyor at CERN who has to adjust the 32 ton LHC dipoles with a resolution of 1/20 of a millimetre, you use the 80 kg jacks which were designed and are being procured by the Centre for Advanced Technology (CAT) in India. The jacks are undergoing final pre-shipment inspection by CAT engineers in India. More than 800 jacks have arrived in recent weeks from India, enough to equip the first sector of the LHC (one octant of the ring). For all the cryo-magnets (dipoles and quadrupoles) of the LHC 7000 jacks are needed in total. They are now being continuously delivered to CERN up to mid-2005. The close collaboration between the Department of Atomic Energy (DAE) in India and CE...

  17. Hybrid beams in the LHC

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    The first proton-ion beams were successfully circulated in the LHC a couple of weeks ago. Everything went so smoothly that the LHC teams had planned the first p-Pb collisions for Wednesday, 16 November. Unfortunately, a last-minute problem with a component of the PS required for proton acceleration prevented the LHC teams from making these new collisions. However, the way is open for a possible physics run with proton-lead collisions in 2012.   Members of the LHC team photographed when the first hybrid beams got to full energy. The proton and lead beams are visible on the leftmost screen up on the wall (click to enlarge the photo). The technical challenge of making different beams circulate in the LHC is by no means trivial. Even if the machine is the same, there are a number of differences when it is operated with beams of protons, beams of lead or beams of proton and lead. Provided that the beams are equal, irrespective of whether they consist of protons or lead nuclei, they revolve at the...

  18. Technological challenges for the LHC

    CERN Multimedia

    CERN. Geneva; Rossi, Lucio; Lebrun, Philippe; Bordry, Frederick; Mess, Karl Hubert; Schmidt, Rüdiger

    2003-01-01

    For the LHC to provide particle physics with proton-proton collisions at the centre of mass energy of 14 TeV with a luminosity of 1034 cm-2s-1, the machine will operate with high-field dipole magnets using NbTi superconductors cooled to below the lambda point of helium. In order to reach design performance, the LHC requires both, the use of existing technologies pushed to the limits as well as the application of novel technologies. The construction follows a decade of intensive R&D and technical validation of major collider sub-systems. The first lecture will focus on the required LHC performance, and on the implications on the technologies. In the following lectures several examples for LHC technologies will be discussed: the superconducting magnets to deflect and focus the beams, the cryogenics to cool the magnets to a temperature below the lambda point of helium along most of the LHC circumference, the powering system supplying about 7000 magnets connected in 1700 electrical circuits with a total curr...

  19. Changes to the LHC Beam Dumping System for LHC Run 2

    CERN Document Server

    Uythoven, Jan; Borburgh, Jan; Carlier, Etienne; Gabourin, Stéphane; Goddard, Brennan; Magnin, Nicolas; Senaj, Viliam; Voumard, Nicolas; Weterings, Wim

    2014-01-01

    The LHC beam dumping system performed according to expectations during Run 1 of the LHC (2009 – 2013). A brief overview of the experience is given, including a summary of the observed performance by comparison to expectations. An important number of changes are applied to the beam dumping system during the present Long Shutdown in order to further improve its safety and performance. They include the addition of a direct link between the Beam Interlock System and the re-triggering system of the dump kickers, the modification of the uninterrupted electrical power distribution architecture, the upgrade of the HV generators, the consolidation of the trigger synchronisation system, the modifications to the triggering system of the power switches and the changes to the dump absorbers TCDQ.

  20. Exotic aspects of hadronic atoms-anomalous quasi-stabilities

    International Nuclear Information System (INIS)

    Yamazaki, Toshimitsu.

    1993-07-01

    Recently revealed, but hitherto unknown, new aspects of hadronic atoms, namely, anomalous quasi-stabilities of negative hadrons, are discussed. One is on long-lived antiprotonic helium atoms, characterized as 'atomic exotic halo' and the other is on deeply bound pionic atoms, characterized as 'nuclear exotic halo'. (author)

  1. Invasion of exotic earthworms into ecosystems inhabited by native earthworms

    Science.gov (United States)

    P. F. Hendrix; G. H. Baker; M. A. Callaham Jr; G. A. Damoff; Fragoso C.; G. Gonzalez; S. W. James; S. L. Lachnicht; T. Winsome; X. Zou

    2006-01-01

    The most conspicuous biological invasions in terrestrial ecosystems have been by exotic plants, insects and vertebrates. Invasions by exotic earthworms, although not as well studied, may be increasing with global commerce in agriculture, waste management and bioremediation. A number of cases has documented where invasive earthworms have caused significant changes in...

  2. A survey of exotic plants in federal wilderness areas

    Science.gov (United States)

    Marilyn Marler

    2000-01-01

    I conducted a survey of wilderness areas to provide an overview of plant invasions in the National Wilderness Preservation System. Fifteen per cent of responding mangers reported that exotic plants were among their top 10 management concerns, either because they are actively dealing with control of exotic pest plants or have prioritized prevention of their...

  3. Comparative study of genetic influence on the susceptibility of exotic ...

    African Journals Online (AJOL)

    This study investigated comparatively the genetic influence on the susceptibility of exotic cockerels, pullets and broilers to natural infection with infectious bursal disease (IBD) virus in a flock of 150 seven-week-old exotic breed of chickens comprising of 50 Black Harco cockerels, 50 Black Harco pullets and 50 White ...

  4. A possible global group structure for exotic states

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xue-Qian [Nankai University, School of Physics, Tianjin (China); Liu, Xiang [Lanzhou University, School of Physical Science and Technology, Lanzhou (China); Lanzhou University and Institute of Modern Physics of CAS, Research Center for Hadron and CSR Physics, Lanzhou (China)

    2014-12-01

    Based on the fact that the long expected pentaquark which possesses the exotic quantum numbers of B = 1 and S = 1 was not experimentally found, although exotic states of XY Z have been observed recently, we conjecture that the heavy flavors may play an important role in stabilizing the hadronic structures beyond the traditional q anti q and qqq composites. (orig.)

  5. Rapid detection of exotic Lymantriids and Scolytids pilot study

    Science.gov (United States)

    Mary Ellen Dix

    2003-01-01

    Exotic invasive species, inadvertently introduced into North America through importation and travel, are threatening the integrity of North American forest ecosystems. The National Invasive Species Council in their 2001 Strategic Plan identified a collaborative program for early detection, diagnosis and response to high-risk, exotic, invasive insects, pathogens and...

  6. Constraints on Models for the Higgs Boson with Exotic Spin and Parity

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Emily Hannah [Michigan State U.

    2016-01-01

    The production of a Higgs boson in association with a vector boson at the Tevatron offers a unique opportunity to study models for the Higgs boson with exotic spin J and parity P assignments. At the Tevatron the V H system is produced near threshold. Different JP assignments of the Higgs boson can be distinguished by examining the behavior of the cross section near threshold. The relatively low backgrounds at the Tevatron compared to the LHC put us in a unique position to study the direct decay of the Higgs boson to fermions. If the Higgs sector is more complex than predicted, studying the spin and parity of the Higgs boson in all decay modes is important. In this Thesis we will examine the WH → ℓνb¯b production and decay mode using 9.7 fb-1 of data collected by the D0 experiment in an attempt to derive constraints on models containing exotic values for the spin and parity of the Higgs boson. In particular, we will examine models for a Higgs boson with JP = 0- and JP = 2+. We use a likelihood ratio to quantify the degree to which our data are incompatible with exotic JP predictions for a range of possible production rates. Assuming the production cross section times branching ratio of the signals in the models considered is equal to the standard model prediction, the WH → ℓνb¯b mode alone is unable to reject either exotic model considered. We will also discuss the combination of the ZH → ℓℓb¯b, WH → ℓνb¯b, and V H → ννb¯b production modes at the D0 experiment and with the CDF experiment. When combining all three production modes at the D0 experiment we reject the JP = 0- and JP = 2+ hypotheses at the 97.6% CL and at the 99.0% CL, respectively, when assuming the signal production cross section times branching ratio is equal to the standard model predicted value. When combining with the CDF experiment we reject the JP = 0- and JP = 2+ hypotheses with significances of 5.0 standard deviations and 4.9 standard deviations

  7. Pauline Gagnon's Blog: Did we build the LHC just to find the Higgs?

    CERN Multimedia

    Pauline Gagnon

    2011-01-01

    There are bosos and bosons, and if the Large Hadron Collider (LHC) were built only to find the Higgs boson, you would be absolutely right to think all physicists belong to the first category. But the fact is, the LHC does much more than search for Higgs bosons.   A selection of recent results obtained by the ATLAS experiment in search for new discoveries. In blue, searches for various supersymmetric models, in turquoise, models involving extra dimensions, and the other colors showing even more exotic models. Despite the media focusing mainly on the Higgs boson, this search only represents one of the many aspects we hope to cover with the LHC. Granted, the Higgs boson brings such an elegant solution to the problem of the origin of mass that its high popularity among physicists has reached even the general public. But the LHC could be opening the door to parallel worlds, extra dimensions or the discovery of as many new particles as the ones we already know. These are but some of the exciting...

  8. An exotic k-essence interpretation of interactive cosmological models

    Energy Technology Data Exchange (ETDEWEB)

    Forte, Monica [Universidad de Buenos Aires, Departamento de Fisica, Facultad de ciencias Exactas y Naturales, Buenos Aires (Argentina)

    2016-01-15

    We define a generalization of scalar fields with non-canonical kinetic term which we call exotic k-essence or, briefly, exotik. These fields are generated by the global description of cosmological models with two interactive fluids in the dark sector and under certain conditions they correspond to usual k-essences. The formalism is applied to the cases of constant potential and of inverse square potential and also we develop the purely exotik version for the modified holographic Ricci type (MHR) of dark energy, where the equations of state are not constant. With the kinetic function F = 1 + mx and the inverse square potential we recover, through the interaction term, the identification between k-essences and quintessences of an exponential potential, already known for Friedmann-Robertson-Walker and Bianchi type I geometries. Worked examples are shown that include the self-interacting MHR and also models with crossing of the phantom divide line (PDL). (orig.)

  9. EXOTIC SPECIES OF SOCOTRA ISLAND, YEMEN: A FIRST CONTRIBUTION

    Directory of Open Access Journals (Sweden)

    R.K. SOMASHEKAR

    2010-04-01

    Full Text Available A first inventory of the exotic species of Socotra has been compiled on the basis of the published literature and original distribution data collected by field surveys from 2006 to 2008. A strictly geographical and conservative approach was adopted including only cultivated species and those with a native range separated from Socotra territory. The extracted aliens (87 taxa, 68 genera, 40 family represent approximately 9% of the total flora of the region (850 taxa. Most were introduced in the past 10 to 20 years. Agricultural cultivated or crop species dominated with 38 species (43.7%, fruit followed by basing 14 species (16.1% and ruder or ornamental species (35 species, 40.2%.

  10. On exotic hybrid meson production in γ*γ collisions

    International Nuclear Information System (INIS)

    Anikin, I.V.; Teryaev, O.V.; Pire, B.; Szymanowski, L.; Universite de Liege; Paris-11 Univ., 91 - Orsay; Wallon, S.

    2006-01-01

    We present a theoretical study of exotic hybrid meson (J PC =1 -+ ) production in photon-photon collisions where one of the photons is deeply virtual, including twist two and twist three contributions. We calculate the cross section of this process, which turns out to be large enough to imply sizeable counting rates in the present high luminosity electron-positron colliders. We emphasize the importance of the πη decay channel for the detection of the hybrid meson candidate π 1 (1400) and calculate the cross section and the angular distribution for πη pair production in the unpolarized case. This angular distribution is a useful tool for disentangling the hybrid meson signal from the background. Finally, we calculate the single spin asymmetry associated with one initial longitudinally polarized lepton. (orig.)

  11. An exotic k-essence interpretation of interactive cosmological models

    International Nuclear Information System (INIS)

    Forte, Monica

    2016-01-01

    We define a generalization of scalar fields with non-canonical kinetic term which we call exotic k-essence or, briefly, exotik. These fields are generated by the global description of cosmological models with two interactive fluids in the dark sector and under certain conditions they correspond to usual k-essences. The formalism is applied to the cases of constant potential and of inverse square potential and also we develop the purely exotik version for the modified holographic Ricci type (MHR) of dark energy, where the equations of state are not constant. With the kinetic function F = 1 + mx and the inverse square potential we recover, through the interaction term, the identification between k-essences and quintessences of an exponential potential, already known for Friedmann-Robertson-Walker and Bianchi type I geometries. Worked examples are shown that include the self-interacting MHR and also models with crossing of the phantom divide line (PDL). (orig.)

  12. Production and decay of exotic fermions in high energy collisions

    International Nuclear Information System (INIS)

    Queiroz Filho, Pedro Pacheco de

    1995-05-01

    In this work, we investigate the production and decay of exotic fermions predicted by some extensions of the standard model. We select for our study the more popular models: vector singlet, vector doublet and Fermion Mirror-Fermion. We want to establish the differences between these models and also in relation to the Standard Model. We make investigations by Monte Carlo simulations, to study the phenomenology of the particles expected in these models, particularly the exotic fermions. These studies were done for electron-proton collisions at DESY HERA energies. We considered the investigation of exotic quark production, electron-positron collisions in LEP II and NLC energies in order to study the production of exotic leptons, and virtual exotic lepton contribution in the specific process e + e - → ιν-bar ι W + . (author)

  13. Computer graphic of LHC in the tunnel

    CERN Multimedia

    1996-01-01

    A computer-generated image of the LHC particle accelerator at CERN in the tunnel originally built for the LEP accelerator that was closed in 2000. The cross-section of an LHC superconducting dipole magnet is also seen.

  14. The HL-LHC accelerator physics challenges

    CERN Document Server

    Fartoukh, S

    2014-01-01

    We review the conceptual baseline of the HL-LHC project, putting into perspective the main beam physics challenges of this new collider in comparison with the existing LHC, and the series of solutions and possible mitigation measures presently envisaged.

  15. The HL-LHC Accelerator Physics Challenges

    Science.gov (United States)

    Fartoukh, S.; Zimmermann, F.

    The conceptual baseline of the HL-LHC project is reviewed, putting into perspective the main beam physics challenges of this new collider in comparison with the existing LHC, and the series of solutions and possible mitigation measures presently envisaged.

  16. The HL-LHC accelerator physics challenges

    CERN Document Server

    Fartoukh, S

    2015-01-01

    The conceptual baseline of the HL-LHC project is reviewed, putting into perspective the main beam physics challenges of this new collider in comparison with the existing LHC, and the series of solutions and possible mitigation measures presently envisaged.

  17. Dashboard for the LHC experiments

    International Nuclear Information System (INIS)

    Andreeva, J; Cirstoiu, C; Miguel, M D F D; Ivanchenko, A; Gaidioz, B; Herrala, J; Janulis, M; Maier, G; Maguire, E J; Rivera, R P; Rocha, R; Saiz, P; Sidorova, I; Belov, S; Berejnoj, A; Kodolova, O; Chen, Y; Chen, T; Chiu, S; Munro, C

    2008-01-01

    In this paper we present the Experiment Dashboard monitoring system, which is currently in use by four Large Hadron Collider (LHC) experiments. The goal of the Experiment Dashboard is to monitor the activities of the LHC experiments on the distributed infrastructure, providing monitoring data from the virtual organization (VO) and user perspectives. The LHC experiments are using various Grid infrastructures (LCG/EGEE, OSG, NDGF) with correspondingly various middleware flavors and job submission methods. Providing a uniform and complete view of various activities like job processing, data movement and publishing, access to distributed databases regardless of the underlying Grid flavor is the challenging task. In this paper we will describe the Experiment Dashboard concept, its framework and main monitoring applications

  18. The LHC road at CERN

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    To explore the 1 TeV energy scale where fundamental particle interactions should encounter new conditions, two major routes were proposed - a high magnetic field proton collider in the LEP tunnel, dubbed LHC for Large Hadron Collider, and the CERN Linear Collider (CLIC) to supply beams of electrons and positrons. Exploratory studies have shown that while CLIC remains a valid long-term goal, LHC appears as the most cost-effective way for CERN to enter the 1 TeV arena. High-field superconducting magnet prototype work demonstrates that a 'two-in-one' design supplying the 10 tesla fields needed to handle LHC's 8 TeV proton beams (collision energy 16 TeV) is a practical proposition. (orig./HSI).

  19. The first LHC insertion quadrupole

    CERN Multimedia

    2004-01-01

    An important milestone was reached in December 2003 at the CERN Magnet Assembly Facility. The team from the Accelerator Technology - Magnet and Electrical Systems group, AT-MEL, completed the first special superconducting quadrupole for the LHC insertions which house the experiments and major collider systems. The magnet is 8 metres long and contains two matching quadrupole magnets and an orbit corrector, a dipole magnet, used to correct errors in quadrupole alignment. All were tested in liquid helium and reached the ultimate performance criteria required for the LHC. After insertion in the cryostat, the superconducting magnet will be installed as the Q9 quadrupole in sector 7-8, the first sector of the LHC to be put in place in 2004. Members of the quadrupole team, from the AT-MEL group, gathered around the Q9 quadrupole at its inauguration on 12 December 2003 in building 181.

  20. The LHC goes 3G

    CERN Multimedia

    Anaïs Schaeffer

    2013-01-01

    A new telecommunications network has been installed in the LHC tunnel to facilitate operations during the long shutdown. Anyone using a smartphone, tablet or laptop computer will now be able to access the Internet from the tunnel.   Results of a download (green) and upload (yellow) test carried out in the LHC tunnel using the new Universal Mobile Telecommunications System (UMTS). The first long shutdown has officially begun, and the teams are about to enter the various tunnels around the Laboratory. It’s a good opportunity to talk telecommunications. As you can well imagine, even the highest of high-tech smartphones remains stubbornly silent and unresponsive 100 metres below the ground. Except at CERN… The IT-CS Group has implemented an impressive state-of-the-art solution to tackle this problem - a new Universal Mobile Telecommunications System (UMTS), better known as “3G”, covering the entire 27-km circumference of the LHC tunnel. Established on th...

  1. Inclusive production at LHC energies

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  2. Access safety systems - New concepts from the LHC experience

    International Nuclear Information System (INIS)

    Ladzinski, T.; Delamare, C.; Luca, S. di; Hakulinen, T.; Hammouti, L.; Havart, F.; Juget, J.F.; Ninin, P.; Nunes, R.; Riesco, T.; Sanchez-Corral Mena, E.; Valentini, F.

    2012-01-01

    The LHC Access Safety System has introduced a number of new concepts into the domain of personnel protection at CERN. These can be grouped into several categories: organisational, architectural and concerning the end-user experience. By anchoring the project on the solid foundations of the IEC 61508/61511 methodology, the CERN team and its contractors managed to design, develop, test and commission on time a SIL3 safety system. The system uses a successful combination of the latest Siemens redundant safety programmable logic controllers with a traditional relay logic hard wired loop. The external envelope barriers used in the LHC include personnel and material access devices, which are interlocked door-booths introducing increased automation of individual access control, thus removing the strain from the operators. These devices ensure the inviolability of the controlled zones by users not holding the required credentials. To this end they are equipped with personnel presence detectors and the access control includes a state of the art bio-metry check. Building on the LHC experience, new projects targeting the refurbishment of the existing access safety infrastructure in the injector chain have started. This paper summarises the new concepts introduced in the LHC access control and safety systems, discusses the return of experience and outlines the main guiding principles for the renewal stage of the personnel protection systems in the LHC injector chain in a homogeneous manner. (authors)

  3. 5th report from the LHC performance workshop

    CERN Multimedia

    Bulletin's correspondent from Chamonix

    2012-01-01

    The morning session on Friday 10 February - the final day of the workshop - saw further examination of the challenges of the High Luminosity LHC and included a look at the state of R&D for the new magnets required for the high luminosity interaction regions. There was then an entertaining look at even more distant future. Possible future projects under consideration include the Large Hadron electron Collider (LHeC) which foresees colliding 60 GeV electrons with 7 TeV protons, and the High Energy LHC (HE-LHC) in which the beam energy of the LHC is increased from 7 to 16.5 TeV. Serious technological challenges exist for both these options. In the afternoon Steve Myers, CERN's Director for Accelerators and Technology, presented a summary of the workshop recommendations. In brief, the LHC should operate at 4 TeV in 2012 with the key priorities being: delivering enough luminosity to ATLAS and CMS to allow them to independently discover or exclude the Higgs; the proton-Lead ion run; and machine deve...

  4. Upgrade of the CMS Tracker for the High Luminosity LHC

    CERN Document Server

    Auzinger, Georg

    2016-01-01

    The LHC machine is planning an upgrade program which will smoothly bring the luminosity to about $ 5 \\times 10^{34}$cm$^{-2}$s$^{-1}$ in 2028, possibly reaching an integrated luminosity of 3000 fb$^{-1}$ by the end of 2037. This High Luminosity LHC scenario, HL-LHC, will require a preparation program of the LHC detectors known as Phase-2 Upgrade. The current CMS Tracker, including both inner pixel and outer strip systems, is already running beyond design specifications and will not be able to survive HL-LHC radiation conditions. CMS will need a completely new device in order to fully exploit the demanding operating conditions and the delivered luminosity. The upgrade plan includes extending the Pixel Detector in the forward region from the current coverage of $ \\lvert \\eta \\rvert < 2.4 $ to $ \\lvert \\eta \\rvert < 4$, where up to seven forward- and four extension disks will compose the new detector. Additionally, the new outer system should also have trigger capabilities. To achieve such goals, R\\&...

  5. Post LHC8 SUSY benchmark points for ILC physics

    Energy Technology Data Exchange (ETDEWEB)

    Baer, Howard [Oklahoma Univ., Norman, OK (United States); List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-07-15

    We re-evaluate prospects for supersymmetry at the proposed International Linear e{sup +}e{sup -} Collider (ILC) in light of the first two years of serious data taking at LHC: LHC7 with {proportional_to}5 fb{sup -1} of pp collisions at {radical}(s)=7 TeV and LHC8 with {proportional_to}20 fb{sup -1} at {radical}(s)=8 TeV. Strong new limits from LHC8 SUSY searches, along with the discovery of a Higgs boson with m{sub h}{approx_equal}125 GeV, suggest a paradigm shift from previously popular models to ones with new and compelling signatures. After a review of the current status of supersymmetry, we present a variety of new ILC benchmark models, including: natural SUSY, radiatively-driven natural SUSY (RNS), NUHM2 with low m{sub A}, a focus point case from mSUGRA/CMSSM, non-universal gaugino mass (NUGM) model, {tau}-coannihilation, Kallosh-Linde/spread SUSY model, mixed gauge-gravity mediation, normal scalar mass hierarchy (NMH), and one example with the recently discovered Higgs boson being the heavy CP-even state H. While all these models at present elude the latest LHC8 limits, they do offer intriguing case study possibilities for ILC operating at {radical}(s){approx_equal} 0.25-1 TeV. The benchmark points also present a view of the widely diverse SUSY phenomena which might still be expected in the post LHC8 era at both LHC and ILC.

  6. How exotic does an exotic information and education initiative about the impact of non-indigenous species need to be?

    Science.gov (United States)

    William F. Hammond

    1998-01-01

    Providing individuals with effective information, programs, and educational materials about "exotics" or non-indigenous species is generally not a very effective way to get people to act to control, eliminate, and restore damage from exotic species to native ecosystems. Information tends to inform the motivated and educated. Educational research and marketing...

  7. Recent Results on SUSY and Exotica Searches at the LHC

    CERN Document Server

    Grout, Zara Jane; The ATLAS collaboration

    2015-01-01

    A review is presented of searches for Beyond the Standard Model (BSM) physics at the ATLAS and CMS experiments at the Large Hadron Collider (LHC) with emphasis on most recent results. This includes a summary of Supersymmetry searches covering strong, electroweak, and R-parity violating scenarios, and a range of exotica searches including heavy boson searches, extra dimensions, and long-lived particles. The status of BSM physics after the first data-taking period (Run 1) of the LHC and the prospects for the second data-taking period (Run 2), beginning in 2015, are discussed.

  8. Recent Results on SUSY and Exotica Searches at the LHC

    Directory of Open Access Journals (Sweden)

    Grout Zara

    2015-01-01

    Full Text Available A review is presented of searches for Beyond the Standard Model (BSM physics at the ATLAS and CMS experiments at the Large Hadron Collider (LHC with emphasis on most recent results. This includes a summary of Supersymmetry searches covering strong, electroweak, and R-parity violating scenarios, and a range of exotica searches including heavy boson searches, extra dimensions, and long-lived particles. The status of BSM physics after the first data-taking period (Run 1 of the LHC and the prospects for the second data-taking period (Run 2, beginning in 2015, are discussed.

  9. Searches for SUSY at LHC

    International Nuclear Information System (INIS)

    Kharchilava, A.

    1997-01-01

    One of the main motivations of experiments at the LHC is to search for SUSY particles. The talk is based on recent analyses, performed by CMS Collaboration, within the framework of the Supergravity motivated minimal SUSY extension of the Standard Model. The emphasis is put on leptonic channels. The strategies for obtaining experimental signatures for strongly and weakly interacting sparticles productions, as well as examples of determination of SUSY masses and model parameters are discussed. The domain of parameter space where SUSY can be discovered is investigated. Results show, that if SUSY is of relevance at Electro-Weak scale it could hardly escape detection at LHC. (author)

  10. HL-LHC tracking challenge

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    We organize on the Kaggle platform a data science competition to stimulate both the ML and HEP communities to renew core tracking algorithms in preparation of the next generation of particle detectors at the LHC. In a nutshell : one event has 100.000 3D points ; how to associate the points onto 10.000 unknown approximately helicoidal trajectories ? avoiding combinatorial explosion ? you have a few seconds. But we do give you 100.000 events to train on. We ran ttbar+200 minimum bias event into ACTS a simplified (yet accurate) simulation of a generic LHC silicon detectors, and wrote out the reconstructed hits, with matching truth. ...

  11. Diffraction dissociation at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Jenkovszky, Laszlo [Bogolyubov Institute for Theoretical Physics (BITP), Ukrainian National Academy of Sciences 14-b, Metrolohichna str., Kiev, 03680, Ukraine and Wigner Research Centre for Physics, Hungarian Academy of Sciences 1525 Budapest, POB 49 (Hungary); Orava, Risto [Institute of Physics, Division of Elementary Particle Physics, P.O. Box 64 (Gustaf Haellstroeminkatu 2a), FI-00014 University of Helsinki, Finland and CERN, CH-1211 Geneva 23 (Switzerland); Salii, Andrii [Bogolyubov Institute for Theoretical Physics (BITP), Ukrainian National Academy of Sciences 14-b, Metrolohichna str., Kiev, 03680 (Ukraine)

    2013-04-15

    We report on recent calculations of low missing mass single (SD) and double (DD) diffractive dissociation at LHC energies. The calculations are based on a dual-Regge model, dominated by a single Pomeron exchange. The diffractively excited states lie on the nucleon trajectory N*, appended by the isolated Roper resonance. Detailed predictions for the squared momentum transfer and missing mass dependence of the differential and integrated single-and double diffraction dissociation in the kinematical range of present and future LHC measurements are given.

  12. Diffraction dissociation at the LHC

    International Nuclear Information System (INIS)

    Jenkovszky, László; Orava, Risto; Salii, Andrii

    2013-01-01

    We report on recent calculations of low missing mass single (SD) and double (DD) diffractive dissociation at LHC energies. The calculations are based on a dual-Regge model, dominated by a single Pomeron exchange. The diffractively excited states lie on the nucleon trajectory N*, appended by the isolated Roper resonance. Detailed predictions for the squared momentum transfer and missing mass dependence of the differential and integrated single-and double diffraction dissociation in the kinematical range of present and future LHC measurements are given.

  13. High Luminosity LHC (HL-LHC) general infographics

    CERN Multimedia

    Landua, Fabienne

    2016-01-01

    The High-Luminosity LHC, which is expected to be operational after 2025, will increase the LHC’s luminosity by a factor of 10. To achieve this major upgrade, several technologies, some of which are completely innovative, are being developed.

  14. Budker INP in the LHC Machine (2)

    CERN Multimedia

    2001-01-01

    The main BINP contributions to the LHC machine are magnets for transfer lines (26 MCHF) and bus- bar sets (23 MCHF). Budker INP is also responsible for construction of some other LHC magnets and vacuum parts. In total, the contribution to the LHC machine will reach about 90 MCHF.

  15. Probing Exotic Physics With Supernova Neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, Chris; Hooper, Dan

    2010-09-01

    Future galactic supernovae will provide an extremely long baseline for studying the properties and interactions of neutrinos. In this paper, we discuss the possibility of using such an event to constrain (or discover) the effects of exotic physics in scenarios that are not currently constrained and are not accessible with reactor or solar neutrino experiments. In particular, we focus on the cases of neutrino decay and quantum decoherence. We calculate the expected signal from a core-collapse supernova in both current and future water Cerenkov, scintillating, and liquid argon detectors, and find that such observations will be capable of distinguishing between many of these scenarios. Additionally, future detectors will be capable of making strong, model-independent conclusions by examining events associated with a galactic supernova's neutronization burst.

  16. Rational F-theory GUTs without exotics

    Science.gov (United States)

    Krippendorf, Sven; Peña, Damián Kaloni Mayorga; Oehlmann, Paul-Konstantin; Ruehle, Fabian

    2014-07-01

    We construct F-theory GUT models without exotic matter, leading to the MSSM matter spectrum with potential singlet extensions. The interplay of engineering explicit geometric setups, absence of four-dimensional anomalies, and realistic phenomenology of the couplings places severe constraints on the allowed local models in a given geometry. In constructions based on the spectral cover we find no model satisfying all these requirements. We then provide a survey of models with additional U(1) symmetries arising from rational sections of the elliptic fibration in toric constructions and obtain phenomenologically appealing models based on SU(5) tops. Furthermore we perform a bottom-up exploration beyond the toric section constructions discussed in the literature so far and identify benchmark models passing all our criteria, which can serve as a guideline for future geometric engineering.

  17. Rational F-theory GUTs without exotics

    International Nuclear Information System (INIS)

    Krippendorf, Sven; Pena, Damian Kaloni Mayorga; Oehlmann, Paul-Konstantin

    2014-01-01

    We construct F-theory GUT models without exotic matter, leading to the MSSM matter spectrum with potential singlet extensions. The interplay of engineering explicit geometric setups, absence of four-dimensional anomalies, and realistic phenomenology of the couplings places severe constraints on the allowed local models in a given geometry. In constructions based on the spectral cover we find no model satisfying all these requirements. We then provide a survey of models with additional U(1) symmetries arising from rational sections of the elliptic fibration in toric constructions and obtain phenomenologically appealing models based on SU(5) tops. Furthermore we perform a bottom-up exploration beyond the toric section constructions discussed in the literature so far and identify benchmark models passing all our criteria, which can serve as a guideline for future geometric engineering.

  18. Rational F-theory GUTs without exotics

    International Nuclear Information System (INIS)

    Krippendorf, Sven; Peña, Damián Kaloni Mayorga; Oehlmann, Paul-Konstantin; Ruehle, Fabian

    2014-01-01

    We construct F-theory GUT models without exotic matter, leading to the MSSM matter spectrum with potential singlet extensions. The interplay of engineering explicit geometric setups, absence of four-dimensional anomalies, and realistic phenomenology of the couplings places severe constraints on the allowed local models in a given geometry. In constructions based on the spectral cover we find no model satisfying all these requirements. We then provide a survey of models with additional U1 symmetries arising from rational sections of the elliptic fibration in toric constructions and obtain phenomenologically appealing models based on SU(5) tops. Furthermore we perform a bottom-up exploration beyond the toric section constructions discussed in the literature so far and identify benchmark models passing all our criteria, which can serve as a guideline for future geometric engineering.

  19. Casimir Energy, Extra Dimensions and Exotic Propulsion

    Science.gov (United States)

    Obousy, R.; Saharian, A.

    It is well known that the Casimir effect is an excellent candidate for the stabilization of the extra dimensions. It has also been suggested that the Casimir effect in higher dimensions may be the underlying phenomenon that is responsible for the dark energy which is currently driving the accelerated expansion of the universe. In this paper we suggest that, in principle, it may be possible to directly manipulate the size of an extra dimension locally using Standard Model fields in the next generation of particle accelerators. This adjustment of the size of the higher dimension could serve as a technological mechanism to locally adjust the dark energy density and change the local expansion of spacetime. This idea holds tantalizing possibilities in the context of exotic spacecraft propulsion.

  20. Exotic meson decay widths using lattice QCD

    International Nuclear Information System (INIS)

    Cook, M. S.; Fiebig, H. R.

    2006-01-01

    A decay width calculation for a hybrid exotic meson h, with J PC =1 -+ , is presented for the channel h→πa 1 . This quenched lattice QCD simulation employs Luescher's finite box method. Operators coupling to the h and πa 1 states are used at various levels of smearing and fuzzing, and at four quark masses. Eigenvalues of the corresponding correlation matrices yield energy spectra that determine scattering phase shifts for a discrete set of relative πa 1 momenta. Although the phase shift data is sparse, fits to a Breit-Wigner model are attempted, resulting in a decay width of about 60 MeV when averaged over two lattice sizes having a lattice spacing of 0.07 fm