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Sample records for tevatron collider experiment

  1. Tevatron Collider physics

    International Nuclear Information System (INIS)

    Eichten, E.J.

    1990-02-01

    The physics of hadron colliders is briefly reviewed. Issues for further study are presented. Particular attention is given to the physics opportunities for a high luminosity (≥ 100 pb -1 /experiment/run) Upgrade of the Tevatron Collider. 25 refs., 10 figs., 2 tabs

  2. Tevatron instrumentation: boosting collider performance

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir; Jansson, Andreas; Moore, Ronald; /Fermilab

    2006-05-01

    The Tevatron in Collider Run II (2001-present) is operating with six times more bunches, many times higher beam intensities and luminosities than in Run I (1992-1995). Beam diagnostics were crucial for the machine start-up and the never-ending luminosity upgrade campaign. We present the overall picture of the Tevatron diagnostics development for Run II, outline machine needs for new instrumentation, present several notable examples that led to Tevatron performance improvements, and discuss the lessons for the next big machines--LHC and ILC.

  3. Longitudinal damping in the Tevatron collider

    Energy Technology Data Exchange (ETDEWEB)

    Kerns, Q.A.; Jackson, G.; Kerns, C.R.; Miller, H.; Reid, J.; Siemann, R.; Wildman, D.

    1989-03-01

    This paper describes the damper design for 6 proton on 6 pbar bunches in the Tevatron collider. Signal pickup, transient phase detection, derivative networks, and phase correction via the high-level rf are covered. Each rf station is controlled by a slow feedback loop. In addition, global feedback loops control each set of four cavities, one set for protons and one set for antiprotons. Operational experience with these systems is discussed. 7 refs., 9 figs.

  4. Longitudinal damping in the Tevatron collider

    International Nuclear Information System (INIS)

    Kerns, Q.A.; Jackson, G.; Kerns, C.R.; Miller, H.; Reid, J.; Siemann, R.; Wildman, D.

    1989-03-01

    This paper describes the damper design for 6 proton on 6 pbar bunches in the Tevatron collider. Signal pickup, transient phase detection, derivative networks, and phase correction via the high-level rf are covered. Each rf station is controlled by a slow feedback loop. In addition, global feedback loops control each set of four cavities, one set for protons and one set for antiprotons. Operational experience with these systems is discussed. 7 refs., 9 figs

  5. Estimates of Fermilab Tevatron collider performance

    International Nuclear Information System (INIS)

    Dugan, G.

    1991-09-01

    This paper describes a model which has been used to estimate the average luminosity performance of the Tevatron collider. In the model, the average luminosity is related quantitatively to various performance parameters of the Fermilab Tevatron collider complex. The model is useful in allowing estimates to be developed for the improvements in average collider luminosity to be expected from changes in the fundamental performance parameters as a result of upgrades to various parts of the accelerator complex

  6. Beam instrumentation for the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Ronald S.; Jansson, Andreas; Shiltsev, Vladimir; /Fermilab

    2009-10-01

    The Tevatron in Collider Run II (2001-present) is operating with six times more bunches and many times higher beam intensities and luminosities than in Run I (1992-1995). Beam diagnostics were crucial for the machine start-up and the never-ending luminosity upgrade campaign. We present the overall picture of the Tevatron diagnostics development for Run II, outline machine needs for new instrumentation, present several notable examples that led to Tevatron performance improvements, and discuss the lessons for future colliders.

  7. Multibunch operation in the Tevatron Collider

    International Nuclear Information System (INIS)

    Holt, J.A.; Finley, D.A.; Bharadwaj, V.

    1993-05-01

    The Tevatron Collider at Fermilab is the world's highest energy hadron collider, colliding protons with antiprotons at a center of mass energy of 1800 GeV. At present six proton bunches collide with six antiproton bunches to generate luminosities of up to 9 x 10 30 cm -2 s -1 . It is estimated that to reach luminosities significantly greater than 10 31 cm -2 s -1 while minimizing the number of interactions per crossing, the number of bunches will have to be increased. Thirty-six bunch operation looks like the most promising plan. This paper looks at the strategies for increasing the number of particle bunches, the new hardware that needs to be designed and changes to the operating mode in filling the Tevatron. An interactive program which simulates the filling of the Tevatron collider is also presented. The time scale for multibunch operation and progress towards running greater than six bunches is given in this paper

  8. Multiplicities and minijets at Tevatron Collider energies

    International Nuclear Information System (INIS)

    Sarcevic, I.

    1989-01-01

    We show that in the parton branching model, the probability distribution does not obey KNO scaling. As energy increases, gluon contribution to multiplicities increases, resulting in the widening of the probability distribution, in agreement with experimental data. We predict that the widening of the distribution will stop at Tevatron Collider energies due to the dominant role of gluons at these energies. We also find that the gluon contribution to the 'minijet' cross section increases with energy and becomes dominant at the Tevatron Collider. We calculate QCD minijet cross sections for a variety of structure functions, QCD scales and p T min . We compare our theoretical results with the experimental data and find that some of the structure functions and choices of scale are preferred by the experimental data. We give theoretical predictions for the minijet cross section at the Tevatron Collider, indicating the possibility of distinguishing between different sets of structure functions and choices of scale. (orig.)

  9. Fundamentally new physics at the Tevatron Collider?

    International Nuclear Information System (INIS)

    Chan Hongmo; Nellen, L.; Tsou Sheungtsun

    1989-02-01

    A new dispersion relation analysis of present pp-bar scattering data suggests the existence by Tevatron Collider energies of a threshold, of such nature, as is unlikely to be explainable in terms of known physics or any of its standard projections. (author)

  10. Multiple Parton Interactions in p$bar{p}$ Collisions in D0 Experiment at the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Golovanov, Georgy [Joint Inst. for Nuclear Research (JINR), Dubna (Russia)

    2016-01-01

    The thesis is devoted to the study of processes with multiple parton interactions (MPI) in a ppbar collision collected by D0 detector at the Fermilab Tevatron collider at sqrt(s) = 1.96 TeV. The study includes measurements of MPI event fraction and effective cross section, a process-independent parameter related to the effective interaction region inside the nucleon. The measurements are done using events with a photon and three hadronic jets in the final state. The measured effective cross section is used to estimate background from MPI for WH production at the Tevatron energy

  11. The Tevatron Hadron Collider: A short history

    International Nuclear Information System (INIS)

    Tollestrup, A.V.

    1994-11-01

    The subject of this presentation was intended to cover the history of hadron colliders. However this broad topic is probably better left to historians. I will cover a much smaller portion of this subject and specialize my subject to the history of the Tevatron. As we will see, the Tevatron project is tightly entwined with the progress in collider technology. It occupies a unique place among accelerators in that it was the first to make use of superconducting magnets and indeed the basic design now forms a template for all machines using this technology. It was spawned in an incredibly productive era when new ideas were being generated almost monthly and it has matured into our highest energy collider complete with two large detectors that provide the major facility in the US for probing high Pt physics for the coming decade

  12. Initial operation of the Tevatron collider

    International Nuclear Information System (INIS)

    Johnson, R.

    1987-03-01

    The Tevatron is now the highest energy proton synchrotron and the only accelerator made with superconducting magnets. Operating since 1983 as a fixed-target machine at energies up to 800 GeV, it has now been modified to operate as a 900 GeV antiproton-proton collider. This paper describes the initial operation of the machine in this mode. The new features of the Fermilab complex, including the antiproton source and the Main Ring injector with its two overpasses and new rf requirements, are discussed. Beam characteristics in the Tevatron (including lifetimes, emittances, luminosity, beam-beam tune shifts, backgrounds, and low beta complications), the coordination of the steps in the accelerator chain, and the commissioning history are also discussed. Finally, some plans for the improvement of the collider are presented

  13. Search for the Production of Gluinos and Squarks with the CDF II Experiment at the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    De Lorenzo, Gianluca [Autonomous Univ. of Barcelona (Spain)

    2010-05-19

    sbottom decays exclusively as $\\tilde{b}$1 → b$\\tilde{x}$10. The expected signal for direct sbottom pair production is characterized by the presence of two jets of hadrons from the hadronization of the bottom quarks and E=T from the two LSPs in the final state. The events are selected with large ET and two energetic jets in the final state, and at least one jet is required to be associated with a b quark. The measurements are in good agreement with SM predictions for backgrounds. The results are translated into 95% CL exclusion limits on production cross sections and sbottom and neutralino masses in the given MSSM scenario. Cross sections down to 0.1 pb are excluded for the sbottom mass range considered. Sbottom masses up to 230 GeV/c2 are excluded at 95% CL for neutralino masses below 70 GeV/c2. This analysis increases the previous CDF limit by more than 40 GeV/c2. The sensitivity of both the inclusive and the exclusive search is dominated by systematic effects and the results of the two analyses can be considered as conclusive for CDF Run II. With the new energy frontier of the newly commissioned Large Hadron Collider in Geneva, the experience from Tevatron will be of crucial importance in the developing of effective strategies to search for SUSY in the next era of particle physics experiments.

  14. Electroweak physics at the Tevatron collider

    International Nuclear Information System (INIS)

    Aihara, H.

    1993-08-01

    Preliminary results on electroweak physics from the 1992--1993 run with the CDF and D0 detectors at the Tevatron collider are presented. New measurements of the ratio of the W and Z production cross sections times the branching fractions for subsequent decay into leptons are shown. The W width, Γ(W), and a limit on the top-quark mass independent of decay mode are extracted. The status of a measurement of the charge asymmetry of electrons from W decay is given. Also shown are a study of diboson (Wγ, Zγ and WZ) production and a search for a new neutral gauge boson (Z')

  15. Physics at the Fermilab Tevatron Proton-Antiproton Collider

    International Nuclear Information System (INIS)

    Geer, S.

    1994-08-01

    These lectures discuss a selection of QCD and Electroweak results from the CDF and D0 experiments at the Fermilab Tevatron Proton-Antiproton Collider. Results are presently based on data samples of about 20 pb -1 at a center-of-mass energy of 1.8 TeV. Results discussed include jet production, direct photon production, W mass and width measurements, the triboson coupling, and most exciting of all, evidence for top quark production

  16. BTEV: a dedicated B physics detector at the Fermilab Tevatron Collider

    International Nuclear Information System (INIS)

    Butler, J.N.

    1996-11-01

    The capabilities of future Dedicated Hadron Collider B Physics experiments are discussed and compared to experiments that will run in the next few years. The design for such an experiment at the Tevatron Collider is presented and an evolutionary path for developing it is outlined. 9 refs., 3 figs., 4 tabs

  17. Online calculation of the Tevatron collider luminosity using accelerator instrumentation

    International Nuclear Information System (INIS)

    Hahn, A.A.

    1997-07-01

    The luminosity of a collision region may be calculated if one understands the lattice parameters and measures the beam intensities, the transverse and longitudinal emittances, and the individual proton and antiproton beam trajectories (space and time) through the collision region. This paper explores an attempt to make this calculation using beam instrumentation during Run 1b of the Tevatron. The instrumentation used is briefly described. The calculations and their uncertainties are compared to luminosities calculated independently by the Collider Experiments (CDF and D0)

  18. Minimax: Multiparticle physics at the TeVatron collider

    International Nuclear Information System (INIS)

    Bjorken, J.D.

    1994-01-01

    The author and two dozen others are engaged in a small test/experiment in the Fermilab Tevatron collider. It is called Minimax, and its purpose is to explore large-cross-section physics in the forward direction. The primary goal of Minimax is search for events containing the residue of disoriented chiral condensate (dcc) produced in the primary collision. The theoretical ideas are very speculative. But if they are right, they could provide an interpretation of the Centauro/anti-Centauro anomalies claimed to have been seen in cosmic-ray events. In this paper, the history and status of Minimax is described

  19. Tevatron The Cinderella story or the art of collider

    CERN Document Server

    CERN. Geneva

    2007-01-01

    The Tevatron Collider at Fermilab (Batavia, IL, USA) is the world's highest energy particle collider at 1.8TeV c.m.e. The machine was a centerpiece of the US and world's High Energy Physics for many years. Currently, the Tevatron is in the last years of its operation in so-called Run II which started 2001 and is tentatively scheduled to end in 2010. In this lecture series, we'll try to learn from the exciting story of the Tevatron Collider Run II: the story of long preparations, great expectations, initial difficulties, years of "blood and sweat", continuous upgrades, exceeding its goals, high emotions, tune-up of accelerator organization for "combat fighting". The lectures will cover Introduction to the Tevatron, its history and Run II; "Plumbing" Issues; Beam Physics Issues; Luminosity Progress; Organization of Troops and Lessons for LHC.

  20. Experimental Study of W Z Intermediate Bosons Associated Production with the CDF Experiment at the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Pozzobon, Nicola; /Pisa U.

    2007-09-01

    Studying WZ associated production at the Fermilab Tevatron Collider is of great importance for two main reasons. On the one hand, this process would be sensitive to anomalies in the triple gauge couplings such that any deviation from the value predicted by the Standard Model would be indicative of new physics. In addition, by choosing to focus on the final state where the Z boson decays to b{bar b} pairs, the event topology would be the same as expected for associated production of a W and a Standard Model light Higgs boson (m{sub H} {approx}< 135 GeV) which decays into b{bar b} pairs most of times. The process WH {yields} W b{bar b} has an expected {sigma} {center_dot} B about five times lower than WZ {yields} Wb{bar b} for m{sub H} {approx_equal} 120 GeV. Therefore, observing this process would be a benchmark for an even more difficult search aiming at discovering the light Higgs in the WH {yields} Wb{bar b} process. After so many years of Tevatron operation only a weak WZ signal was recently observed in the full leptonic decay channel, which suffers from much less competition from background. Searching for the Z in the b{bar b} decay channel in this process is clearly a very challenging endeavour. In the work described in this thesis, WZ production is searched for in a final state where the W decays leptonically to an electron-neutrino pair or a muon-neutrino pair, with associated production of a jet pair consistent with Z decays. A set of candidate events is obtained by applying appropriate cuts to the parameters of events collected by wide acceptance leptonic triggers. To improve the signal fraction of the selected events, an algorithm was used to tag b-flavored jets by means of their content of long lived b-hadrons and corrections were developed to the jet algorithm to improve the b-jet energy resolution for a better reconstruction of the Z mass. In order to sense the presence of a signal one needs to estimate the amount of background. The relative content of

  1. Tevatron operational experiences

    International Nuclear Information System (INIS)

    Norris, B.L.; Theilacker, J.C.

    1989-02-01

    Fermilabs superconducting accelerator, the Tevatron has been operational for nearly six years. The history of its operation is presented. Several long shutdowns for superconducting dipole repairs are discussed. The dominant factor influencing the repair was conductor motion which fatigued the cable in the magnet ends. Borescoping and x-raying techniques were used to determine which magnet ends required repair. Detailed downtime logs were kept for each of the running periods. A discussion of the sources of downtime and a comparison for different operating modes is presented

  2. The dijet invariant mass at the Tevatron Collider

    International Nuclear Information System (INIS)

    Giannetti, P.

    1990-01-01

    The differential cross section of the process p + pbar → jet + jet + X as a function of the dijet invariant mass has been measured with the CDF detector at a center of mass energy of 1.8 TeV at the Tevatron Collider in Fermilab. The present analysis is based on the sample of events collected in the 1988/89 run, amounting to a total integrated luminosity of 4.2 pb -1 . A comparison to leading order QCD and quark compositeness predictions is presented as well as a study of the sensitivity of the mass spectrum to the gluon radiation. 10 refs., 6 figs

  3. Successful observation of Schottky signals at the Tevatron collider

    International Nuclear Information System (INIS)

    Goldberg, D.A.; Lambertson, G.R.

    1989-08-01

    We have constructed a Schottky detector for the Tevatron collider in the form of a high-Q (∼5000) cavity which operates at roughly 2 GHz, well above the frequency at which the Tevatron's single-bunch frequency spectrum begins to roll off. Initial spectra obtained from the detector show clearly observable Schottky betatron lines, free of coherent contaminants; also seen are the ''common-mode'' longitudinal signals due to the offset of the beam from the detector center. The latter signals indicate that at 2 GHz, the coherent single-bunch spectrum from the detector is reduced by >80 dB; therefore, in normal collider operation, the Schottky betatron lines are >40 dB greater than their coherent counterparts. We describe how the data we have obtained give information on transverse and longitudinal emittances, synchrotron frequency, and betatron tunes, as well as reveal what may be previously unobserved phenomena. Space limitations restrict us to presenting only as much data as should be necessary to convince even the skeptical reader of the validity of the claim made in the paper's title. 3 refs., 2 figs

  4. Position sensitive silicon detectors inside the Tevatron collider

    International Nuclear Information System (INIS)

    Apollinari, G.; Bedeschi, F.; Bellettini, G.; Bosi, F.; Bosisio, L.; Cervelli, F.; Del Fabbro, R.; Dell'Orso, M.; Di Virgilio, A.; Focardi, E.; Giannetti, P.; Giorgi, M.; Menzione, A.; Ristori, L.; Scribano, A.; Sestini, P.; Stefanini, A.; Tonelli, G.; Zetti, F.; Bertolucci, S.; Cordelli, M.; Curatolo, M.; Dulach, B.; Esposito, B.; Giromini, P.; Miscetti, S.; Sansoni, A.

    1986-01-01

    Four position sensitive silicon detectors have been tested inside the Tevatron beam pipe at Fermilab. The system is the prototype of the small angle silicon spectrometer designed to study primarily p-anti p elastic and diffractive cross-sections at the Collider of Fermilab (CDF). Particles in the beam halo during p-anti p storage tests were used to study the performance of the detectors. Efficiency, linearity of response and spatial resolution are shown. Measurements performed at different distances from the beam axis have shown that the detectors could be operated at 8.5 mm from the beam with low rates and no disturbance to the circulating beams. This distance corresponds to about 11 times the standard half-width of the local beam envelope. The behaviour of the detectors with the radiation dose has also been investigated. (orig.)

  5. Electroweak and b-physics at the Tevatron collider

    International Nuclear Information System (INIS)

    Hara, K.

    1994-04-01

    The CDF and D0 experiments have collected integrated luminosities of 21 pb -1 and 16 pb -1 , respectively, in the 1992--1993 run (Run Ia) at the Fermilab Tevatron. Preliminary results on electroweak physics are reported from both experiments: the W mass, the leptonic branching ratios Τ(W → ell ν), the total W width, gauge boson couplings, W decay asymmetry and W'/Z' search. Preliminary new results on b physics are presented: B o - bar B o mixing from D0, and masses and lifetimes of B-mesons from CDF

  6. Tevatron

    International Nuclear Information System (INIS)

    Yamada, R.

    1978-01-01

    The main ongoing project at Fermilab is called the Tevatron, meaning 1,000 GeV in beam energy. The following is a list of major constituents for this project: Super Ring; upgrading external beam lines for experimental areas; electron cooling and antiproton acceleration; and colliding beam facility and its detectors. At present the Super Ring is being build and installed in the Main Ring tunnel. Its injection line is completed and under test. Modification of the tunnel for the Switchyard beam lines is finished. All magnets for the Electron Cooling Ring are installed. Protons are being injected into the cooling ring for study. The designs for the colliding beam facility and its detectors will be finalized shortly. These facilities and their development are described

  7. A realistic study on a forward geometry collider spectrometer: Performance of a typical fixed target spectrometer at the tevatron collider

    International Nuclear Information System (INIS)

    Lebrun, P.

    1993-01-01

    The performance of a forward heavy quark experiment at the collider can be estimated in a very realistic way, by simply carrying an existing fixed target spectrometer (E687) to the Tevatron Collider, changing only the beam/target configuration while keeping all reconstruction cuts identical to those used in reconstructing real charmed particles collected during the last fixed target run. Based on the golden - and typical - decay mode D → Kππ, it is found that the overall charm acceptance x efficiency is ∼ 3%, the 5-body B decay B → Dππ being about .6%. Such an experiment compares very favorably to E-831 and has real potential to study in great detail doubly suppressed Cabbibo decays and to observe D 0 - D 0 mixing. In addition, this exercise allows one to perform a rough but effective reality check on similar design (e.g. COBEX)

  8. Upgrading the Tevatron to a 1 TeV on 1 TeV pp collider

    International Nuclear Information System (INIS)

    Teng, L.C.

    1987-01-01

    This report describes the tasks necessary to change the Tevatron into a proton-proton collider. Also included in the discussion is an estimate of the cost to carry out the modification. 4 figs., 3 tabs

  9. Search for chargino and neutralino at Run II of the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Canepa, Anadi [Purdue Univ., West Lafayette, IN (United States)

    2006-08-01

    In this dissertation we present a search for the associated production of charginos and neutralinos, the supersymmetric partners of the Standard Model bosons. We analyze a data sample representing 745 pb-1 of integrated luminosity collected by the CDF experiment at the p$\\bar{p}$ Tevatron collider. We compare the Standard Model predictions with the observed data selecting events with three leptons and missing transverse energy. Finding no excess, we combine the results of our search with similar analyses carried out at CDF and set an upper limit on the chargino mass in SUSY scenarios.

  10. A new Tevatron Collider working point near the integer

    International Nuclear Information System (INIS)

    Johnson, R.P.; Zhang, P.

    1989-12-01

    It is well established that in hadron colliders the beam-beam interaction is more harmful in the presence of machine resonances of the form mν x + nν y = p, where |m| + |n| is the order of the resonance. Since the closest a resonance line can be to the integer stopband is 1/order, the closer the working point is to the integer, the fewer lower order resonances there are to enhance the beam-beam effects. A shift of the working point of the Tevatron from 19.4 to values near 19 and 20 has been studied. Problems with closed orbit control, dispersion matching, and matched low β insertions were considered. An excellent solution for the B0 insertion was found which has an improved β*. A new injection optics allows a transition to the low β optics which is much easier than the one now used. Results from the first machine studies demonstrate the ability to control the orbit with tunes of 19.03 horizontal and 20.03 vertical. Further studies require the activation of additional quadrupole compensation circuits. 4 refs. , 2 figs

  11. Status of the Tevatron CDF and D0 experiments

    International Nuclear Information System (INIS)

    Rolli, Simona

    2010-01-01

    The status of the Tevatron Collider is reviewed and highlights of the rich physics program carried out by the CDF and D0 experiments are presented. The Tevatron Collider has been performing remarkably well in the past few years and it is continuing to deliver record luminosity. The machine collides proton and anti-proton beams at an energy in the center of mass of 1.96 TeV, with average peak luminosity of 300E30 cm -2 s -1 . The total delivered luminosity is slightly above 9 fb -1 . The CDF and D0 experiments have been collecting data with an average efficiency of 90%, while the experiments have enjoyed an annual doubling of the integrated luminosity delivered and recorded. This has led to an avalanche of new results from areas as diverse as QCD, top, searches for new physics and the area of electroweak symmetry breaking with particular focus on direct searches for the Higgs boson. The physics reach of the Tevatron is built on a mountain of measurements that confirm the ability of the Tevatron collaborations to use their detectors to discover new particles. Each measurement is of itself a significant result. Measurements begin with the largest cross section processes, those of B physics, but move on to processes with small branching ratios and backgrounds that are hard to distinguish from the signal. The measurement of Bs oscillations demonstrates the performance of the silicon tracking and vertexing. Discovery of single top production, WZ production, and evidence for the ZZ production in both leptonic and now hadronic modes provide the final base camp from which the Higgs summit is in sight. Processes such as single top and ZZ act as important messengers heralding the impending arrival of the Higgs. This journey through lower and lower cross section processes represents our approach to provide convincing evidence of these processes, first as discovery then as measurements that constrain the Standard Model.

  12. Searches for Long-lived Particles at the Tevatron Collider

    International Nuclear Information System (INIS)

    Adams, T.; Florida State U.

    2008-01-01

    Several searches for long-lived particles have been performed using data from p(bar p) collisions from Run II at the Tevatron. In most cases, new analysis techniques have been developed to carry out each search and/or estimate the backgrounds. These searches expand the discovery potential of the CDF and D0 experiments to new physics that may have been missed by traditional search techniques. This review discusses searches for (1) neutral, long-lived particles decaying to muons, (2) massive, neutral, long-lived particles decaying to a photon and missing energy, (3) stopped gluinos, and (4) charged massive stable particles. It summarizes some of the theoretical and experimental motivations for such searches

  13. 2007 2008 ACADEMIC TRAINING PROGRAMME: Tevatron: The Cinderella Story or The Art Of Collider Commissioning

    CERN Multimedia

    2007-01-01

    LECTURE SERIES 01, 03, 04, 05 October 2007 Main Auditorium, bldg. 500 Tevatron: The Cinderella Story or The Art Of Collider Commissioning V. SHILTSEV / Fermi National Accelerator Laboraty, Batavia IL, USA The Tevatron Collider at Fermilab (Batavia, IL, USA) is the world’s highest energy particle collider at 1.8TeV c.m.e. The machine was a centerpiece of the US and world’s High Energy Physics for many years. Currently, the Tevatron is in the last years of its operation in so-called Run II which started 2001 and is tentatively scheduled to end in 2010. In this lecture series, we’ll try to learn from the exciting story of the Tevatron Collider Run II: the story of long preparations, great expectations, initial difficulties, years of "blood and sweat", continuous upgrades, exceeding its goals, high emotions, tune-up of accelerator organization for "combat fighting". The lectures will cover Introduction to the Tevatron, its history and Run II; "Plumbing"...

  14. Investigation of hadronic matter at the Fermilab Tevatron Collider: Technical progress report, 1986 October-1987 October

    International Nuclear Information System (INIS)

    Anderson, E.W.

    1987-01-01

    An investigation of hadronic matter at very high energy densities is reported. The present experiment, E-735, is a search for a deconfined quark-gluon plasma phase of matter expected to occur when temperatures of 240 MeV are achieved. Preliminary data have been obtained during the first operation of the Fermilab Tevatron Collider during the period January to May 1987. The collaboration is about to publish first results on the charged particle multiplicity and transverse momentum distributions. In addition, we have data on the particle identification of the produced secondaries. Both measurements are regarded on theoretical grounds to be sensitive indicators of the formation of a high temperature plasma. The capital project funded under this contract was a 240-element trigger hodoscope array, with associated electronics and monitor. The hodoscope was completed and performed to design expectations in the high-rate and high-radiation environment of the Collider. Scientific personnel supported under this contract were also responsible for the implementation of the data acquisition system used for E-735. Although the system underwent several unanticipated modifications in response to changing schedules, the required service was provided. Preparations are currently under way for the principal data acquisition during the spring of 1988. At that time we will have in place the central tracking chamber, and the remainder of the spectrometer chambers. Tests will also be made on backgrounds and detector materials appropriate to our proposal, P-787, to measure leptons and photons in the third Collider running period

  15. Search for new fermions ('Quirks') at the Fermilab Tevatron Collider

    Czech Academy of Sciences Publication Activity Database

    Abazov, V. M.; Abbott, B.; Abolins, M.; Kupčo, Alexander; Lokajíček, Miloš

    2010-01-01

    Roč. 105, č. 21 (2010), "211803-1"-"211803-6" ISSN 0031-9007 R&D Projects: GA MŠk LA08047; GA MŠk LC527 Institutional research plan: CEZ:AV0Z10100502 Keywords : missing-energy * transverse energy * D0 * Batavia TEVATRON Coll * interaction Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 7.621, year: 2010 http://arxiv.org/abs/arXiv:1008.3547

  16. 132 ns Bunch Spacing in the Tevatron Proton-Antiproton Collider

    International Nuclear Information System (INIS)

    Holmes, S.D.; Holt, J.; Johnstone, J.A.; Marriner, J.; Martens, M.; McGinnis, D.

    1994-12-01

    Following completion of the Fermilab Main Injector it is expected that the Tevatron proton-antiproton collider will be operating at a luminosity in excess of 5x10 3l cm -2 with 36 proton and antiproton bunches spaced at 396 nsec. At this luminosity, each of the experimental detectors will see approximately 1.3 interactions per crossing. Potential improvements to the collider low beta and rf systems could push the luminosity beyond 10x10 3l cm -2 sec -1 , resulting in more than three interactions per crossing if the bunch separation is left unchanged. This paper discusses issues related to moving to ∼100 bunch operation, with bunch spacings of 132 nsec, in the Tevatron. Specific scenarios and associated hardware requirements are described

  17. Advanced forward calorimetry for the SSC and TeVatron collider

    International Nuclear Information System (INIS)

    DiBitonto, D.; Van Peteghem, P.M.; Geiger, R.L.; McIntyre, P.M.; Pang, Y.; Thane, J.M.; White, J.T.; Atac, M.

    1989-01-01

    We describe a project to develop fast, radiation hardened forward calorimetry for the SSC and TeVatron collider. Detector technologies discussed are based on gas and warm liquid media. In particular, we present the design of an ultrasensitive hybrid charge preamplifier for liquid technology capable of operating at 0.1-1 GHz. The actual detector bandwidth will depend on the choice of detector media used and the maximum allowable operating high voltage. (orig.)

  18. Physics at the Tevatron

    CERN Multimedia

    CERN. Geneva

    2006-01-01

    Physics Results from the Tevatron : The Tevatron proton-antiproton collider at Fermilab in the US is currently the world's highest energy collider. At the experiments CDF and D0 a broad physics programme is being pursued, ranging from flavour physics via electroweak precision measurements to searches for the Higgs boson and new particles beyond the Standard Model. In my lecture I will describe some of the highlight measurements in the flavour, electroweak and searches sectors, and the experimental techniques that are used.

  19. Nonlinear dynamics experiment in the Tevatron

    International Nuclear Information System (INIS)

    Merminga, N.; Edwards, D.; Finley, D.

    1989-01-01

    Results of the continuing analysis of the nonlinear dynamics experiment E778 are presented. Sixteen special sextupoles introduced nonlinearities in the Tevatron. 'Smear,' which is one of the parameters used to quantify the degree of nonlinearity, was extracted from the data and compared with calculation. Injection efficiency in the presence of nonlinearities was studied. Measurements of the dynamic aperture were performed. The final results in one degree of freedom of the smear, the injection efficiency and the dynamic aperture are presented. Particles captured on nonlinear resonance islands were directly observed and measurements were performed. The capture efficiency was extracted from the data and compared with prediction. The influence of tune modulation on the stability of these islands was investigated. Plans for future measurements are discussed. 4 refs., 6 figs

  20. Searches for the Standard Model Higgs boson at the Tevatron collider

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Wade C. [Michigan State Univ., East Lansing, MI (United States). Dept. of Physics and Astronomy; Junk, Thomas R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2016-01-01

    +τ-, H → γγ, and H → ZZ. This chapter summarizes the search methods and the results of the Higgs boson search at the Tevatron. The increased sophistication of the analysis techniques as the collider run progressed is discussed, covering the strategies used over time to improve the sensitivity and breadth of the analyses. Using the full Tevatron data sample for both experiments, the combined Higgs search in all channels observes an excess consistent with the predicted SM Higgs boson signal with mass of 125 GeV, with a significance of 3.0 standard deviations above the background prediction.

  1. Production measurements on the quadrupole correctors for the new Low- Beta System for the Tevatron Collider

    International Nuclear Information System (INIS)

    Mokhtarani, A.; Brown, B.C.; Hanft, R.; Oleck, A.R.; Peterson, T.; Turkot, F.

    1991-05-01

    Each of the Low Beta Systems for the Tevatron Collider requires 12 spool pieces; eight of the spool pieces contain superconducting quadrupoles as part of the low beta insertion as well as standard correction magnets. The remaining four provide correction magnets, beam position monitors, and current feeds for the neighboring low beta main quadrupoles. Thirty-two of these new spools have been fabricated. We describe here the mechanical, cryogenic and magnetic properties of these new spools as determined in the production test and measurement activities. 8 refs., 7 figs., 1 tab

  2. Considerations of bunch-spacing options for multi-bunch operation of the Tevatron Collider

    International Nuclear Information System (INIS)

    Dugan, G.

    1989-01-01

    This discussion will consider a number of points relevant to limitations, advantages and disadvantages of various arrangements of bunches in the Tevatron proton-antiproton collider. The considerations discussed here will be limited to: (a) bunch spacing symmetry and relation to the relative luminosity at B0 and D0 and the beam-beam interaction with separated beams; (b) bunch spacing constraints imposed by Main Ring RF coalescing and the optics of beam separation at B0 and D0; and (c) bunch spacing constraints imposed by injection and abort kicker timing requirements, and by the Antiproton Source RF unstacking process. 20 figs., 17 tabs

  3. Calculation of integrated luminosity for beams stored in the Tevatron collider

    International Nuclear Information System (INIS)

    Finley, D.A.

    1989-01-01

    A model for calculating the integrated luminosity of beams stored in the Tevatron collider will be presented. The model determines the instantaneous luminosity by calculating the overlap integral of bunched beams passing through the interaction region. The calculation accounts for the variation in beam size due to the beta functions and also for effects due to finite longitudinal emittance and non-zero dispersion in the interaction region. The integrated luminosity is calculated for the beams as they evolve due to processes including collisions and intrabeam scattering. The model has been applied to both the extant and upgraded Tevatron collider, but is not limited to them. The original motivation for developing the computer model was to determine the reduction in luminosity due to beams with non-zero longitudinal emittances. There are two effects: the transverse beam size is increased where the dispersion is non-zero; the finite length of the beam bunch combined with an increasing β function results in an increased transverse beam size at the ends of the bunch. The derivation of a sufficiently useful analytic expression for the luminosity proved to be intractable. Instead, a numerical integration computer program was developed to calculate the luminosity in the presence of a finite longitudinal emittance. The program was then expanded into a model which allows the luminosity to vary due to changes in emittances and reduction in bunch intensities. At that point, it was not difficult to calculate the integrated luminosity. 5 refs., 2 figs., 4 tabs

  4. Recent QCD results from the Tevatron bar pp collider at √s = 1.8 TeV

    International Nuclear Information System (INIS)

    Yu, Jaehoon

    1994-06-01

    Abstract: Recent results of QCD studies from the CDF and D0 experiments at the Tevatron bar pp collider at Fermilab are presented. The inclusive jet cross section, the internal structure of jets, di-jet angular distributions, di-jet triple differential cross sections, and properties of multi-jet final states are studied and compared with NLO QCD predictions. The comparisons show good agreement between theoretical predictions and the experimental data in general. Some systematic disagreement between LO predictions and the data are observed in di-jet triple differential cross sections. Results of a rapidity gap study are also presented together with an upper limit on the gap fraction. In addition, the inclusive photon cross section and the di-photon cross sections are presented and compared with NLO QCD predictions

  5. Linear beam-beam tune shift calculations for the Tevatron Collider

    International Nuclear Information System (INIS)

    Johnson, D.

    1989-01-01

    A realistic estimate of the linear beam-beam tune shift is necessary for the selection of an optimum working point in the tune diagram. Estimates of the beam-beam tune shift using the ''Round Beam Approximation'' (RBA) have over estimated the tune shift for the Tevatron. For a hadron machine with unequal lattice functions and beam sizes, an explicit calculation using the beam size at the crossings is required. Calculations for various Tevatron lattices used in Collider operation are presented. Comparisons between the RBA and the explicit calculation, for elliptical beams, are presented. This paper discusses the calculation of the linear tune shift using the program SYNCH. Selection of a working point is discussed. The magnitude of the tune shift is influenced by the choice of crossing points in the lattice as determined by the pbar ''cogging effects''. Also discussed is current cogging procedures and presents results of calculations for tune shifts at various crossing points in the lattice. Finally, a comparison of early pbar tune measurements with the present linear tune shift calculations is presented. 17 refs., 13 figs., 3 tabs

  6. Search for New Physics at the Fermilab Tevatron p(bar p) Collider

    International Nuclear Information System (INIS)

    Rolli, Simona

    2011-01-01

    We report on selected recent results from the CDF and D0 experiments on searches for physics beyond the Standard Model using data from the Tevatron collider running p(bar p) collisions at √s = 1960 GeV. Over the past decades the Standard Model (SM) of particle physics has been surprisingly successful. Although the precision of experimental tests improved by orders of magnitude no significant deviation from the SM predictions has been observed so far. Still, there are many questions that the Standard Model does not answer and problems it can not solve. Among the most important ones are the origin of the electro-weak symmetry breaking, hierarchy of scales, unification of fundamental forces and the nature of gravity. Recent cosmological observations indicates that the SM particles only account for 4% of the matter of the Universe. Many extensions of the SM (Beyond the Standard Model, BSM) have been proposed to make the theory more complete and solve some of the above puzzles. Some of these extension includes SuperSymmetry (SUSY), Grand Unification Theory (GUT) and Extra Dimensions. At CDF and D0 we search for evidence of such processes in proton-antiproton collisions at √(s) = 1960 GeV. The phenomenology of these models is very rich, although the cross sections for most of these exotic processes is often very small compared to those of SM processes at hadron colliders. It is then necessary to devise analysis strategies that would allow to disentangle the small interesting signals, often buried under heavy instrumental and/or physics background. Two main approaches to search for physics beyond the Standard Model are used in a complementary fashion: model-based analyses and signature based studies. In the more traditional model-driven approach, one picks a favorite theoretical model and/or a process, and the best signature is chosen. The selection cuts are optimized based on acceptance studies performed using simulated signal events. The expected background is

  7. Radiation hard silicon microstrip detectors for Tevatron experiments

    International Nuclear Information System (INIS)

    Korjenevski, Sergey

    2004-01-01

    The Silicon Microstrip Tracking detectors at the CDF and D0 experiments have now been operating for almost three years at Fermilab. These detectors were designed originally for an integrated luminosity of 2fb -1 . As the expected luminosity for Run IIb at the Tevatron collider was initially envisioned to reach 15fb -1 , radiation tolerances of both devices were revisited, culminating in proposals for new systems. With reduced expectations for total luminosity at ∼6fb -1 , the full detector-replacement projects were terminated. The CDF detector is expected nevertheless to cope efficiently with the lower anticipated dose, however, the D0 experiment is planning a smaller-scale project: a Layer-0 (L0) upgrade of the silicon tracker (D0SMT). The new device will fit between the beam line and the inner layer of the current Tracker. Built of single-sided sensors, this upgrade is expected to perform well in the harsh radiation environment, and be able to withstand an integrated luminosity of 15fb -1 . Prototypes of Run IIb sensors were irradiated using 10MeV protons at the tandem Van de Graaff at the James R. McDonald Laboratory at Kansas State University. A fit to the 10MeV proton data yields a damage parameter αp=11x10-17Acm. This is consistent with results from RD48 (αp=9.9x10-17Acm). The scaling of damage to 1MeV neutron fluence uses a hardness factor (κ) derived from the non-ionizing components of the energy loss (NEIL). NEIL predicts a hardness factor of 3.87 for 10MeV protons. We obtained an experimental value of this factor of 2.54, or 34% smaller than scaling predictions from NEIL

  8. Investigation of hadronic matter at the Fermilab Tevatron Collider. Technical progress report

    International Nuclear Information System (INIS)

    Anderson, E.W.

    1985-01-01

    Hadronic matter at very high energy densities is investigated. The present experimental effort is focused on a search for a new quark-gluon plasma phase expected to occur when temperatures of 240 MeV are achieved. Instrumentation for several unique signatures is being developed to exploit the first operation of the Fermilab Tevatron Collider in 1986. The capital projects funded under this contract are a 240-element trigger hodoscope array, and in phase II a segmented photon detector. For these projects $172K are requested for the period 1986 February 1 through 1987 January 31 to complete the trigger hodoscope, and $160K for the period 1987 February 1 through 1988 January 31 to construct a portion of the photon detector. These figures are as presented in the original proposal. Due to budget constraints on the Fermilab experimental support program, we will not be able to receive the full complement of necessary electronics from the Fermilab PREP pool in the required period. Consequently, an additional $35K is requested for the period 1986 February 1 through 1987 January 31 for a portion of the electronics for the 240-channel trigger hodoscope. For the same reasons, Fermilab cannot provide the required magnet on schedule; a one year delay is proposed. As this would seriously impact our physics goals, the collaboration is attempting to fund the magnet without delay through the universities. Efforts to date have concentrated on the design and testing of the hodoscope. Extensive measurements on the radiation levels and effects during the various accelerator cycles have been made. These data are essential to the proper selection of scintillator and design of electronics. These tests are now complete, and final construction is beginning. 11 refs

  9. Tevatron physics results

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    I will summarize the physics results from the Tevatron experiments with particular emphasis on the experimental methods used in different kinds of analysis. In particular, the Tevatron is a proton-antiproton collider that has now accumulated more than 2 fb^-1 of luminosity in the two experiments, called CDF and D0. In this lecture I will review the results on inclusive productions of jets, W- and Z-bosons, the results in the flavor sector, the measurements of top production, searches for Higgs boson production and searches for physics beyond the Standard Model. In each case I will explain the basic experimental concepts and methods needed for making the measurement.

  10. Recent results from the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Vellidis, Costas; Bravina, L.; Foka, Y.; Kabana, S.

    2015-01-01

    The Tevatron p$\\bar{p}$ collider was shut down in 2011, after 10 years of high performance operation at a center-of-mass energy √s = 1.96 TeV in Run II. The two experiments, CDF and DZero, continue to analyze the collected data, aiming to extract all possible information regarding studies of the standard model and searches for new physics. A short review of some of the recent measurements at the Tevatron, and of the impact of the Tevatron program to high energy physics, is presented.

  11. Tevatron as an SSC prototype; experience versus predictions

    International Nuclear Information System (INIS)

    Johnson, R.P.

    1984-01-01

    Early machine experiments on the Tevatron which are relevant to the SSC are discussed. Despite the preliminary nature of the data, there have been some interesting observations which may influence the design of the SSC. In particular, comparisons of measured betatron tunes, chromaticities, and resonance line widths with those predicted from computer simulations using magnetic field measurements have been made; the predictability for low order phenomena seems acceptable. Coasting beam studies indicate long lifetime and lack of strong resonance driving terms. Low energy studies of beam behavior indicate that a dynamic range of a factor of 15 from injection to operation energy should be possible

  12. Combination of measurements of the top-quark pair production cross section from the Tevatron Collider

    Czech Academy of Sciences Publication Activity Database

    Aaltonen, T.; Abazov, V. M.; Abbott, B.; Kupčo, Alexander; Lokajíček, Miloš; Lysák, Roman

    2014-01-01

    Roč. 89, č. 7 (2014), "072001-1"-"072001-16" ISSN 1550-7998 R&D Projects: GA MŠk(CZ) LG12006 Institutional support: RVO:68378271 Keywords : Batavia TEVATRON Coll * quantum chromodynamics * perturbation theory * statistical analysis * CDF * DZERO Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.643, year: 2014

  13. Search for the Higgs-Boson with the CDF experiment at Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Hennecke, Martin [Univ. of Karlsruhe (Germany)

    2005-06-10

    A search for a low-mass SM Higgs-Boson in the channel WH → lvb$\\bar{b}$ has been performed using neural networks. The data were taken by the CDF experiment at the p-$\\bar{p}$ collider Tevatron from 2000-2003, corresponding to in integrated luminosity of Lint = 162 pb-1 at a CMS-energy of √s = 1.96 TeV. 95% confidence level upper limits are set on σ × BR, the product of the production cross section times the Branching ratio, as a function of the Higgs boson mass. Cross sections above 8 pb are excluded for six different Higgs masses between 110 GeV/c2 and 150 GeV/c2. The required integrated luminosities for a 95% C.L. exclusion, 3σ evidence and 5σ discovery are calculated.

  14. A search for the Higgs boson in the zh channel with the D0 detector at the Fermilab Tevatron collider

    Energy Technology Data Exchange (ETDEWEB)

    Heinmiller, James Matthew [Univ. of Illinois, Chicago, IL (United States)

    2006-01-01

    This analysis describes a search for a standard model Higgs boson produced in association with a Z boson through the decay mode ZH → e+e-b$\\bar{b}$ in p$\\bar{p}$ collisions at √s = 1.96 TeV at the Fermilab Tevatron Collider. The data sample used in this analysis corresponds to 452 pb-1 of integrated luminosity accumulated with the D0 detector. Agreement between data and standard model predictions is observed. A 95% confidence level upper exclusion limit for the σ(p$\\bar{p}$ → ZH) x BR(H → b$\\bar{b}$) channel is set between 3.2-8.2 pb for Higgs masses of 105 to 145 GeV.

  15. A search for the Higgs boson in the zh channel with the D0 detector at the Fermilab Tevatron collider

    International Nuclear Information System (INIS)

    Heinmiller, James Matthew; Illinois U., Chicago

    2006-01-01

    This analysis describes a search for a standard model Higgs boson produced in association with a Z boson through the decay mode ZH → e + e - b(bar b) in p(bar p) collisions at √s = 1.96 TeV at the Fermilab Tevatron Collider. The data sample used in this analysis corresponds to 452 pb -1 of integrated luminosity accumulated with the D(null) detector. Agreement between data and standard model predictions is observed. A 95% confidence level upper exclusion limit for the σ(p(bar p) → ZH) x BR(H → b(bar b)) channel is set between 3.2-8.2 pb for Higgs masses of 105 to 145 GeV

  16. Recent Results from the Tevatron

    International Nuclear Information System (INIS)

    Demorden, L.

    1998-06-01

    We review recent results from fixed-target and collider experiments at the Fermilab Tevatron. Among the topics discussed are jet production rates, α S measurements, the anti d/anti u ratio in the proton sea, diffraction, heavy quark physics and leptoquark searches

  17. B physics at the Tevatron

    International Nuclear Information System (INIS)

    Morello, M.J.

    2011-01-01

    The CDF and DO experiments at the Tevatron pp collider established that extensive and detailed exploration of the b-quark dynamics is possible in hadron collisions, with results competitive and supplementary to those from e + e - colliders. This provides a rich, and highly rewarding program that is currently reaching full maturity. I report a few recent world-leading results on rare decays, CP-violation in B 0 s s mixing, b→s penguin decays, and charm physics.

  18. Complementarity of the CERN LEP collider, the Fermilab Tevatron, and the CERN LHC in the search for a light MSSM Higgs boson

    CERN Document Server

    Carena, M S; Wagner, C E M

    2000-01-01

    We study the discovery potential of the CERN LHC, Fermilab Tevatron and CERN LEP colliders in the search for the neutral CP-even Higgs boson of the MSSM which couples to the weak gauge bosons with a strength close to the standard model one and, hence, plays a relevant role in the mechanism of electroweak symmetry breaking. We place special emphasis on the radiative effects which influence the discovery reach of these colliders. We concentrate on the Vbb channel, with V=Z or W, and on the channels with diphoton final states, which are the dominant ones for the search for a light standard model Higgs boson at LEP or Tevatron and LHC, respectively. By analyzing the parameters of the MSSM for which the searches become difficult at one or more of these three colliders, we demonstrate their complementarity in the search for a light Higgs boson which plays a relevant role in the mechanism of electroweak symmetry breaking. (32 refs).

  19. Microwave Schottky diagnostic systems for the Fermilab Tevatron, Recycler, and CERN Large Hadron Collider

    Directory of Open Access Journals (Sweden)

    Ralph J. Pasquinelli

    2011-07-01

    Full Text Available A means for noninvasive measurement of transverse and longitudinal characteristics of bunched beams in synchrotrons has been developed based on high sensitivity slotted waveguide pickups. The pickups allow for bandwidths exceeding hundreds of MHz while maintaining good beam sensitivity characteristics. Wide bandwidth is essential to allow bunch-by-bunch measurements by means of a fast gate. The Schottky detector system is installed and successfully commissioned in the Fermilab Tevatron, Recycler and CERN LHC synchrotrons. Measurement capabilities include tune, chromaticity, and momentum spread of single or multiple beam bunches in any combination. With appropriate calibrations, emittance can also be measured by integrating the area under the incoherent tune sidebands.

  20. First observation of vector boson pairs in a hadronic final state at the tevatron collider.

    Science.gov (United States)

    Aaltonen, T; Adelman, J; Akimoto, T; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Beringer, J; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burke, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Calancha, C; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Chwalek, T; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cordelli, M; Cortiana, G; Cox, C A; Cox, D J; Crescioli, F; Almenar, C Cuenca; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lorenzo, G; Dell'Orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Derwent, P F; Di Canto, A; di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Elagin, A; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Garosi, P; Genser, K; Gerberich, H; Gerdes, D; Gessler, A; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Han, B-Y; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Hussein, M; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Ketchum, W; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhr, T; Kulkarni, N P; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, E; Lee, H S; Lee, S W; Leone, S; Lewis, J D; Lin, C-S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lucchesi, D; Luci, C; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Merkel, P; Mesropian, C; Miao, T; Miladinovic, N; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moggi, N; Mondragon, M N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Fernandez, P Movilla; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Nett, J; Neu, C; Neubauer, M S; Neubauer, S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Osterberg, K; Griso, S Pagan; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Peiffer, T; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Renton, P; Renz, M; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Rutherford, B; Saarikko, H; Safonov, A; Sakumoto, W K; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shon, Y; Shreyber, I; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soha, A; Somalwar, S; Sorin, V; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Suh, J S; Sukhanov, A; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Ttito-Guzmán, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Tourneur, S; Trovato, M; Tsai, S-Y; Tu, Y; Turini, N; Ukegawa, F; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wagner-Kuhr, J; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Weinelt, J; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Würthwein, F; Xie, S; Yagil, A; Yamamoto, K; Yamaoka, J; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zhang, X; Zheng, Y; Zucchelli, S

    2009-08-28

    We present the first observation in hadronic collisions of the electroweak production of vector boson pairs (VV, V = W, Z) where one boson decays to a dijet final state. The data correspond to 3.5 fb(-1) of integrated luminosity of pp[over ] collisions at sqrt[s] = 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron. We observe 1516 + or - 239(stat) + or - 144(syst) diboson candidate events and measure a cross section sigma(pp[over ]-->VV + X) of 18.0 + or - 2.8(stat) + or - 2.4(syst) + or -1.1(lumi) pb, in agreement with the expectations of the standard model.

  1. Proposed Fermilab fixed target experiment: Kaons at the Tevatron

    International Nuclear Information System (INIS)

    1993-12-01

    The US Department of Energy (DOE) has prepared an Environmental Assessment (EA), DOE/EA-0898, evaluating the impacts associated with the proposed fixed target experiment at the Fermi National Accelerator Laboratory (Femilab) in Batavia, Illinois, known as Kaons at the Tevatron (KTeV). The proposed KTeV project includes reconfiguration of an existing target station, enhancement of an existing beam transport system connected to existing utility facilities, and construction of a new experimental detector hall area. The study of the K meson, a type of subatomic particle, has been going on at Fermilab for 20 years. The proposed KTEV project advances the search for the origins of a violation of a fundamental symmetry of nature called charge parity (CP) violation. Based on the analysis in the EA, the DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement is not required

  2. Particle physics experiments at high energy colliders

    International Nuclear Information System (INIS)

    Hauptman, John

    2011-01-01

    Written by one of the detector developers for the International Linear Collider, this is the first textbook for graduate students dedicated to the complexities and the simplicities of high energy collider detectors. It is intended as a specialized reference for a standard course in particle physics, and as a principal text for a special topics course focused on large collider experiments. Equally useful as a general guide for physicists designing big detectors. (orig.)

  3. Supersymmetry at the Tevatron?

    International Nuclear Information System (INIS)

    Lammel, S.

    1998-02-01

    These lectures contain an introduction to the search for supersymmetry at hadron colliders. The Tevatron is one of high-energy physics most sophisticated tools. The high center-of-mass energy of its proton-antiproton collisions makes it an ideal place to search for physics beyond the Standard Model, such as supersymmetry. Two experiments, CDF and D0, completed a long data taking period in summer of 1995, yielding over 100 pb -1 of proton-antiproton interactions. The data recorded by the experiments are still being analyzed. The lectures outline the strategies in the search for supersymmetry at the Tevatron and examine the major analyses in detail. Results obtained by the two experiments are included where available

  4. Regge pole plus cut model for proton-antiproton elastic scattering at collider and tevatron energies

    International Nuclear Information System (INIS)

    Aleem, Fazal; Saleem, Mohammad

    1988-01-01

    The Regge pole plus cut model has been used to explain the data at the collider energies √=546 and 630 GeV and the most recent differential cross-section results at √=1.8 TeV. Predictions of the model at 1.8 and 40 TeV are compared with those of Bourrely et al. (1984). (author). 22 refs., 7 figs

  5. Recent results from E-735 at the Fermilab tevatron proton-antiproton collider with √s=1.8 TeV

    International Nuclear Information System (INIS)

    Alexopoulos, T.; Erwin, A.; Findeisen, C.; Nelson, K.; Thompson, M.; Banerjee, S.; Beery, P.D.; Biswas, N.N.; DeBonte, R.; Kenney, V.P.; LoSecco, J.M.; McManus, A.P.; Piekarz, J.; Stampke, S.R.; Carter, T.; Goshaw, A.T.; Oh, S.A.; Walker, W.D.; Wesson, D.K.

    1989-01-01

    E-735 is searching for signs of the quark-gluon-plasma phase transition in minimum bias proton-antiproton events. Results from the 1987 run at the Tevatron Collider at √s=1.8 TeV are presented. Included are distributions of the average p t versus multiplicity dependence for charged particles, and preliminary particle identification analysis using time of flight. (orig.)

  6. Observation of Exclusive Dijet Production at the Fermilab Tevatron p-pbar Collider

    OpenAIRE

    CDF Collaboration; Aaltonen, T.

    2007-01-01

    We present the first observation and cross section measurement of exclusive dijet production in pbar-p interactions, pbar + p --> pbar + dijet + p. Using a data sample of 310 pb-1 collected by the Run II Collider Detector at Fermilab at sqrt{s}=1.96 TeV, exclusive cross sections for events with two jets of transverse energy ET >= 10 GeV have been measured as a function of minimum ET(jet). The exclusive signal is extracted from fits to data distributions based on Monte Carlo simulations of exp...

  7. Observation of exclusive dijet production at the Fermilab Tevatron pp collider

    International Nuclear Information System (INIS)

    Aaltonen, T.; Maki, T.; Mehtala, P.; Orava, R.; Osterberg, K.; Saarikko, H.; Remortel, N. van; Adelman, J.; Brubaker, E.; Fedorko, W. T.; Grosso-Pilcher, C.; Kim, Y. K.; Kwang, S.; Levy, S.; Paramonov, A. A.; Schmidt, M. A.; Shochet, M.; Wolfe, C.; Yang, U. K.; Yorita, K.

    2008-01-01

    We present the first observation and cross section measurement of exclusive dijet production in pp interactions, pp→p+dijet+p. Using a data sample of 310 pb -1 collected by the Run II Collider Detector at Fermilab at √(s)=1.96 TeV, exclusive cross sections for events with two jets of transverse energy E T jet ≥10 GeV have been measured as a function of minimum E T jet . The exclusive signal is extracted from fits to data distributions based on Monte Carlo simulations of expected dijet signal and background shapes. The simulated background distribution shapes are checked in a study of a largely independent data sample of 200 pb -1 of b-tagged jet events, where exclusive dijet production is expected to be suppressed by the J z =0 total angular momentum selection rule. Results obtained are compared with theoretical expectations, and implications for exclusive Higgs boson production at the pp Large Hadron Collider at √(s)=14 TeV are discussed.

  8. Observation of Exclusive Dijet Production at the Fermilab Tevatron p-pbar Collider

    International Nuclear Information System (INIS)

    Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, M.G.; Gonzalez, B. Alvarez; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Aoki, M.

    2007-01-01

    The authors present the first observation and cross section measurement of exclusive dijet production in (bar p)p interactions, (bar p)p → (bar p) + dijet + p. Using a data sample of 310 pb -1 collected by the Run II Collider Detector at Fermilab at √s = 1.96 TeV, exclusive cross sections for events with two jets of transverse energy E T jet (ge) 10 GeV have been measured as a function of minimum E T jet . The exclusive signal is extracted from fits to data distributions based on Monte Carlo simulations of expected dijet signal and background shapes. The simulated background distribution shapes are checked in a study of a largely independent data sample of 200 pb -1 of b-tagged jet events, where exclusive dijet production is expected to be suppressed by the J z = 0 total angular momentum selection rule. Results obtained are compared with theoretical expectations, and implications for exclusive Higgs boson production at the pp Large Hadron Collider at √s = 14 TeV are discussed

  9. Experience with the new reverse injection scheme in the Tevatron

    International Nuclear Information System (INIS)

    Saritepe, S.; Goderre, G.; Annala, G.; Hanna, B.; Braun, A.

    1993-01-01

    In the new injection scenario the antiproton beam is injected onto a helical Tevatron orbit to avoid the detrimental effects of the beam-beam interaction at 150 GeV. The new scenario required changes in the tuning procedures. Antiprotons are too precious to be used for tuning, therefore the antiproton injection line has to be tuned with protons by reverse injecting them from the Tevatron into the Main Ring. Previously, the reverse injection was performed in one supercycle. One batch of uncoalesced bunches was injected into the Tevatron and ejected after 40 seconds. The orbit closure was performed in the Main Ring. In the new scheme the lambertson magnets have to be moved, separator polarities have to be switched, activities that cannot be completed in one supercycle. Therefore, the reverse injection sequence was changed. This involved the redefinition of TVBS (Tevatron Beam Synchronized Clock) event $D8 as MRBS (Main Ring Beam Synchronized Clock) $D8 thus making it possible to inject 6 proton batches (or coalesced bunches) and eject them one at a time on command, performing orbit closure each time in the Main Ring

  10. Achievements and Lessons from Tevatron

    International Nuclear Information System (INIS)

    Shiltsev, V.

    2011-01-01

    For almost a quarter of a century, the Tevatron proton-antiproton collider was the centerpiece of the world's high energy physics program - beginning operation in December of 1985 until it was overtaken by LHC in 2011. The aim of the this unique scientific instrument was to explore the elementary particle physics reactions with center of mass collision energies of up to 1.96 TeV. The initial design luminosity of the Tevatron was 10 30 cm -2 s -1 , however as a result of two decades of upgrades, the accelerator has been able to deliver 430 times higher luminosities to each of two high luminosity experiments, CDF and D0. Tevatron will be shut off September 30, 2011. The collider was arguably one of the most complex research instruments ever to reach the operation stage and is widely recognized for many technological breakthroughs and numerous physics discoveries. Below we briefly present the history of the Tevatron, major advances in accelerator physics, and technology implemented during the long quest for better and better performance. We also discuss some lessons learned from our experience.

  11. Electroweak results from the tevatron

    International Nuclear Information System (INIS)

    Wood, D.

    1997-01-01

    Electroweak results are presented from the CDF and DO experiments based on data collected in recent runs of the Fermilab Tevatron Collider. The measurements include the mass and width of the W boson, the production cross sections of the W and Z bosons, and the W charge asymmetry. Additional results come from studies of events with pairs of electroweak gauge bosons and include limits on anomalous couplings

  12. Electroweak results from the tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Wood, D. [Fermi National Accelerator Laboratory, Batavia, IL (United States)

    1997-01-01

    Electroweak results are presented from the CDF and DO experiments based on data collected in recent runs of the Fermilab Tevatron Collider. The measurements include the mass and width of the W boson, the production cross sections of the W and Z bosons, and the W charge asymmetry. Additional results come from studies of events with pairs of electroweak gauge bosons and include limits on anomalous couplings.

  13. Search for squarks and gluinos in the D0 experiment of the Run-II-a at the Tevatron

    International Nuclear Information System (INIS)

    Verdier, P.

    2007-11-01

    The D0 experiment is recording pp-bar collisions at a center-of-mass energy of 1.96 TeV since the beginning of the Run II-a of the Tevatron in 2001. The design of processor boards for the D0 level 2 trigger system is first presented. Those boards were installed in 2003, and they have been working perfectly since that date. Performances of missing transverse energy (/ ET ) reconstruction are then described. This quantity is important at hadron colliders especially for new particles searches. Finally, squarks and gluinos, supersymmetric partners of quarks and gluons, could be the most copiously produced supersymmetric particles at the Tevatron, if they are sufficiently light. Those particles were searched for in 0.96 fb -1 of data recorded by D0 during the Run II-a. The final state consists of jets and missing transverse energy. The numbers of observed events are in good agreement with the Standard Model predictions. Lower mass limits at 95 % confidence level are obtained on the squark and gluino masses in the framework of the mSUGRA model. Contributions to other D0 data analyses are also shortly described. Those analyses are the search for first generation leptoquarks and the search for squarks in jets+τ(s)+E T events. The possibility to constrain a 'Little Higgs' model using the results of the jets+E T searches is then discussed. (author)

  14. Baryon number violation and particle collider experiments

    International Nuclear Information System (INIS)

    Klinkhamer, F.R.; Nationaal Inst. voor Kernfysica en Hoge-Energiefysica

    1992-09-01

    Baryon number non-conservation, due to non-perturbative effects (sphalerons) in the standard model, may have been important in the early Universe. In this paper the possibility is discussed that similar effects could show up at future particle collider experiments. (author). 16 refs.; 3 figs

  15. Experiments at future hadron colliders

    International Nuclear Information System (INIS)

    Paige, F.E.

    1991-01-01

    This report summarizes signatures and backgrounds for processes in high-energy hadronic collisions, particularly at the SSC. It includes both signatures for new particles -- t quarks, Higgs bosons, new Ζ' bosons, supersymmetric particles, and technicolor particles -- and other experiments which might be done. It is based on the 1990 Snowmass Workshop and on work contained in the Expressions of Interest submitted to the SSC. 46 refs., 19 figs., 1 tab

  16. Coupling in the Tevatron

    International Nuclear Information System (INIS)

    Gelfand, N.M.

    1994-12-01

    The performance of the Fermilab Tevatron Collider at the commencement of run Ib was far below expectations. After a frustrating period of several months, a low-β quad downstream of the interaction point at B0 was found to be rolled. This rolled quadrupole coupled the horizontal and vertical motion of the Tevatron beams. It also made matching the beam from the Main Ring to the Tevatron impossible, resulting in emittance blow up on injection. The net result of the roll was a significant reduction in the Tevatron luminosity. When the roll in the quadrupole was corrected the performance of the Tevatron improved dramatically. This note will discuss the experimental data indicating the presence of coupling and subsequent calculations which show how coupling an affect the luminosity. It is not intended to exhaust a discussion of coupling, which hopefully will be understood well enough to be discussed in a subsequent note

  17. Tevatron-for-LHC Report of the QCD Working Group

    Energy Technology Data Exchange (ETDEWEB)

    Albrow, Michael G.; Begel, M.; Bourilkov, D.; Campanelli, M.; Chlebana, F.; De Roeck, A.; Dittmann, J.R.; Ellis, S.D.; Field, B.; Field, R.; Gallinaro, M.; /Fermilab

    2006-10-01

    The experiments at Run 2 of the Tevatron have each accumulated over 1 fb{sup -1} of high-transverse momentum data. Such a dataset allows for the first precision (i.e. comparisons between theory and experiment at the few percent level) tests of QCD at a hadron collider. While the Large Hadron Collider has been designed as a discovery machine, basic QCD analyses will still need to be performed to understand the working environment. The Tevatron-for-LHC workshop was conceived as a communication link to pass on the expertise of the Tevatron and to test new analysis ideas coming from the LHC community. The TeV4LHC QCD Working Group focused on important aspects of QCD at hadron colliders: jet definitions, extraction and use of Parton Distribution Functions, the underlying event, Monte Carlo tunes, and diffractive physics. This report summarizes some of the results achieved during this workshop.

  18. Top and Electroweak Measurements at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Bartos, P. [Comenius U.

    2016-01-01

    In this report, we summarize the latest results of the top-quark mass and electroweak measurements from the Tevatron. Since the world combination of top-quark mass measurements was done, CDF and D0 experiments improved the precision of several results. Some of them reach the relative precition below 1% for a single measurement. From the electroweak results, we report on the WW and WZ production cross section, measurements of the weak mixing angle and indirect measurements of W boson mass. The Tevatron results of the weak mixing angle are still the most precise ones of hadron colliders.

  19. Calorimetry for the Future Circular Collider experiments

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00510572; Kisiel, Adam

    2017-11-21

    The Future Circular Collider (FCC) Collaboration is preparing the next generation of experiments in high energy physics. The goal is to collide protons at 100 TeV centre–of–mass energy, seven times higher than at the most powerful existing accelerator, the Large Hadron Collider (LHC). Such machine would extend the research carried out at the LHC including the study of the Higgs boson, the search for the origin of the baryon asymmetry, the mass of neutrinos, and the dark matter. The detectors designed for the FCC experiments need to tackle the harsh conditions of the unprecedented collision energy and luminosity. At the same time, they need to provide precise measurements in a wider range of pseudorapidity than the existing experiments. The focus of this thesis is a design and performance studies of one of the sub-detectors, the electromagnetic calorimeter. Its aim is to measure the energy and the position of electrons, positrons, and photons produced in the collisions. The detector proposed in this thesis...

  20. Measurements of beam halo diffusion and population density in the Tevatron and in the Large Hadron Collider

    CERN Document Server

    Stancari, Giulio

    Halo dynamics influences global accelerator performance: beam lifetimes, emittance growth, dynamic aperture, and collimation efficiency. Halo monitoring and control are also critical for the operation of high-power machines. For instance, in the high-luminosity upgrade of the LHC, the energy stored in the beam tails may reach several megajoules. Fast losses can result in superconducting magnet quenches, magnet damage, or even collimator deformation. The need arises to measure the beam halo and to remove it at controllable rates. In the Tevatron and in the LHC, halo population densities and diffusivities were measured with collimator scans by observing the time evolution of losses following small inward or outward collimator steps, under different experimental conditions: with single beams and in collision, and, in the case of the Tevatron, with a hollow electron lens acting on a subset of bunches. After the LHC resumes operations, it is planned to compare measured diffusivities with the known strength of tran...

  1. Search for supersymmetric Higgs bosons in the D0 experiment at the Tevatron; Recherche de bosons de Higgs supersymetriques au Tevatron dans l'experience D0

    Energy Technology Data Exchange (ETDEWEB)

    Michaut, M

    2006-09-15

    A search for the neutral Higgs bosons of the minimal supersymmetric extension of the standard model is performed in the 3 or 4 jets channels, pp-bar {yields} {phi}({yields} bb-bar)b(b-bar) with {phi} = h, H or A. For this purpose, the data collected with the D0 detector from 2002 to 2006 at the Tevatron hadronic collider with a center of mass energy of 1.96 TeV are analyzed. A complete study of the triggering is first done. The triggering conditions are optimized in order to keep the more signal fraction possible. Furthermore, a method is developed to predict the triggering efficiencies on our signal and backgrounds using only the data. Then an analysis method that allows the prediction of our background without the help of simulations is studied. No excess in events is observed in the data sample analyzed, corresponding to an integrated luminosity of 0.9 fb{sup -1}, so limits are set in the minimal supersymmetric extension of the standard model. At 95% confidence level, the following limits are found: tan({beta}) < 46 - 121 for m{sub {phi}} equals 100 - 170 GeV. (author)

  2. Search for supersymmetric Higgs bosons in the D0 experiment at the Tevatron; Recherche de bosons de Higgs supersymetriques au Tevatron dans l'experience D0

    Energy Technology Data Exchange (ETDEWEB)

    Michaut, M

    2006-09-15

    A search for the neutral Higgs bosons of the minimal supersymmetric extension of the standard model is performed in the 3 or 4 jets channels, pp-bar {yields} {phi}({yields} bb-bar)b(b-bar) with {phi} = h, H or A. For this purpose, the data collected with the D0 detector from 2002 to 2006 at the Tevatron hadronic collider with a center of mass energy of 1.96 TeV are analyzed. A complete study of the triggering is first done. The triggering conditions are optimized in order to keep the more signal fraction possible. Furthermore, a method is developed to predict the triggering efficiencies on our signal and backgrounds using only the data. Then an analysis method that allows the prediction of our background without the help of simulations is studied. No excess in events is observed in the data sample analyzed, corresponding to an integrated luminosity of 0.9 fb{sup -1}, so limits are set in the minimal supersymmetric extension of the standard model. At 95% confidence level, the following limits are found: tan({beta}) < 46 - 121 for m{sub {phi}} equals 100 - 170 GeV. (author)

  3. Diagnostics of the Fermilab Tevatron using an AC dipole

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Ryoichi [Univ. of Texas, Austin, TX (United States)

    2008-08-01

    The Fermilab Tevatron is currently the world's highest energy colliding beam facility. Its counter-rotating proton and antiproton beams collide at 2 TeV center-of-mass. Delivery of such intense beam fluxes to experiments has required improved knowledge of the Tevatron's beam optical lattice. An oscillating dipole magnet, referred to as an AC dipole, is one of such a tool to non-destructively assess the optical properties of the synchrotron. We discusses development of an AC dipole system for the Tevatron, a fast-oscillating (f ~ 20 kHz) dipole magnet which can be adiabatically turned on and off to establish sustained coherent oscillations of the beam particles without affecting the transverse emittance. By utilizing an existing magnet and a higher power audio amplifier, the cost of the Tevatron AC dipole system became relatively inexpensive. We discuss corrections which must be applied to the driven oscillation measurements to obtain the proper interpretation of beam optical parameters from AC dipole studies. After successful operations of the Tevatron AC dipole system, AC dipole systems, similar to that in the Tevatron, will be build for the CERN LHC. We present several measurements of linear optical parameters (beta function and phase advance) for the Tevatron, as well as studies of non-linear perturbations from sextupole and octupole elements.

  4. Measurement of the Top Mass in the All - Jets Channel with the D0 Detector at the Fermilab Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Connolly, Brian M. [Florida State U.

    2002-01-01

    We describe a measurement of the top quark mass in $t\\overline{t}$ production where the final state is 6 or more jets, which is otherwise known as the all-jets channel. The mass is extracted from 110.2 $pb^{-1}$ of data taken with the D0 detector at the Fermilab Tevatron (center-of-mass energy ps = 1.8 TeV) from 1993-96. The top quark mass is measured to be $176.6^{+17.1}_{-13.4}$ $GeV/c^2$. The corresponding cross section is estimated to be $11.5^{+4.9}_{-4.7}$ pb.

  5. Advanced silicon sensors for future collider experiments

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00437143; Moll, Michael; Mannelli, Marcello

    In this thesis, we address two key technological challenges: the radiation tolerance assessment and timing performance studies of thin planar diodes to be used as sensing technology in the recently approved CMS forward sampling calorimeter for the HL-LHC operation, the High Granularity Calorimeter (HGCAL); and, complementary, we carried out a detailed study of a novel kind of position sensitive microstrip sensors for ionising particles which implements the well established charge-division method to determine the particle impinging position along the microstrip electrode direction; this technology could become an interesting low-material budget solution for the new generation of tracking detectors to be operated in the future lepton collider experiments.

  6. Measurements of beam halo diffusion and population density in the Tevatron and in the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, Giulio [Fermilab

    2015-03-01

    Halo dynamics influences global accelerator performance: beam lifetimes, emittance growth, dynamic aperture, and collimation efficiency. Halo monitoring and control are also critical for the operation of high-power machines. For instance, in the high-luminosity upgrade of the LHC, the energy stored in the beam tails may reach several megajoules. Fast losses can result in superconducting magnet quenches, magnet damage, or even collimator deformation. The need arises to measure the beam halo and to remove it at controllable rates. In the Tevatron and in the LHC, halo population densities and diffusivities were measured with collimator scans by observing the time evolution of losses following small inward or outward collimator steps, under different experimental conditions: with single beams and in collision, and, in the case of the Tevatron, with a hollow electron lens acting on a subset of bunches. After the LHC resumes operations, it is planned to compare measured diffusivities with the known strength of transverse damper excitations. New proposals for nondestructive halo population density measurements are also briefly discussed.

  7. Asymmetric collider

    International Nuclear Information System (INIS)

    Bharadwaj, V.; Colestock, P.; Goderre, G.; Johnson, D.; Martin, P.; Holt, J.; Kaplan, D.

    1993-01-01

    The study of CP violation in beauty decay is one of the key challenges facing high energy physics. Much work has not yielded a definitive answer how this study might best be performed. However, one clear conclusion is that new accelerator facilities are needed. Proposals include experiments at asymmetric electron-positron colliders and in fixed-target and collider modes at LHC and SSC. Fixed-target and collider experiments at existing accelerators, while they might succeed in a first observation of the effect, will not be adequate to study it thoroughly. Giomataris has emphasized the potential of a new approach to the study of beauty CP violation: the asymmetric proton collider. Such a collider might be realized by the construction of a small storage ring intersecting an existing or soon-to-exist large synchrotron, or by arranging collisions between a large synchrotron and its injector. An experiment at such a collider can combine the advantages of fixed-target-like spectrometer geometry, facilitating triggering, particle identification and the instrumentation of a large acceptance, while the increased √s can provide a factor > 100 increase in beauty-production cross section compared to Tevatron or HERA fixed-target. Beams crossing at a non-zero angle can provide a small interaction region, permitting a first-level decay-vertex trigger to be implemented. To achieve large √s with a large Lorentz boost and high luminosity, the most favorable venue is the high-energy booster (HEB) at the SSC Laboratory, though the CERN SPS and Fermilab Tevatron are also worth considering

  8. Collider workshop

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    The promise of initial results after the start of operations at CERN's SPS proton-antiproton collider and the prospects for high energy hadron collisions at Fermilab (Tevatron) and Brookhaven (ISABELLE) provided a timely impetus for the recent Topical Workshop on Forward Collider Physics', held at Madison, Wisconsin, from 10-12 December. It became the second such workshop to be held, the first having been in 1979 at the College de France, Paris. The 100 or so participants had the chance to hear preliminary results from the UA1, UA4 and UA5 experiments at the CERN SPS collider, together with other new data, including that from proton-antiproton runs at the CERN Intersecting Storage Rings

  9. Photons and diphotons from the Tevatron

    International Nuclear Information System (INIS)

    Blair, R.

    1997-08-01

    Photon measurements from the CDF and D0 collaboration are described. The subjects touched on are loosely organized around the fact that they all have some bearing on the structure functions and pQCD. The methodology of collider measurements is briefly reviewed, and the results for single photons, photons plus jets, photons plus charm and diphotons are discussed. Finally there is a very brief indication of what is expected from the Tevatron based experiments in the future

  10. Searches for new physics at the Tevatron

    International Nuclear Information System (INIS)

    Merritt, K. Wyatt

    1997-01-01

    This paper summarizes searches at the Fermilab Tevatron for a wide variety of signatures for physics beyond the Standard Model. These include searches for supersymmetric particles, in the two collider detectors and in one fixed target experiment. Also covered are searches for leptoquarks, dijet resonances, heavy gauge bosons, and particles from a fourth generation, as well as searches for deviations from the Standard Model predictions in dijet angular distributions, dilepton mass distributions, and trilinear gauge boson couplings

  11. The large hadron collider beauty experiment calorimeters

    International Nuclear Information System (INIS)

    Martens, A.; LHCb Collaboration; Martens, A.

    2010-01-01

    The Large Hadron Collider beauty experiment (LHCb), one of the four largest experiments at the LHC at CERN, is dedicated to precision studies of CP violation and other rare effects, in particular in the b and c quark sectors. It aims at precisely measuring the Standard Model parameters and searching for effects inconsistent with this picture. The LHCb calorimeter system comprises a scintillating pad detector, a pre-shower (PS), electromagnetic (ECAL) and hadronic calorimeters, all of these employing the principle of transporting the light from scintillating layers with wavelength shifting fibers to photomultipliers. The fast response of the calorimeters ensures their key role in the LHCb trigger, which has to cope with the LHC collision rate of 40MHz. After discussing the design and expected performance of the LHCb calorimeter system, one addresses the time and energy calibration issues. The results obtained with the calorimeter system from the first LHC data will be shown.

  12. Search for Leptoquarks Decaying to $\\mu$ + $X$ Meson with the D0 Detector at the Fermilab Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Karmgard, Daniel John [Florida State U., SCRI

    1999-01-01

    We describe a search for the pair production of second generation leptoquarks that decay to muons plus other particles in 94 $pb^{-1}$ of data taken with the D0 detector at the Fermilab Tevatron (center-of-mass energy $\\sqrt{s}$ = 1.8 TeV) from 1993{96. The search places limits on the cross sections and mass of second generation leptoquarks for various branching ratios and couplings. For both scalar leptoquarks decaying into a muon and a quark the mass limit is 200 GeV/$c^2$ while for one scalar leptoquark decaying into a muon and a quark with the other scalar leptoquark decaying into a neutrino and a quark the mass limit is 160 GeV/$c^2$ at the 95% confidence level.

  13. Measurement of cross section of quark pair production top with the D0 experiment at the Tevatron and determination the top quark mass using this measure

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier-Thery, Solene [Univ. Pierre et Marie Curie, Paris (France)

    2010-06-01

    The top quark has been discovered by CDF and D0 experiments in 1995 at the proton-antiproton collider Tevatron. The amount of data recorded by both experiments makes it possible to accurately study the properties of this quark: its mass is now known to better than 1% accuracy. This thesis describes the measurement of the top pair cross section in the electron muon channel with 4, 3 fb -1 recorded data between 2006 and 2009 by the D0 experiment. Since the final state included a muon, improvements of some aspects of its identification have been performed : a study of the contamination of the cosmic muons and a study of the quality of the muon tracks. The cross section measurement is in good agreement with the theoretical calculations and the other experimental measurements. This measurement has been used to extract a value for the top quark mass. This method allows for the extraction of a better defined top mass than direct measurements as it depends less on Monte Carlo simulations. The uncertainty on this extracted mass, dominated by the experimental one, is however larger than for direct measurements. In order to decrease this uncertainty, the ratio of the Z boson and the top pair production cross sections has been studied to look for some possible theoretical correlations. At the Tevatron, the two cross sections are not theoretically correlated: no decrease of the uncertainty on the extracted top mass is therefore possible.

  14. Measurement of cross section of quark pair production top with the D0 experiment at the Tevatron and determination the top quark mass using this measure

    International Nuclear Information System (INIS)

    Chevalier-Thery, Solene

    2010-01-01

    The top quark has been discovered by CDF and D0 experiments in 1995 at the proton-antiproton collider Tevatron. The amount of data recorded by both experiments makes it possible to accurately study the properties of this quark: its mass is now known to better than 1% accuracy. This thesis describes the measurement of the top pair cross section in the electron muon channel with 4, 3 fb -1 recorded data between 2006 and 2009 by the D0 experiment. Since the final state included a muon, improvements of some aspects of its identification have been performed : a study of the contamination of the cosmic muons and a study of the quality of the muon tracks. The cross section measurement is in good agreement with the theoretical calculations and the other experimental measurements. This measurement has been used to extract a value for the top quark mass. This method allows for the extraction of a better defined top mass than direct measurements as it depends less on Monte Carlo simulations. The uncertainty on this extracted mass, dominated by the experimental one, is however larger than for direct measurements. In order to decrease this uncertainty, the ratio of the Z boson and the top pair production cross sections has been studied to look for some possible theoretical correlations. At the Tevatron, the two cross sections are not theoretically correlated: no decrease of the uncertainty on the extracted top mass is therefore possible.

  15. Search for supersymmetric Higgs bosons in the D0 experiment at the Tevatron

    International Nuclear Information System (INIS)

    Michaut, M.

    2006-09-01

    A search for the neutral Higgs bosons of the minimal supersymmetric extension of the standard model is performed in the 3 or 4 jets channels, pp-bar → φ(→ bb-bar)b(b-bar) with φ = h, H or A. For this purpose, the data collected with the D0 detector from 2002 to 2006 at the Tevatron hadronic collider with a center of mass energy of 1.96 TeV are analyzed. A complete study of the triggering is first done. The triggering conditions are optimized in order to keep the more signal fraction possible. Furthermore, a method is developed to predict the triggering efficiencies on our signal and backgrounds using only the data. Then an analysis method that allows the prediction of our background without the help of simulations is studied. No excess in events is observed in the data sample analyzed, corresponding to an integrated luminosity of 0.9 fb -1 , so limits are set in the minimal supersymmetric extension of the standard model. At 95% confidence level, the following limits are found: tan(β) φ equals 100 - 170 GeV. (author)

  16. Top production at hadron colliders

    Indian Academy of Sciences (India)

    New results on top quark production are presented from four hadron collider experiments: CDF and D0 at the Tevatron, and ATLAS and CMS at the LHC. Cross-sections for single top and top pair production are discussed, as well as results on the top–antitop production asymmetry and searches for new physics including ...

  17. Measurement of the top quark properties at the Tevatron and the LHC

    CERN Document Server

    INSPIRE-00040958

    2014-01-01

    Almost two decades after its discovery at Fermilab's Tevatron collider experiments, the top quark is still under the spotlight due to its connections to some of the most interesting puzzles in the Standard Model. The Tevatron has been shut down two years ago, yet some interesting results are coming out of the CDF and D0 collaborations. The LHC collider at CERN produced two orders of magnitude more top quarks than Tevatron's, thus giving birth to a new era for top quark physics. While the LHC is also down at the time of this writing, many top quark physics results are being extracted out of the 7\\,TeV and 8\\,TeV proton proton collisions by the ATLAS and CMS collaborations, and many more are expected to appear before the LHC will be turned on again sometime in 2015. These proceedings cover a selection of recent results produced by the Tevatron and LHC experiments.

  18. Physics at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Field, Rick; /Florida U.

    2006-04-01

    The theme of the XXXIV International Meeting on Fundamental Physics held in El Escorial, Spain on April 2-7, 2006 was ''From HERA and the TEVATRON to the LHC''. This is a summary of the four lectures I presented on ''Physics at the Tevatron''. Heavy quark production and the production of photons, bosons, and jets at the Tevatron are discussed. Also, a detailed study at the ''underlying event'' at CDF is presented together with a discussion of PYTHIA 6.2 tunes. A look back at the ''old days'' of Feynman-Field collider phenomenology is included.

  19. Dreams collide with reality for international experiment

    CERN Document Server

    Cho, Adrian

    2007-01-01

    "Three weeks ago, an international team released a design and cost estimate for the International Linear Collider (ILC). American physicists want to build the ILC at Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois, and researchers had hoped to break ground in 2012 and fire up the ILC's beams of electrons and positrons in 2019." (1 page)

  20. Colliders

    CERN Document Server

    Chou, Weiren

    2014-01-01

    The idea of colliding two particle beams to fully exploit the energy of accelerated particles was first proposed by Rolf Wideröe, who in 1943 applied for a patent on the collider concept and was awarded the patent in 1953. The first three colliders — AdA in Italy, CBX in the US, and VEP-1 in the then Soviet Union — came to operation about 50 years ago in the mid-1960s. A number of other colliders followed. Over the past decades, colliders defined the energy frontier in particle physics. Different types of colliers — proton–proton, proton–antiproton, electron–positron, electron–proton, electron-ion and ion-ion colliders — have played complementary roles in fully mapping out the constituents and forces in the Standard Model (SM). We are now at a point where all predicted SM constituents of matter and forces have been found, and all the latest ones were found at colliders. Colliders also play a critical role in advancing beam physics, accelerator research and technology development. It is timel...

  1. Study of the heavy flavour fractions in z+jets events from $p\\bar{p}$ collisions at energy √s = 1.96 TeV with the CDF II detector at the Tevatron collider

    Energy Technology Data Exchange (ETDEWEB)

    Mastrandrea, Paolo [Univ. of Siena (Italy)

    2008-06-01

    The Standard Model of field and particles is the theory that provides the best description of the known phenomenology of the particle physics up to now. Data collected in the last years, mainly by the experiments at the big particle accelerators (SPS, LEP, TEVATRON, HERA, SLAC), allowed to test the agreement between measurements and theoretical calculations with a precision of 10-3 / 10-4. The Standard Model is a Quantum Field Theory based on the gauge symmetry group SU(3)C x SU(2)L x U(1)Y , with spontaneous symmetry breaking. This gauge group includes the color symmetry group of the strong interaction, SU(3)C, and the symmetry group of the electroweak interactions, SU(2)L x U(1)Y. The formulation of the Standard Model as a gauge theory guarantees its renormalizability, but forbids explicit mass terms for fermions and gauge bosons. The masses of the particles are generated in a gauge-invariant way by the Higgs Mechanism via a spontaneous breaking of the electroweak symmetry. This mechanism also implies the presence of a massive scalar particle in the mass spectrum of the theory, the Higgs boson. This particle is the only one, among the basic elements for the minimal formulation of the Standard Model, to have not been confirmed by the experiments yet. For this reason in the last years the scientific community has been focusing an increasing fraction of its efforts on the search of the Higgs boson. The mass of the Higgs boson is a free parameter of the Standard Model, but the unitarity of the theory requires values not higher than 1 TeV and the LEP experiments excluded values smaller than 115 GeV. To explore this range of masses is under construction at CERN the Large Hadron Collider (LHC), a proton-proton collider with a center of mass energy of 14 TeV and a 1034 cm-2 s-1 peak luminosity. According to the present schedule, this machine will start

  2. Results from E735 at the Tevatron proton-antiproton collider with radical s = 1. 8 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Lindsey, C.

    1991-11-01

    Experiment E735{dagger} searched for evidence of the transition to quark-gluon plasma in p{bar p} collisions at {radical}{bar s} = 1.8 TeV. Using data from a high statistics run in 1988--1989, results are presented on multiplicity distributions, hyperon and phi production, and Bose-Einstein correlations. Some data was also taken at lower collision energies and results will be compared to previous experiments.

  3. Hadron collider luminosity limitations

    CERN Document Server

    Evans, Lyndon R

    1992-01-01

    The three colliders operated to date have taught us a great deal about the behaviour of both bunched and debunched beams in storage rings. The main luminosity limitations are now well enough understood that most of them can be stronglu attenuated or eliminated by approriate design precautions. Experience with the beam-beam interaction in both the SPS and the Tevatron allow us to predict the performance of the new generation of colliders with some degree of confidence. One of the main challenges that the accelerator physicist faces is the problem of the dynamic aperture limitations due to the lower field quality expected, imposed by economic and other constraints.

  4. Hadron collider physics 2005. Proceedings

    International Nuclear Information System (INIS)

    Campanelli, M.; Clark, A.; Wu, X.

    2006-01-01

    The Hadron Collider Physics Symposia (HCP) are a new series of conferences that follow the merger of the Hadron Collider Conferences with the LHC Symposia series, with the goal of maximizing the shared experience of the Tevatron and LHC communities. This book gathers the proceedings of the first symposium, HCP2005, and reviews the state of the art in the key physics directions of experimental hadron collider research: - QCD physics - precision electroweak physics - c-, b-, and t-quark physics - physics beyond the Standard Model - heavy ion physics The present volume will serve as a reference for everyone working in the field of accelerator-based high-energy physics. (orig.)

  5. New diffractive results from the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Gallinaro, Michele; /Rockefeller U.

    2005-05-01

    Experimental results in diffractive processes are summarized and a few notable characteristics described in terms of Quantum Chromodynamics. Exclusive dijet production is used to establish a benchmark for future experiments in the quest for diffractive Higgs production at the Large Hadron Collider. Using new data from the Tevatron and dedicated diffractive triggers, no excess over a smooth falling distribution for exclusive dijet events could be found. Stringent upper limits on the exclusive dijet production cross section are presented. The quark/gluon composition of dijet final states is used to provide additional hints on exclusive dijet production.

  6. Tau identification at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Levy, Stephen; /Chicago U., EFI

    2005-07-01

    Methods for reconstructing and identifying the hadronic decays of tau leptons with the CDF and D0 detectors at the Fermilab Tevatron collider in Run II are described. Precision electroweak measurements of W and Z gauge boson cross sections are presented as well as results of searches for physics beyond the Standard Model with hadronically decaying tau leptons in the final state.

  7. Double-diffractive processes in high-resolution missing-mass experiments at the Tevatron

    International Nuclear Information System (INIS)

    Khoze, V.A.; Martin, A.D.

    2001-01-01

    We evaluate, in a model-independent way, the signal-to-background ratio for Higgs→b anti b detection in exclusive double-diffractive events at the Tevatron and the LHC. For the missing-mass approach to be able to identify the Higgs boson, it will be necessary to use a central jet detector and to tag b quark jets. The signal is predicted to be very small at the Tevatron, but observable at the LHC. However we note that the background, that is double-diffractive dijet production, may serve as a unique gluon factory. We also give estimates for the double-diffractive production of χ c and χ b mesons at the Tevatron. We emphasize that a high-resolution missing-mass measurement, on its own, is insufficient to identify rare processes. (orig.)

  8. Recent results on QCD at the Tevatron (CDF and D0)

    International Nuclear Information System (INIS)

    Meschi, E.

    1993-11-01

    In the last run the Tevatron collider delivered an integrated luminosity of 29.9 pb -1 to CDF and D0. We describe here some preliminary result from analyses of relevant QCD processes in the 1992--1993 data from the two experiments

  9. A TRD Trigger for the tevatron collider experiment at D0

    Energy Technology Data Exchange (ETDEWEB)

    Utes, M.; Johnson, M.; Martin, M.

    1991-11-01

    A VME-based module for use as an input to the D0 Detector Level 1.5 Trigger is described. Its main function will be the confirmation of electron candidates flagged by the First Level Calorimeter Trigger using digitized data from the Transition Radiation Detector. Features of the board include the use of fast FIFOs to store incoming track coordinates, dual ported SRAM lookup tables for addressing integrated charge data and forming scalars, multiplier/accumulators for speed of calculation, and a single synchronous finite state machine to control all board operations. 4 refs., 3 figs.

  10. A TRD Trigger for the tevatron collider experiment at D0

    International Nuclear Information System (INIS)

    Utes, M.; Johnson, M.; Martin, M.

    1991-11-01

    A VME-based module for use as an input to the D0 Detector Level 1.5 Trigger is described. Its main function will be the confirmation of electron candidates flagged by the First Level Calorimeter Trigger using digitized data from the Transition Radiation Detector. Features of the board include the use of fast FIFOs to store incoming track coordinates, dual ported SRAM lookup tables for addressing integrated charge data and forming scalars, multiplier/accumulators for speed of calculation, and a single synchronous finite state machine to control all board operations. 4 refs., 3 figs

  11. Hunting electroweakinos at future hadron colliders and direct detection experiments

    Energy Technology Data Exchange (ETDEWEB)

    Cortona, Giovanni Grilli di [SISSA - International School for Advanced Studies,Via Bonomea 265, I-34136 Trieste (Italy); INFN - Sezione di Trieste,via Valerio 2, I-34127 Trieste (Italy)

    2015-05-07

    We analyse the mass reach for electroweakinos at future hadron colliders and their interplay with direct detection experiments. Motivated by the LHC data, we focus on split supersymmetry models with different electroweakino spectra. We find for example that a 100 TeV collider may explore Winos up to ∼7 TeV in low scale gauge mediation models or thermal Wino dark matter around 3 TeV in models of anomaly mediation with long-lived Winos. We show moreover how collider searches and direct detection experiments have the potential to cover large part of the parameter space even in scenarios where the lightest neutralino does not contribute to the whole dark matter relic density.

  12. Measurement of the top quark mass using dilepton events and a neutrino weighting algorithm with the DOe experiment at the Tevatron (Run II)

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, J.

    2007-07-01

    Several measurements of the top quark mass in the dilepton final states with the DOe experiment are presented. The theoretical and experimental properties of the top quark are described together with a brief introduction of the Standard Model of particle physics and the physics of hadron collisions. An overview over the experimental setup is given. The Tevatron at Fermilab is presently the highest-energy hadron collider in the world with a center-of-mass energy of 1.96 TeV. There are two main experiments called CDF and DOe, A description of the components of the multipurpose DOe detector is given. The reconstruction of simulated events and data events is explained and the criteria for the identification of electrons, muons, jets, and missing transverse energy is given. The kinematics in the dilepton final state is underconstraint. Therefore, the top quark mass is extracted by the so-called Neutrino Weighting method. This method is introduced and several different approaches are described, compared, and enhanced. Results for the international summer conferences 2006 and winter 2007 are presented. The top quark mass measurement for the combination of all three dilepton channels with a dataset of 1.05 1/fb yields: mtop=172.5{+-}5.5 (stat.) {+-} 5.8 (syst.) GeV. This result is presently the most precise top quark mass measurement of the DOe experiment in the dilepton chann el. It entered the top quark mass wold average from March 2007. (orig.)

  13. FERMILAB: Tevatron upgrade; Magnetic precession in bent crystals

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1993-01-15

    The Fermilab accelerator complex is in the middle of a major upgrade to increase the luminosity beyond the original design goal. During Phase I of this upgrade, there have been major modifications to the Tevatron. These modifications were commissioned at the start of the latest collider run and include the installation of electrostatic separators to separate the orbits of the stored beams and new low beta insertions to squeeze the colliding proton and antiproton beams at both experiment interaction regions. These modifications have already enabled the Tevatron to achieve a record peak luminosity of 6.93 x 10{sup 30} per sq cm per s and a record weekly integrated luminosity of 10{sup 60} inverse nanobarns. The peak goal for the present run of 5.0 x 10{sup 30} has already been exceeded.

  14. FERMILAB: Tevatron upgrade; Magnetic precession in bent crystals

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The Fermilab accelerator complex is in the middle of a major upgrade to increase the luminosity beyond the original design goal. During Phase I of this upgrade, there have been major modifications to the Tevatron. These modifications were commissioned at the start of the latest collider run and include the installation of electrostatic separators to separate the orbits of the stored beams and new low beta insertions to squeeze the colliding proton and antiproton beams at both experiment interaction regions. These modifications have already enabled the Tevatron to achieve a record peak luminosity of 6.93 x 10 30 per sq cm per s and a record weekly integrated luminosity of 10 60 inverse nanobarns. The peak goal for the present run of 5.0 x 10 30 has already been exceeded

  15. Fermilab Tevatron and Pbar source status report

    International Nuclear Information System (INIS)

    Edwards, H.

    1986-08-01

    The antiproton production cycle is enumerated, and the commissioning of the antiproton source is described, giving milestones and major obstacles. The Tevatron collider operation is described, including procedure to load the Tevatron with three bunches of protons and three bunches of antiprotons. Commissioning of the Main Ring and Tevatron for collider operation is described. Development and accelerator studies in four areas were necessary: main ring RF manipulations; controls and applications software support; Tevatron storage and low-beta squeeze sequence; and study of various beam transfers, storage steps, and sequences. Final tests are described. A long range upgrade program is presently under evaluation to accomplish these goals: luminosity increase to 5 x 10 31 cm -2 sec -1 , production rates up to 4 x 10 11 antiprotons/hr, and intensity increase for fixed target operation. Beam quality is to be improved by the injector and main ring upgrades, and the luminosity goal is addressed by the Collider upgrade

  16. The VEPP-2000 Collider Control System: Operational Experience

    CERN Document Server

    Senchenko, A I; Lysenko, A P; Rogovsky, Yu A; Shatunov, P Yu

    2017-01-01

    The VEPP-2000 collider was commissioned and operated successfully in 2010-2013. During the operation the facility underwent continuous updates and experience in maintenance was acquired. Strong cooperation between the staff of the accelerator complex and the developers of the control system proved effective for implementing the necessary changes in a short time.

  17. Collider Physics

    OpenAIRE

    Zeppenfeld, D.

    1999-01-01

    These lectures are intended as a pedagogical introduction to physics at $e^+e^-$ and hadron colliders. A selection of processes is used to illustrate the strengths and capabilities of the different machines. The discussion includes $W$ pair production and chargino searches at $e^+e^-$ colliders, Drell-Yan events and the top quark search at the Tevatron, and Higgs searches at the LHC.

  18. Tevatron targets three-year extension

    CERN Multimedia

    Harris, Margaret

    2010-01-01

    "Fermilab's Tevatron collider could get a new lease on life following a campaign to keep the facility running beyond the end of 2011, when the rival Large Hadron Collider (LHC) at Cern is scheduled to shut down for 15 months of repairs" (0.75 page)

  19. Implication of collider experiments for detecting cold dark matter

    International Nuclear Information System (INIS)

    Bednyakov, V.A.

    2000-01-01

    Investigation of Minimal Supersymmetry Standard Model shows, that any discovery with high-energy colliders at least one supersymmetric particle would strongly enhance importance of very accurate experiments. which search for lightest supersymmetric neutralinos as cold dark matter particles. Form other side, non-observations of any signal of cold dark matter in such experiments would force us to change strategy of searching for, for instance, light charged Higgs bosons at high energies [ru

  20. Fermilab | Tevatron | Tevatron Symposium | Agenda

    Science.gov (United States)

    Industry Students and teachers Media Tevatron Navbar Toggle About Leadership and Organization Leadership and video archive Resources for Employees Researchers Job seekers Neighbors Industry Students and Haun Music: John Zorn Costumes: Ariane Dolan Dancers: Simone Baechle, Zada Cheeks, Katie Graves, and

  1. The Compact Muon Solenoid Experiment at the Large Hadron Collider The Compact Muon Solenoid Experiment at the Large Hadron Collider

    Directory of Open Access Journals (Sweden)

    David Delepine

    2012-02-01

    Full Text Available The Compact Muon Solenoid experiment at the CERN Large Hadron Collider will study protonproton collisions at unprecedented energies and luminosities. In this article we providefi rst a brief general introduction to particle physics. We then explain what CERN is. Thenwe describe the Large Hadron Collider at CERN, the most powerful particle acceleratorever built. Finally we describe the Compact Muon Solenoid experiment, its physics goals,construction details, and current status.El experimento Compact Muon Solenoid en el Large Hadron Collider del CERN estudiarácolisiones protón protón a energías y luminosidades sin precedente. En este artículo presentamos primero una breve introducción general a la física de partículas. Despuésexplicamos lo que es el CERN. Luego describimos el Large Hadron Collider, el más potente acelerador de partículas construido por el hombre, en el CERN. Finalmente describimos el experimento Compact Muon Solenoid, sus objetivos en física, los detalles de su construcción,y su situación presente.

  2. FERMILAB: Preparing to collide

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Against the background of stringent Environment, Safety and Health (ES&H) regulations mandated by the US Department of Energy for all national Labs, Fermilab prepared to mount the next major Tevatron proton-antiproton collider run

  3. Computing and data handling requirements for SSC [Superconducting Super Collider] and LHC [Large Hadron Collider] experiments

    International Nuclear Information System (INIS)

    Lankford, A.J.

    1990-05-01

    A number of issues for computing and data handling in the online in environment at future high-luminosity, high-energy colliders, such as the Superconducting Super Collider (SSC) and Large Hadron Collider (LHC), are outlined. Requirements for trigger processing, data acquisition, and online processing are discussed. Some aspects of possible solutions are sketched. 6 refs., 3 figs

  4. FERMILAB: Collider detectors -2

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Last month's edition (April, page 12) included a status report on data collection and preliminary physics results from the 'newcomer' DO detector at Fermilab's Tevatron proton-antiproton collider. This time the spotlight falls in the Veteran' CDF detector, in action since 1985 and meanwhile significantly upgraded. Meanwhile the Tevatron collider continues to improve, with record collision rates

  5. Experiments and detectors for high energy heavy ion colliders

    Energy Technology Data Exchange (ETDEWEB)

    Ludlam, T.

    1984-01-01

    Problems and possibilities are discussed for experiments at the highest collision energies achievable in man-made accelerators; i.e., colliding beams of heavy nuclei at cm energies greater than or equal to 100 GeV/amu, well beyond the threshold of nuclear transparency. Here the final state consists of two hot, dense, baryon-rich fireballs flying away from each other at large rapidity (the fragmentation regions), and thermally-produced particles with near-zero net baryon number populating the central rapidity range. The matter produced at central rapidity (the lab frame for a collider) may reach extremely high temperatures and energy densities, and it is here that one expects to produce thermodynamic conditions similar to those which existed when the early universe condensed from a plasma of quarks and gluons to a gas of hadrons. The problem of tracking, lepton measurements, and calorimeters are discussed. (WHK)

  6. Luminosity lifetime in the Tevatron

    International Nuclear Information System (INIS)

    Jackson, G.; Finley, D.; Johnson, R.P.; Kerns, Q.; McCarthy, J.; Siemann, R.; Zhang, P.

    1988-01-01

    Since the inauguration of colliding proton-antiproton operations in 1987, the Tevatron has exhibited luminosity lifetimes shorter than expected. During a typical colliding beam storage period, called a store, luminosity is calculated periodically by measuring the charge and emittances of each bunch. The growth of the transverse bunch emittances is the dominant cause of luminosity deterioration. Throughout, this period, the position spectrum of the bunches exhibited betatron signals larger than expected from Schottky noise. A model assuming externally driven betatron oscillations explains both the betatron signals and the emittance growth. A program is underway to improve the Tevatron luminosity lifetime. The abort kickers have been identified as sources of emittance growth, and some quadrupole power supplies are further candidates. Because the horizontal dispersion through the RF cavities is nonzero, RF phase noise has been investigated. Noise in the main dipole regulation circuit has also been studied. 13 refs., 4 figs

  7. Top Production at the Tevatron: The Antiproton Awakens

    Energy Technology Data Exchange (ETDEWEB)

    Bloom, Kenneth [Nebraska U.

    2017-07-01

    A long time ago, at a laboratory far, far away, the Fermilab Tevatron collided protons and antiprotons at $\\sqrt{s} = 1.96$ TeV. The CDF and D0 experiments each recorded datasets of about 10 fb$^{-1}$. As such experiments may never be repeated, these are unique datasets that allow for unique measurements. This presentation describes recent results from the two experiments on top-quark production rates, spin orientations, and production asymmetries, which are all probes of the $p\\bar{p}$ initial state.

  8. Impact of detector simulation in particle physics collider experiments

    Science.gov (United States)

    Daniel Elvira, V.

    2017-06-01

    Through the last three decades, accurate simulation of the interactions of particles with matter and modeling of detector geometries has proven to be of critical importance to the success of the international high-energy physics (HEP) experimental programs. For example, the detailed detector modeling and accurate physics of the Geant4-based simulation software of the CMS and ATLAS particle physics experiments at the European Center of Nuclear Research (CERN) Large Hadron Collider (LHC) was a determinant factor for these collaborations to deliver physics results of outstanding quality faster than any hadron collider experiment ever before. This review article highlights the impact of detector simulation on particle physics collider experiments. It presents numerous examples of the use of simulation, from detector design and optimization, through software and computing development and testing, to cases where the use of simulation samples made a difference in the precision of the physics results and publication turnaround, from data-taking to submission. It also presents estimates of the cost and economic impact of simulation in the CMS experiment. Future experiments will collect orders of magnitude more data with increasingly complex detectors, taxing heavily the performance of simulation and reconstruction software. Consequently, exploring solutions to speed up simulation and reconstruction software to satisfy the growing demand of computing resources in a time of flat budgets is a matter that deserves immediate attention. The article ends with a short discussion on the potential solutions that are being considered, based on leveraging core count growth in multicore machines, using new generation coprocessors, and re-engineering HEP code for concurrency and parallel computing.

  9. Beta measurements and modeling the Tevatron

    International Nuclear Information System (INIS)

    Gelfand, N.M.

    1993-06-01

    The Tevatron collider is now able with two low-β (β*=0.25--0.5m) interaction regions denoted as B0 and D0. This lattice allows independent operation of the interaction regions which required that the previous collider lattice, used in 1988--89, had to be modified. In order to see how well the lattice conforms to the design, measurements of the β function have been carried out at 15 locations in the new Tevatron collider lattice. Agreement can be obtained between the measurements and a computer model for the Tevatron, based on the design, only if the strengths of the gradients in the quadrupoles in the low-β triplet are allowed to differ from their design values. It is also observed that the lattice is very sensitive to the precise values of the gradients in these magnets

  10. Search for electroweak top quark production in the electron + jets channel in the D0 experiment at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Busato, Emmanuel [Paris Univ. (France)

    2005-04-01

    The top quark, whose mass approaches the electroweak symmetry breaking scale, is by far the heaviest known elementary particle. New physics is therefore expected to have its most important effect in the top sector. The Tevatron is, currently, the only collider able to produce the top quark. Among all possible production processes in the standard model, the top-antitop pair production via strong interaction, first observed in 1995, is the one with the largest cross section. The production via electroweak interaction (known as single top production), more difficult to extract from the background because of a lower cross section and of a lower signal to background ratio, has never been observed. In this thesis, we have searched for these processes by studying proton-antiproton collisions at $\\sqrt{s}$ =1.96 TeV produced by the Tevatron and detected with the DØ detector. The experimental study of the top quark is very sensitive to the quality of the data taken by the calorimeter. This detector showed, at the beginning of the Run II, rather important noise problems. Having identified the origin of the noise, new treatments at the offline level were implemented and their effects studied. It has been shown that these treatments reduce very significantly the effect of the noise in the reconstruction of physical quantities without notable degradation of the signal. Within the standard model, the top quark decays into W b with a branching ratio close to 100%. Leptonic decays of the into electron + neutrino have been used to identify the from the top decay. The main backgrounds to the single top signal ( +jets and QCD) are made essentially of light quark jets in the final state. Two ..-tagging algorithms have therefore been applied in order to improve the signal to background ratio. No evidence for electroweak top quark production has been found. Upper limits at the 95 % confidence level on the observed (expected) cross sections have be computed. They are found to be 14

  11. Academic Training - Tevatron: studying pp collisions at the highest energy

    CERN Multimedia

    2006-01-01

    ACADEMIC TRAINING LECTURE SERIES 15, 16, 17, 18 May Main Auditorium, bldg. 500 on 15, 16, 17 May - Council Chamber on 18 May Physics at the Tevatron B. HEINEMANN, Univ. of Liverpool, FERMILAB Physics Results from the Tevatron The Tevatron proton-antiproton collider at Fermilab in the US is currently the world's highest energy collider. At the experiments CDF and D0 a broad physics programme is being pursued, ranging from flavour physics via electroweak precision measurements to searches for the Higgs boson and new particles beyond the Standard Model. In my lecture I will describe some of the highlight measurements in the flavour, electroweak and searches sectors, and the experimental techniques that are used. ENSEIGNEMENT ACADEMIQUE ACADEMIC TRAINING Françoise Benz 73127 academic.training@cern.ch If you wish to participate in one of the following courses, please tell to your supervisor and apply electronically from the course description pages that can be found on the Web at: http://www.cern.ch/...

  12. 'TRISTAN'; a database for electron colliding beam experiments

    International Nuclear Information System (INIS)

    Shimizu, Y.; Igarashi, M.; Nakazawa, N.; Oyanagi, Y.

    1982-01-01

    In this data base, the reference papers on the experiments of positron-electron colliding beam were collected for the purpose to utilize them for the TRISTAN project. The on-line retrieval of the references is possible. The number of the references is 289 during the period from January, 1974, to September, 1981. The collection of data will be continued hereafter. The terms retrievable are accelerator, incident beam, code, and radiation correction formula. The SC (name of the first author, year), incident energy, detector, luminocity, integrated luminosity, reaction, purpose and comments are also included as the data. The system is written in FORTRAN 77, and is portable. (Kato, T.)

  13. Report on the α subgroup forward collider experiments

    International Nuclear Information System (INIS)

    Kwan, S.; Luk, K.B.

    1993-01-01

    The subgroup studied the potential of forward collider experiments for measuring the angle α using the B 0 →π + π - decay. In particular, they tried to answer the questions of what sensitivities the two different proposals (COBEX and forward BCD) could probe CP violation in the above decay mode in units of 10 7 seconds. A detailed comparison of the capabilities of the experiments would require extensive Monte Carlo estimates of the total number of reconstructed and tagged exclusive B meson decays as well as realistic estimates of the background. Both experiments have performed most of these calculations and their numbers have been used as the basis of discussion. Given the short time available in the workshop, the authors took the approach of examining the numbers presented by the proponents of the two experiments at the workshop and estimated what would be achievable

  14. Fermilab Tevatron and CERN LEP II probes of minimal and string-motivated supergravity models

    International Nuclear Information System (INIS)

    Baer, H.; Gunion, J.F.; Kao, C.; Pois, H.

    1995-01-01

    We explore the ability of the Fermilab Tevatron to probe minimal supersymmetry with high-energy-scale boundary conditions motivated by supersymmetry breaking in the context of minimal and string-motivated supergravity theory. A number of boundary condition possibilities are considered: dilatonlike string boundary conditions applied at the standard GUT unification scale or alternatively at the string scale; and extreme (''no-scale'') minimal supergravity boundary conditions imposed at the GUT scale or string scale. For numerous specific cases within each scenario the sparticle spectra are computed and then fed into ISAGET 7.07 so that explicit signatures can be examined in detail. We find that, for some of the boundary condition choices, large regions of parameter space can be explored via same-sign dilepton and isolated trilepton signals. For other choices, the mass reach of Tevatron collider experiments is much more limited. We also compare the mass reach of Tevatron experiments with the corresponding reach at CERN LEP 200

  15. Identification of tau leptons in the D0 experiment at the Tevatron and search for supersymmetric particles violating R-parity through decay; Identification des leptons taus dans l'experience D0 aupres du tevatron et recherche de particules supersymetriques se desintegrant avec R-parite violee (couplage {lambda}{sub 133})

    Energy Technology Data Exchange (ETDEWEB)

    Le Bihan, A.C

    2005-04-15

    This thesis concerns the search for supersymmetric particles in data collected by the D0 experiment in Run II at Fermilab Tevatron proton-antiproton collider. Data corresponding to an integrated luminosity of 352 pb{sup -1} (2001-2004) at a center-of-mass energy of {radical}s=1.96 TeV have been used to search for two electrons plus hadronic tau final states accompanied by missing transverse energy. These topologies are expected to arise if R-parity is violated and the lightest neutralino is allowed to decay through a {lambda}{sub 133} coupling. The data seen is consistent with the Standard Model and with instrumental background expectations which suggests no evidence for supersymmetry with {lambda}{sub 133} coupling. Thus lower limits on the masses of the lightest chargino and neutralino have been set. A significant part of the work has been dedicated to identify decaying tau in an hadronic way. The developed method uses neural networks and exploits the narrowness and low particle multiplicity of tau jets by means of the calorimeter and tracker information. The efficiency and capability of this method have been measured and demonstrated in data using the Z {yields} {tau}{tau} {yields} {mu}{tau}(hadr) process. This algorithm allows us to reduce the important QCD background by a factor 100 for 50% tau identification efficiency. (author)

  16. Recent heavy flavor results from the Tevatron

    International Nuclear Information System (INIS)

    Dorigo, Mirco

    2012-01-01

    The CDF and D0 experiments at the Tevatron p(bar p) collider have pioneered and established the role of flavor physics in hadron collisions. A broad program is now at its full maturity. We report on three new results sensitive to physics beyond the standard model, obtained using the whole CDF dataset: a measurement of the difference of CP asymmetries in K + K - and π + π - decays of D 0 mesons, new bounds on the B s 0 mixing phase and on the decay width difference of B s 0 mass-eigenstates, and an update of the summer 2011 search for B (s) 0 mesons decaying into pairs of muons. Finally, the D0 confirmation of the observation of a new hadron, the χ b (3P) state, is briefly mentioned.

  17. Tevatron in the 1990s

    International Nuclear Information System (INIS)

    Lederman, L.M.

    1989-01-01

    This paper reports that in 1978, Fermilab set out a goal of building a superconducting accelerator (Energy Saver) which would raise the proton energy to close to 1000 GeV for operation in two modes. Tevatron I would provide proton-antiproton collisions at a total CM energy of near 2.0 TeV to study the particle mass domain beyond 100 GeV. Tevatron II would provide extensive facilities for the programmatic study of Standard Model physics in an upgraded fixed-target program. There was of course the realization that with the right mixture of precision and imagination, the collider could add significantly to Standard Model physics (e.g. W and Z physics, W, Z pairs, B-physics) and that the fixed-target program could explore beyond the Standard Model (e.g., rare K-decays, CP violation). In 1988, we are engaged in setting out the future program of the Laboratory based upon the success of the Energy Saver, TeV I and TeV II construction programs. This future program assures the operation of the TEVATRON facility for physics is the overriding priority between now and perhaps 1993 and it also assumes that the Superconducting Super Collider (SSC) will be funded for construction in 1990 and will begin producing physics by 1999. A brief history of upgrades is presented in section XI

  18. Non-SUSY Searches at the Tevatron

    International Nuclear Information System (INIS)

    Strologas, John

    2011-01-01

    We present recent results from searches for new physics beyond supersymmetry performed at the Tevatron accelerator at Fermilab. The CDF and D0 analyses presented here utilized data of integrated luminosity up to 6 fb -1 . We cover leptonic and bosonic resonances interpreted in the Randall-Sundrum graviton and new-boson models, rare final states, and the search for vector-like quarks. The search for new phenomena beyond the weak-scale supersymmetry is a vital part of the Fermilab program. Both CDF and D0 experiments at the Tevatron collider actively look for signals not expected by the standard model (SM) or minimal supersymmetric models. The searches can be sorted in three categories: (a) searches for generic resonances that can be interpreted in several new-physics models; (b) searches for exotic combinations of final-state objects or abnormal kinematics (not necessarily predicted by current theories); and (c) model-dependent searches that test a particular theory. We present here latest results from all these categories: searches for new dilepton and diboson resonances (interpreted as gravitons and new gauge bosons), searches for anomalous γ + E T + X production, and searches for vector-like quarks.

  19. Review of physics results from the Tevatron: QCD physics

    Energy Technology Data Exchange (ETDEWEB)

    Mesropian, Christina [Rockefeller U.; Bandurin, Dmitry [Virginia U.

    2015-02-17

    We present a summary of results from studies of quantum chromodynamics at the Fermilab Tevatron collider by the CDF and the D0 experiments. These include Run II results for the time period up to the end of Summer 2014. A brief description of Run I results is also given. This review covers a wide spectrum of topics, and includes measurements with jet and vector boson final states in the hard (perturbative) energy regime, as well as studies of soft physics such as diffractive and elastic scatterings, underlying and minimum bias events, hadron fragmentation, and multiple parton interactions.

  20. A real-time tracker for hadronic collider experiments

    International Nuclear Information System (INIS)

    Bardi, A.; Belforte, S.; Galeotti, S.; Giannetti, P.; Morsani, F.; Spinella, F.; Dell'Orso, M.; Meschi, E.

    1999-01-01

    In this paper the authors propose highly parallel dedicated processors, able to provide precise on-line track reconstruction for future hadronic collider experiments. The processors, organized in a 2-level pipelined architecture, execute very fast algorithms based on the use of a large bank of pre-stored patterns of trajectory points. An associative memory implements the first stage by recognized track candidates at low resolution to match the demanding task of tracking at the detector readout rate. Alternative technological implementations for the associative memory are compared. The second stage receives track candidates and high resolution hits to refine pattern recognition at the associative memory output rate. A parallel and pipelines hardware implements a binary search strategy inside a hierarchically structured pattern bank, stored in the high density commercial RAMs

  1. Introduction to colliding beams at Fermilab

    International Nuclear Information System (INIS)

    Thompson, J.

    1994-10-01

    The Fermi National Accelerator Laboratory is currently the site of the world's highest center-of-mass energy proton-antiproton colliding beam accelerator, the Tevatron. The CDF and D OE detectors each envelop one of two luminous regions in the collider, and are thus wholly dependent on the accelerator for their success. The Tevatron's high operating energy, reliability, and record setting integrated luminosity have allowed both experiments to make world-class measurements and defined the region of physics that each can explore. The following sections are an overview of the highlights of the accelerator operation and are compiled from many sources. The major sources for each section are listed at the beginning of that section

  2. TOP AND HIGGS PHYSICS AT THE HADRON COLLIDERS

    Energy Technology Data Exchange (ETDEWEB)

    Jabeen, Shabnam

    2013-10-20

    This review summarizes the recent results for top quark and Higgs boson measurements from experiments at Tevatron, a proton–antiproton collider at a center-of-mass energy of √ s =1 . 96 TeV, and the Large Hadron Collider, a proton–proton collider at a center- of-mass energy of √ s = 7 TeV. These results include the discovery of a Higgs-like boson and measurement of its various properties, and measurements in the top quark sector, e.g. top quark mass, spin, charge asymmetry and production of single top quark.

  3. Research for the boson of Higgs and for couplings of capacity quartic abnormal in the channel WW in electrons in the experiment D0 in Tevatron

    International Nuclear Information System (INIS)

    Chapon, Emilien

    2013-01-01

    Two physics analyzes are presented in this thesis, both probing the electroweak sector of the Standard Model using events with two oppositely charged electrons and missing transverse energy. The events are selected from the full Run II data sample of 9.7 fb -1 of proton-antiproton collisions collected with the D0 detector at the Fermilab Tevatron Collider at √s=1.96 TeV. The first analysis is a search for the Higgs boson in H → WW → evev decays. To validate the search methodology, the non-resonant WW production cross section is measured. In the Higgs boson search, no significant excess above the background expectation is observed. Upper limits on the Higgs boson production cross section are therefore derived, within the Standard Model, but also within a theoretical framework with a fourth generation of fermions, and in the context of fermiophobic Higgs boson couplings. A search for anomalous quartic gauge couplings between the photon and the W boson is then presented, using exclusive W boson pair production, allowing to probe new physics effects. The selection of the events and the analysis techniques used are mostly identical to those used in the first analysis, the search for the Higgs boson. The limits set on this type of anomalous couplings are the first ones from the Tevatron and the most stringent ones at the time of the publication. (author) [fr

  4. The ATLAS experiment at the CERN Large Hadron Collider

    NARCIS (Netherlands)

    Aad, G.; et al., [Unknown; Bentvelsen, S.; Bobbink, G.J.; Bos, K.; Boterenbrood, H.; Brouwer, G.; Buis, E.J.; Buskop, J.J.F.; Colijn, A.P.; Dankers, R.; Daum, C.; de Boer, R.; de Jong, P.; Ennes, P.; Gosselink, M.; Groenstege, H.; Hart, R.G.G.; Hartjes, F.; Hendriks, P.J.; Hessey, N.P.; Jansweijer, P.P.M.; Kieft, G.; Klok, P.F.; Klous, S.; Kluit, P.; Koffeman, E.; Koutsman, A.; Liebig, W.; Limper, M.; Linde, F.; Luijckx, G.; Massaro, G.; Muijs, A.; Peeters, S.J.M.; Reichold, A.; Rewiersma, P.; Rijpstra, M.; Scholte, R.C.; Schuijlenburg, H.W.; Snuverink, J.; van der Graaf, H.; van der Kraaij, E.; van Eijk, B.; van Kesteren, Z.; van Vulpen, I.; Verkerke, W.; Vermeulen, J.C.; Vreeswijk, M.; Werneke, P.

    2008-01-01

    The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.

  5. Cryogenic testing and analysis associated with Tevatron lower temperature operation

    International Nuclear Information System (INIS)

    Theilacker, J.C.

    1996-01-01

    An upgrade of the Tevatron cryogenic system was installed and commissioned in 1993 to allow lower temperature operation. As a result, higher energy operation of the Fermilab superconducting Tevatron accelerator is possible. Following the installation and initial commissioning, it was decided to continue the current colliding beam physics run at the previous energy of 900 GeV. This has allowed the author to perform parasitic lower temperature tests in the Tevatron over the last year and a half. This paper presents the results of operational experiences and thermal and hydraulic testing which have taken place. The primary goal of the testing is to better understand the operation of the cold compressor system, associated instrumentation, and the performance of the existing magnet system during lower temperature operation. This will lead to a tentatively scheduled higher energy test run in the fall of 1995. The test results have shown that more elaborate controlling methods are necessary in order to achieve reliable system operation. Fortunately, the new satellite refrigerator controls system is capable of the expansion necessary to reach this goal. New features are being added to the controls systems which will allow for more intelligent control and better diagnostics for component monitoring and trending

  6. Time domain structures in a colliding magnetic flux rope experiment

    Science.gov (United States)

    Tang, Shawn Wenjie; Gekelman, Walter; Dehaas, Timothy; Vincena, Steve; Pribyl, Patrick

    2017-10-01

    Electron phase-space holes, regions of positive potential on the scale of the Debye length, have been observed in auroras as well as in laboratory experiments. These potential structures, also known as Time Domain Structures (TDS), are packets of intense electric field spikes that have significant components parallel to the local magnetic field. In an ongoing investigation at UCLA, TDS were observed on the surface of two magnetized flux ropes produced within the Large Plasma Device (LAPD). A barium oxide (BaO) cathode was used to produce an 18 m long magnetized plasma column and a lanthanum hexaboride (LaB6) source was used to create 11 m long kink unstable flux ropes. Using two probes capable of measuring the local electric and magnetic fields, correlation analysis was performed on tens of thousands of these structures and their propagation velocities, probability distribution function and spatial distribution were determined. The TDS became abundant as the flux ropes collided and appear to emanate from the reconnection region in between them. In addition, a preliminary analysis of the permutation entropy and statistical complexity of the data suggests that the TDS signals may be chaotic in nature. Work done at the Basic Plasma Science Facility (BaPSF) at UCLA which is supported by DOE and NSF.

  7. SLC and SLD: Experimental experience with a linear collider

    International Nuclear Information System (INIS)

    Breidenbach, M.

    1993-08-01

    The SLAC Linear Collider (SLC) is the prototype e + e - linear collider. This talk will consist of an introduction to SLC, a description of the strategy for luminosity, a description of the systems for the transport and measurement of the polarized electrons, and a description of the present performance of the SLC and planned upgrades. The detector, SLD, and the status of the polarization asymmetry measurement A LR will be described

  8. Race for the Higgs hots up as Tevatron seeks extension

    CERN Multimedia

    Banks, Michael

    2009-01-01

    "With researchers at Cern's Large Hadron Collider (LHC) having circulated protons for the first time since last year's accident, the US Department of Energy (DOE) is requesting $25m so that the Tevatron collider at the Fermi National Accelerator Laboratory in Illinois can run for an extra year until 2011" (0.25 page)

  9. Discovering a Light Scalar or Pseudoscalar at The Large Hadron Collider

    DEFF Research Database (Denmark)

    Frandsen, Mads Toudal; Sannino, Francesco

    2012-01-01

    The allowed standard model Higgs mass range has been reduced to a region between 114 and 130 GeV or above 500 GeV, at the 99% confidence level, since the Large Hadron Collider (LHC) program started. Furthermore some of the experiments at Tevatron and LHC observe excesses that could arise from...

  10. Results from E735 at the Tevatron proton-antiproton collider with √s=1.8 teV

    International Nuclear Information System (INIS)

    Lindsey, C.S.; Bhat, P.; Hojvat, C.; Reeves, D.; Turkot, F.; Wesson, D.K.; Alexopoulos, T.; Erwin, A.R.; Findeisen, C.; Jennings, J.R.; Nelson, K.; Thompson, M.; Allen, C.; Bujak, A.; Carmony, D.D.; Cole, P.; Choi, Y.; DeBonte, R.; Gutay, L.J.; Hirsch, A.S.; McMahon, T.; Morgan, N.; Porile, N.T.; Rimai, A.; Scharenberg, R.P.; Stringfellow, B.C.; Anderson, E.W.; Wang, C.H.; Balamurali, V.; Banerjee, S.; Beery, P.D.; Biswas, N.N.; Kenny, V.P.; LoSecco, J.M.; McManus, A.P.; Stampke, S.R.; Warchol, J.; Zhan, Y.; Carter, T.; Goshaw, A.T.; Loomis, G.; Oh, S.H.; Robertson, W.J.; Walker, W.D.; DeCarlo, V.

    1992-01-01

    Experiment E735* searched for evidence of the transition to quark-gluon plasma in panti p collisions at √s = 1.8 TeV. Using data from a high statistics run in 1988-1989, results are presented on multiplicity distributions, hyperon and phi production, and Bose-Einstein correlations. Some data were also taken at lower collision energies and results will be compared to previous experiments. (orig.)

  11. Physics at Future Colliders

    CERN Document Server

    Ellis, John R.

    1999-01-01

    After a brief review of the Big Issues in particle physics, we discuss the contributions to resolving that could be made by various planned and proposed future colliders. These include future runs of LEP and the Fermilab Tevatron collider, B factories, RHIC, the LHC, a linear electron-positron collider, an electron-proton collider in the LEP/LHC tunnel, a muon collider and a future larger hadron collider (FLHC). The Higgs boson and supersymmetry are used as benchmarks for assessing their capabilities. The LHC has great capacities for precision measurements as well as exploration, but also shortcomings where the complementary strengths of a linear electron-positron collider would be invaluable. It is not too soon to study seriously possible subsequent colliders.

  12. The Multi-Purpose Detector (MPD) of the collider experiment

    Energy Technology Data Exchange (ETDEWEB)

    Golovatyuk, V.; Kekelidze, V.; Kolesnikov, V.; Rogachevsky, O. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Sorin, A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); National Research Nuclear University (MEPhI), Moscow (Russian Federation)

    2016-08-15

    The project NICA (Nuclotron-based Ion Collider fAcility) is aimed to study dense baryonic matter in heavy-ion collisions in the energy range up to √(s{sub NN}) = 11 GeV with average luminosity of L = 10{sup 27} cm{sup -2}s{sup -1} (for {sup 197}Au{sup 79}). The experimental program at the NICA collider will be performed with the Multi-Purpose Detector (MPD). We report on the main physics objectives of the NICA heavy-ion program and present the main detector components. (orig.)

  13. From the Tevatron to Project X

    CERN Multimedia

    Pier Oddone, Fermilab director (from CERN Courier)

    2011-01-01

    In the October issue of the CERN Courier, Fermilab Director Pier Oddone will present the past, present and future of the US laboratory after the Tevatron. The Bulletin presents some early extracts from his article…   Fermilab Director, Pier Oddone. The end of September marks the end of an era at Fermilab, with the shutdown of the Tevatron after 28 years of operation at the frontiers of particle physics. The Tevatron’s far-reaching legacy spans particle physics, accelerator science and industry. The collider established Fermilab as a world leader in particle physics research, a role that will be strengthened with a new set of facilities, programmes and projects in neutrino and rare-process physics, astroparticle physics, and accelerator and detector technologies. The Tevatron exceeded every expectation ever set for it. This remarkable machine achieved luminosities with antiprotons once considered impossible, reaching more than 4x1032 cm-2s-1 instantaneous luminosity and...

  14. Tevatron energy and luminosity upgrades beyond the Main Injector

    International Nuclear Information System (INIS)

    Amidei, D.; Kamon, T.; Lopez, J.; McIntyre, P.; White, J.

    1994-08-01

    The Fermilab Tevatron will be the world's highest energy hadron collider until the LHC is commissioned, it has the world's highest energy fixed target beams, and Fermilab will be the leading high energy physics laboratory in the US for the foreseeable future. Following the demise of the SSC, a number of possible upgrades to the Tevatron complex, beyond construction of the Main Injector, are being discussed. Using existing technology, it appears possible to increase the luminosity of the bar pp Collider to at least 10 33 cm -2 sec -1 (Tevatron-Star) and to increase the beam energy to 2 TeV (DiTevatron). Fixed target beam of energy about 1.5 TeV could also be delivered. Leaving the existing Tevatron in the tunnel and constructing bypasses around the collider halls would allow simultaneous 800 GeV fixed target and √s = 4 TeV collider operation. These upgrades would give Fermilab an exciting physics program which would be complementary to the LHC, and they would lay the groundwork for the construction of a possible post-LHC ultra-high energy hadron collider

  15. Precision electroweak physics at the Tevatron

    International Nuclear Information System (INIS)

    James, Eric B.

    2006-01-01

    An overview of Tevatron electroweak measurements performed by the CDF and Dφ experiments is presented. The current status and future prospects for high precision measurements of electroweak parameters and detailed studies of boson production are highlighted. (author)

  16. Simulation of signal and background processes for collider experiments

    International Nuclear Information System (INIS)

    Schumann, S.

    2008-01-01

    In this thesis new theoretical tools for the accurate simulation of scattering processes at present and future collider experiments have been developed. Special emphasis has thereby to be given to multi-particle/multi-jet final states that often constitute signals for interesting (new) physics. Considering final states with a number of hard jets, there seems to be enough evidence that the traditional simulation tools HERWIG and PYTHIA cannot fully accomplish their description. Starting from a 2→2 core process, they account only for soft and collinear QCD emissions through parton-shower models. Only recently, theoretical prescriptions have been found to consistently combine tree-level matrix-element calculations with the existing parton-shower algorithms. The gain of such methods is that phase-space regions covered by hard and by soft parton kinematics are simultaneously well described. In Chapter 2 of this thesis the working principles of such prescriptions have been discussed with special attention being paid to the merging scheme implemented in the SHERPA Monte Carlo. To consistently match QCD higher-order calculations (at one-loop or tree-level) with parton showers, a good analytical control over the perturbative terms present in the latter is required. This has triggered the demand for improved parton-shower models that facilitate the inclusion of exact matrix elements. In this line a completely new shower algorithm has been presented in Chapter 3. It is based on the Catani-Seymour dipole subtraction formalism, a universal method for calculating arbitrary processes at next-to-leading order in QCD. The splitting kernels used in the shower are justified approximations of the Catani-Seymour dipole functions. The kinematics of the individual splittings is accomplished such that exact four-momentum conservation can be ensured for each single branching. Accordingly, the shower can be stopped and started again at each intermediate stage of the evolution. The model

  17. Simulation of signal and background processes for collider experiments

    Energy Technology Data Exchange (ETDEWEB)

    Schumann, S.

    2008-10-08

    In this thesis new theoretical tools for the accurate simulation of scattering processes at present and future collider experiments have been developed. Special emphasis has thereby to be given to multi-particle/multi-jet final states that often constitute signals for interesting (new) physics. Considering final states with a number of hard jets, there seems to be enough evidence that the traditional simulation tools HERWIG and PYTHIA cannot fully accomplish their description. Starting from a 2{yields}2 core process, they account only for soft and collinear QCD emissions through parton-shower models. Only recently, theoretical prescriptions have been found to consistently combine tree-level matrix-element calculations with the existing parton-shower algorithms. The gain of such methods is that phase-space regions covered by hard and by soft parton kinematics are simultaneously well described. In Chapter 2 of this thesis the working principles of such prescriptions have been discussed with special attention being paid to the merging scheme implemented in the SHERPA Monte Carlo. To consistently match QCD higher-order calculations (at one-loop or tree-level) with parton showers, a good analytical control over the perturbative terms present in the latter is required. This has triggered the demand for improved parton-shower models that facilitate the inclusion of exact matrix elements. In this line a completely new shower algorithm has been presented in Chapter 3. It is based on the Catani-Seymour dipole subtraction formalism, a universal method for calculating arbitrary processes at next-to-leading order in QCD. The splitting kernels used in the shower are justified approximations of the Catani-Seymour dipole functions. The kinematics of the individual splittings is accomplished such that exact four-momentum conservation can be ensured for each single branching. Accordingly, the shower can be stopped and started again at each intermediate stage of the evolution. The

  18. Dedicating Fermilab's Collider

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1986-01-15

    It was a bold move to have a fullscale dedication ceremony for the new proton-antiproton Collider at the Fermilab Tevatron on 13 October, two days before the first collisions were seen. However the particles dutifully behaved as required, and over the following weekend the Collider delivered its goods at a total energy of 1600 GeV, significantly boosting the world record for laboratory collisions.

  19. The Next Linear Collider: NLC2001

    International Nuclear Information System (INIS)

    Burke, D.

    2002-01-01

    Recent studies in elementary particle physics have made the need for an e + e - linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever [1]. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it is. These experiments must also define the next important threshold in energy. The need is to understand physics at the TeV energy scale as well as the physics at the 100-GeV energy scale is now understood. This will require both the LHC and a companion linear electron-positron collider. A first Zeroth-Order Design Report (ZDR) [2] for a second-generation electron-positron linear collider, the Next Linear Collider (NLC), was published five years ago. The NLC design is based on a high-frequency room-temperature rf accelerator. Its goal is exploration of elementary particle physics at the TeV center-of-mass energy, while learning how to design and build colliders at still higher energies. Many advances in accelerator technologies and improvements in the design of the NLC have been made since 1996. This Report is a brief update of the ZDR

  20. The Next Linear Collider: NLC2001

    Energy Technology Data Exchange (ETDEWEB)

    D. Burke et al.

    2002-01-14

    Recent studies in elementary particle physics have made the need for an e{sup +}e{sup -} linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever [1]. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it is. These experiments must also define the next important threshold in energy. The need is to understand physics at the TeV energy scale as well as the physics at the 100-GeV energy scale is now understood. This will require both the LHC and a companion linear electron-positron collider. A first Zeroth-Order Design Report (ZDR) [2] for a second-generation electron-positron linear collider, the Next Linear Collider (NLC), was published five years ago. The NLC design is based on a high-frequency room-temperature rf accelerator. Its goal is exploration of elementary particle physics at the TeV center-of-mass energy, while learning how to design and build colliders at still higher energies. Many advances in accelerator technologies and improvements in the design of the NLC have been made since 1996. This Report is a brief update of the ZDR.

  1. Measurements of Top Properties at the Tevatron

    International Nuclear Information System (INIS)

    Husemann, Ulrich; Yale U.

    2007-01-01

    The large data samples of thousands of top events collected at the Tevatron experiments CDF and D(O) allow for a variety of measurements to analyze the properties of the top quark. Guided by the question ''Is the top quark observed at the Tevatron really the top quark of the standard model,'' we present Tevatron analyses studying the top production mechanism including resonant t(bar t) production, the V -A structure of the t → Wb decay vertex, the charge of the top quark, and single-top production via flavor-changing neutral currents

  2. Higgs boson studies at the Tevatron

    Czech Academy of Sciences Publication Activity Database

    Aaltonen, L.; Abbott, B.; Abazov, V. M.; Kupčo, Alexander; Lokajíček, Miloš; Lysák, Roman

    2013-01-01

    Roč. 88, č. 5 (2013), "052014-1"-"052014-29" ISSN 1550-7998 R&D Projects: GA MŠk(CZ) LG12006 Institutional support: RVO:68378271 Keywords : Higgs particle * mass * vector boson * gluon * fusion * Batavia TEVATRON Coll * CDF * DZERO * anti-p p * interaction Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 4.864, year: 2013

  3. Twenty years of diffraction at the Tevatron

    International Nuclear Information System (INIS)

    Goulianos, K.; Rockefeller U.

    2005-01-01

    Results on diffractive particle interactions from the Fermilab Tevatron (bar p)p collider are placed in perspective through a QCD inspired phenomenological approach, which exploits scaling and factorization properties observed in data. The results discussed are those obtained by the CDF Collaboration from a comprehensive set of single, double, and multigap soft and hard diffraction processes studied during the twenty year period since 1985, when the CDF diffractive program was proposed and the first Blois Workshop was held

  4. Applying EVM principles to Tevatron Beam Position Monitor Project

    International Nuclear Information System (INIS)

    Banerjee, Bakul

    2005-01-01

    At Fermi National Accelerator Laboratory (Fermilab), the Tevatron high energy particle collider must meet the increasing scientific demand of higher beam luminosity. To achieve this higher luminosity goal, U. S. Department of Energy (DOE) sponsored a major upgrade of capabilities of Fermilab's accelerator complex that spans five years and costs over fifty million dollars. Tevatron Beam Position Monitor (BPM) system upgrade is a part of this project, generally called RunII upgrade project. Since the purpose of the Tevatron collider is to detect the smashing of proton and anti-protons orbiting the circular accelerator in opposite directions, capability to detect positions of both protons and antiprotons at a high resolution level is a desirable functionality of the monitoring system. The original system was installed during early 1980s, along with the original construction of the Tevatron. However, electronic technology available in 1980s did not allow for the detection of significantly smaller resolution of antiprotons. The objective of the upgrade project is to replace the existing BPM system with a new system utilizing capabilities of modern electronics enhanced by a front-end software driven by a real-time operating software. The new BPM system is designed to detect both protons and antiprotons with increased resolution of up to an order of magnitude. The new system is capable of maintaining a very high-level of data integrity and system reliability. The system consists of 27 VME crates installed at 27 service buildings around the Tevatron ring servicing 236 beam position monitors placed underground, inside the accelerator tunnel. Each crate consists of a single Timing Generator Fanout module, custom made by Fermilab staff, one MVME processor card running VxWorks 5.5, multiple Echotek Digital Receiver boards complimented by custom made Filter Board. The VxWorks based front-end software communicates with the Main Accelerator Control software via a special

  5. The Next Linear Collider Design: NLC 2001

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Alberta

    2001-08-21

    Recent studies in elementary particle physics have made the need for an e{sup +}e{sup -} linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it is. These experiments must also define the next important threshold in energy. The need is to understand physics at the TeV energy scale as well as the physics at the 100-GeV energy scale is now understood. This will require both the LHC and a companion linear electron-positron collider.

  6. The Next Linear Collider Design: NLC 2001

    International Nuclear Information System (INIS)

    Larsen, Alberta

    2001-01-01

    Recent studies in elementary particle physics have made the need for an e + e - linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it is. These experiments must also define the next important threshold in energy. The need is to understand physics at the TeV energy scale as well as the physics at the 100-GeV energy scale is now understood. This will require both the LHC and a companion linear electron-positron collider

  7. Celebrating the Tevatron legacy

    CERN Multimedia

    2012-01-01

    Fermilab hosted an exceptional event on 11 June: the Tevatron Impact symposium. More than 800 people attended to hear how the Tevatron advanced our understanding of fundamental physics.   A version of this "Director's Corner" by Pier Oddone first appeared in Fermilab Today on 12 June.   The development of accelerator technology for the Tevatron has influenced every subsequent major hadron accelerator. We heard reviews on the detector technologies and trigger systems developed with the Tevatron that are essential today for high-luminosity machines like the LHC. There were also talks on the superconducting-wire industry that made MRI magnets ubiquitous, and we discussed the major computational systems that use large farms of Linux-based commodity processors. Researchers who worked on the Tevatron also established multivariate analysis techniques that now allow us to squeeze the maximum information from complex data sets. One focus of the symposium was the ...

  8. GARLIC: GAmma Reconstruction at a LInear Collider experiment

    International Nuclear Information System (INIS)

    Jeans, D; Brient, J-C; Reinhard, M

    2012-01-01

    The precise measurement of hadronic jet energy is crucial to maximise the physics reach of a future Linear Collider. An important ingredient required to achieve this is the efficient identification of photons within hadronic showers. One configuration of the ILD detector concept employs a highly granular silicon-tungsten sampling calorimeter to identify and measure photons, and the GARLIC algorithm described in this paper has been developed to identify photons in such a calorimeter. We describe the algorithm and characterise its performance using events fully simulated in a model of the ILD detector.

  9. GARLIC: GAmma Reconstruction at a LInear Collider experiment

    Science.gov (United States)

    Jeans, D.; Brient, J.-C.; Reinhard, M.

    2012-06-01

    The precise measurement of hadronic jet energy is crucial to maximise the physics reach of a future Linear Collider. An important ingredient required to achieve this is the efficient identification of photons within hadronic showers. One configuration of the ILD detector concept employs a highly granular silicon-tungsten sampling calorimeter to identify and measure photons, and the GARLIC algorithm described in this paper has been developed to identify photons in such a calorimeter. We describe the algorithm and characterise its performance using events fully simulated in a model of the ILD detector.

  10. A feedback microprocessor for hadron colliders

    International Nuclear Information System (INIS)

    Herrup, D.A.; Chapman, L.; Franck, A.; Groves, T.; Lublinsky, B.

    1992-12-01

    A feedback microprocessor has been built for the TEVATRON. It has been constructed to be applicable to hadron colliders in general. Its inputs are realtime accelerator measurements, data describing the state of the TEVATRON, and ramp tables. The microprocessor software includes a finite state machine. Each state corresponds to a specific TEVATRON operation and has a state-specific TEVATRON model. Transitions between states are initiated by the global TEVATRON clock. Each state includes a cyclic routine which is called periodically and where all calculations are performed. The output corrections are inserted onto a fast TEVATRON-wide link from which the power supplies will read the realtime corrections. We also store all of the input data and output corrections in a set of buffers which can easily be retrieved for diagnostic analysis. In this paper we will describe this device and its use to control the TEVATRON tunes as well as other possible applications

  11. Electron density and plasma dynamics of a colliding plasma experiment

    Energy Technology Data Exchange (ETDEWEB)

    Wiechula, J., E-mail: wiechula@physik.uni-frankfurt.de; Schönlein, A.; Iberler, M.; Hock, C.; Manegold, T.; Bohlender, B.; Jacoby, J. [Plasma Physics Group, Institute of Applied Physics, Goethe University, 60438 Frankfurt am Main (Germany)

    2016-07-15

    We present experimental results of two head-on colliding plasma sheaths accelerated by pulsed-power-driven coaxial plasma accelerators. The measurements have been performed in a small vacuum chamber with a neutral-gas prefill of ArH{sub 2} at gas pressures between 17 Pa and 400 Pa and load voltages between 4 kV and 9 kV. As the plasma sheaths collide, the electron density is significantly increased. The electron density reaches maximum values of ≈8 ⋅ 10{sup 15} cm{sup −3} for a single accelerated plasma and a maximum value of ≈2.6 ⋅ 10{sup 16} cm{sup −3} for the plasma collision. Overall a raise of the plasma density by a factor of 1.3 to 3.8 has been achieved. A scaling behavior has been derived from the values of the electron density which shows a disproportionately high increase of the electron density of the collisional case for higher applied voltages in comparison to a single accelerated plasma. Sequences of the plasma collision have been taken, using a fast framing camera to study the plasma dynamics. These sequences indicate a maximum collision velocity of 34 km/s.

  12. Top quarks at the Tevatron: Measurements of the top quark production and decay with the D0 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Strandberg, Jonas [Stockholm Univ. (Sweden)

    2006-01-01

    This thesis presents two measurements of the to pquark using 230 pb-1 of data recorded with the D0 detector at the Tevatron accelerator. The first measurement determines the top pair production cross section at √s = 1.96 TeV in proton-antiproton collisions. In the standard model of particle physics the top quark decays almost exclusively into a W boson and a b quark. Candidate events are selected by requiring that at least one jet in the event is tagged with the secondary vertex algorithm.

  13. Study of jet production in ALICE experiment at LHC collider

    CERN Document Server

    Jangal, Swensy

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

  14. Search for the Higgs boson in the ZH → νν-bar bb-bar channel with the D0 experiment at the TeVatron

    International Nuclear Information System (INIS)

    Ochando, Ch.

    2008-09-01

    The origin of the electroweak symmetry breaking is one the pending questions at the beginning of the 21. century. Imagined in the 1960's, the Higgs mechanism offers a theoretical solution to this problem, while predicting a new particle, the Higgs boson, undiscovered up to now. This particle has been searched with the DO detector at the Tevatron hadronic collider, with a center of mass energy of 1,96 TeV. The analysis channel is ZH → νν-bar bb-bar. For this search, an optimization of the trigger conditions specific to signals with jets plus missing transverse energy final states has been performed. Moreover, a tool was designed to measure the corresponding efficiencies. A precise determination of the jet energies is also an essential ingredient for this analysis. A method was developed in order to correct the simulated jets for the differences observed in jet energy scale, energy resolution and reconstruction efficiency between data and simulation. The data analysis, performed with an integrated luminosity of 2.1 fb -1 , did not reveal any excess. For a Higgs boson mass of 115 GeV, a limit has been set at 95% C.L. on the cross section times branching fraction of (pp-barb → H(Z/W)) x (H → bar bb-bar), which is 7.5 times larger than the standard model value. (author)

  15. Tevatron lower temperature operation

    International Nuclear Information System (INIS)

    Theilacker, J.C.

    1994-07-01

    This year saw the completion of three accelerator improvement projects (AIP) and two capital equipment projects pertaining to the Tevatron cryogenic system. The projects result in the ability to operate the Tevatron at lower temperature, and thus higher energy. Each project improves a subsystem by expanding capabilities (refrigerator controls), ensuring reliability (valve box, subatmospheric hardware, and compressor D), or enhancing performance (cold compressors and coldbox II). In January of 1994, the Tevatron operated at an energy of 975 GeV for the first time. This was the culmination, of many years of R ampersand D, power testing in a sector (one sixth) of the Tevatron, and final system installation during the summer of 1993. Although this is a modest increase in energy, the discovery potential for the Top quark is considerably improved

  16. Effect of 3D Polarization profiles on polarization measurements and colliding beam experiments

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, W.; Bazilevsky, A.

    2011-08-18

    The development of polarization profiles are the primary reason for the loss of average polarization. Polarization profiles have been parametrized with a Gaussian distribution. We derive the effect of 3-dimensional polarization profiles on the measured polarization in polarimeters, as well as the observed polarization and the figure of merit in single and double spin experiments. Examples from RHIC are provided. The Relativistic Heavy Ion Collider (RHIC) is the only collider of spin polarized protons. During beam acceleration and storage profiles of the polarization P develop, which affect the polarization measured in a polarimeter, and the polarization and figure of merit (FOM) in colliding beam experiments. We calculate these for profiles in all dimensions, and give examples for RHIC. Like in RHIC we call the two colliding beams Blue and Yellow. We use the overbar to designate intensity-weighted averages in polarimeters (e.g. {bar P}), and angle brackets to designate luminosity-weighted averages in colliding beam experiments (e.g.

    ).

  17. Effect of 3D Polarization profiles on polarization measurements and colliding beam experiments

    International Nuclear Information System (INIS)

    Fischer, W.; Bazilevsky, A.

    2011-01-01

    The development of polarization profiles are the primary reason for the loss of average polarization. Polarization profiles have been parametrized with a Gaussian distribution. We derive the effect of 3-dimensional polarization profiles on the measured polarization in polarimeters, as well as the observed polarization and the figure of merit in single and double spin experiments. Examples from RHIC are provided. The Relativistic Heavy Ion Collider (RHIC) is the only collider of spin polarized protons. During beam acceleration and storage profiles of the polarization P develop, which affect the polarization measured in a polarimeter, and the polarization and figure of merit (FOM) in colliding beam experiments. We calculate these for profiles in all dimensions, and give examples for RHIC. Like in RHIC we call the two colliding beams Blue and Yellow. We use the overbar to designate intensity-weighted averages in polarimeters (e.g. (bar P)), and angle brackets to designate luminosity-weighted averages in colliding beam experiments (e.g. ).

  18. Electroweak, top and bottom physics at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Ukegawa, Fumihiko; /Tsukuba U.

    2004-10-01

    The Tevatron Run-II program has been in progress since 2001, and the CDF and D0 experiments have been operational with upgraded detectors. Coupled with recent improvements in the Tevatron accelerator performance, the experiments have started producing important physics results and measurements. They report these measurements as well as prospects in the near future.

  19. GEM Detectors in the Experiments at e+e- Colliders in BINP

    CERN Document Server

    Maltsev, T V

    2017-01-01

    Micro-pattern gaseous detectors possess a high spatial resolution in tens micron scale together with high rate capability up to 107 cm-2s-1. In addition, they have all advantages of gaseous detectors, such as relatively low costs per unit area, the possibility to equip a large area as well as a high uniformity. Cascaded Gas Electron Multiplier (GEM) based detectors are used in the collider experiments at Budker Institute of Nuclear Physics (BINP), and they are being developed for a number of new projects. In this article the review of GEM based detectors for the tagging system of the KEDR experiment at the VEPP-4M collider and for the DEUTERON facility at the VEPP-3 storage ring is presented. The GEM detector application of the CMD-3 detector upgrade at the VEPP-2000 collider and the Super τ Factory detector are discussed.

  20. Cryogenic testing and analysis associated with Tevatron lower temperature operation

    International Nuclear Information System (INIS)

    Theilacker, J.C.

    1996-09-01

    An upgrade of the Tevatron cryogenic system was installed and commissioned in 1993 to allow lower temperature operation. As a result, higher energy operation is possible. Following the installation and initial commissioning, it was decided to continue the current colliding beam physics at the previous energy of 900 GeV. This has allowed us to perform parasitic lower temperature tests in the Tevatron over the last year and a half. This paper presents the results of operational experiences and thermal and hydraulic testing which has taken place. The primary goal of the testing is to better understand the operation of the cold compressor system, associated instrumentation, and the performance of the existing magnet system during lower temperature operation. This will lead to a tentatively scheduled higher energy test run in the fall of 1995. The test results have shown that more elaborate controlling methods are necessary in order to achieve reliable system operation. Fortunately, our new satellite refrigerator controls system is capable of the expansion necessary to reach our goal. New features are being added to the control system which will allow for more intelligent control and better diagnostics for component monitoring and trending

  1. Review of Physics Results from the Tevatron: Searches for New Particles and Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Toback, David [Texas A-M; ŽIvković, Lidija [Belgrade U.

    2015-02-17

    We present a summary of results for searches for new particles and interactions at the Fermilab Tevatron collider by the CDF and the D0 experiments. These include results from Run I as well as Run II for the time period up to July 2014. We focus on searches for supersymmetry, as well as other models of new physics such as new fermions and bosons, various models of excited fermions, leptoquarks, technicolor, hidden-valley model particles, long-lived particles, extra dimensions, dark matter particles, and signature-based searches.

  2. 2nd CERN-Fermilab Hadron Collider Physics Summer School

    CERN Document Server

    Gian Giudice; Ellis, Nick; Jakobs, Karl; Mage, Patricia; Seymour, Michael H; Spiropulu, Maria; Wilkinson, Guy; CERN-FNAL Summer School; Hadron Collider Physics Summer School

    2007-01-01

    For the past few years, experiments at the Fermilab Tevatron Collider have once again been exploring uncharted territory at the current energy frontier of particle physics. With CERN's LHC operations to start in 2007, a new era in the exploration of the fundamental laws of nature will begin. In anticipation of this era of discovery, Fermilab and CERN are jointly organizing a series of "Hadron Collider Physics Summer Schools", whose main goal is to offer a complete picture of both the theoretical and experimental aspects of hadron collider physics. Preparing young researchers to tackle the current and anticipated challenges at hadron colliders, and spreading the global knowledge required for a timely and competent exploitation of the LHC physics potential, are concerns equally shared by CERN, the LHC host laboratory, and by Fermilab, the home of the Tevatron and host of CMS's LHC Physics Center in the U.S. The CERN-Fermilab Hadron Collider Physics Summer School is targeted particularly at young postdocs in exp...

  3. Present searches for Higgs signatures at the Tevatron

    International Nuclear Information System (INIS)

    Groer, L.

    1997-08-01

    We present results for various searches for signatures of standard and non-standard model Higgs boson decays conducted at the collider detectors CDF and D0 using ∼100 pb -1 of integrated luminosity each from the Tevatron collider Run 1 (1992-96) at √s=1.8 TeV. No evidence for a Higgs boson decay is found and various limits are set

  4. Increasing the energy of the Fermilab Tevatron accelerator

    International Nuclear Information System (INIS)

    Fuerst, J.D.; Theilacker, J.C.

    1994-07-01

    The superconducting Tevatron accelerator at Fermilab has reached its eleventh year of operation since being commissioned in 1983. Last summer, four significant upgrades to the cryogenic system became operational which allow Tevatron operation at higher energy. This came after many years of R ampersand D, power testing in sectors (one sixth) of the Tevatron, and final system installation. The improvements include the addition of cold helium vapor compressors, supporting hardware for subatmospheric operation, a new satellite refrigerator control system, and a higher capacity central helium liquefier. A description of each cryogenic upgrade, commissioning experience, and attempts to increase the energy of the Tevatron are presented

  5. Channeling and Volume Reflection Based Crystal Collimation of Tevatron Circulating Beam Halo

    CERN Document Server

    Shiltsev, V.; Drozhdin, A.; Johnson, T.; Legan, A.; Mokhov, N.; Reilly, R.; Still, D.; Tesarek, R.; Zagel, J.; Peggs, S.; Assmann, R.; Previtali, V.; Scandale, W.; Chesnokov, Y.; Yazynin, I.; Guidi, V.; Ivanov, Y.

    2010-01-01

    The T980 crystal collimation experiment is underway at the Tevatron to determine if this technique could increase 980 GeV beam-halo collimation efficiency at high-energy hadron colliders such as the Tevatron and the LHC. T980 also studies various crystal types and parameters. The setup has been substantially enhanced during the Summer 2009 shutdown by installing a new O-shaped crystal in the horizontal goniometer, as well as adding a vertical goniometer with two alternating crystals (O-shaped and multi-strip) and additional beam diagnostics. First measurements with the new system are quite encouraging, with channeled and volume-reflected beams observed on the secondary collimators as predicted. Investigation of crystal collimation efficiencies with crystals in volume reflection and channeling modes are described in comparison with an amorphous primary collimator. Results on the system performance are presented for the end-of-store studies and for entire collider stores. The first investigation of colliding be...

  6. New Experiments with Antiprotons

    Science.gov (United States)

    Kaplan, D. M.

    2011-12-01

    Fermilab operates the world's most intense antiproton source. Recently proposed experiments can use those antiprotons either parasitically during Teva-tron Collider running or after the Tevatron Collider finishes in about 2011. For example, the annihilation of 8 GeV antiprotons might make the world's most intense source of tagged D0 mesons, and thus the best near-term opportunity to study charm mixing and search for new physics via its CP-violation signature. Other possible precision measurements include properties of the X(3872) and the charmonium system. An experiment using a Penning trap and an atom interferometer could make the world's first measurement of the gravitational force on antimatter. These and other potential measurements using antiprotons could yield a broad physics program at Fermilab in the post-Tevatron era.

  7. Tests of QCD in W and Z production at Tevatron

    International Nuclear Information System (INIS)

    Abachi, S.

    1995-01-01

    We present measurements of the production cross sections times leptonic branching fractions and the transverse momentum distributions of W and Z bosons in p bar p collisions at √s = 1.8 TeV using data collected with the DO detector at the Fermilab Tevatron p bar p collider. A preliminary measurement of the W charge asymmetry is also presented

  8. Antiproton acceleration in the Fermilab Main Ring and Tevatron

    International Nuclear Information System (INIS)

    Martin, P.; Dinkel, J.; Ducar, R.

    1987-01-01

    The operation of the Fermilab Main Ring and Tevatron rf systems for colliding beams physics is discussed. The changes in the rf feedback system required for acceleration of antiprotons, and the methods for achieving proper transfer of both protons and antiprotons are described. Data on acceleration and transfer efficiencies are presented

  9. Generation and diagnostics of uncaptured beam in the Fermilab Tevatron and its control by electron lenses

    Directory of Open Access Journals (Sweden)

    Xiao-Long Zhang

    2008-05-01

    Full Text Available In the collider run II, the Tevatron operates with 36 high intensity bunches of 980 GeV protons and antiprotons. Particles not captured by the Tevatron rf system pose a threat since they can quench the superconducting magnets during acceleration or at beam abort. We describe the main mechanisms for the origination of this uncaptured beam, and present measurements of its main parameters by means of a newly developed diagnostics system. The Tevatron electron lens is effectively used in the collider run II operation to remove uncaptured beam and keep its intensity in the abort gaps at a safe level.

  10. RHIC Workshop: experiments for a relativistic heavy ion collider

    International Nuclear Information System (INIS)

    Haustein, P.E.; Woody, C.L.

    1985-01-01

    Separate abstracts were prepared for individual papers in this workshop proceedings, covering such topics as: calorimeter-based experiments, dimuon detection, large magnetic spectrometers, experiments in the fragmentation region, two-photon physics, and theoretical questions relevant to experimental work at the RHIC

  11. Colliding beam experiments in the Siberian Institute for Nuclear Physics (Present status and prospects)

    International Nuclear Information System (INIS)

    Budker, G.I.

    1982-01-01

    Present status of construction of colliding (electron, positron, proton, antiproton and muon) beam facilities is described. Experiments conducted at the VEP-1 and VEPP-2 facilities in 1968-1970 are enumerated. The program of forthcoming investigations at the VAPP-NAP facility is described in brief

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

    CERN Document Server

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

    2015-01-01

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

  13. An example of e-p colliding machine experiments at TRISTAN

    International Nuclear Information System (INIS)

    1980-01-01

    This is a design report of a possible detector system of the e-p colliding machine experiment at TRISTAN. The aim of this note is to know what kind of detectors should be developed and what kind of requirements the TRISTAN machines and the environmental supporting facilities should fulfill. (author)

  14. High gradient experiment by accelerator test facility for Japan Linear Collider

    International Nuclear Information System (INIS)

    Takeda, Seishi; Akemoto, Mitsuo; Hayano, Hitoshi; Naito, Takashi; Matsumoto, Hiroshi

    1991-01-01

    For the e + e - linear colliders in TeV energy region such as the Japan Linear Collider (JLC), the accelerating gradient will be one of the important parameters affecting the over all design of main linacs. The gradient determines the accelerating structures, RF frequencies, peak power, AC power, total length and cost. High gradient experiment by using a traveling wave structure in S-band frequencies is presented. Discussions are given about the dependence of dark current and structure length. As one of the parameters indicating the quality of the structure, the multiplication factor η has been proposed

  15. The STAR experiment at the relativistic heavy ion collider

    Energy Technology Data Exchange (ETDEWEB)

    Adams, D L; Added, N; Ahmad, S; Akimenko, S A; Anderson, B D; Anderson, G T; Anjos, R M; Aprahamian, A; Arestov, Yu I; Atkin, E; Baldwin, A; Baublis, V; Beddo, M E; Belikov, N I; Bellwied, R; Belousov, V I; Bennett, S; Bercovitz, J; Bertram, I; Bielecki, J; Bieser, F; Biswas, N N; Bloomer, M A; Bonner, B E; Brady, F P; Braithwaite, W J; Braun, L; Buchanan, J A; Carlin, N; Carroll, J B; Cebra, D A; Chacon, A D; Chan, C S; Chan, K S; Chase, S I; Cherney, M G; Choudhury, R K; Christie, W; Chujko, B V; Clement, J M; Corcoran, M D; Cormier, T M; Cramer, J G; Crawford, H J; Davidenko, A M; Dawson, J W; Debbe, R; Derevschikov, A A; DeYoung, P A; Dominik, W; Dou, L; Draper, J E; Duck, I; Edwards, W R; Eiseman, S E; Engelage, J M; Erin, S V; Etkin, A; Ferenc, D; Flores, I; Foley, K J; Fraenkel, Z; French, A; Friedlander, E; Fritz, D; Garg, U; Gazdzicki, M; Ghazikhanian, V; Glass, G; Gong, W; Grachov, O A; Grebiezkow, J; Greiner, D; Greiner, L C; Grimson, E; Grosnick, D P; Grushin, V; Guarino, V J; Haberichter, W N; Hackenburg, R W; Hall, J; Hallman, T J; Harris, J W; Hearn, W E; Hill, D A; Hill, N; Hirsch, A S; Hjort, E; Hoffmann, G W; Huang, H; Humanic, T J; Igo, G J; Jacobs, P M; Jayanti, R; Jones, P G; Judd, E; Justice, M L; Kadija, K; Kaplan, M; Karol, P J; Kasprzyk, T; Keane, D; Kenney, V P; Khodinov, A; Kleinfelder, S A; Konstantinov, A S; Kostin, D; Kotov, I; Kozlov, V; Kramer, M A; Kuryatkov, V; LaPierre, R L; Lasiuk, B; Lebedev, A; LeVine, M J; Li, Q; Lindenbaum, S J; Lindenstruth, V; Lindstrom, P J; Ljubicic, A Jr; Llope, W J; Longacre, R S; Lopiano, D X; Love, W A; Madansky, L; Margetis, S; Marx, J; Matis, H S; Matulenko, Yu A; McParland, C P; McShane, T S; Meschanin, A P; Milosevich, Z; Miphtakhov, N; Mirk, K; Mitchell, J; Mitchell, J L; Moore, C F; Mordechai, S; Morse, R; Murgatroyd, J; Mutchler, G S; STAR Collaboration

    1994-01-03

    The authors describe an experiment at the Brookhaven RHIC for the study of hadron production in order to detect signatures of QGP formation. The detector is a solenoidal tracker. Expected results for hard QCD processes in pp, pAu, and AuAu reactions are presented. (HSI)

  16. Update to Proposal for an Experiment to Measure Mixing, CP Violation and Rare Decays in Charm and Beauty Particle Decays at the Fermilab Collider - BTeV

    Energy Technology Data Exchange (ETDEWEB)

    Butler, Joel [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Stone, Sheldon [Syracuse Univ., NY (United States)

    2002-03-01

    We have been requested to submit an update of the BTeV plan to the Fermilab Physics Advisory Committee, where to save money the detector has only one arm and there is no new interaction region magnet construction planned. These are to come from a currently running collider experiment at the appropriate time. The "Physics Case" section is complete and updated with the section on the "New Physics" capabilites of BTeV greatly expanded. We show that precise measurements of rare flavor-changing neutral current processes and CP violation are and will be complementary to the Tevatron and LHC in unraveling the electroweak breaking puzzle. We include a revised summary of the physics sensitivities for the one-arm detector, which are not simply taking our proposal numbers and dividing by two, because of additional improvements. One important change resulted from an improved understanding of just how important the RJCH detector is to muon and electron identification, that we can indeed separate electrons from pions and muons from pions, especially at relatively large angles beyond the physical aperture of the EM calorimeter or the Muon Detector. This is documented in the "Physics Sensitivities" section. The section on the detector includes the motivation for doing b and c physics at a hadron collider, and shows the changes in the detector since the proposal based on our ongoing R&D program. We do not here include a detailed description of the entire detector. That is available in the May, 2000 proposal. We include a summary of our R&D activities for the entire experiment. Finally, we also include a fully updated cost estimate for the one-arm system.

  17. Benchmarking the Particle Background in the Large Hadron Collider Experiments

    CERN Document Server

    Gschwendtner, Edda; Fabjan, Christian Wolfgang; Hessey, N P; Otto, Thomas

    2002-01-01

    Background benchmarking measurements have been made to check the low-energy processes which will contribute via nuclear reactions to the radiation background in the LHC experiments at CERN. Previously these processes were only evaluated with Monte Carlo simulations, estimated to be reliable within an uncertainty factor of 2.5. Measurements were carried out in an experimental set-up comparable to the shielding of ATLAS, one of the general-purpose experiments at LHC. The absolute yield and spectral measurements of photons and neutrons emanating from the final stages of the hadronic showers were made with a Bi_4Ge_3O_{12} (BGO) detector. The particle transport code FLUKA was used for detailed simulations. Comparison between measurements and simulations show that they agree within 20% and hence the uncertainty factor resulting from the shower processes can be reduced to a factor of 1.2.

  18. The TOTEM Experiment at the CERN Large Hadron Collider

    Science.gov (United States)

    TOTEM Collaboration; Anelli, G.; Antchev, G.; Aspell, P.; Avati, V.; Bagliesi, M. G.; Berardi, V.; Berretti, M.; Boccone, V.; Bottigli, U.; Bozzo, M.; Brücken, E.; Buzzo, A.; Cafagna, F.; Calicchio, M.; Capurro, F.; Catanesi, M. G.; Catastini, P. L.; Cecchi, R.; Cerchi, S.; Cereseto, R.; Ciocci, M. A.; Cuneo, S.; Da Vià, C.; David, E.; Deile, M.; Dimovasili, E.; Doubrava, M.; Eggert, K.; Eremin, V.; Ferro, F.; Foussat, A.; Galuška, M.; Garcia, F.; Gherarducci, F.; Giani, S.; Greco, V.; Hasi, J.; Haug, F.; Heino, J.; Hilden, T.; Jarron, P.; Joram, C.; Kalliopuska, J.; Kaplon, J.; Kašpar, J.; Kundrát, V.; Kurvinen, K.; Lacroix, J. M.; Lami, S.; Latino, G.; Lauhakangas, R.; Lippmaa, E.; Lokajíček, M.; Lo Vetere, M.; Rodriguez, F. Lucas; Macina, D.; Macrí, M.; Magazzù, C.; Magazzù, G.; Magri, A.; Maire, G.; Manco, A.; Meucci, M.; Minutoli, S.; Morelli, A.; Musico, P.; Negri, M.; Niewiadomski, H.; Noschis, E.; Notarnicola, G.; Oliveri, E.; Oljemark, F.; Orava, R.; Oriunno, M.; Perrot, A.-L.; Österberg, K.; Paoletti, R.; Pedreschi, E.; Petäjäjärvi, J.; Pollovio, P.; Quinto, M.; Radermacher, E.; Radicioni, E.; Rangod, S.; Ravotti, F.; Rella, G.; Robutti, E.; Ropelewski, L.; Ruggiero, G.; Rummel, A.; Saarikko, H.; Sanguinetti, G.; Santroni, A.; Scribano, A.; Sette, G.; Snoeys, W.; Spinella, F.; Squillacioti, P.; Ster, A.; Taylor, C.; Tazzioli, A.; Torazza, D.; Trovato, A.; Trummal, A.; Turini, N.; Vacek, V.; Van Remortel, N.; Vinš, V.; Watts, S.; Whitmore, J.; Wu, J.

    2008-08-01

    The TOTEM Experiment will measure the total pp cross-section with the luminosity-independent method and study elastic and diffractive scattering at the LHC. To achieve optimum forward coverage for charged particles emitted by the pp collisions in the interaction point IP5, two tracking telescopes, T1 and T2, will be installed on each side in the pseudorapidity region 3.1 <= |η| <= 6.5, and Roman Pot stations will be placed at distances of ±147 m and ±220 m from IP5. Being an independent experiment but technically integrated into CMS, TOTEM will first operate in standalone mode to pursue its own physics programme and at a later stage together with CMS for a common physics programme. This article gives a description of the TOTEM apparatus and its performance.

  19. Light dark sector at colliders and fixed target experiments

    OpenAIRE

    Darmé, Luc; Rao, Soumya; Roszkowski, Leszek

    2018-01-01

    Minimal scenarios with light (sub-GeV) thermal dark matter are usually accompanied by a correspondingly light "dark sector". Taking as an example a simple fermionic dark matter model, we will show that the presence of the dark sector plays a key role in constraining such scenarios at accelerators experiments. The effect of including a dark Higgs boson in the light spectrum is in particular investigated.

  20. A new trend in photomultiplier techniques and its implications in future collider experiments

    International Nuclear Information System (INIS)

    Kuroda, K.

    1989-01-01

    A recent trend in photomultiplier techniques, characterized by immunity to magnetic fields and position sensitivity of modern photomultiplier tubes, would potentially have great importance in future collider experiments. This article presents a survey on the actual status of the art, and some implications of such new techniques in future high-energy experiments. As an example of applications, our recent project of constructing an ultrafast scintillating-fibre detector on the basis of upgraded position-sensitive PMTs is outlined. (orig.)

  1. High performance distributed objects in large hadron collider experiments

    International Nuclear Information System (INIS)

    Gutleber, J.

    1999-11-01

    This dissertation demonstrates how object-oriented technology can support the development of software that has to meet the requirements of high performance distributed data acquisition systems. The environment for this work is a system under planning for the Compact Muon Solenoid experiment at CERN that shall start its operation in the year 2005. The long operational phase of the experiment together with a tight and puzzling interaction with custom devices make the quest for an evolvable architecture that exhibits a high level of abstraction the driving issue. The question arises if an existing approach already fits our needs. The presented work casts light on these problems and as a result comprises the following novel contributions: - Application of object technology at hardware/software boundary. Software components at this level must be characterised by high efficiency and extensibility at the same time. - Identification of limitations when deploying commercial-off-the-shelf middleware for distributed object-oriented computing. - Capturing of software component properties in an efficiency model for ease of comparison and improvement. - Proof of feasibility that the encountered deficiencies in middleware can be avoided and that with the use of software components the imposed requirements can be met. - Design and implementation of an on-line software control system that allows to take into account the ever evolving requirements by avoiding hardwired policies. We conclude that state-of-the-art middleware cannot meet the required efficiency of the planned data acquisition system. Although new tool generations already provide a certain degree of configurability, the obligation to follow standards specifications does not allow the necessary optimisations. We identified the major limiting factors and argue that a custom solution following a component model with narrow interfaces can satisfy our requirements. This approach has been adopted for the current design

  2. Mixing in the $D^0$ system Results from collider experiments

    CERN Document Server

    Grothe, Monika

    2003-01-01

    Mixing in the $D^0$ system may provide a sensitive probe for new physics beyond the Standard Model (SM) but has so far eluded experimental observation. The SM predictions are typically small ($< 10^{-3}$) for the mixing parameters $x$, $y$ which, in the absence of charge-parity ($CP$) symmetry violation, measure the mass ($x= Delta m/ Gamma$) and lifetime ($y= Delta Gamma / 2 Gamma$) difference of the $CP$ eigenstates in the $D^0$ system. The asymmetric $B$-factory experiments BABAR and Belle open up the opportunity of measuring $x$, $y$ with unprecedented statistical precision and sample purities. Results from BABAR and Belle, and from CLEO are reviewed.

  3. 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.)

  4. Present state of Tevatron lower temperature operation

    International Nuclear Information System (INIS)

    Norris, B.L.

    1996-09-01

    Fermilab continues to work on raising the particle energy of the Tevatron by lowering magnet temperatures using cold vapor compressors. In 1995, another two rounds of power tests were completed. These power tests, although showing significant improvement over the initial tests of 1993-94, have led to the conclusion that 1000 GeV operation cannot be attained without replacing/rearranging magnets with lower quench currents before the next Collider Run in 1999. Development of more cold compressor control strategies also continues

  5. Electron Beam Generation in Tevatron Electron Lenses

    International Nuclear Information System (INIS)

    Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; Tiunov, M.

    2006-01-01

    New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices

  6. Electron beam generation in Tevatron electron lenses

    International Nuclear Information System (INIS)

    Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; Tiunov, M.

    2006-01-01

    New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices

  7. Experiments at the Large Hadron Collider - How are discoveries made?

    CERN Multimedia

    Emma Sanders

    2011-01-01

    With the LHC up and running, some might imagine physicists just waiting for a Higgs boson to pop up in one of the four experiments, before publishing a paper and moving on to solve science’s next Big Mystery. However this picture is very far from the reality of experimental particle physics today, where results are based on statistics, statistics and yet more statistics.   Simulated Higgs decaying into four muons in the ATLAS detector. This is because new particles are hardly ever detected directly. Depending on the design of the experiment, there can be several centimetres between the collision point and the first layer of detector electronics. This is a vast distance on the scale of a subatomic particle. Particles created in the collisions interact and indeed decay before ever reaching the detector. If created in an LHC collision, the Higgs boson, for example, is expected to last for a mere trillionth of a trillionth of a second*, before decaying into other particles – not l...

  8. Standard model Higgs physics at colliders

    International Nuclear Information System (INIS)

    Rosca, A.

    2007-01-01

    In this report we briefly review the experimental status and prospects to verify the Higgs mechanism of spontaneous symmetry breaking. The focus is on the most relevant aspects of the phenomenology of the Standard Model Higgs boson at current (Tevatron) and future (Large Hadron Collider, LHC and International Linear Collider, ILC) particle colliders. We review the Standard Model searches: searches at the Tevatron, the program planned at the LHC and prospects at the ILC. Emphasis is put on what follows after a candidate discovery at the LHC: the various measurements which are necessary to precisely determine what the properties of this Higgs candidate are. (author)

  9. Hard diffraction at HERA and Tevatron

    International Nuclear Information System (INIS)

    Kaidalov, A.B.

    2001-01-01

    A relation between hard diffraction at HERA and Tevatron is discussed. A model, which takes into account unitarity effects is developed for interaction of high-energy virtual photons with nucleons. It is shown that this model gives a good description of HERA data on both total γ* p total cross section and diffractive dissociation of virtual photons in a broad region of Q 2 . It is shown how to describe the CDF data on diffractive jet production at Tevatron using an information on distribution of partons in the Pomeron from HERA experiments

  10. Detector implications for eletroweak physics at the Tevatron

    International Nuclear Information System (INIS)

    Madaras, R.J.

    1996-12-01

    D0 and CDF are two large, powerful, multipurpose detectors with outstanding tracking, calorimeter and muon systems that have done an excellent job in exploiting the Top Quark, b Quark, QCD, New Phenomena/Exotics and Electroweak Physics at the Fermilab Tevatron Collider. The upgrades of the D0 and CDF detectors will further enhance their capabilities for physics at the Tevatron. The addition of a magnetic field and silicon vertex chamber will open up new physical opportunities for D0, and the replacement of the plug and forward gas calorimeters with new scintillator based calorimeters will give CDF uniform calorimetry over all η

  11. 'Electron compression' of beam-beam footprint in the Tevatron

    International Nuclear Information System (INIS)

    Shiltsev, V.; Finley, D.A.

    1997-08-01

    The beam-beam interaction in the Tevatron collider sets some limits on bunch intensity and luminosity. These limits are caused by a tune spread in each bunch which is mostly due to head-on collisions, but there is also a bunch-to-bunch tune spread due to parasitic collisions in multibunch operation. We describe a counter-traveling electron beam which can be used to eliminate these effects, and present general considerations and physics limitations of such a device which provides 'electron compression' of the beam-beam footprint in the Tevatron

  12. Production of single top quark - results from the Tevatron and the LHC

    CERN Document Server

    Moon, Chang-Seong

    2014-01-01

    We present the most recent measurements of single top quark production cross section by the CDF and D0 experiments at the Fermilab Tevatron Collider and the ATLAS and CMS experiments at the Large Hadron Collider (LHC). The data were collected at the Tevatron corresponding to an integrated luminosity of up to 9.7 fb$^{-1}$ of proton-antiproton ($p\\bar p$) collisions at a centre-of-mass energy of 1.96 TeV and at the LHC corresponding to an integrated luminosity of up to 4.9 fb$^{-1}$ of proton-proton ($pp$) collisions at a centre-of-mass energy of 7 TeV in 2011 and up to 20.3 fb$^{-1}$ at a centre-of-mass energy of 8 TeV in 2012. The measurements of single top quark production in $s$-channel, $t$-channel and associated production of a top quark and a $W$-boson ($tW$ production) are presented separately and lower limits on the CKM matrix element $|V_{tb}|$ from the single top quark cross section are set.

  13. Scintillator calorimeters for a future linear collider experiment

    Energy Technology Data Exchange (ETDEWEB)

    Hartbrich, Oskar

    2016-07-15

    shower start shows considerable differences between physics lists, especially for the higher end of beam energies available in this analysis. Two separate energy reconstruction algorithms are presented in this thesis. The standard reconstruction uses constant weights per sub-detector to reconstruct the primary pion energy. The implementation of a software compensation reconstruction developed for this analysis aims to distinguish electromagnetic sub-shower depositions in hadronic showers by the deposited energy in each hit. The implementation differs from a previous software compensation scheme used within CALICE by forcing less dependencies on the shapes of the optimised weights, increasing the number of free parameters but ultimately resulting in a more stable parameter optimisation. The software compensation reconstruction improves the energy resolution of data events by 10% to 20%. Applying the software compensation weights obtained from simulations to data events yields a similar performance compared to the native data weights, slightly degrading the response linearity while even slightly improving the energy resolution. The calorimeter prototypes used in the testbeam analysis presented in this thesis were built to prove the general feasibility of high granularity scintillator-SiPM calorimeters, which they fully accomplished. To demonstrate the scalability of such calorimeters to the size and requirements of a full-scale particle physics experiment as ILD, second generation prototypes with fully integrated readout electronics are developed within the CALICE collaboration. A toy simulation study performed for this thesis shows that the development of scintillator-SiPM tile systems should target a lightyield of 15 (px)/(MIP) in order to maintain a 95% MIP efficiency even for 2σ outliers, when assuming a hit energy threshold of 0.5 MIP. An efficient method to extract and validate trigger thresholds positions for all cells of the detector system is presented, requiring

  14. Scintillator calorimeters for a future linear collider experiment

    International Nuclear Information System (INIS)

    Hartbrich, Oskar

    2016-07-01

    shower start shows considerable differences between physics lists, especially for the higher end of beam energies available in this analysis. Two separate energy reconstruction algorithms are presented in this thesis. The standard reconstruction uses constant weights per sub-detector to reconstruct the primary pion energy. The implementation of a software compensation reconstruction developed for this analysis aims to distinguish electromagnetic sub-shower depositions in hadronic showers by the deposited energy in each hit. The implementation differs from a previous software compensation scheme used within CALICE by forcing less dependencies on the shapes of the optimised weights, increasing the number of free parameters but ultimately resulting in a more stable parameter optimisation. The software compensation reconstruction improves the energy resolution of data events by 10% to 20%. Applying the software compensation weights obtained from simulations to data events yields a similar performance compared to the native data weights, slightly degrading the response linearity while even slightly improving the energy resolution. The calorimeter prototypes used in the testbeam analysis presented in this thesis were built to prove the general feasibility of high granularity scintillator-SiPM calorimeters, which they fully accomplished. To demonstrate the scalability of such calorimeters to the size and requirements of a full-scale particle physics experiment as ILD, second generation prototypes with fully integrated readout electronics are developed within the CALICE collaboration. A toy simulation study performed for this thesis shows that the development of scintillator-SiPM tile systems should target a lightyield of 15 (px)/(MIP) in order to maintain a 95% MIP efficiency even for 2σ outliers, when assuming a hit energy threshold of 0.5 MIP. An efficient method to extract and validate trigger thresholds positions for all cells of the detector system is presented, requiring

  15. Initial performance of upgraded Tevatron cryogenic systems

    International Nuclear Information System (INIS)

    Norris, B.L.

    1996-09-01

    Fermilab began operating a re-designed satellite refrigerator systems in November 1993. Upgrades were installed to operate the Tevatron at a magnet temperature of 3.5 K, approximately 1K lower than the original design. Refrigerator upgrades included new valve boxes, larger reciprocating expanders, the installation of cold vapor compressors, new sub-atmospheric instrumentation and an entirely new distributed controls system. Cryogenic system reliability data for Colliding Physics Run 1B is presented emphasizing a failure analysis for each aspect of the upgrade. Comparison to data for Colliding Physics Run 1A (previous to upgrade) is presented to show the impact of a major system overhaul. New operational problems and their solutions are presented in detail

  16. Physics Accomplishments and Future Prospects of the BES Experiments at the Beijing Electron-Positron Collider

    Science.gov (United States)

    Briere, Roy A.; Harris, Frederick A.; Mitchell, Ryan E.

    2016-10-01

    The cornerstone of the Chinese experimental particle physics program is a series of experiments performed in the τ-charm energy region. China began building e+e- colliders at the Institute for High Energy Physics in Beijing more than three decades ago. Beijing Electron Spectrometer (BES) is the common root name for the particle physics detectors operated at these machines. We summarize the development of the BES program and highlight the physics results across several topical areas.

  17. Operational Experience with and Performance of the ATLAS Pixel Detector at the Large Hadron Collider

    CERN Document Server

    Grummer, Aidan; The ATLAS collaboration

    2018-01-01

    The operational experience and requirements to ensure optimum data quality and data taking efficiency with the 4-layer ATLAS Pixel Detector are discussed. The detector has undergone significant hardware and software upgrades to meet the challenges imposed by the fact that the Large Hadron Collider is exceeding expectations for instantaneous luminosity by more than a factor of two (more than $2 \\times 10^{34}$ cm$^{-2}$ s$^{-1}$). Emphasizing radiation damage effects, the key status and performance metrics are described.

  18. Linear Collider Physics Resource Book Snowmass 2001

    Energy Technology Data Exchange (ETDEWEB)

    Ronan (Editor), M.T.

    2001-06-01

    The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decade or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e{sup +}e{sup -} linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e{sup +}e{sup -} linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e{sup +}e{sup -} linear collider; in any scenario that is now discussed, physics will benefit from the new information that e{sup +}e{sup -} experiments can provide. This last point merits further emphasis. If a new accelerator could be designed and

  19. Linear Collider Physics Resource Book Snowmass 2001

    International Nuclear Information System (INIS)

    Ronan, M.T.

    2001-01-01

    The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decade or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e + e - linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e + e - linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e + e - linear collider; in any scenario that is now discussed, physics will benefit from the new information that e + e - experiments can provide. This last point merits further emphasis. If a new accelerator could be designed and built in a few years, it would make

  20. Vacuum technology issues for the SSC [Superconducting Super Collider

    International Nuclear Information System (INIS)

    Joestlein, H.

    1989-01-01

    The Superconducting Super Collider, to be built in Texas, will provide an energy of 40 TeV from colliding proton beams. This energy is twenty times higher than currently available from the only other cryogenic collider, the Fermilab Tevatron, and will allow experiments that can lead to a better understanding of the fundamental properties of matter. The energy scale and the size of the new machine pose intriguing challenges and opportunities for the its vacuum systems. The discussion will include the effects of synchrotron radiation on cryogenic beam tubes, cold adsorption pumps for hydrogen, methods of leak checking large cryogenic systems, the development of cold beam valves, and radiation damage to components, especially electronics. 9 figs., 1 tab

  1. Academic Training Lecture: Higgs Boson Searches at Hadron Colliders

    CERN Multimedia

    HR Department

    2010-01-01

    Regular Programme 21, 22, 23 & 24 June 2010 from 11:00 to 12:00 - Main Auditorium, Bldg. 500-1-001 Higgs Boson Searches at Hadron Colliders by Dr. Karl Jakobs (University of Freiburg) In these Academic Training lectures, the phenomenology of Higgs bosons and search strategies at hadron colliders are discussed. After a brief introduction on Higgs bosons in the Standard Model and a discussion of present direct and indirect constraints on its mass the status of the theoretical cross section calculations for Higgs boson production at hadron colliders is reviewed. In the following lectures important experimental issues relevant for Higgs boson searches (trigger, measurements of leptons, jets and missing transverse energy) are presented. This is followed by a detailed discussion of the discovery potential for the Standard Model Higgs boson for both the Tevatron and the LHC experiments. In addition, various scenarios beyond the Standard Model, primarily the MSSM, are considered. Finally, the potential and ...

  2. Are PDFs still consistent with Tevatron data?

    Directory of Open Access Journals (Sweden)

    Sullivan Zack

    2018-01-01

    Full Text Available As active data taking has moved to the LHC at CERN, more and more LHC data have been included into fits of parton distribution functions. An anomaly has arisen where formerly excellent agreement between theoretical predictions and experiment in single-top-quark production at the Tevatron is no longer quite as good. Is this indicative of a deeper issue?

  3. Review of searches for Higgs bosons and beyond the standard model physics at the Tevatron

    International Nuclear Information System (INIS)

    Duperrin, Arnaud

    2009-01-01

    The energy frontier is currently at the Fermilab Tevatron accelerator, which collides protons and antiprotons at a center-of-mass energy of 1.96 TeV. The luminosity delivered to the CDF and DOe experiments has now surpassed the 4 fb -1 . This paper reviews the most recent direct searches for Higgs bosons and beyond-the-standard-model (BSM) physics at the tevatron. The results reported correspond to an integrated luminosity of up to 2.5 fb -1 of Run II data collected by the two Collaborations. Searches covered include the standard model (SM) Higgs boson (including sensitivity projections), the neutral Higgs bosons in the minimal supersymmetric extension of the standard model (MSSM), charged Higgs bosons and extended Higgs models, supersymmetric decays that conserve or violate R-parity, gauge-mediated supersymmetric breaking models, long-lived particles, leptoquarks, compositeness, extra gauge bosons, extra dimensions, and finally signature-based searches. Given the excellent performance of the collider and the continued productivity of the experiments, the Tevatron physics potential looks promising for discovery with the coming larger data sets. In particular, evidence for the SM Higgs boson could be obtained if its mass is light or near 160 GeV. The observed (expected) upper limits are currently a factor of 3.7 (3.3) higher than the expected SM Higgs boson cross section at m H =115 GeV and 1.1(1.6) at m H =160 GeV at 95% C.L. (orig.)

  4. Beam-related machine protection for the CERN Large Hadron Collider experiments

    Directory of Open Access Journals (Sweden)

    R. B. Appleby

    2010-06-01

    Full Text Available The Large Hadron Collider at CERN, Geneva stores 360 MJ per beam of protons at the top machine energy. This amount of energy storage presents a considerable challenge to the machine protection systems designed to protect both the machine and the six LHC experiments. This paper provides an overview of the machine protection systems relevant to the protection of the experiments, and demonstrates their operation and level of protection through a series of injection and stored beam failure scenarios. We conclude that the systems provide sufficient coverage for the protection of the experiments as far as reasonably possible.

  5. The feasibility of experiments at high luminosity at the large hadron collider

    International Nuclear Information System (INIS)

    Mulvey, J.H.

    1988-01-01

    The studies reported in this volume extend some of those made during Workshop on Physics at Future Accelerators held at La Thuile and CERN in January 1987 (CERN 87-07, Vol. 1 and 2). They consider the feasibility of performing experiments with a 16 TeV proton-proton collider, the Large Hadron Collider (LHC), at luminosities as high as 5.10 34 cm -2 s -1 . To illustrate the difficulties and the extent to which the potential for discovery at the LHC might be improved by such a step, three specific topics were chosen: searches for a) a massive Higgs boson, b) SUSY gluinos and squarks, and c) a new Z'. Following the Summary Report of the High Luminosity Study Group are papers discussing a possible detector system, radiation levels, and the analyses leading to estimated mass-limits for the searches. (orig.)

  6. Reach of the Fermilab Tevatron and CERN LHC for gaugino mediated SUSY breaking models

    International Nuclear Information System (INIS)

    Baer, Howard; Belyaev, Alexander; Krupovnickas, Tadas; Tata, Xerxes

    2002-01-01

    In supersymmetric models with gaugino mediated SUSY breaking (gMSB), it is assumed that SUSY breaking on a hidden brane is communicated to the visible brane via gauge superfields which propagate in the bulk. This leads to GUT models where the common gaugino mass m 1/2 is the only soft SUSY breaking term to receive contributions at the tree level. To obtain a viable phenomenology, it is assumed that the gaugino mass is induced at some scale M c beyond the GUT scale, and that additional renormalization group running takes place between M c and M GUT as in a SUSY GUT. We assume an SU(5) SUSY GUT above the GUT scale, and compute the SUSY particle spectrum expected in models with gMSB. We use the Monte Carlo program ISAJET to simulate signals within the gMSB model, and compute the SUSY reach including cuts and triggers appropriate to Fermilab Tevatron and CERN LHC experiments. We find no reach for SUSY by the Tevatron collider in the trilepton channel. At the CERN LHC, values of m 1/2 =1000 (1160) GeV can be probed with 10 (100) fb -1 of integrated luminosity, corresponding to a reach in terms of m g-tilde of 2150 (2500) GeV. The gMSB model and MSUGRA can likely only be differentiated at a linear e + e - collider with sufficient energy to produce sleptons and charginos

  7. Conceptual design of hollow electron lenses for beam halo control in the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, Giulio [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Previtali, Valentina [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Valishev, Alexander [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Bruce, Roderik [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Redaelli, Stefano [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Rossi, Adriana [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Salvachua Ferrando, Belen [European Organization for Nuclear Research (CERN), Geneva (Switzerland)

    2014-06-26

    Collimation with hollow electron beams is a technique for halo control in high-power hadron beams. It is based on an electron beam (possibly pulsed or modulated in intensity) guided by strong axial magnetic fields which overlaps with the circulating beam in a short section of the ring. The concept was tested experimentally at the Fermilab Tevatron collider using a hollow electron gun installed in one of the Tevatron electron lenses. We are proposing a conceptual design for applying this technique to the Large Hadron Collider at CERN. A prototype hollow electron gun for the LHC was built and tested. The expected performance of the hollow electron beam collimator was based on Tevatron experiments and on numerical tracking simulations. Halo removal rates and enhancements of halo diffusivity were estimated as a function of beam and lattice parameters. Proton beam core lifetimes and emittance growth rates were checked to ensure that undesired effects were suppressed. Hardware specifications were based on the Tevatron devices and on preliminary engineering integration studies in the LHC machine. Required resources and a possible timeline were also outlined, together with a brief discussion of alternative halo-removal schemes and of other possible uses of electron lenses to improve the performance of the LHC.

  8. Undergraduate Laboratory Experiment: Measuring Matter Antimatter Asymmetries at the Large Hadron Collider

    CERN Document Server

    Parkes, Chris; Gutierrez, J

    2015-01-01

    This document is the student manual for a third year undergraduate laboratory experiment at the University of Manchester. This project aims to measure a fundamental difference between the behaviour of matter and antimatter through the analysis of data collected by the LHCb experiment at the Large Hadron Collider. The three-body dmecays $B^\\pm \\rightarrow h^\\pm h^+ h^-$, where $h^\\pm$ is a $\\pi^\\pm$ or $K^\\pm$ are studied. The inclusive matter antimatter asymmetry is calculated, and larger asymmetries are searched for in localized regions of the phase-space.

  9. Research of the Higgs boson in dimuon final state and study of the tt-bar production asymmetry with the D0 experiment at the Tevatron

    International Nuclear Information System (INIS)

    Faure, Alexandre

    2014-01-01

    Two high energy particle physics analyses are presented in this PhD report using events with two leptons oppositely charged and with missing transverse energy. These events are selected using 9.7 fb -1 of total pp collisions data collected with the D0 detector at the Tevatron at √s=1.96 TeV. The first analysis is the research of the Higgs boson decaying in the H→W→μvμv channel. No significant excess above the background prediction is observed. Upper limits on Higgs boson production cross-section are computed in the standard model framework but also in the 4. generation of fermions and in the fermiophobic coupling to Higgs boson hypotheses. In order to validate the research methodology, the W boson pair production cross-section is measured. The second analysis is the measurement of the forward-backward asymmetry of the tt pair production. This is the first measurement in the di-leptonic channel at D0 experiment. In this context, a new tt pair kinematic reconstruction is used (matrix element method) to give a raw measurement of the forward-backward asymmetry. Thanks to a dedicated calibration method, we give a final measurement of AFB=18.0 ± 6.0 (stat) ± 3.3 (syst). (author) [fr

  10. Ion Colliders

    CERN Document Server

    Fischer, W

    2014-01-01

    High-energy ion colliders are large research tools in nuclear physics to study the Quark-Gluon-Plasma (QGP). The range of collision energy and high luminosity are important design and operational considerations. The experiments also expect flexibility with frequent changes in the collision energy, detector fields, and ion species. Ion species range from protons, including polarized protons in RHIC, to heavy nuclei like gold, lead and uranium. Asymmetric collision combinations (e.g. protons against heavy ions) are also essential. For the creation, acceleration, and storage of bright intense ion beams, limits are set by space charge, charge change, and intrabeam scattering effects, as well as beam losses due to a variety of other phenomena. Currently, there are two operating ion colliders, the Relativistic Heavy Ion Collider (RHIC) at BNL, and the Large Hadron Collider (LHC) at CERN.

  11. 1987 DOE review: First collider run operation

    International Nuclear Information System (INIS)

    Childress, S.; Crawford, J.; Dugan, G.

    1987-05-01

    This review covers the operations of the first run of the 1.8 TeV superconducting super collider. The papers enclosed cover: PBAR source status, fixed target operation, Tevatron cryogenic reliability and capacity upgrade, Tevatron Energy upgrade progress and plans, status of the D0 low beta insertion, 1.8 K and 4.7 K refrigeration for low-β quadrupoles, progress and plans for the LINAC and booster, near term and long term and long term performance improvements

  12. Prospects for antiproton experiments at Fermilab

    International Nuclear Information System (INIS)

    Kaplan, Daniel M.

    2012-01-01

    Fermilab operates the world’s most intense antiproton source. Newly proposed experiments can use those antiprotons either parasitically during Tevatron Collider running or after the end of the Tevatron Collider program. For example, the annihilation of 5 to 8 GeV antiprotons is expected to yield world-leading sensitivities to hyperon rare decays and CP violation. It could also provide the world’s most intense source of tagged D 0 mesons, and thus the best near-term opportunity to study charm mixing and, via CP violation, to search for new physics. Other measurements that could be made include properties of the X(3872) and the charmonium system. An experiment using a Penning trap and an atom interferometer could make the world’s most precise measurement of the gravitational force on antimatter. These and other potential measurements using antiprotons offer a great opportunity for a broad and exciting physics program at Fermilab in the post-Tevatron era.

  13. Present status and future prospects for a Higgs boson discovery at the Tevatron and LHC

    International Nuclear Information System (INIS)

    Haber, Howard E

    2010-01-01

    Discovering the Higgs boson is one of the primary goals of both the Tevatron and the Large Hadron Collider (LHC). The present status of the Higgs search is reviewed and future prospects for discovery at the Tevatron and LHC are considered. This talk focuses primarily on the Higgs boson of the Standard Model and its minimal supersymmetric extension. Theoretical expectations for the Higgs boson and its phenomenological consequences are reviewed.

  14. The A0 abort system for the Tevatron upgrade

    International Nuclear Information System (INIS)

    Crawford, C.

    1989-01-01

    The installation of electrostatic separator modules at B48 and C17 in the Tevatron necessitates changes to the Tevatron abort system. There will no longer be room for either the proton or antiproton kicker magnets used in the present system. The kickers at C17 will be permanently removed. The kickers at B48 will be temporarily removed for collider operation and will be replaced for fixed target operation. The existing proton abort system will remain unchanged during fixed target operation. This note describes a proposed abort system for operation in the collider mode for 22 on 22 bunches and provides details of specifications for the required components. In certain cases, for example in the case of the pulsers for the magnets and the absorber assembly, system components are designed with the option of upgrading to 44 on 44 bunch operation in mind. 8 refs., 14 figs

  15. SSC [Superconducting Super Collider] dipole coil production tooling

    International Nuclear Information System (INIS)

    Carson, J.A.; Barczak, E.J.; Bossert, R.C.; Brandt, J.S.; Smith, G.A.

    1989-03-01

    Superconducting Super Collider dipole coils must be produced to high precision to ensure uniform prestress and even conductor distribution within the collared coil assembly. Tooling is being prepared at Fermilab for the production of high precision 1M and 16.6M SSC dipole coils suitable for mass production. The design and construction methods builds on the Tevatron tooling and production experience. Details of the design and construction methods and measured coil uniformity of 1M coils will be presented. 4 refs., 10 figs

  16. Ion colliders

    International Nuclear Information System (INIS)

    Fischer, W.

    2010-01-01

    Ion colliders are research tools for high-energy nuclear physics, and are used to test the theory of Quantum Chromo Dynamics (QCD). The collisions of fully stripped high-energy ions create matter of a temperature and density that existed only microseconds after the Big Bang. Ion colliders can reach higher densities and temperatures than fixed target experiments although at a much lower luminosity. The first ion collider was the CERN Intersecting Storage Ring (ISR), which collided light ions (77Asb1, 81Bou1). The BNL Relativistic Heavy Ion Collider (RHIC) is in operation since 2000 and has collided a number of species at numerous energies. The CERN Large Hadron Collider (LHC) started the heavy ion program in 2010. Table 1 shows all previous and the currently planned running modes for ISR, RHIC, and LHC. All three machines also collide protons, which are spin-polarized in RHIC. Ion colliders differ from proton or antiproton colliders in a number of ways: the preparation of the ions in the source and the pre-injector chain is limited by other effects than for protons; frequent changes in the collision energy and particle species, including asymmetric species, are typical; and the interaction of ions with each other and accelerator components is different from protons, which has implications for collision products, collimation, the beam dump, and intercepting instrumentation devices such a profile monitors. In the preparation for the collider use the charge state Z of the ions is successively increased to minimize the effects of space charge, intrabeam scattering (IBS), charge change effects (electron capture and stripping), and ion-impact desorption after beam loss. Low charge states reduce space charge, intrabeam scattering, and electron capture effects. High charge states reduce electron stripping, and make bending and acceleration more effective. Electron stripping at higher energies is generally more efficient. Table 2 shows the charge states and energies in the

  17. Ion colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, W.

    2011-12-01

    Ion colliders are research tools for high-energy nuclear physics, and are used to test the theory of Quantum Chromo Dynamics (QCD). The collisions of fully stripped high-energy ions create matter of a temperature and density that existed only microseconds after the Big Bang. Ion colliders can reach higher densities and temperatures than fixed target experiments although at a much lower luminosity. The first ion collider was the CERN Intersecting Storage Ring (ISR), which collided light ions [77Asb1, 81Bou1]. The BNL Relativistic Heavy Ion Collider (RHIC) is in operation since 2000 and has collided a number of species at numerous energies. The CERN Large Hadron Collider (LHC) started the heavy ion program in 2010. Table 1 shows all previous and the currently planned running modes for ISR, RHIC, and LHC. All three machines also collide protons, which are spin-polarized in RHIC. Ion colliders differ from proton or antiproton colliders in a number of ways: the preparation of the ions in the source and the pre-injector chain is limited by other effects than for protons; frequent changes in the collision energy and particle species, including asymmetric species, are typical; and the interaction of ions with each other and accelerator components is different from protons, which has implications for collision products, collimation, the beam dump, and intercepting instrumentation devices such a profile monitors. In the preparation for the collider use the charge state Z of the ions is successively increased to minimize the effects of space charge, intrabeam scattering (IBS), charge change effects (electron capture and stripping), and ion-impact desorption after beam loss. Low charge states reduce space charge, intrabeam scattering, and electron capture effects. High charge states reduce electron stripping, and make bending and acceleration more effective. Electron stripping at higher energies is generally more efficient. Table 2 shows the charge states and energies in the

  18. Recent QCD Studies at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Group, Robert Craig

    2008-04-01

    Since the beginning of Run II at the Fermilab Tevatron the QCD physics groups of the CDF and D0 experiments have worked to reach unprecedented levels of precision for many QCD observables. Thanks to the large dataset--over 3 fb{sup -1} of integrated luminosity recorded by each experiment--important new measurements have recently been made public and will be summarized in this paper.

  19. Nucleon Decay and Neutrino Experiments, Experiments at High Energy Hadron Colliders, and String Theor

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Chang Kee [State University of New York at Stony Brook; Douglas, Michaek [State University of New York at Stony Brook; Hobbs, John [State University of New York at Stony Brook; McGrew, Clark [State University of New York at Stony Brook; Rijssenbeek, Michael [State University of New York at Stony Brook

    2013-07-29

    This is the final report of the DOE grant DEFG0292ER40697 that supported the research activities of the Stony Brook High Energy Physics Group from November 15, 1991 to April 30, 2013. During the grant period, the grant supported the research of three Stony Brook particle physics research groups: The Nucleon Decay and Neutrino group, the Hadron Collider Group, and the Theory Group.

  20. Search for the Higgs boson in the WH channel and production of Wbb-bar in 1.96 TeV pp-bar collisions in the D0 experiment at the Fermilab Tevatron; Recherche du boson de Higgs dans le canal WH et etude de la production Wbb-bar dans les collisions pp-bar a 1.96 TeV dans l'experience D0 aupres du Tevatron de Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Beauceron, St

    2004-05-15

    The introduction of the Higgs boson in the standard model provides a mechanism to explain the origin of the masses of the elementary particles. The Higgs boson has not yet been discovered but a lower limit on its mass has been set at 114.4 GeV at 95% confidence level by LEP experiments. The search for the Higgs boson has been pursued at the Tevatron, proton-antiproton collider, in the associated production channel WH with a Higgs mass lower than 135 GeV where the Higgs decay in bb-bar. The detector D0 is used to record the signals. For this analysis, the calorimeter and the tracker are the main sub-detector. The signals from the calorimeter have been studied through a calibration and a study on the noise level in order to improve the reconstruction of the objects. The missing transverse energy, the electrons and the jets are well identified objects so they can be used in our analysis W({yields} e{nu}) + jets. As D0 has a new tracker and solenoid system, information from this system allow us to tag jets when they are originating from a b-quark. The analysis of events W({yields} e{nu}) + 2*b-tag jets has been made on 174 pb{sup -1}. An upper limit of the cross section production of the process W({yields} e{nu})bb-bar has been derived at 20.3 pb at 95% confidence level. This process is the main irreducible background of the WH {yields} e{nu}bb-bar. In the second part of the analysis, the search for the Higgs boson has been done for different mass values between 105 GeV and 135 GeV. Upper Limits on cross section production times branching ratio have been set. For a Higgs mass of 115 GeV, the upper limit is set of 12.4 pb at 95% confidence limit. (author)

  1. Search for the Higgs boson in the WH channel and production of Wbb-bar in 1.96 TeV pp-bar collisions in the D0 experiment at the Fermilab Tevatron; Recherche du boson de Higgs dans le canal WH et etude de la production Wbb-bar dans les collisions pp-bar a 1.96 TeV dans l'experience D0 aupres du Tevatron de Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Beauceron, St

    2004-05-15

    The introduction of the Higgs boson in the standard model provides a mechanism to explain the origin of the masses of the elementary particles. The Higgs boson has not yet been discovered but a lower limit on its mass has been set at 114.4 GeV at 95% confidence level by LEP experiments. The search for the Higgs boson has been pursued at the Tevatron, proton-antiproton collider, in the associated production channel WH with a Higgs mass lower than 135 GeV where the Higgs decay in bb-bar. The detector D0 is used to record the signals. For this analysis, the calorimeter and the tracker are the main sub-detector. The signals from the calorimeter have been studied through a calibration and a study on the noise level in order to improve the reconstruction of the objects. The missing transverse energy, the electrons and the jets are well identified objects so they can be used in our analysis W({yields} e{nu}) + jets. As D0 has a new tracker and solenoid system, information from this system allow us to tag jets when they are originating from a b-quark. The analysis of events W({yields} e{nu}) + 2*b-tag jets has been made on 174 pb{sup -1}. An upper limit of the cross section production of the process W({yields} e{nu})bb-bar has been derived at 20.3 pb at 95% confidence level. This process is the main irreducible background of the WH {yields} e{nu}bb-bar. In the second part of the analysis, the search for the Higgs boson has been done for different mass values between 105 GeV and 135 GeV. Upper Limits on cross section production times branching ratio have been set. For a Higgs mass of 115 GeV, the upper limit is set of 12.4 pb at 95% confidence limit. (author)

  2. Review of Physics Results from the Tevatron: Top Quark Physics

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, Cecilia E.; Vellidis, Costas

    2014-09-17

    We present results on top quark physics from the CDF and D0 collaborations at the Fermilab Tevatron proton anti-proton collider. These include legacy results from Run II that were published or submitted for publication before mid-2014, as well as a summary of Run I results. The historical perspective of the discovery of the top quark in Run I is also described.

  3. Tests of QCD in W and Z production at Tevatron

    International Nuclear Information System (INIS)

    Alitti, J.; Chevalier, L.; Ducros, Y.; Lebrat, J.F.; Mangeot, P.

    1995-01-01

    We present measurements of the production cross sections times leptonic branching fractions and the transverse momentum distributions of W and Z bosons in pp-bar collisions at √ s = 1.8 TeV using data collected with the DΦ detector at the Fermilab Tevatron pp-bar collider. A preliminary measurement of the W charge asymmetry is also presented. (authors). 27 refs., 9 figs., 3 tabs

  4. Tevatron extraction microcomputer

    International Nuclear Information System (INIS)

    Chapman, L.; Finley, D.A.; Harrison, M.; Merz, W.; Batavia, IL)

    1985-01-01

    Extraction in the Fermilab Tevatron is controlled by a multi-processor Multibus microcomputer system called QXR (Quad eXtraction Regulator). QXR monitors several analog beam signals and controls three sets of power supplies: the ''bucker'' and ''pulse'' magnets at a rate of 5760 Hz, and the ''QXR'' magnets at 720 Hz. QXR supports multiple slow spills (up to a total of 35 seconds) with multiple fast pulses intermixed. It linearizes the slow spill and bucks out the high frequency components. Fast extraction is done by outputting a variable pulse waveform. Closed loop learning techniques are used to improve performance from cycle to cycle for both slow and fast extraction. The system is connected to the Tevatron clock system so that it can track the machine cycle. QXR is also connected to the rest of the Fermilab control system, ACNET. Through ACNET, human operators and central computers can monitor and control extraction through communications with QXR. The controls hardware and software both employ some standard and some specialized components. This paper gives an overview of QXR as a control system; another paper (1) summarizes performance

  5. Tevatron extraction microcomputer

    International Nuclear Information System (INIS)

    Chapman, L.; Finley, D.A.; Harrison, M.; Merz, W.

    1985-06-01

    Extraction in the Fermilab Tevatron is controlled by a multi-processor Multibus microcomputer system called QXR (Quad eXtraction Regulator). QXR monitors several analog beam signals and controls three sets of power supplies: the ''bucker'' and ''pulse'' magnets at a rate of 5760 Hz, and the ''QXR'' magnets at 720 Hz. QXR supports multiple slow spills (up to a total of 35 seconds) with multiple fast pulses intermixed. It linearizes the slow spill and bucks out the high frequency components. Fast extraction is done by outputting a variable pulse waveform. Closed loop learning techniques are used to improve performance from cycle to cycle for both slow and fast extraction. The system is connected to the Tevatron clock system so that it can track the machine cycle. QXR is also connected to the rest of the Fermilab control system, ACNET. Through ACNET, human operators and central computers can monitor and control extraction through communications with QXR. The controls hardware and software both employ some standard and some specialized components. This paper gives an overview of QXR as a control system; another paper summarizes performance

  6. Semiconductor devices as track detectors in high energy colliding beam experiments

    International Nuclear Information System (INIS)

    Ludlam, T.

    1980-01-01

    In considering the design of experiments for high energy colliding beam facilities one quickly sees the need for better detectors. The full exploitation of machines like ISABELLE will call for detector capabilities beyond what can be expected from refinements of the conventional approaches to particle detection in high energy physics experiments. Over the past year or so there has been a general realization that semiconductor device technology offers the possibility of position sensing detectors having resolution elements with dimensions of the order of 10 microns or smaller. Such a detector could offer enormous advantages in the design of experiments, and the purpose of this paper is to discuss some of the possibilities and some of the problems

  7. Semiconductor devices as track detectors in high energy colliding beam experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ludlam, T

    1980-01-01

    In considering the design of experiments for high energy colliding beam facilities one quickly sees the need for better detectors. The full exploitation of machines like ISABELLE will call for detector capabilities beyond what can be expected from refinements of the conventional approaches to particle detection in high energy physics experiments. Over the past year or so there has been a general realization that semiconductor device technology offers the possibility of position sensing detectors having resolution elements with dimensions of the order of 10 microns or smaller. Such a detector could offer enormous advantages in the design of experiments, and the purpose of this paper is to discuss some of the possibilities and some of the problems.

  8. Search for the supersymmetric partner of bottom quark at DO at Tevatron. Studies on missing transverse energy; Recherche du partenaire supersymetrique du quark bottom au sein de l'experience DO aupres du TeVatron. Etudes sur l'energie transverse manquante

    Energy Technology Data Exchange (ETDEWEB)

    Calvet, S

    2007-09-15

    Supersymmetry, the extension of the Standard Model of particle physics, is searched for, by trying to observe the supersymmetric partner of the bottom quark (b-bar). This search is performed by using events with a final state comprising 2 coplanar b-quark jets and missing transverse energy and coming from a sample of 992 pb{sup -1} of data collected by the D0 detector at the Tevatron, the Fermilab pp-bar collider. The absence of an excess of events in comparison to Standard Model expectations leads to exclude sb masses up to 201 GeV and neutralino masses up to 94 GeV. The missing transverse energy has been studied carefully under 2 points of view, because of its fundamental role in this search. First, at the level of the trigger system which allows the online selection candidate events, and then during the process Z {yields} {nu}{nu} + jets that is an important background noise and in which the transverse momentum of Z turns into missing energy because of the no-detection of the neutrinos. (author)

  9. Search for the supersymmetric partner of bottom quark at DO at Tevatron. Studies on missing transverse energy; Recherche du partenaire supersymetrique du quark bottom au sein de l'experience DO aupres du TeVatron. Etudes sur l'energie transverse manquante

    Energy Technology Data Exchange (ETDEWEB)

    Calvet, S

    2007-09-15

    Supersymmetry, the extension of the Standard Model of particle physics, is searched for, by trying to observe the supersymmetric partner of the bottom quark (b-bar). This search is performed by using events with a final state comprising 2 coplanar b-quark jets and missing transverse energy and coming from a sample of 992 pb{sup -1} of data collected by the D0 detector at the Tevatron, the Fermilab pp-bar collider. The absence of an excess of events in comparison to Standard Model expectations leads to exclude sb masses up to 201 GeV and neutralino masses up to 94 GeV. The missing transverse energy has been studied carefully under 2 points of view, because of its fundamental role in this search. First, at the level of the trigger system which allows the online selection candidate events, and then during the process Z {yields} {nu}{nu} + jets that is an important background noise and in which the transverse momentum of Z turns into missing energy because of the no-detection of the neutrinos. (author)

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

    Science.gov (United States)

    Schukraft, J

    2012-02-28

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

  11. Assessing Risk in Costing High-energy Accelerators: from Existing Projects to the Future Linear Collider

    CERN Document Server

    Lebrun, Philippe

    2010-01-01

    High-energy accelerators are large projects funded by public money, developed over the years and constructed via major industrial contracts both in advanced technology and in more conventional domains such as civil engineering and infrastructure, for which they often constitute one-of markets. Assessing their cost, as well as the risk and uncertainty associated with this assessment is therefore an essential part of project preparation and a justified requirement by the funding agencies. Stemming from the experience with large circular colliders at CERN, LEP and LHC, as well as with the Main Injector, the Tevatron Collider Experiments and Accelerator Upgrades, and the NOvA Experiment at Fermilab, we discuss sources of cost variance and derive cost risk assessment methods applicable to the future linear collider, through its two technical approaches for ILC and CLIC. We also address disparities in cost risk assessment imposed by regional differences in regulations, procedures and practices.

  12. Operational Experience and Performance with the ATLAS Pixel Detector at the Large Hadron Collider

    CERN Document Server

    Grummer, Aidan; The ATLAS collaboration

    2018-01-01

    The tracking performance of the ATLAS detector relies critically on its 4-layer Pixel Detector, that has undergone significant hardware and software upgrades to meet the challenges imposed by the higher collision energy, pileup and luminosity that are being delivered by the Large Hadron Collider, with record breaking instantaneous luminosities of 2 x 10^34 cm-2 s-1 recently surpassed. The key status and performance metrics of the ATLAS Pixel Detector are summarised, and the operational experience and requirements to ensure optimum data quality and data taking efficiency will be described, with special emphasis to radiation damage experience. In particular, radiation damage effects will be showed and signs of degradation which are visible but which are not impacting yet the tracking performance (but will): dE/dX, occupancy reduction with integrated luminosity, under-depletion effects with IBL in 2016, effects of annealing that is not insignificant for the inner-most layers. Therefore the offline software strat...

  13. Top quark production at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Varnes, Erich W.; /Arizona U.

    2010-09-01

    The Fermilab Tevatron has, until recently, been the only accelerator with sufficient energy to produce top quarks. The CDF and D0 experiments have collected large samples of top quarks. We report on recent top quark production measurements of the single top and t{bar t} production cross sections, as well as studies of the t{bar t} invariant mass distribution and a search for highly boosted top quarks.

  14. A new micro-strip tracker for the new generation of experiments at hadron colliders

    International Nuclear Information System (INIS)

    Dinardo, Mauro E.; Milan U.

    2005-01-01

    This thesis concerns the development and characterization of a prototype Silicon micro-strip detector that can be used in the forward (high rapidity) region of a hadron collider. These detectors must operate in a high radiation environment without any important degradation of their performance. The innovative feature of these detectors is the readout electronics, which, being completely data-driven, allows for the direct use of the detector information at the lowest level of the trigger. All the particle hits on the detector can be readout in real-time without any external trigger and any particular limitation due to dead-time. In this way, all the detector information is available to elaborate a very selective trigger decision based on a fast reconstruction of tracks and vertex topology. These detectors, together with the new approach to the trigger, have been developed in the context of the BTeV RandD program; our aim was to define the features and the design parameters of an optimal experiment for heavy flavour physics at hadron colliders

  15. Linear colliders - prospects 1985

    International Nuclear Information System (INIS)

    Rees, J.

    1985-06-01

    We discuss the scaling laws of linear colliders and their consequences for accelerator design. We then report on the SLAC Linear Collider project and comment on experience gained on that project and its application to future colliders. 9 refs., 2 figs

  16. Status of superconducting magnets for the Superconducting Super Collider

    International Nuclear Information System (INIS)

    Schermer, R.I.

    1993-09-01

    The arc sections of the High Energy Booster and the two Collider Rings will need more than 10,000, very large, superconducting dipole and quadrupole magnets. Development work on these magnets was carried out at US/DOE laboratories in a program that began in the mid 1980's. In 1991-1992, the technology was transferred to industry and twenty, full-length, Collider dipoles were successfully fabricated and tested. This program, along with HERA and Tevatron experience, has provided industry a data base to use in formulating detailed designs for the prototypes of the accelerator magnets, with an eye to reducing cost and enhancing producibility. Several model magnets from this latest phase of the industrial program have already been tested. The excessive ramp-rate sensitivity of the magnets is understood and solutions are under investigation

  17. Status of superconducting magnets for the Superconducting Super Collider

    International Nuclear Information System (INIS)

    Schermer, R.I.

    1994-01-01

    The arc sections of the High Energy Booster and the two Collider Rings will need more than 10,000, very large, superconducting dipole and quadrupole magnets. Development work on these magnets was carried out at US/DOE laboratories in a program that began in the mid 1980's. In 1991--92, the technology was transferred to industry and twenty, full-length, Collider dipoles were successfully fabricated and tested. This program, along with HERA and Tevatron experience, has provided industry a data base to use in formulating detailed designs for the prototypes of the accelerator magnets, with an eye to reducing cost and enhancing producibility. Several model magnets from this latest phase of the industrial program have already been tested. The excessive ramp-rate sensitivity of the magnets is understood and solutions are under investigation

  18. Higgs Boson Searches at Hadron Colliders (1/4)

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    In these Academic Training lectures, the phenomenology of Higgs bosons and search strategies at hadron colliders are discussed. After a brief introduction on Higgs bosons in the Standard Model and a discussion of present direct and indirect constraints on its mass the status of the theoretical cross section calculations for Higgs boson production at hadron colliders is reviewed. In the following lectures important experimental issues relevant for Higgs boson searches (trigger, measurements of leptons, jets and missing transverse energy) are presented. This is followed by a detailed discussion of the discovery potential for the Standard Model Higgs boson for both the Tevatron and the LHC experiments. In addition, various scenarios beyond the Standard Model, primarily the MSSM, are considered. Finally, the potential and strategies to measured Higgs boson parameters and the investigation of alternative symmetry breaking scenarios are addressed.

  19. Physics at Hadronic Colliders (4/4)

    CERN Multimedia

    CERN. Geneva

    2008-01-01

    Hadron colliders are often called "discovery machines" since they produce the highest mass particles and thus give often the best chance to discover new high mass particles. Currently they are particularly topical since the Large Hadron Collider will start operating later this year, increasing the centre-of-mass energy by a factor of seven compared to the current highest energy collider, the Tevatron. I will review the benefits and challenges of hadron colliders and review some of the current physics results from the Tevatron and give an outlook to the future results we are hoping for at the LHC. Prerequisite knowledge: Introduction to Particle Physics (F. Close), Detectors (W. Riegler, at least mostly) and The Standard Model (A. Pich)

  20. Physics at Hadronic Colliders (1/4)

    CERN Multimedia

    CERN. Geneva

    2008-01-01

    Hadron colliders are often called "discovery machines" since they produce the highest mass particles and thus give often the best chance to discover new high mass particles. Currently they are particularly topical since the Large Hadron Collider will start operating later this year, increasing the centre-of-mass energy by a factor of seven compared to the current highest energy collider, the Tevatron. I will review the benefits and challenges of hadron colliders and review some of the current physics results from the Tevatron and give an outlook to the future results we are hoping for at the LHC. Prerequisite knowledge: Introduction to Particle Physics (F. Close), Detectors (W. Riegler, at least mostly) and The Standard Model (A. Pich)

  1. Physics at Hadronic Colliders (2/4)

    CERN Multimedia

    CERN. Geneva

    2008-01-01

    Hadron colliders are often called "discovery machines" since they produce the highest mass particles and thus give often the best chance to discover new high mass particles. Currently they are particularly topical since the Large Hadron Collider will start operating later this year, increasing the centre-of-mass energy by a factor of seven compared to the current highest energy collider, the Tevatron. I will review the benefits and challenges of hadron colliders and review some of the current physics results from the Tevatron and give an outlook to the future results we are hoping for at the LHC. Prerequisite knowledge: Introduction to Particle Physics (F. Close), Detectors (W. Riegler, at least mostly) and The Standard Model (A. Pich)

  2. Physics at Hadronic Colliders (3/4)

    CERN Multimedia

    CERN. Geneva

    2008-01-01

    Hadron colliders are often called "discovery machines" since they produce the highest mass particles and thus give often the best chance to discover new high mass particles. Currently they are particularly topical since the Large Hadron Collider will start operating later this year, increasing the centre-of-mass energy by a factor of seven compared to the current highest energy collider, the Tevatron. I will review the benefits and challenges of hadron colliders and review some of the current physics results from the Tevatron and give an outlook to the future results we are hoping for at the LHC. Prerequisite knowledge: Introduction to Particle Physics (F. Close), Detectors (W. Riegler, at least mostly) and The Standard Model (A. Pich)

  3. Grid computing in pakistan and: opening to large hadron collider experiments

    International Nuclear Information System (INIS)

    Batool, N.; Osman, A.; Mahmood, A.; Rana, M.A.

    2009-01-01

    A grid computing facility was developed at sister institutes Pakistan Institute of Nuclear Science and Technology (PINSTECH) and Pakistan Institute of Engineering and Applied Sciences (PIEAS) in collaboration with Large Hadron Collider (LHC) Computing Grid during early years of the present decade. The Grid facility PAKGRID-LCG2 as one of the grid node in Pakistan was developed employing mainly local means and is capable of supporting local and international research and computational tasks in the domain of LHC Computing Grid. Functional status of the facility is presented in terms of number of jobs performed. The facility developed provides a forum to local researchers in the field of high energy physics to participate in the LHC experiments and related activities at European particle physics research laboratory (CERN), which is one of the best physics laboratories in the world. It also provides a platform of an emerging computing technology (CT). (author)

  4. Development of Advanced Gaseous Detectors for Muon Tracking and Triggering in Collider Experiments

    CERN Document Server

    Guan, Liang; Zhao, Zhengguo; Zhu, Junjie

    High luminosity and high energy collider experiments impose big challenges to conventional gaseous detectors used for muon tracking and triggering. Stringent requirements, in terms of time and spatial resolutions, rate capabilities etc. are expected. In the context of ATLAS muon upgrade project, we present extensive researches and developments of advanced gas detectors for precision muon tracking and triggering in high rate environments. Particularly, this dissertation focuses on the studies of Micro-mesh Gaseous structure (Micromegas), thin gap Resistive Plate Chamber (RPC) and small strip Thin Gap multi-wire Chambers (sTGC). In this dissertation, we first present a novel method, based on thermally bonding micro-meshes to anodes, to construct Micromegas detectors. Without employing the traditional photo-lithography process, it is a convenient alternative to build Micromegas. Both experimental and simulation studies of basic performance parameters of thermo-bonded Micromegas will be reported. Development...

  5. Development of prototype luminosity detector modules for future experiments on linear colliders

    CERN Document Server

    AUTHOR|(CDS)2081248; Idzik, Marek

    The main objective of this dissertation is to develop and validate the prototype module of the LumiCal luminosity detector. The dissertation presents the works executed from the first detector concept, through all subsequent R&D stages, ending with the test beam results obtained using the complete detector module. Firstly, the linear electron positron colliders and planned experiments are introduced, together with their role in our understanding of the basis of matter and sensing for the New Physics. The signal extraction from radiation sensors and further signal processing techniques are discussed in chapter 2. Besides the commonly accepted techniques of amplitude and time measurements, a novel readout implementation, utilizing digital signal processing and deconvolution principle, is proposed, and its properties are analyzed in details. The architecture, design, and measurements of the LumiCal readout chain components are presented in chapter 3. A dedicated test setups prepared for their parameterizatio...

  6. Search for the scalar partner of the top quark and contribution to the improvement of the calorimetry of the experiment D zero for the phase 2 of Tevatron; Recherche du partenaire supersymetrique du quark top et contribution a l'amelioration de la calorimetrie de l'experience D zero pour la phase 2 du tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Olivier, B

    2001-04-01

    Supersymmetry could be the most natural extension of the Standard Model. In this thesis we present a new search for the sTop, the hypothetical scalar partner of the Top quark, that we performed in the framework of the Minimal Supersymmetric Standard Model (MSSM), using the Run I data of the DO experiment, which corresponds to an integrated luminosity of 108 pb{sup -1}. We selected events with one electron, one muon and missing transverse energy in the final state, which can be the decay product of pair of sTop quarks in 3 (t-tilde {yields} bl{nu}-tilde), or 4-body (t-tilde {yields} b{chi}-tilde{sub 1}{sup 0}l{nu}{sub l}). No signal is seen and the results are interpreted in terms of limits on the sTop production cross-section and exclusion regions in the parameter space (m{sub t}-tilde,m{sub {chi}}-tilde{sub 1{sup 0}}) or (m{sub t}-tilde,m{sub {nu}}-tilde). This new type of selection at the Tevatron for the search of the sTop allowed us to put stronger constraints than those previously published at LEP or at the Tevatron in the t-tilde {yields} bl{nu}-tilde channel, and the first limits ever set in the 4-body decay channel. For the 3-body channel, assuming that the sneutrino is the lightest supersymmetric particle (LSP), the excluded region at 95% confidence level extends up to a sTop mass of 142 (130) GeV if the sneutrino mass (m{sub {nu}}-tilde) is 43 (86) GeV. If the 4-body decay channel dominates, assuming that the neutralino is the LSP, the limit depends on the sneutrino mass. If it is light enough (m{sub {nu}}-tilde {approx}< 100 GeV) this limit reaches a sTop mass of 132 GeV for a neutralino mass of 60 GeV. In all searches for new particles, the calorimetry plays a crucial role from the experimental point of view. The expected increase in integrated luminosity in the Run II which started on the 1. of March 2001, and the detector upgrade which has been achieved over the last three years will allow to extend these exclusion domains or to discover the sTop. We

  7. B physics at the tevatron

    International Nuclear Information System (INIS)

    1998-07-01

    Precision B-physics results from the CDF and D0 Collaborations based on data collected during the Tevatron 1992-96 run are presented. In particular we discuss the measurement of the B s meson lifetime, B c meson observation, and B 0 - anti B 0 mixing results obtained using time-evolution analyses. Prospects for the next Tevatron run, starting in 1999, are also reported

  8. Production of c and b quarks in $p\\bar{p}$ collisions at the Tevatron collider at $\\sqrt{s}$ = 1.96 ТеV; Народження $c$ та $b$ кварків в $p\\bar{p}$ зіткненнях на колайдері Tevatron при $Е_{цм}$ = 1.96 ТеВ

    Energy Technology Data Exchange (ETDEWEB)

    Gogota, Olga [Taras Shevchenko National Univ. of Kyiv, Kiev (Ukraine)

    2016-01-01

    The results of the measurements of c and b quarks productions in proton-antiproton collisions at the D0 experiment at the Tevatron are presented in this thesis. Measurements have been done in 2 aspects: measurement of the W +b-jet and W +c-jet differential production cross sections and a measurement of the fiducial cross sections of quarkonium productions of c quark, simultaneously production of two J/ψ mesons, simultaneously production of J/ψ and Υ mesons in the muon channel decay.

  9. Nucleon PDF separation with the collider and fixed-target data

    International Nuclear Information System (INIS)

    Alekhin, Sergey; Bluemlein, Johannes; Lohwasser, Kristin; Caminada, Lea Michaela; Moch, Sven-Olaf; Petti, Roberto

    2014-10-01

    We consider the impact of the recent data obtained by the LHC, Tevatron, and fixed-target experiments on the nucleon quark distributions with a particular focus on disentangling different quark species. An improved determination of the poorly known strange sea distribution is obtained due to including data from the neutrino-induced deep-inelastic scattering experiments NOMAD and CHORUS. The impact of the associated (W+c) production data by CMS and ATLAS on the strange sea determination is also studied and a comparison with earlier results based on the collider data is discussed. Finally, the recent LHC and Tevatron data on the charged lepton asymmetry are compared to the NNLO ABM predictions and the potential of this input in improving the non-strange sea distributions is evaluated.

  10. The upgraded data acquisition system for beam loss monitoring at the Fermilab Tevatron and Main Injector

    International Nuclear Information System (INIS)

    Baumbaugh, A.; Briegel, C.; Brown, B.C.; Capista, D.; Drennan, C.; Fellenz, B.; Knickerbocker, K.; Lewis, J.D.; Marchionni, A.; Needles, C.; Olson, M.

    2011-01-01

    A VME-based data acquisition system for beam-loss monitors has been developed and is in use in the Tevatron and Main Injector accelerators at the Fermilab complex. The need for enhanced beam-loss protection when the Tevatron is operating in collider-mode was the main driving force for the new design. Prior to the implementation of the present system, the beam-loss monitor system was disabled during collider operation and protection of the Tevatron magnets relied on the quench protection system. The new Beam-Loss Monitor system allows appropriate abort logic and thresholds to be set over the full set of collider operating conditions. The system also records a history of beam-loss data prior to a beam-abort event for post-abort analysis. Installation of the Main Injector system occurred in the fall of 2006 and the Tevatron system in the summer of 2007. Both systems were fully operation by the summer of 2008. In this paper we report on the overall system design, provide a description of its normal operation, and show a number of examples of its use in both the Main Injector and Tevatron.

  11. Dedicating Fermilab's Collider

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    It was a bold move to have a fullscale dedication ceremony for the new proton-antiproton Collider at the Fermilab Tevatron on 13 October, two days before the first collisions were seen. However the particles dutifully behaved as required, and over the following weekend the Collider delivered its goods at a total energy of 1600 GeV, significantly boosting the world record for laboratory collisions

  12. Preparations for Muon Experiments at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Syphers, M.J.; Popovic, M.; Prebys, E.; /Fermilab; Ankenbrandt, C.; /Muons Inc., Batavia

    2009-05-01

    The use of existing Fermilab facilities to provide beams for two muon experiments--the Muon to Electron Conversion Experiment (Mu2e) and the New g-2 Experiment--is under consideration. Plans are being pursued to perform these experiments following the completion of the Tevatron Collider Run II, utilizing the beam lines and storage rings used today for antiproton accumulation without considerable reconfiguration.

  13. Single top quarks at the Tevatron and observation of the s-channel production mode

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    The presentation gives an overview of single-top-quark production at the Tevatron proton-antiproton collider. The talk covers measurements of the total s+t channel production cross section and the extraction of the CKM matrix element |V_tb|. Furthermore, separate analyses of the s-channel and t-channel production modes are discussed. The data correspond to total integrated luminosities of up to 9.7 fb-1 per experiment and represent in most cases the full Run-II dataset. Through a combination of the CDF and D0 measurements the first observation of single-top-quark production in the s-channel is claimed. This is particularly highlighted in the seminar.

  14. Hunting for CDF multi-muon ''ghost'' events at collider and fixed-target experiments

    International Nuclear Information System (INIS)

    Bornhauser, Nicki; Drees, Manuel

    2011-01-01

    In 2008 the CDF collaboration discovered a large excess of events containing two or more muons, at least one of which seemed to have been produced outside the beam pipe. We investigate whether similar ''ghost'' events could (and should) have been seen in already completed experiments. The CDF di-muon data can be reproduced by a simple model where a relatively light X particle undergoes 4-body decay. This model predicts a large number of ghost events in Fermilab fixed-target experiments E772, E789 and E866, applying the cuts optimized for analyses of Drell-Yan events. A correct description of events with more than two muons requires a more complicated model, where two X particles are produced from a very broad resonance Y. This model can be tested in fixed-target experiments only if the cut on the angles, or rapidities, of the muons can be relaxed. Either way, the UA1 experiment at the CERN p anti p collider should have observed O(100) ghost events. (orig.)

  15. The Fermilab proton-antiproton collider upgrades

    International Nuclear Information System (INIS)

    Marriner, J.P.

    1996-10-01

    The plans for increases in the Tevatron proton-antiproton collider luminosity in the near future (Run II) and the more distant future (TeV33) are described. While there are many important issues, the fundamental requirement is to produce more antiprotons and to use them more efficiently

  16. Search for $WZ/ZZ$ Production in the Lepton(s) + MET + Jets Channel with the CDF Experiment at the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Trovato, Marco [Superior Graduate School in Italy, Pisa (Italy)

    2014-01-01

    In this thesis we present a search for the WZ and ZZ production in a final state ("W+2 jets") with a leptonically-decaying W and two energetic jets. We use the full dataset ( ∫ Ldt = 8:9 fb-1) recorded with the CDF detector at Fermilab. The challenge consists in extracting the small Z-hadronic peak from the large amount of background processes. Those processes also include the WW, whose hadronic peak cannot be distinguished from the Z peak, due to the poor calorimeter resolution. In the past such a signature was used to measure the diboson cross section, which is highly dominated by the WW cross section.

  17. Search for The Standard Model Higgs Boson in the four lepton final state by the D0 experiment at Run II of the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Menezes, Diego [Northern Illinois Univ., DeKalb, IL (United States)

    2013-01-01

    This dissertation presents a measurement of Z boson pair production in p¯p collisions at 1.96 TeV with 9.6 fb-1 to 9.8 fb-1 of D0 data. We examine the final states eeee, eeμμ, and μμμμ. Based on selected data, the measured cross section in the mass region M(Z/γ*) > 30 GeV is σ(p¯p → Z/γ* Z/γ*) = 1.26+0.44 -0.36 (stat)+0.17 -0.15 (syst) ± 0.08 (lumi) pb.

  18. Colliding pulse injection experiments in non-collinear geometry for controlled laser plasma wakefield acceleration of electrons

    International Nuclear Information System (INIS)

    Toth, Carl B.; Esarey, Eric H.; Geddes, Cameron G.R.; Leemans, Wim P.; Nakamura, Kei; Panasenko, Dmitriy; Schroeder, Carl B.; Bruhwiler, D.; Cary, J.R.

    2007-01-01

    An optical injection scheme for a laser-plasma based accelerator which employs a non-collinear counter-propagating laser beam to push background electrons in the focusing and acceleration phase via ponderomotive beat with the trailing part of the wakefield driver pulse is discussed. Preliminary experiments were performed using a drive beam of a 0 = 2.6 and colliding beam of a 1 = 0.8 both focused on the middle of a 200 mu m slit jet backed with 20 bar, which provided ∼ 260 mu m long gas plume. The enhancement in the total charge by the colliding pulse was observed with sharp dependence on the delay time of the colliding beam. Enhancement of the neutron yield was also measured, which suggests a generation of electrons above 10 MeV

  19. Conceptual design of hollow electron lenses for beam halo control in the Large Hadron Collider

    CERN Document Server

    Stancari, Giulio; Valishev, Alexander; Bruce, Roderik; Redaelli, Stefano; Rossi, Adriana; Salvachua Ferrando, Belen

    2014-01-01

    Collimation with hollow electron beams is a technique for halo control in high-power hadron beams. It is based on an electron beam (possibly pulsed or modulated in intensity) guided by strong axial magnetic fields which overlaps with the circulating beam in a short section of the ring. The concept was tested experimentally at the Fermilab Tevatron collider using a hollow electron gun installed in one of the Tevatron electron lenses. Within the US LHC Accelerator Research Program (LARP) and the European FP7 HiLumi LHC Design Study, we are proposing a conceptual design for applying this technique to the Large Hadron Collider at CERN. A prototype hollow electron gun for the LHC was built and tested. The expected performance of the hollow electron beam collimator was based on Tevatron experiments and on numerical tracking simulations. Halo removal rates and enhancements of halo diffusivity were estimated as a function of beam and lattice parameters. Proton beam core lifetimes and emittance growth rates were check...

  20. The Reach of CERN LEP2 and Fermilab Tevatron Upgrades for Higgs Bosons in Supersymmetric Models

    CERN Document Server

    Baer, Howard W; Tata, Xerxes; Baer, Howard; Tata, Xerxes

    1999-01-01

    Luminosity upgrades of the Fermilab Tevatron pbar-p collider have been shown to allow experimental detection of a Standard Model (SM) Higgs boson up to $m_{H_{SM}}\\sim 120$ GeV via $WH_{SM} \\to \\ell\

  1. Angular Distributions of Three Jet Events in Proton - Anti-Proton Collisions at the Fermilab Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Carey, Robert Matthew [Harvard U.

    1989-07-01

    A measurement of three jet angular distributions is made at $\\sqrt{s}$ = 1.8 TeV in protonantiproton collisions at the F'ermilab Tevatron using the Collider Detector _at Ferm.ilab (CDF). Results are presented for three different center of mass variables, cos $\\theta$, $\\psi$, and $\\xi$ and are compared to QCD predictions.

  2. Colliding muons

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Is a muon-muon collider really practical? That is the question being asked by Bob Palmer. Well known in particle physics, Palmer, with Nick Samios and Ralph Shutt, recently won the American Physical Society's Panofsky Prize for their 1964 discovery of the omega minus. As well as contributing to other major experiments, both at CERN and in the US, he has contributed ideas to stochastic cooling and novel acceleration schemes

  3. The Thermosiphon Cooling System of the ATLAS Experiment at the CERN Large Hadron Collider

    CERN Document Server

    Battistin, M; Bitadze, A; Bonneau, P; Botelho-Direito, J; Boyd, G; Corbaz, F; Crespo-Lopez, O; Da Riva, E; Degeorge, C; Deterre, C; DiGirolamo, B; Doubek, M; Favre, G; Godlewski, J; Hallewell, G; Katunin, S; Lefils, D; Lombard, D; McMahon, S; Nagai, K; Robinson, D; Rossi, C; Rozanov, A; Vacek, V; Zwalinski, L

    2015-01-01

    The silicon tracker of the ATLAS experiment at CERN Large Hadron Collider will operate around –15°C to minimize the effects of radiation damage. The present cooling system is based on a conventional evaporative circuit, removing around 60 kW of heat dissipated by the silicon sensors and their local electronics. The compressors in the present circuit have proved less reliable than originally hoped, and will be replaced with a thermosiphon. The working principle of the thermosiphon uses gravity to circulate the coolant without any mechanical components (compressors or pumps) in the primary coolant circuit. The fluorocarbon coolant will be condensed at a temperature and pressure lower than those in the on-detector evaporators, but at a higher altitude, taking advantage of the 92 m height difference between the underground experiment and the services located on the surface. An extensive campaign of tests, detailed in this paper, was performed using two small-scale thermosiphon systems. These tests confirmed th...

  4. CERN-Fermilab Hadron Collider Physics Summer School

    CERN Multimedia

    2007-01-01

    Applications are now open for the 2nd CERN-Fermilab Hadron Collider Physics Summer School, which will take place at CERN from 6 to 15 June 2007. The school web site is http://cern.ch/hcpss with links to the academic program and application procedure. The application deadline is 9 March 2007. The results of the selection process will be announced shortly thereafter. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The first school in the series, held last summer at Fermilab, covered extensively the physics at the Tevatron collider experiments. The second school to be held at CERN, will focus on the technology and physics of the LHC experiments. Emphasis will be given on the first years of data-taking at the LHC and on the discovery potential of the programme. The series of lectures will be  supported by in-depth discussion sess...

  5. An experimental study of the SSC [Superconducting Super Collider] magnet aperture criterion

    International Nuclear Information System (INIS)

    Merminga, N.; Edwards, D.; Finley, D.

    1988-01-01

    A beam dynamics experiment, performed in the Fermilab Tevatron, that was mainly motivated by planning for the Superconducting Super Collider (SSC) is described. Nonlinearities are introduced in the Tevatron by special sextupoles in order to stimulate the SSC environment. ''Smear'' is one of the parameters used to characterize the deviation from linear behavior. Smear is extracted from experimental data and compared with calculation over a wide range of conditions. The agreement is excellent. The closed orbit at injection trajectory reveal no deterioration even at the highest sextupole excitations. Measurements of the dynamic aperture are in general agreement with prediction. Particles captured on nonlinear resonance islands are directly observed and measurements are performed for the first time. The stability of the islands under tune modulation is investigated. 4 refs., 8 figs

  6. Squark production at the Tevatron

    International Nuclear Information System (INIS)

    Beenakker, W.; Hoepker, R.; Spira, M.; Zerwas, P.M.

    1994-11-01

    We have determined the QCD corrections to the production of squark-antisquark pairs in p anti p collisions at the Tevatron. If the next-to-leading order corrections are taken into account, the renormalization/factorization scale dependence of the theoretical prediction for the cross section is reduced considerably. The higher order corrections increase the production cross section at the Tevatron by about a factor two if we compare the next-to-leading order prediction at a scale near the sqaurk mass with the lowest order prediction for which, in the experimental analyses, the scale was identified with the invariant energy of the parton subprocess. This results in a rise of the experimental lower bound on the squark mass from the Tevatron by about 20 GeV. (orig.)

  7. How hadron collider experiments contributed to the development of QCD: from hard-scattering to the perfect liquid

    Science.gov (United States)

    Tannenbaum, M. J.

    2018-05-01

    A revolution in elementary particle physics occurred during the period from the ICHEP1968 to the ICHEP1982 with the advent of the parton model from discoveries in Deeply Inelastic electron-proton Scattering at SLAC, neutrino experiments, hard-scattering observed in p+p collisions at the CERN ISR, the development of QCD, the discovery of the J/ Ψ at BNL and SLAC and the clear observation of high transverse momentum jets at the CERN SPS p¯ + p collider. These and other discoveries in this period led to the acceptance of QCD as the theory of the strong interactions. The desire to understand nuclear physics at high density such as in neutron stars led to the application of QCD to this problem and to the prediction of a Quark-Gluon Plasma (QGP) in nuclei at high energy density and temperatures. This eventually led to the construction of the Relativistic Heavy Ion Collider (RHIC) at BNL to observe superdense nuclear matter in the laboratory. This article discusses how experimental methods and results which confirmed QCD at the first hadron collider, the CERN ISR, played an important role in experiments at the first heavy ion collider, RHIC, leading to the discovery of the QGP as a perfect liquid as well as discoveries at RHIC and the LHC which continue to the present day.

  8. Search for Higgs bosons and for Supersymmetric particles at particle collider experiments

    CERN Document Server

    Muanza, Steve

    The corner stone of the Standard Model (SM) of Particle Physics is the Higgs mechanism. It explains how the bosons W, Z and H acquire a mass via weak interactions. In addition it explains how the charged fermions also acquire a mass through Yukawa interactions. And on top of this, it regularizes the scattering of longitudinal W and Z bosons at high energy. The discovery of a Higgs boson by the ATLAS and the CMS collaborations in 2012 marked the culminating success of the SM at explaining most of the known phenomena. However a few other phenomena such as the Dark Matter and the Dark energy cannot be explained by the SM particles. What's more, the SM leaves several open questions such as a quest for a quantum theory for gravity, the naturalness in the Higgs sector, a possible Grand Unification,... The common thread in topics presented in this habilitation thesis is the search for manifestations of a TeV scale supersymmetric (SUSY) extension of the Standard Model at particle collider experiments. Among the predi...

  9. The upgraded Pixel Detector of the ATLAS Experiment for Run 2 at the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Backhaus, M., E-mail: malte.backhaus@cern.ch

    2016-09-21

    During Run 1 of the Large Hadron Collider (LHC), the ATLAS Pixel Detector has shown excellent performance. The ATLAS collaboration took advantage of the first long shutdown of the LHC during 2013 and 2014 and extracted the ATLAS Pixel Detector from the experiment, brought it to surface and maintained the services. This included the installation of new service quarter panels, the repair of cables, and the installation of the new Diamond Beam Monitor (DBM). Additionally, a completely new innermost pixel detector layer, the Insertable B-Layer (IBL), was constructed and installed in May 2014 between a new smaller beam pipe and the existing Pixel Detector. With a radius of 3.3 cm the IBL is located extremely close to the interaction point. Therefore, a new readout chip and two new sensor technologies (planar and 3D) are used in the IBL. In order to achieve best possible physics performance the material budget was improved with respect to the existing Pixel Detector. This is realized using lightweight staves for mechanical support and a CO{sub 2} based cooling system. This paper describes the improvements achieved during the maintenance of the existing Pixel Detector as well as the performance of the IBL during the construction and commissioning phase. Additionally, first results obtained during the LHC Run 2 demonstrating the distinguished tracking performance of the new Four Layer ATLAS Pixel Detector are presented.

  10. The new Level-1 Topological Trigger for the ATLAS experiment at the Large Hadron Collider

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00047907; The ATLAS collaboration

    2017-01-01

    At the CERN Large Hadron Collider, the world’s most powerful particle accelerator, the ATLAS experiment records high-energy proton collision to investigate the properties of fundamental particles. These collisions take place at a 40 MHz, and the ATLAS trigger system selects the interesting ones, reducing the rate to 1 kHz, allowing for their storage and subsequent offline analysis. The ATLAS trigger system is organized in two levels, with increasing degree of details and of accuracy. The first level trigger reduces the event rate to 100 kHz with a decision latency of less than 2.5 micro seconds. It is composed of the calorimeter trigger, muon trigger and central trigger processor. A new component of the first-level trigger was introduced in 2015: the Topological Processor (L1Topo). It allows to use detailed real-time information from the Level-1 calorimeter and muon systems, to compute advanced kinematic quantities using state of the art FPGA processors, and to select interesting events based on several com...

  11. Study of Drell-Yan process in CMS experiment at Large Hadron Collider

    CERN Document Server

    Jindal, Monika

    The proton-proton collisions at the Large Hadron Collider (LHC) is the begining of a new era in the high energy physics. It enables the possibility of the discoveries at high-energy frontier and also allows the study of Standard Model physics with high precision. The new physics discoveries and the precision measurements can be achieved with highly efficient and accurate detectors like Compact Muon Solenoid. In this thesis, we report the measurement of the differential production cross-section of the Drell-Yan process, $q ar{q} ightarrow Z/gamma^{*} ightarrowmu^{+}mu^{-}$ in proton-proton collisions at the center-of-mass energy $sqrt{s}=$ 7 TeV using CMS experiment at the LHC. This measurement is based on the analysis of data which corresponds to an integrated luminosity of $intmath{L}dt$ = 36.0 $pm$ 1.4 pb$^{-1}$. The measurement of the production cross-section of the Drell-Yan process provides a first test of the Standard Model in a new energy domain and may reveal exotic physics processes. The Drell...

  12. Studies of supersymmetry models for the ATLAS experiment at the Large Hadron Collider

    CERN Document Server

    Barr, A J

    2002-01-01

    This thesis demonstrates that supersymmetry can be discovered with the ATLAS experiment even if nature conspires to choose one of two rather difficult cases. In the first case where baryon-number is weakly violated, the lightest supersymmetric particle decays into three quarks. This leads to events with a very large multiplicity of jets which presents a difficult combinatorical problem at a hadronic collider. The distinctive property of the second class of model -- anomaly-mediation -- is the near degeneracy of the super-partners of the SU(2) weak bosons. The heavier charged wino decays producing its invisible neutral partner, the presence of which must be inferred from the apparent non-conservation of transverse momentum, as well as secondary particle(s) with low transverse momentum which must be extracted from a large background. Monte-Carlo simulations are employed to show that for the models examined not only can the distinctive signature of the model can be extracted, but that a variety of measurements (...

  13. Accelerator Preparations for Muon Physics Experiments at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Syphers, M.J.; /Fermilab

    2009-10-01

    The use of existing Fermilab facilities to provide beams for two muon experiments - the Muon to Electron Conversion Experiment (Mu2e) and the New g-2 Experiment - is under consideration. Plans are being pursued to perform these experiments following the completion of the Tevatron Collider Run II, utilizing the beam lines and storage rings used today for antiproton accumulation without considerable reconfiguration. Operating scenarios being investigated and anticipated accelerator improvements or reconfigurations will be presented.

  14. Beyond the standard model at Tevatron

    International Nuclear Information System (INIS)

    Pagliarone, C.

    2000-01-01

    Tevatron experiments performed extensive searches for physics beyond the Standard Model. No positive results have been found so far showing that the data are consistent with the SM expectations. CDF and D0 continue the analysis of Run I data placing limits on new physics, including Supersymmetry, large space time dimensions and leptoquark models. With the Run II upgrades, providing an higher acceptance and higher luminosity, it will be possible to make important progresses in the search for new phenomena as well as in setting limits on a larger variety of theoretical models

  15. Resonant second generation slepton production at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Autermann, Christian Tobias [RWTH Aachen Univ. (Germany)

    2006-12-01

    A search for R-parity violating supersymmetry with the D0 detector at the Fermilab Tevatron p$\\bar{p}$-collider is presented. Assuming a non-zero LQ$\\bar{d}$ coupling λ$'\\atop{2jk}$ leads to final state with two muons and jets. A total integrated luminosity of 375 pb-1 collected between April 2002 and August 2004 is utilized. The observed number of events is in agreement with the Standard Model expectation, and limits on Rp supersymmetry are derived.

  16. $B$ physics at the Tevatron: Run II and beyond

    CERN Document Server

    Anikeev, K; Azfar, F.; Bailey, S.; Bauer, C.W.; Bell, W.; Bodwin, G.; Braaten, E.; Burdman, G.; Butler, J.N.; Byrum, K.; Cason, N.; Cerri, A.; Cheung, H.W.K.; Dighe, A.; Donati, S.; Ellis, R.K.; Falk, A.; Feild, G.; Fleming, S.; Furic, I.; Gardner, S.; Grossman, Y.; Gutierrez, G.; Hao, W; Harris, B.W.; Hewett, J.; Hiller, G.; Jesik, R.; Jones, M.; Kasper, P.A.; El-Khadra, A.; Kirk, M.; Kiselev, V.V.; Kroll, J.; Kronfeld, A.S.; Kutschke, R.; Kuznetsov, V.E.; Laenen, E.; Lee, J.; Leibovich, A.K.; Lewis, J.D.; Ligeti, Z.; Likhoded, A.K.; Logan, H.E.; Luke, M.; Maciel, A.; Majumder, G.; Maksimovic, P.; Martin, M.; Menary, S.; Nason, P.; Nierste, U.; Nir, Y.; Nogach, L.; Norrbin, E.; Oleari, C.; Papadimitriou, V.; Paulini, M.; Paus, C.; Petteni, M.; Poling, R.; Procario, M.; Punzi, G.; Quinn, H.; Rakitine, A.; Ridolfi, G.; Shestermanov, K.; Signorelli, G.; Silva, J.P.; Skwarnicki, T.; Smith, A.; Speakman, B.; Stenson, K.; Stichelbaut, F.; Stone, S.; Sumorok, K.; Tanaka, M.; Taylor, W.; Trischuk, W.; Tseng, J.; Van Kooten, R.; Vasiliev, A.; Voloshin, M.; Wang, J.C.; Wicklund, A.B.; Wurthwein, F.; Xuan, N.; Yarba, J.; Yip, K.; Zieminski, A.

    2002-01-01

    This report provides a comprehensive overview of the prospects for B physics at the Tevatron. The work was carried out during a series of workshops starting in September 1999. There were four working groups: 1) CP Violation, 2) Rare and Semileptonic Decays, 3) Mixing and Lifetimes, 4) Production, Fragmentation and Spectroscopy. The report also includes introductory chapters on theoretical and experimental tools emphasizing aspects of B physics specific to hadron colliders, as well as overviews of the CDF, D0, and BTeV detectors, and a Summary.

  17. High Mass Standard Model Higgs searches at the Tevatron

    Directory of Open Access Journals (Sweden)

    Petridis Konstantinos A.

    2012-06-01

    Full Text Available We present the results of searches for the Standard Model Higgs boson decaying predominantly to W+W− pairs, at a center-of-mass energy of √s = 1.96 TeV, using up to 8.2 fb−1 of data collected with the CDF and D0 detectors at the Fermilab Tevatron collider. The analysis techniques and the various channels considered are discussed. These searches result in exclusions across the Higgs mass range of 156.5< mH <173.7 GeV for CDF and 161< mH <170 GeV for D0.

  18. Identification of $\\tau$ leptons and Higgs boson search in the $\\mu+\\tau$ final state at the D0 experiment at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Madar, Romain [Univ. of Paris, Orsay (France)

    2011-01-01

    The gauge symmetry is the heart of our understanding of the electroweak interaction and describes all the current experimental results. However, the intrinsic incompatibility between the gauge invariance and the mass of particles leads to the introduction of a new particle, the Higgs boson, for which we have no experimental evidence as of today. This thesis describes the Higgs boson search in the μ + τ final state in 7.3 fb-1 of pp collisions at √s = 1.96 TeV collected by the DØ detector at the Tevatron. This analysis completes the golden channels (dimuons, electron-muon, dielectrons) exploiting the decay chain H → WW → ℓvℓv , which is the main Higgs boson decay mode in the mass window accessible to the Tevatron. Since the final state includes a lepton, work was done to improve their identification among jets. An increase of 15% was achieved thanks to the the following : changing tuning parameters for the identification neural network, use of the kinematical dependence of the algorithm performances, incorporation of the τ lepton life time information and full study of the additionnal information coming from the central preshower measurements. Then, since the dominant background of the μ + τ Higgs boson search is W+jets (where one jet fakes a τ ), a method was developed to obtain good modeling of this background, not provided by the default simulation. This method is based, among other things, on the charge correlation between the muon and the τ candidate which allows for calibration of this background in the data excluding the signal region. Finally, all the kinematic and/or topological differences between the signal and the background were exploited to optimize this search, reaching an (observed) expected sensitivity of 7.8 (6.6) times the Standard Model for mH = 165 GeV=c2. In addition, this result was also interpreted in a fourth fermion generation scenario. For the first time, this analysis is included in the D

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

    NARCIS (Netherlands)

    de Rooij, R. S.

    2013-01-01

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

  20. Neural networks at the Tevatron

    International Nuclear Information System (INIS)

    Badgett, W.; Burkett, K.; Campbell, M.K.; Wu, D.Y.; Bianchin, S.; DeNardi, M.; Pauletta, G.; Santi, L.; Caner, A.; Denby, B.; Haggerty, H.; Lindsey, C.S.; Wainer, N.; Dall'Agata, M.; Johns, K.; Dickson, M.; Stanco, L.; Wyss, J.L.

    1992-10-01

    This paper summarizes neural network applications at the Fermilab Tevatron, including the first online hardware application in high energy physics (muon tracking): the CDF and DO neural network triggers; offline quark/gluon discrimination at CDF; ND a new tool for top to multijets recognition at CDF

  1. Measurement of the Oscillation Frequency of Bs Mesons in the Hadronic Decay Mode Bs→ π Ds(Φ π)X with the D0 Detector at the Fermilab Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Gernot August [Univ. of Mainz (Germany). Inst. for Physics

    2009-03-01

    The standard model (SM) of particle physics is a theory, describing three out of four fundamental forces. In this model the Cabibbo-Kobayashi-Maskawa (CKM) matrix describes the transformation between the mass and weak eigenstates of quarks. The matrix properties can be visualized as triangles in the complex plane. A precise measurement of all triangle parameters can be used to verify the validity of the SM. The least precisely measured parameter of the triangle is related to the CKM element |Vtd|, accessible through the mixing frequency (oscillation) of neutral B mesons, where mixing is the transition of a neutral meson into its anti-particle and vice versa. It is possible to calculate the CKM element |Vtd| and a related element |Vts| by measuring the mass differences Δmd(Δms) between neutral Bd and $\\bar{B}$d (Bs and $\\bar{B}$s) meson mass eigenstates. This measurement is accomplished by tagging the initial and final state of decaying B mesons and determining their lifetime. Currently the Fermilab Tevatron Collider (providing p$\\bar{p}$ collisions at {radical}s = 1.96 TeV) is the only place, where Bs oscillations can be studied. The first selection of the 'golden', fully hadronic decay mode Bs → πDs(Φπ)X at D0 is presented in this thesis. All data, taken between April 2002 and August 2007 with the D0 detector, corresponding to an integrated luminosity of integral Ldt = 2.8 fb-1 is used. The oscillation frequency Δms and the ratio |Vtd|/|Vts| are determined as Δms = (16.6-0.4+0.5(stat)-0.3+0.4(sys)) ps-1, |Vtd|/|Vts| = 0.213-0.003+0.004(exp) ± 0.008(theor). These results are consistent with the standard model expectations and no evidence for new physics is

  2. Accelerator/Experiment operations - FY 2006

    Energy Technology Data Exchange (ETDEWEB)

    Brice, S.; Conrad, J.; Denisov, D.; Ginther, G.; Holmes, S.; James, C.; Lee, W.; Louis, W.; Moore, C.; Plunkett, R.; Raja, R.; /Fermilab

    2006-10-01

    This Technical Memorandum (TM) summarizes the Fermilab accelerator and experiment operations for FY 2006. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2006 Run II at the Tevatron Collider, the MiniBooNE experiments running in the Booster Neutrino Beam in neutrino and antineutrino modes, MINOS using the Main Injector Neutrino Beam (NuMI), and SY 120 activities.

  3. B factory at RHIC [Relativistic Heavy Ion Collider]?

    International Nuclear Information System (INIS)

    Lockyer, N.S.; Van Berg, R.; Newcomer, F.M.

    1988-01-01

    A dedicated B physics experiment located in the proposed Relativistic Heavy Ion Collider at Brookhaven (RHIC) is considered. The machine may operate in a p-p mode with a luminosity in excess of 10 32 cm/sup /minus/2/ sec/sup /minus/1/ at 250 /times/ 250 GeV. The estimated B/bar B/ cross section at these energies is about 10 μbarns and a run of 10 7 sec would produce roughly 10 10 B/bar B/ pairs. A comparison to similar ideas proposed for the Fermilab Tevatron Upgrade and the SSC are discussed. The most ambitious physics objective of such an experiment would be the study of CP nonconservation. Particular emphasis at this workshop was given to the self tagging mode B → K + π/sup /minus//. Experimental techniques developed during this experiment would be extremely useful for more ambitious projects anticipated at the SSC. 36 refs., 10 figs

  4. Top quark mass measurement in the dilepton channel during the D0 experiment at the Tevatron. Mesure de la masse du quark top dans les canaux di-leptoniques auprès de l’expérience D0 au Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Croc, Aurelien [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA) Saclay, Gif-sur-Yvette (France). IRFU

    2011-01-01

    The top quark is the heaviest standard model quark. Discovered in 1995 by the two Tevatron experiments it has atypical properties. In particular its time life is so short that it decays before hadronizing, so the top quark mass could be measured with a high precision. Data collected by the DØ experiment between 2002 and 2009, which represent an integrated luminosity of 5.4 fb⁻¹, are used to measure the top quark mass by using the matrix element method in the three dilepton channels: dielectron, electron--muon and dimuon. The measured mass, 174.0 ± 1.8 (stat.) ± 2.4 (syst.) GeV, is in a good agreement with other measurements and limited by the systematic uncertainties for the first time in these channels. In this thesis different approaches have been studied to improve the accuracy of this measurement: the use of b-quark jet identification in order to optimize the selection of top--anti-top events and a better determination of the main systematic uncertainties. A special attention has been paid to the Monte-Carlo simulation of muons in D0: the improved smearing procedure for the simulated muons, discussed in this thesis, will be used to increase the accuracy of the top properties measurements as well as the precision of many other D0 measurements.

  5. Determination of the Muonic Branching Ratio of the W Boson and its Total Width via Cross-Section Measurements at the Tevatron and LHC

    CERN Document Server

    Camarda, Stefano; Schott, Matthias

    2016-01-01

    The total $W$-boson decay width $\\Gamma_W$ is an important observable which allows testing of the standard model. The current world average value is based on direct measurements of final state kinematic properties of $W$-boson decays, and has a relative uncertainty of 2\\%. The indirect determination of $\\Gamma_W$ via the cross-section measurements of vector-boson production can lead to a similar accuracy. The same methodology leads also to a determination of the leptonic branching ratio. This approach has been successfully pursued by the CDF and D0 experiments at the Tevatron collider, as well as by the CMS collaboration at the LHC. In this paper we present for the first time a combination of the available measurements at hadron colliders, accounting for the correlations of the associated systematic uncertainties. Our combination leads to values of $\\textrm{BR}(W\\rightarrow\\mu\

  6. Simulation of beam-beam effects in tevatron

    International Nuclear Information System (INIS)

    Mishra, C.S.; Assadi, S.; Talman, R.

    1995-08-01

    The Fermilab accelerator complex is in the middle of an upgrade plan Fermilab III. In the last phase of this upgrade the luminosity of the Tevatron will increase by at least one order of magnitude. In order to keep the number of interactions per crossing manageable for experiments, the number of bunches will be increased from 6 x 6 to 36 x 36 and finally to ∼100 x 100 bunches. The beam dynamics of the Tevatron has been studied from Beam-Beam effect point of view in a ''Strong-Weak'' representation with a single particle being tracked in presence of other beam. This paper describes the beam-beam effect in 6 x 6 operation of Tevatron

  7. Performance of the Scintillator-Strip Electromagnetic Calorimeter Prototype for the Linear Collider Experiment

    International Nuclear Information System (INIS)

    Uozumi, Satoru

    2011-01-01

    The scintillator-strip electromagnetic calorimeter (ScECAL) is one of fine granular calorimeters proposed to realize Particle Flow Algorithm for the International Linear Collider experiment. The ScECAL is a sandwitch calorimeter with tungsten and scintillator layers, where the scintillator layer consists of plastic scintillator strips which size of 1 cm x 4.5 cm x 0.2 cm with a small photo-sensor (MPPC) attached at the its edge. In alternate scintillator layers, strips are orthogonally aligned to make a virtual 1x 1 cm 2 cell with its crossing area. To establish the ScECAL technology, we have built a prototype of the ScECAL which consists of 30 layers of tungsten and scintillator layers with 2160 scintillator strips in total. In 2008 and 2009 the beam test has been performed at Fermilab meson test beam line to evaluate performance of the ScECAL prototype with various types of beams ranging 1 to 32 GeV. As a preliminary result of the beam test in 2008, we have obtained linearity of energy measurement less than 6% from the perfect linear response. Energy resolution is measured to be σ/E(15.15±0.03)%/√E+(1.44±0.02)%. Although detailed analyses are still ongoing, those results already establishes feasibility of the ScECAL as the fine granular calorimeter. However as the next step to precisely measure even higher energy jets, we will proceed to even more finely segmented calorimeter with 5 mm width scintillator strips.

  8. Availability modeling approach for future circular colliders based on the LHC operation experience

    CERN Document Server

    AUTHOR|(CDS)2096726; Apollonio, Andrea; Gutleber, Johannes; Sollander, Peter; Penttinen, Jussi-Pekka; Virtanen, Seppo Johannes

    2016-01-01

    Reaching the challenging integrated luminosity production goals of a future circular hadron collider (FCC-hh) and high luminosity LHC (HL-LHC) requires a thorough understanding of today’s most powerful high energy physics research infrastructure, the LHC accelerator complex at CERN. FCC-hh, a 4 times larger collider ring aims at delivering 10–20  ab$^-$$^1$ of integrated luminosity at 7 times higher collision energy. Since the identification of the key factors that impact availability and cost is far from obvious, a dedicated activity has been launched in the frame of the future circular collider study to develop models to study possible ways to optimize accelerator availability. This paper introduces the FCC reliability and availability study, which takes a fresh new look at assessing and modeling reliability and availability of particle accelerator infrastructures. The paper presents a probabilistic approach for Monte Carlo simulation of the machine operational cycle, schedule and availability for p...

  9. Future Hadron Colliders

    CERN Document Server

    Keil, Eberhard

    1998-01-01

    Plans for future hadron colliders are presented, and accelerator physics and engineering aspects common to these machines are discussed. The Tevatron is presented first, starting with a summary of the achievements in Run IB which finished in 1995, followed by performance predictions for Run II which will start in 1999, and the TeV33 project, aiming for a peak luminosity $L ~ 1 (nbs)^-1$. The next machine is the Large Hadron Collider LHC at CERN, planned to come into operation in 2005. The last set of machines are Very Large Hadron Colliders which might be constructed after the LHC. Three variants are presented: Two machines with a beam energy of 50 TeV, and dipole fields of 1.8 and 12.6 T in the arcs, and a machine with 100 TeV and 12 T. The discussion of accelerator physics aspects includes the beam-beam effect, bunch spacing and parasitic collisions, and the crossing angle. The discussion of the engineering aspects covers synchrotron radiation and stored energy in the beams, the power in the debris of the p...

  10. The dijet invariant mass at the Tevatron Collider

    International Nuclear Information System (INIS)

    1990-01-01

    The differential cross section as a function of the dijet invariant mass has been measured in 1.8 TeV ppbar collisions. A comparison to leading order QCD predictions is presented as well as a study of the sensitivity of the mass spectrum to the gluon radiation. The need to take radiation into account requires the study of its spatial distribution and the comparison of the data to the predictions of shower Monte Carlo programs like Isajet and Herwig. 12 refs., 10 figs

  11. Physics with W's, Z's and leptons at the Tevatron collider

    International Nuclear Information System (INIS)

    Bodek, A.

    1996-10-01

    Recent data from proton-antiproton collisions at high energy provide information on the masses of the Top quark and W boson. The W asymmetry data constrains the slope of the d/u quark distributions and significantly reduces the systematic error on the extracted value of the W mass. Drell-Yan dilepton production at high invariant mass yield limits on extra Z' bosons, and place strong limits on quark substructure. Compositeness limits from CDF Run 1, and expected sensitivity in Run II and TEV33 are presented

  12. LINEAR COLLIDER PHYSICS RESOURCE BOOK FOR SNOWMASS 2001

    International Nuclear Information System (INIS)

    ABE, T.; DAWSON, S.; HEINEMEYER, S.; MARCIANO, W.; PAIGE, F.; TURCOT, A.S.; ET

    2001-01-01

    The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decade or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e + e - linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e + e - linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e + e - linear collider; in any scenario that is now discussed, physics will benefit from the new information that e + e - experiments can provide

  13. Managing discovery risks--A Tevatron case study

    International Nuclear Information System (INIS)

    Bakul Banerjee

    2004-01-01

    To meet the increasing need for higher performance, Management of Fermi National Accelerator Laboratory has undertaken various projects to improve systems associated with the Tevatron high-energy particle collider located at Batavia, Illinois. One of the larger projects is the Tevatron Beam Position Monitor (BPM) system. The objective of this project is to replace the existing BPM electronics and software system that was originally installed during early 1980s, along with the original construction of the Tevatron.The original system consists of 236 beam position monitors located around the underground tunnel of the accelerator. Above ground control systems are attached to these monitors using pickup cables. When the Tevatron collider is operational, signals received from the BPMs are used to perform a number of control and diagnostic tasks. The original system can only capture the proton signals from the collider. The new system, when fully operational, will be able to capture combined proton and antiproton signals and will be able to separate the antiproton signal from the combined signal at high resolution. This significant enhancement was beyond the range of technical capabilities when the Tevatron was constructed about two decades ago. To take advantage of exceptional progress made in the hardware and software area in past two decades, Department of Energy approved funding of the BPM electronics and software replacement project. The approximate length of the project is sixteen months with a budget of four million dollars not including overhead, escalation, and contingencies. Apart from cost and schedule risks, there are two major risks associated with this research and development project. The primary risk is the risk of discovery. Since the Tevatron beam path is highly complex, BPMs have to acquire and process a large amount of data. In this environment, analysis of data to separate antiproton signals is even more complex. Finding an optimum algorithm that can

  14. HIGH ENERGY PHYSICS POTENTIAL AT MUON COLLIDERS

    International Nuclear Information System (INIS)

    PARSA, Z.

    2000-01-01

    In this paper, high energy physics possibilities and future colliders are discussed. The μ + μ - collider and experiments with high intensity muon beams as the stepping phase towards building Higher Energy Muon Colliders (HEMC) are briefly reviewed and encouraged

  15. Tevatron-for-LHC Report: Preparations for Discoveries

    CERN Document Server

    Abdullin, Salavat; Asai, Shoji; Atramentov, Oleksiy Vladimirovich; Baer, Howard; Balazs, Csaba; Bartalini, Paolo; Belyaev, Alexander; Bernhard, Ralf Patrick; Birkedal, Andreas; Buescher, Volker; Cavanaugh, Richard; Chen, Mu-Chun; Clement, Christophe; Datta, AseshKrishna; de Boer, Ytsen R.; De Roeck, Albert; Dobrescu, Bogdan A.; Drozdetskiy, Alexey; Gershtein, Yuri S.; Glenzinski, Douglas A.; Group, Robert Craig; Heinemeyer, Sven; Heldmann, Michael; Hubisz, Jay; Karlsson, Martin; Kong, Kyoungchul; Korytov, Andrey; Kraml, Sabine; Krupovnickas, Tadas; Lafaye, Remi; Lane, Kenneth; Ledroit, Fabienne; Lehner, Frank; Lin, Cheng-Ju; Macesanu, Cosmin; Matchev, Konstantin T.; Menon, Arjun; Milstead, David; Mitselmakher, Guenakh; Morel, Julien; Morrissey, David; Mrenna, Steve; O'Farrill, Jorge; Pakhotin, Yu.; Perelstein, Maxim; Plehn, Tilman; Rainwater, David; Raklev, Are; Schmitt, Michael; Scurlock, Bobby; Sherstnev, Alexander; Skands, Peter Z.; Sullivan, Zack; Tait, Timothy M.P.; Tata, Xerxes; Torchiani, Ingo; Trocme, Benjamin; Wagner, Carlos; Weiglein, Georg; Zerwas, Dirk

    2006-01-01

    This is the "TeV4LHC" report of the "Physics Landscapes" Working Group, focused on facilitating the start-up of physics explorations at the LHC by using the experience gained at the Tevatron. We present experimental and theoretical results that can be employed to probe various scenarios for physics beyond the Standard Model.

  16. Tevatron: recent results and prospects at the upgrade

    International Nuclear Information System (INIS)

    Mondal, Naba K.

    1998-01-01

    In this article, we review some of the recent results from CDF and DΦ experiments at the Tevatron and their prospects at the upgrade. Among the topics discussed are top quark physics, electroweak physics, QCD physics and new physics beyond standard model. (author)

  17. Explaining Tevatron leptons photons missing- T events with ...

    Indian Academy of Sciences (India)

    Abstract. The CDF experiment reported a lepton photon missing transverse energy. (/ET) signal 3σ in excess of the standard model prediction in Tevatron Run I data. The excess can be explained by the resonant production of a smuon, which subsequently decays to a muon, a photon and a gravitino. Here, we perform ...

  18. B factory with hadron colliders

    International Nuclear Information System (INIS)

    Lockyer, N.S.

    1990-01-01

    The opportunities to study B physics in a hadron collider are discussed. Emphasis is placed on the technological developments necessary for these experiments. The R and D program of the Bottom Collider Detector group is reviewed. (author)

  19. The development of colliders

    International Nuclear Information System (INIS)

    Sessler, A.M.

    1997-03-01

    During the period of the 50's and the 60's colliders were developed. Prior to that time there were no colliders, and by 1965 a number of small devices had worked, good understanding had been achieved, and one could speculate, as Gersh Budker did, that in a few years 20% of high energy physics would come from colliders. His estimate was an under-estimate, for now essentially all of high energy physics comes from colliders. The author presents a brief review of that history: sketching the development of the concepts, the experiments, and the technological advances which made it all possible

  20. Tevatron serial data repeater system

    International Nuclear Information System (INIS)

    Ducar, R.J.

    1981-01-01

    A ten megabit per second serial data repeater system has been developed for the 6.28km Tevatron accelerator. The repeaters are positioned at each of the thirty service buildings and accommodate control and abort system communications as well as distribution of the Tevatron time and energy clocks. The repeaters are transparent to the particular protocol of the transmissions. Serial data are encoded locally as unipolar two volt signals employing the self-clocking Manchester Bi-Phase code. The repeaters modulate the local signals to low-power bursts of 50 MHz rf carrier for the 260m transmission between service buildings. The repeaters also demodulate the transmission and restructure the data for local utilization. The employment of frequency discrimination techniques yields high immunity to the characteristic noise spectrum

  1. Accelerating polarized beams in Tevatron

    International Nuclear Information System (INIS)

    Teng, L.C.

    1989-02-01

    In this paper, we will examine the totality of equipment, manpower and cost necessary to obtain a polarized proton beam in the Tevatron. We will not, however, be concerned with the acquisition and acceleration of polarized /bar p/ beams. Furthermore we will consider only a planar main ring without overpass, although it is expected that Siberian snake schemes could be made to apply equally well to non-planar machines. In addition to not wanting to tackle here the task of reformulating the theory for a non-planar closed orbit, we also anticipate that as part of the Tevatron upgrade the main ring will in the not too distant future, be replaced by a planar main injector situated in a separate tunnel. 4 refs., 11 figs., 1 tab

  2. 2nd CERN-Fermilab Hadron Collider Physics Summer School

    CERN Document Server

    2007-01-01

    June 6-15, 2007, CERN The school web site is http://cern.ch/hcpss with links to the academic programme and the application procedure. The APPLICATION DEADLINE IS 9 MARCH 2007 The results of the selection process will be announced shortly thereafter. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The first school in the series, held last summer at Fermilab, extensively covered the physics at the Tevatron collider experiments. The second school, to be held at CERN, will focus on the technology and physics of the LHC experiments. Emphasis will be placed on the first years of data-taking at the LHC and on the discovery potential of the programme. The series of lectures will be supported by in-depth discussion sessions and will include the theory and phenomenology of hadron collisions, discovery physics topics, detector and analysis t...

  3. An Ionization Profile Monitor for the Tevatron

    CERN Document Server

    Jansson, Andreas; Bowie, Kwame; Bross, Alan; Dysert, Robert; Fitzpatrick, Thomas; Kwarciany, Richard; Lundberg, Carl; Nguyen, Hogan; Rivetta, Claudio H; Slimmer, David; Valerio, Linda; Zagel, James

    2005-01-01

    Primarily to study emittance blowup during injection and ramping, an ionization profile monitor has been developed for the Tevatron. It is based on a prototype installed in the Main Injector, although with extensive modifications. In particular, the electromagnetic shielding has been improved, the signal path has been cleaned up, and provisions have been made for an internal electron source. Due to the good Tevatron vacuum, a local pressure bump is introduced to increase the primary signal, which is then amplified by a microchannel plate and detected on anode strips. For the DAQ, a custom ASIC developed for the CMS experiment is used. It is a combined charge integrator and digitizer, with a sensitivity of a few fC, and a time-resolution that allows single bunch measurement. Digitization is done in the tunnel to reduce noise. Preparations for detector installation were made during the long 2004 shutdown, with the installation of magnets, vacuum chambers, vacuum pumps and cabling. The actual detector will be in...

  4. Sonic Helium Detectors in the Fermilab Tevatron

    Science.gov (United States)

    Bossert, R. J.

    2006-04-01

    In the Fermilab Tevatron cryogenic system there are many remotely located low-pressure plate relief valves that must vent large volumes of cold helium gas when magnet quenches occur. These valves can occasionally stick open or not reseat completely, resulting in a large helium loss. As such, the need exists for a detector to monitor the relief valve's discharge area for the presence of helium. Due to the quantity needed, cost is an important factor. A unit has been developed and built for this purpose that is quite inexpensive. Its operating principle is based on the speed of sound, where two closely matched tubes operate at their acoustic resonant frequency. When helium is introduced into one of these tubes, the resulting difference in acoustic time of flight is used to trigger an alarm. At present, there are 39 of these units installed and operating in the Tevatron. They have detected many minor and major helium leaks, and have also been found useful in detecting a rise in the helium background in the enclosed refrigerator buildings. This paper covers the construction, usage and operational experience gained with these units over the last several years.

  5. Sonic helium detectors in the Fermilab Tevatron

    International Nuclear Information System (INIS)

    Bossert, R.J.; Fermilab

    2006-01-01

    In the Fermilab Tevatron cryogenic system there are many remotely located low-pressure plate relief valves that must vent large volumes of cold helium gas when magnet quenches occur. These valves can occasionally stick open or not reseat completely, resulting in a large helium loss. As such, the need exists for a detector to monitor the relief valve's discharge area for the presence of helium. Due to the quantity needed, cost is an important factor. A unit has been developed and built for this purpose that is quite inexpensive. Its operating principle is based on the speed of sound, where two closely matched tubes operate at their acoustic resonant frequency. When helium is introduced into one of these tubes, the resulting difference in acoustic time of flight is used to trigger an alarm. At present, there are 39 of these units installed and operating in the Tevatron. They have detected many minor and major helium leaks, and have also been found useful in detecting a rise in the helium background in the enclosed refrigerator buildings. This paper covers the construction, usage and operational experience gained with these units over the last several years

  6. Search for a standard Higgs boson in the WH associated production channel with the final statistics of the Tevatron DO experiment

    International Nuclear Information System (INIS)

    Miconi, F.

    2012-01-01

    Higgs mechanism, introduced in 1964, gives a satisfactory solution to a major problem of the standard model of elementary particles: the origin of the mass. It predicts the existence of the Higgs scalar boson, which mass is not defined by the theory and which has not been discovered experimentally yet (June 2012). The Tevatron, a hadron accelerator based at Fermi National Accelerator Laboratory near Chicago, took data with its two multi-purpose detectors CDF and DO since 1983 up to september 2011. Leaving about 10 fb -1 of statistics to analyze. Associated production of Higgs (H) and vector gauge boson (W) is the main search channel for a light standard Higgs boson. A light Higgs boson is expected to decay in a pair of beauty quarks. Using data collected by DO, we are looking for this production mode taking advantage of sophisticated techniques to improve the signal sensitivity like b-jet identification and multivariate discriminating factors. In the end, a statistical approach allows us to set an upper limit on the ratio between the observed (resp. expected) Higgs production and its theoretical cross section. The results obtained in the WH channel using 9.7 fb -1 at DO is 3.15 (resp. 3.96) for a 115 GeV/c 2 Higgs boson. (author)

  7. CERN scientists take part in the Tevatron Run II performance review committee

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Tevatron Run II is under way at Fermilab, exploring the high-energy frontier with upgraded detectors that will address some of the biggest questions in particle physics.Until CERN's LHC switches on, the Tevatron proton-antiproton collider is the world's only source of top quarks. It is the only place where we can search for supersymmetry, for the Higgs boson, and for signatures of additional dimensions of space-time. The US Department of Energy (DOE) recently convened a high-level international review committee to examine Fermilab experts' first-phase plans for the accelerator complex. Pictured here with a dipole magnet in CERN's LHC magnet test facility are the four CERN scientists who took part in the DOE's Tevatron review. Left to right: Francesco Ruggiero, Massimo Placidi, Flemming Pedersen, and Karlheinz Schindl. Further information: CERN Courier 43 (1)

  8. Top quark pair production and calorimeter energy resolution studies at a future collider experiment

    CERN Document Server

    Seidel, Katja

    This thesis is focused on detector concepts and analyses investigated at a future linear electron positron collider. For precision measurements at such a collider, the CALICE collaboration develops imaging calorimeters, which are characterized by a fine granularity. CALICE has constructed prototypes of several design options for electromagnetic and hadronic calorimeters and has successfully operated these detectors during combined test beam programs at DESY, CERN and Fermilab. To improve the hadronic energy reconstruction and energy resolution of a hadron calorimeter prototype with analog readout three software compensation techniques are presented in this thesis, of which one is a local and two are global software compensation approaches. One method is based on a neural network to optimize the energy reconstruction, while two are energy weighting techniques, depending on the energy density. Weight factors are extracted from and applied to simulated and test beam data and result in an average energy resolutio...

  9. A realtime feedback microprocessor for the TEVATRON

    International Nuclear Information System (INIS)

    Herrup, D.A.; Chapman, L.; Franck, A.; Groves, T.; Lublinsky, B.

    1993-01-01

    A feedback microprocessor has been built for the TEVATRON. Its inputs are realtime accelerator measurements, data describing the state of the TEVATRON, and ramp tables. The microprocessor includes a finite state machine. Each state corresponds to a specific TEVATRON operation. Transitions between states are initiated by the global TEVATRON clock. Each state includes a cyclic routine which is called periodically and where all calculations are performed. The output corrections are inserted onto a fast TEVATRON-wide link from which the power supplies will read the realtime correction. The authors also store all of the input data and output corrections in a set of buffers which can easily be retrieved for diagnostic analysis. This talk will describe use of this device to control the TEVATRON tunes and discuss other uses

  10. Design Study for a Staged Very Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Alex W.

    2002-02-27

    Particle physics makes its greatest advances with experiments at the highest energy. The only sure way to advance to a higher-energy regime is through hadron colliders--the Tevatron, the LHC, and then, beyond that, a Very Large Hadron Collider. At Snowmass-1996 [1], investigators explored the best way to build a VLHC, which they defined as a 100 TeV collider. The goals in this study are different. The current study seeks to identify the best and cheapest way to arrive at frontier-energy physics, while simultaneously starting down a path that will eventually lead to the highest-energy collisions technologically possible in any accelerator using presently conceivable technology. This study takes the first steps toward understanding the accelerator physics issues, the technological possibilities and the approximate cost of a particular model of the VLHC. It describes a staged approach that offers exciting physics at each stage for the least cost, and finally reaches an energy one-hundred times the highest energy currently achievable.

  11. Collider shot setup for Run 2 observations and suggestions

    International Nuclear Information System (INIS)

    Annala, J.; Joshel, B.

    1996-01-01

    This note is intended to provoke discussion on Collider Run II shot setup. We hope this is a start of activities that will converge on a functional description of what is needed for shot setups in Collider Run II. We will draw on observations of the present shot setup to raise questions and make suggestions for the next Collider run. It is assumed that the reader has some familiarity with the Collider operational issues. Shot setup is defined to be the time between the end of a store and the time the Main Control Room declares colliding beams. This is the time between Tevatron clock events SCE and SCB. This definition does not consider the time experiments use to turn on their detectors. This analysis was suggested by David Finley. The operational scenarios for Run II will require higher levels of reliability and speed for shot setup. See Appendix I and II. For example, we estimate that a loss of 3 pb -1 /week (with 8 hour stores) will occur if shot setups take 90 minutes instead of 30 minutes. In other words: If you do 12 shots for one week and accept an added delay of one minute in each shot, you will loose more than 60 nb -1 for that week alone (based on a normal shot setup of 30 minutes). These demands should lead us to be much more pedantic about all the factors that affect shot setups. Shot setup will be viewed as a distinct process that is composed of several inter- dependent 'components': procedures, hardware, controls, and sociology. These components don't directly align with the different Accelerator Division departments, but are topical groupings of the needed accelerator functions. Defining these components, and categorizing our suggestions within them, are part of the goal of this document. Of course, some suggestions span several of these components

  12. Long-range beam-beam experiments in the relativistic heavy ion collider

    International Nuclear Information System (INIS)

    Calaga, R; Fischer, W; Milas, N; Robert-Demolaize, G

    2014-01-01

    Long-range beam-beam effects are a potential limit to the LHC performance with the nominal design parameters, and certain upgrade scenarios under discussion. To mitigate long-range effects, current carrying wires parallel to the beam were proposed and space is reserved in the LHC for such wires. Two current carrying wires were installed in RHIC to study the effect of strong long-range beam-beam effects in a collider, as well as test the compensation of a single long-range interaction. The experimental data were used to benchmark simulations. We summarize this work

  13. Top quark pair production and calorimeter energy resolution studies at a future collider experiment

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, Katja

    2012-03-27

    This thesis is focused on detector concepts and analyses investigated at a future linear electron positron collider. For precision measurements at such a collider, the CALICE collaboration develops imaging calorimeters, which are characterized by a fine granularity. CALICE has constructed prototypes of several design options for electromagnetic and hadronic calorimeters and has successfully operated these detectors during combined test beam programs at DESY, CERN and Fermilab. To improve the hadronic energy reconstruction and energy resolution of a hadron calorimeter prototype with analog readout three software compensation techniques are presented in this thesis, of which one is a local and two are global software compensation approaches. One method is based on a neural network to optimize the energy reconstruction, while two are energy weighting techniques, depending on the energy density. Weight factors are extracted from and applied to simulated and test beam data and result in an average energy resolution improvement of 15 - 25% compared to a reconstruction without software compensation. Whether such software compensation techniques are also applicable to a detector concept for a future linear electron positron collider is studied in the second part of this thesis. Simulated data, two different hadronic detector models and a local software compensation technique are used for this study. The energy resolutions for single hadrons and for jets are presented with and without software compensation. In the third part of this thesis, a study on top quark pair production at a center-of-mass energy of 500 GeV at the proposed electron positron collider CLIC is presented. The analysis is based on full detector simulations, including realistic background contributions dominated by two photon processes. The mass and width of the top quark are studied in fully-hadronic and semi-leptonic decays of top quark pairs using event samples of signal and Standard Model background

  14. Top quark pair production and calorimeter energy resolution studies at a future collider experiment

    International Nuclear Information System (INIS)

    Seidel, Katja

    2012-01-01

    This thesis is focused on detector concepts and analyses investigated at a future linear electron positron collider. For precision measurements at such a collider, the CALICE collaboration develops imaging calorimeters, which are characterized by a fine granularity. CALICE has constructed prototypes of several design options for electromagnetic and hadronic calorimeters and has successfully operated these detectors during combined test beam programs at DESY, CERN and Fermilab. To improve the hadronic energy reconstruction and energy resolution of a hadron calorimeter prototype with analog readout three software compensation techniques are presented in this thesis, of which one is a local and two are global software compensation approaches. One method is based on a neural network to optimize the energy reconstruction, while two are energy weighting techniques, depending on the energy density. Weight factors are extracted from and applied to simulated and test beam data and result in an average energy resolution improvement of 15 - 25% compared to a reconstruction without software compensation. Whether such software compensation techniques are also applicable to a detector concept for a future linear electron positron collider is studied in the second part of this thesis. Simulated data, two different hadronic detector models and a local software compensation technique are used for this study. The energy resolutions for single hadrons and for jets are presented with and without software compensation. In the third part of this thesis, a study on top quark pair production at a center-of-mass energy of 500 GeV at the proposed electron positron collider CLIC is presented. The analysis is based on full detector simulations, including realistic background contributions dominated by two photon processes. The mass and width of the top quark are studied in fully-hadronic and semi-leptonic decays of top quark pairs using event samples of signal and Standard Model background

  15. Muon collider progress

    Energy Technology Data Exchange (ETDEWEB)

    Noble, Robert J. FNAL

    1998-08-01

    Recent progress in the study of muon colliders is presented. An international collaboration consisting of over 100 individuals is involved in calculations and experiments to demonstrate the feasibility of this new type of lepton collider. Theoretical efforts are now concentrated on low-energy colliders in the 100 to 500 GeV center-of-mass energy range. Credible machine designs are emerging for much of a hypothetical complex from proton source to the final collider. Ionization cooling has been the most difficult part of the concept, and more powerful simulation tools are now in place to develop workable schemes. A collaboration proposal for a muon cooling experiment has been presented to the Fermilab Physics Advisory Committee, and a proposal for a targetry and pion collection channel experiment at Brookhaven National Laboratory is in preparation. Initial proton bunching and space-charge compensation experiments at existing hadron facilities have occurred to demonstrate proton driver feasibility.

  16. BFKL Tests at the Tevatron

    International Nuclear Information System (INIS)

    Goussiou, A.

    1997-06-01

    The azimuthal decorrelation of jets as a function of their rapidity separation and the dependence of the fraction of jet events with central rapidity gaps on the center of mass energy are studied in p anti p collisions at the Tevatron. The preliminary results on jet decorrelation are in disagreement with calculations based on the Leading Logarithmic Approximation for BFKL resummation. The preliminary results on the √s--dependence of the central rapidity gap events are in disagreement with the two-gluon model for color-singlet exchange

  17. Probing GeV-scale MSSM neutralino dark matter in collider and direct detection experiments

    Science.gov (United States)

    Duan, Guang Hua; Wang, Wenyu; Wu, Lei; Yang, Jin Min; Zhao, Jun

    2018-03-01

    Given the recent constraints from the dark matter (DM) direct detections, we examine a light GeV-scale (2-30 GeV) neutralino DM in the alignment limit of the Minimal Supersymmetric Standard Model (MSSM). In this limit without decoupling, the heavy CP-even scalar H plays the role of the Standard Model (SM) Higgs boson while the other scalar h can be rather light so that the DM can annihilate through the h resonance or into a pair of h to achieve the observed relic density. With the current collider and cosmological constraints, we find that such a light neutralino DM above 6 GeV can be excluded by the XENON-1T (2017) limits while the survivied parameter space below 6 GeV can be fully tested by the future germanium-based light dark matter detections (such as CDEX), by the Higgs coupling precison measurements or by the production process e+e- → hA at an electron-positron collider (Higgs factory).

  18. Muon colliders

    International Nuclear Information System (INIS)

    Palmer, R.B.; Sessler, A.; Skrinsky, A.

    1996-01-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. Parameters are given of 4 TeV and 0.5 TeV high luminosity micro + micro - colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Problems of detector background are also discussed

  19. Muon colliders

    International Nuclear Information System (INIS)

    Cline, David

    1995-01-01

    The increasing interest in the possibility of positive-negative muon colliders was reflected in the second workshop on the Physics Potential and Development of Muon Colliders, held in Sausalito, California, from 16-19 November, with some 60 attendees. It began with an overview of the particle physics goals, detector constraints, the muon collider and mu cooling, and source issues. The major issue confronting muon development is the possible luminosity achievable. Two collider energies were considered: 200 + 200 GeV and 2 + 2 TeV. The major particle physics goals are the detection of the higgs boson(s) for the lower energy collider, together with WW scattering and supersymmetric particle discovery. At the first such workshop, held in Napa, California, in 1992, it was estimated that a luminosity of some 10 30 and 3 x 10 32 cm -2 s -1 for the low and high energy collider might be achieved (papers from this meeting were published in the October issue of NIM). This was considered a somewhat conservative estimate at the time. At the Sausalito workshop the goal was to see if a luminosity of 10 32 to 10 34 for the two colliders might be achievable and usable by a detector. There were five working groups - physics, 200 + 200 GeV collider, 2 + 2 TeV collider, detector design and backgrounds, and muon cooling and production methods. Considerable progress was made in all these areas at the workshop.

  20. Parton distribution and Tevatron jet data

    International Nuclear Information System (INIS)

    Alekhin, S.; Bluemlein, J.; Moch, S.

    2011-05-01

    We study the impact of Tevatron jet data on a global fit of parton distribution functions and on the determination of the value of the strong coupling constant α s (M Z ). The consequences are illustrated for cross sections of Higgs boson production at Tevatron and the LHC. (orig.)

  1. Super High Energy Colliding Beam Accelerators

    International Nuclear Information System (INIS)

    Abdelaziz, M.E.

    2009-01-01

    This lecture presents a review of cyclic accelerators and their energy limitations. A description is given of the phase stability principle and evolution of the synchrotron, an accelerator without energy limitation. Then the concept of colliding beams emerged to yield doubling of the beam energy as in the Tevatron 2 trillion electron volts (TeV) proton collider at Fermilab and the Large Hadron Collider (LHC) which is now planned as a 14-TeV machine in the 27 kilometer tunnel of the Large Electron Positron (LEP) collider at CERN. Then presentation is given of the Superconducting Supercollider (SSC), a giant accelerator complex with energy 40-TeV in a tunnel 87 kilometers in circumference under the country surrounding Waxahachie in Texas, U.S.A. These superhigh energy accelerators are intended to smash protons against protons at energy sufficient to reveal the nature of matter and to consolidate the prevailing general theory of elementary particle.

  2. The 20th Hadron Collider Physics Symposium in Evian

    CERN Multimedia

    Ludwik Dobrzynski and Emmanuel Tsesmelis

    The 20th Hadron Collider Physics Symposium took place in Evian from 16 to 20 November 2009. The Hadron Collider Physics Symposium series has been a major forum for presentations of physics at the Tevatron over the past two decades. The merger of the former Topical Conference on Hadron Collider Physics with the LHC Symposium in 2005 brought together the Tevatron and LHC communities in a single forum. The 20th Hadron Collider Physics Symposium took place in Evian, on the shores of Lake Geneva, from 16-20 November 2009, some 17 years after the historic ECFA-CERN Evian meeting in March 1992 when Expressions of Interest for LHC detectors were presented for the first time. The 2009 event was organized jointly by CERN and the French high-energy physics community (CNRS-IN2P3 and CEA-IRFU). More than 170 people registered for this symposium. This year’s symposium was held at an important time for both the Tevatron and the LHC. It stimulated the completion of analyses for a significant Tevatron data sam...

  3. Ageing collider throws up hint or dark matter

    CERN Multimedia

    Ananthaswamy, Anil

    2008-01-01

    "Never mind the Large Hadron Collider at CERN, its ageing predecessor may have discovered a new and unexpected kind of particle. The announcement last week from the Tevatron particle accelerator at Fermilab in Batavai, Illinois, provided some excitement amid the frustration of ongoing repairs to the LHC."

  4. Twistor Spinoffs for Collider Physics

    International Nuclear Information System (INIS)

    Dixon, Lance

    2006-01-01

    In the coming decade, the search for the Higgs boson, and for new particles representing physics beyond the Standard Model, will be carried out by colliding protons at the Tevatron and the Large Hadron Collider. A collision of two protons, each of which is made out of quarks and gluons, is inherently messy. Feynman likened it to smashing two Swiss watches together to figure out how they work. In recent decades, we have learned better how the Swiss watches work, using the theory of quark-gluon interactions, quantum chromodynamics. Armed with this knowledge, we can better predict the results of collisions at the Tevatron and the LHC, to see whether the Standard Model holds up or fails, or whether new particles are in the data. But a major bottleneck is simply in adding up Feynman diagrams, for which the rules are well known, yet there can be thousands of extremely complicated diagrams. In fact, the sum of all diagrams is often much simpler than the typical one, suggesting hidden symmetries and better ways to compute. In the past two years, spinoffs from a new theory, 'twistor string theory', have led to very efficient alternatives to Feynman diagrams for making such predictions, as I will explain.

  5. Theory-motivated benchmark models and superpartners at the Fermilab Tevatron

    International Nuclear Information System (INIS)

    Kane, G.L.; Nelson, Brent D.; Wang Liantao; Wang, Ting T.; Lykken, J.; Mrenna, Stephen

    2003-01-01

    Recently published benchmark models have contained rather heavy superpartners. To test the robustness of this result, several benchmark models have been constructed based on theoretically well-motivated approaches, particularly string-based ones. These include variations on anomaly- and gauge-mediated models, as well as gravity mediation. The resulting spectra often have light gauginos that are produced in significant quantities at the Fermilab Tevatron collider, or will be at a 500 GeV linear collider. The signatures also provide interesting challenges for the CERN LHC. In addition, these models are capable of accounting for electroweak symmetry breaking with less severe cancellations among soft supersymmetry breaking parameters than previous benchmark models

  6. Study of New Silicon Sensors for Experiments at Future Particle Colliders

    CERN Document Server

    Muñoz Sánchez, Francisca Javiela

    In this work, two new technologies for future tracker detectors at future colliders are studied. In addition, the characterization techniques are described and the obtained results are presented. On one side, we studied two-dimensional position-sensitive microstrip sensors. This sensors use a resistive material as electrode instead of the standard metallic one. In this way, using a single sensor we can get information about two coordinates of a particle hit. On the other side, we studied double-sided double-type 3D pixel sensors. This sensors are manufactured in 3D technology instead of in the planar technology. They show more radiation hardness and require less energy to be efficiently operated than sensors manufactured in planar technology. With this work, we demonstrate the resistive microstrip sensors functionality as particle detector and the radiation hardness of 3D pixel detectors has been evaluated.

  7. Reconstructing neutrino properties from collider experiments in a Higgs triplet neutrino mass model

    International Nuclear Information System (INIS)

    Aristizabal Sierra, D.; Hirsch, M.; Valle, J. W. F.; Villanova del Moral, A.

    2003-01-01

    We extend the minimal supersymmetric standard model with bilinear R-parity violation to include a pair of Higgs triplet superfields. The neutral components of the Higgs triplets develop small vacuum expectation values (VEVs) quadratic in the bilinear R-parity breaking parameters. In this scheme the atmospheric neutrino mass scale arises from bilinear R-parity breaking while for reasonable values of parameters the solar neutrino mass scale is generated from the small Higgs triplet VEVs. We calculate neutrino masses and mixing angles in this model and show how the model can be tested at future colliders. The branching ratios of the doubly charged triplet decays are related to the solar neutrino angle via a simple formula

  8. Study of a prototype electromagnetic calorimeter in the CALICE experiment under the Linear Collider International project

    International Nuclear Information System (INIS)

    Benyamna, Mustapha

    2010-01-01

    This thesis is conducted within the framework of the International Linear Collider and the international collaboration so called CALICE. This work focuses on a study of a prototype of the electromagnetic calorimeter. This prototype has been used in various test period at CERN, DESY and FNAL. The author presents two subjects of study: The first part is about the instrumentation for the resolution of the square event discovered during the taking data in 2006 at CERN. To explain the origin and solve the problem caused by crosstalk between peripherals pixels and the guard ring that surrounds the sensor, two studies were made: a simulation study using SILVACO software and a test bench to study several kinds of sensors. The second part of this thesis is a study on the identification of photons using estimators that are related to the parameters of the electromagnetic pattern of the shower. (author)

  9. Long-range beam-beam interactions in the Tevatron: Comparing simulation to tune shift data

    International Nuclear Information System (INIS)

    Saritepe, S.; Michelotti, L.; Peggs, S.

    1990-07-01

    Fermilab upgrade plans for the collider operation include a separation scheme in the Tevatron, in which protons and antiprotons are placed on separate helical orbits. The average separation distance between the closed orbits will be 5σ (σ of the proton bunch) except at the interaction regions, B0 and D0, where they collide head-on. The maximum beam-beam total tune shift in the Tevatron is approximately 0.024 (the workable tune space between 5th and 7th order resonances), which was reached in the 1988--1989 collider tun. Helical separation scheme allows us to increase the luminosity by reducing the total beam-beam tune shift. The number of bunches per beam will be 6 in the 1991 collider tun, to be increased to 36 in the following collider runs. To test the viability of this scenario, helical orbit studies are being conducted. The most recent studies concentrated on the injection of 36 proton bunches, procedures related to opening and closing of the helix, the feed-down circuits and the beam-beam interaction. In this paper, we present the results of the beam-beam interaction studies only. Our emphasis is on the tune shift measurements and the comparison to simulation. 4 refs., 9 figs., 2 tabs

  10. A New Chicane Experiment In PEP-II to Test Mitigations of the Electron Cloud Effect for Linear Colliders

    International Nuclear Information System (INIS)

    Pivi, M

    2008-01-01

    Beam instability caused by the electron cloud has been observed in positron and proton storage rings, and it is expected to be a limiting factor in the performance of future colliders [1-3]. The effect is expected to be particularly severe in magnetic field regions. To test possible mitigation methods in magnetic fields, we have installed a new 4-dipole chicane experiment in the PEP-II Low Energy Ring (LER) at SLAC with both bare and TiN-coated aluminum chambers. In particular, we have observed a large variation of the electron flux at the chamber wall as a function of the chicane dipole field. We infer this is a new high order resonance effect where the energy gained by the electrons in the positron beam depends on the phase of the electron cyclotron motion with respect to the bunch crossing, leading to a modulation of the secondary electron production. Presumably the cloud density is modulated as well and this resonance effect could be used to reduce its magnitude in future colliders. We present the experimental results obtained during January 2008 until the April final shut-down of the PEP-II machine

  11. Discovery of the B_{c}(2S) Meson and Development of Pixel Detectors for Future Particle Collider Experiments

    CERN Document Server

    Wang, Rui

    This work involves an analysis of data recorded at the Large Hadron Collider combined with a program to develop detectors for future collider experiments. Using the full 4.9 fb$^{-1}$ of 7 \\TeV~data collected in 2011 and the 19.2 fb$^{-1}$ of 8 \\TeV~data collected in 2012, the $\\Bc(2S)$ meson has been observed with the ATLAS detector in the hadronic decay mode $\\Bc(2S)\\rightarrow \\Bc\\pi^{+}\\pi^{-}$, $\\Bc\\rightarrow J/\\psi\\pi$. This new state has been found in the mass difference distribution with invariant mass $6842 \\pm 7_{stat.} \\pm 4_{syst.}$ \\MeV. To prepare for the high radiation environment at the High Luminosity LHC, diamond sensors are being developed. Their leakage current and resistivity are measured at fluences and temperatures relevant to the ATLAS upgrade. No evidence of dependence of the resistivity on fluence or temperature has been observed for the ranges [-10 $^\\circ$C, +20 $^\\circ$C] and [0, $1.0\\times10^{16} \\rm{n_{eq}/cm^2}$]. To study the radiation damage of the sensors in the ATLAS Pixel...

  12. Energy calibration of the jets in the experiment D0

    International Nuclear Information System (INIS)

    Coss, J.

    2003-12-01

    This thesis have been performed in the D0 group of the Nuclear Physics Institute at Lyon. This work is about the calibration of the jets in the D0 experiment located on the proton-antiproton collider Tevatron. I studied the Jet Offset Correction and we have proposed a new method to calibrate the b-jets. We have calculated the response of the calorimeter for these jets in the 'photon + b - jets' events. (author)

  13. Measurement of the inclusive isolated prompt photon production cross section at the Tevatron using the CDF detector

    International Nuclear Information System (INIS)

    Deluca Silberberg, Carolina

    2009-01-01

    In this thesis we present the measurement of the inclusive isolated prompt photon cross section with a total integrated luminosity of 2.5 fb -1 of data collected with the CDF Run II detector at the Fermilab Tevatron Collider. The prompt photon cross section is a classic measurement to test perturbative QCD (pQCD) with potential to provide information on the parton distribution function (PDF), and sensitive to the presence of new physics at large photon transverse momentum. Prompt photons also constitute an irreducible background for important searches such as H → γγ, or SUSY and extra-dimensions with energetic photons in the final state. The Tevatron at Fermilab (Batavia, U.S.A.) is currently the hadron collider that operates at the highest energies in the world. It collides protons and antiprotons with a center-of-mass energy of 1.96 TeV. The CDF and the D0 experiments are located in two of its four interaction regions. In Run I at the Tevatron, the direct photon production cross section was measured by both CDF and DO, and first results in Run II have been presented by the DO Collaboration based on 380 pb -1 . Both Run I and Run II results show agreement with the theoretical predictions except for the low p T γ region, where the observed and predicted shapes are different. Prompt photon production has been also extensively measured at fixed-target experiments in lower p T γ ranges, showing excess of data compared to the theory, particularly at high x T . From an experimental point of view, the study of the direct photon production has several advantages compared to QCD studies using jets. Electromagnetic calorimeters have better energy resolution than hadronic calorimeters, and the systematic uncertainty on the photon absolute energy scale is smaller. Furthermore, the determination of the photon kinematics does not require the use of jet algorithms. However, the measurements using photons require a good understanding of the background, mainly dominated by

  14. Tevatron-for-LHC Report: Preparations for Discoveries

    Energy Technology Data Exchange (ETDEWEB)

    Buescher, V.; Carena, Marcela S.; Dobrescu, Bogdan A.; Mrenna, S.; Rainwater, D.; Schmitt, M.

    2006-08-01

    This is the ''TeV4LHC'' report of the ''Physics Landscapes'' Working Group, focused on facilitating the start-up of physics explorations at the LHC by using the experience gained at the Tevatron. We present experimental and theoretical results that can be employed to probe various scenarios for physics beyond the Standard Model.

  15. Fermilab enters the Tevatron era

    International Nuclear Information System (INIS)

    Southworth, B.

    1985-01-01

    The advent of the world's first superconducting accelerator/storage ring has transformed the physics programme at the Fermi National Accelerator Laboratory. The primary and secondary beam energies (and the coming colliding beam energies) are double those previously available at Fermilab and at the CERN SPS. There is heavy investment in the fixed target programme to use these beam energies and, at present, even more pressure is driving the preparations for proton-antiproton colliding beam operation at energies up to 1 TeV per beam. Since it is the revitalized machine which is making all this possible, we begin with news on machine performance and development. (orig.).

  16. Search for excited leptons in the data of the H1 experiment at the HERA collider

    International Nuclear Information System (INIS)

    Delerue, N.

    2002-09-01

    Composite models are one of the possible extensions of the Standard Model. One of their implications, at the energy in the reach of present particles accelerators, would be the excitation of leptons. This PhD. thesis describes the search for excited leptons with the H1 detector installed on the electron-proton collider HERA in Hamburg (Germany). The data used were accumulated between 1994 and 2000 and amount to an integrated luminosity of 120 pb -1 . The analysis of 6 different topologies were done and cover all the branching ratios of desexcitation of excited electron and neutrino. The numbers of candidates found during those analysis is in agreement with the Standard Model expectations. This means that no evidence of excited leptons production was found at HERA. This result was translated in the form of exclusion limits on the coupling of excited leptons (f/A) depending on the mass of the excited lepton. For the first time at HERA we addressed the case were the natural decay width of the excited neutrino is wider than the experimental resolution. For the first time also, a study of the variation of limit depending on the ratio f' / f was carried out. This study lead to the setting of limits independent of this ratio. The limits obtained extend results previously obtained at HERA and also the results of direct searches at LEP. (orig.)

  17. Operational Experience and Consolidations for the Current Lead Control Valves of the Large Hadron Collider

    CERN Document Server

    Perin, A; Pirotte, O; Krieger, B; Widmer, A

    2012-01-01

    The Large Hadron Collider superconducting magnets are powered by more than 1400 gas cooled current leads ranging from 120 A to 13000 A. The gas flow required by the leads is controlled by solenoid proportional valves with dimensions from DN 1.8 mm to DN 10 mm. During the first months of operation, signs of premature wear were found in the active parts of the valves. This created major problems for the functioning of the current leads threatening the availability of the LHC. Following the detection of the problems, a series of measures were implemented to keep the LHC running, to launch a development program to solve the premature wear problem and to prepare for a global consolidation of the gas flow control system. This article describes first the difficulties encountered and the measures taken to ensure a continuous operation of the LHC during the first year of operation. The development of new friction free valves is then presented along with the consolidation program and the test equipment developed to val...

  18. R and D of MPGD-readout TPC for the International Linear Collider experiment

    International Nuclear Information System (INIS)

    Yonamine, R

    2012-01-01

    A Time Projection Chamber (TPC) is chosen for the central tracker of the ILD detector, one of two detector concepts planned for the International Linear Collider (ILC). Physics goals at the ILC will require a TPC with a position resolution of 100 μm and superior track separation, which are not achievable with a conventional Multi-Wire Proportional Chamber (MWPC) readout. A MPGD readout offers improved position resolution and track separation due to measuring the signal at the anode and minimization of E × B effect. For several years, the LC TPC collaboration has been developing a MPGD readout using various small TPC prototypes and the Large Prototype TPC that is operated in a test beam at DESY. The MPGD technologies being tested are GEM and Micromegas with resistive charge broadening, with both traditional pad and CMOS pixel readout. Readout modules with both GEM and Micromegas gas amplification have achieved a position resolution on the order of 100 μm at B = 1 T. In this paper we report on the recent R and D toward the ILD TPC.

  19. High-performance DIRC detector for the future Electron Ion Collider experiment

    Science.gov (United States)

    Kalicy, G.; Allison, L.; Cao, T.; Dzhygadlo, R.; Hartlove, T.; Horn, T.; Hyde, C.; Ilieva, Y.; Nadel-Turonski, P.; Park, K.; Peters, K.; Schwarz, C.; Schwiening, J.; Stevens, J.; Xi, W.; Zorn, C.

    2018-04-01

    Excellent particle identification (PID) is an essential requirement for a future Electron-Ion Collider (EIC) detector. Identification of the hadrons in the final state is critical to study how different quark flavors contribute to nucleon properties. A detector based on the Detection of Internally Reflected Cherenkov light (DIRC) principle, with a radial size of only a few cm, is a perfect solution for those requirements. The R&D process performed by the EIC PID consortium (eRD14) is focused on designing a high-performance DIRC that would extend the momentum coverage well beyond the state-of-the-art, allowing 3 standard deviations or more separation of π/K up to 6 GeV/c, e/π up to 1.8 GeV/c, and p/K up to 10 GeV/c. A key component to reach such a performance is a special 3-layer compound lens. This article describes the status of the High-Performance DIRC R&D for the EIC detector, with a focus on the detailed Monte Carlo simulation results and performance tests of the 3-layer lens.

  20. Electron Lenses for the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, Giulio [Fermilab; Valishev, Alexander [Fermilab; Bruce, Roderik [CERN; Redaelli, Stefano [CERN; Rossi, Adriana [CERN; Salvachua, Belen [CERN

    2014-07-01

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in RHIC at BNL. Within the US LHC Accelerator Research Program and the European HiLumi LHC Design Study, hollow electron beam collimation was studied as an option to complement the collimation system for the LHC upgrades. This project is moving towards a technical design in 2014, with the goal to build the devices in 2015-2017, after resuming LHC operations and re-assessing needs and requirements at 6.5 TeV. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compensation in LHC luminosity upgrade scenarios with small crossing angles.

  1. Weak boson emission in hadron collider processes

    International Nuclear Information System (INIS)

    Baur, U.

    2007-01-01

    The O(α) virtual weak radiative corrections to many hadron collider processes are known to become large and negative at high energies, due to the appearance of Sudakov-like logarithms. At the same order in perturbation theory, weak boson emission diagrams contribute. Since the W and Z bosons are massive, the O(α) virtual weak radiative corrections and the contributions from weak boson emission are separately finite. Thus, unlike in QED or QCD calculations, there is no technical reason for including gauge boson emission diagrams in calculations of electroweak radiative corrections. In most calculations of the O(α) electroweak radiative corrections, weak boson emission diagrams are therefore not taken into account. Another reason for not including these diagrams is that they lead to final states which differ from that of the original process. However, in experiment, one usually considers partially inclusive final states. Weak boson emission diagrams thus should be included in calculations of electroweak radiative corrections. In this paper, I examine the role of weak boson emission in those processes at the Fermilab Tevatron and the CERN LHC for which the one-loop electroweak radiative corrections are known to become large at high energies (inclusive jet, isolated photon, Z+1 jet, Drell-Yan, di-boson, tt, and single top production). In general, I find that the cross section for weak boson emission is substantial at high energies and that weak boson emission and the O(α) virtual weak radiative corrections partially cancel

  2. Electron lenses for the large hadron collider

    CERN Document Server

    Stancari†, G; Bruce, R; Redaelli, S; Rossi, A; Salvachua Ferrando, B

    2014-01-01

    Electron lenses are pulsed, magnetically confined electron beamswhose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-bybunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beamcompensation, and for the demonstration of halo scrapingwith hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in RHIC at BNL. Within the US LHC Accelerator Research Program and the European HiLumi LHC Design Study, hollow electron beam collimation was studied as an option to complement the collimation system for the LHC upgrades. A conceptual design was recently completed, and the project is moving towards a technical design in 2014–2015 for construction in 2015–2017, if needed, after resuming LHC operations and re-assessing collimation needs and requirements at 6.5 TeV. Because of the...

  3. Future proton and electron colliders: Dreams for the 1990's

    International Nuclear Information System (INIS)

    Richter, B.

    1988-10-01

    In this paper I have reviewed the possibilities for new colliders that might be available in the 1990's. One or more new proton should be available in the late-90s based on plans of Europe, the US and the USSR. The two very high energy machines, LHC and SSC, are quite expensive, and their construction will be more decided by the politicians' view on the availability of resources than by the physicists' view of the need for new machines. Certainly something will be built, but the question is when. New electron colliders beyond LEP II could be available in the late 1990's as well. Most of the people who have looked at this problem believe that at a minimum three years of RandD are required before a proposal can be made, two years will be required to convince the authorities to go ahead, and five years will be required to build such a machine. Thus the earliest time a new electron collider at high energy could be available is around 1988. A strong international RandD program will be required to meet that schedule. In the field of B factories, PSI's proposal is the first serious step beyond the capabilities of CESR. There are other promising techniques but these need more RandD. The least RandD would be required for the asymmetric storage ring systems, while the most would be required for high luminosity linear colliders. For the next decade, high energy physics will be doing its work at the high energy frontier with Tevatron I and II, UNK, SLC, LEP I and II, and HERA. The opportunities for science presented by experiments at these facilities are very great, and it is to be hoped that the pressure for funding to construct the next generation facilities will not badly affect the operating budgets of the ones we now have or which will soon be turning on. 9 refs., 12 figs., 6 tabs

  4. Searches for standard model Higgs boson and supersymmetry - Trigger studies and software tools development for new phenomena in the DO experiment

    International Nuclear Information System (INIS)

    Duperrin, A.

    2007-04-01

    This document presents a summary of my research work during the past 7 years for the preparation of the D0 experiment at Fermilab and the analysis of the data collected at the Tevatron hadron collider. It mainly focuses on 2 topics: trigger and direct search for new phenomena, particularly on supersymmetry and standard model Higgs boson searches. This document is divided into 5 chapters: 1) the phenomenology of the standard model and beyond, 2) the phenomenology of pp-bar events, 3) the Tevatron and D0 detector, 4) the trigger system and data acquisition, and 5) data analysis: search for supersymmetry and Higgs boson

  5. Colliding druthers

    International Nuclear Information System (INIS)

    Ankenbrandt, C.; Johnson, R.P.

    1977-01-01

    Recommendations are made to maximize the usefulness of the colliding beam facility of the Main Ring and Energy Doubler at the Fermilab accelerator. The advantages of the transposed crossing geometry over the kissing geometry are pointed out

  6. Proton-Proton and Proton-Antiproton Colliders

    CERN Document Server

    Scandale, Walter

    2014-01-01

    In the last five decades, proton–proton and proton–antiproton colliders have been the most powerful tools for high energy physics investigations. They have also deeply catalyzed innovation in accelerator physics and technology. Among the large number of proposed colliders, only four have really succeeded in becoming operational: the ISR, the SppbarS, the Tevatron and the LHC. Another hadron collider, RHIC, originally conceived for ion–ion collisions, has also been operated part-time with polarized protons. Although a vast literature documenting them is available, this paper is intended to provide a quick synthesis of their main features and key performance.

  7. CERN-Fermilab Hadron Collider Physics Summer School 2013 open for applications

    CERN Multimedia

    2013-01-01

    Mark your calendar for 28 August - 6 September 2013, when CERN will welcome students to the eighth CERN-Fermilab Hadron Collider Physics Summer School.   Experiments at hadron colliders will continue to provide our best tools for exploring physics at the TeV scale for some time. With the completion of the 7-8 TeV runs of the LHC, and the final results from the full Tevatron data sample becoming available, a new era in particle physics is beginning, heralded by the Higgs-like particle recently discovered at 125 GeV. To realize the full potential of these developments, CERN and Fermilab are jointly offering a series of "Hadron Collider Physics Summer Schools", to prepare young researchers for these exciting times. The school has alternated between CERN and Fermilab, and will return to CERN for the eighth edition, from 28 August to 6 September 2013. The CERN-Fermilab Hadron Collider Physics Summer School is an advanced school which particularly targets young postdocs in exper...

  8. Tevatron alignment issues 2003-2004

    International Nuclear Information System (INIS)

    Volk, J.T.; Annala, J.; Elementi, L.; Gelfand, N.; Gollwitzer, K.E.; Greenwood, J.; Martens, M.; Moore, C.; Nobrega, A.; Russell, A.D.; Shiltsev, V.; Stefanski, R.; Sager, T.; Syphers, M.J.; Wojcik, G.

    2005-01-01

    It was observed during the early part of Run II that dipole corrector currents in the Tevatron were changing over time. Measurement of the roll for dipoles and quadrupoles confirmed that there was a slow and systematic movement of the magnets from their ideal position. A simple system using a digital protractor and laptop computer was developed to allow roll measurements of all dipoles and quadrupoles. These measurements showed that many magnets in the Tevatron had rolled more than 1 milliradian. To aid in magnet alignment a new survey network was built in the Tevatron tunnel. This network is based on the use of free centering laser tracker. During the measurement of the network coordinates for all dipole, quadrupole and corrector magnets were obtained. This paper discusses roll measurement techniques and data, the old and new Tevatron alignment network

  9. Supersymmetry Reach of Tevatron Upgrades and LHC in Gauge-mediated Supersymmetry-breaking Models

    CERN Document Server

    Wang, Y

    2002-01-01

    We examine signals for sparticle production at the Fermilab Tevatron and the CERN Large Hadron Collider (LHC) within the framework of gauge mediated supersymmetry breaking models. We divide our analysis into four different model lines, each of which leads to qualitatively different signatures. We identify cuts to enhance the signal above Standard Model backgrounds, and use ISAJET to evaluate the SUSY reach of experiments at the Fermilab Main Injector and at its luminosity upgrades and also at the LHC. We examine the reach of the LHC via the canonical E/ and multilepton channels that have been advocated within the mSUGRA framework. For the model lines that we have examined, we find that the reach is at least as large, and frequently larger, than in the mSUGRA framework. For two of these model lines, we find that the ability to identify b-quarks and τ-leptons with high efficiency and purity is essential for the detection of the signal.

  10. Search for super symmetry at the Tevatron using the trilepton signature

    Energy Technology Data Exchange (ETDEWEB)

    Dube, Sourabh Shishir [Rutgers Univ., New Brunswick, NJ (United States)

    2008-10-01

    This dissertation describes a search for the associated production of the supersymmetric particles, the chargino and the neutralino, through their R-parity conserving decays to three leptons and missing energy. This search is carried out using the data collected at the CDF experiment at the Tevatron √s = 1.96 TeV p$\\bar{p}$ collider at Fermilab. The results are obtained by combining five independent channels with varying signal to background ratio. Overall, a total of 6.4 ± 1.1 background events from standard model processes and 11.4 ± 1.1 signal events for a particular choice of mSUGRA model parameters are expected. The observation of 7 events in data is consistent with the standard model background expectation, and the mSUGRA model is constrained. Limits are set on the cross section of Chargino-Neutralino pair production, and a limit on the mass of the chargino is extracted. A method of obtaining model-independent results is also discussed.

  11. Searches for standard model Higgs boson and supersymmetry - Trigger studies and software tools development for new phenomena in the DO experiment; Recherche du boson de Higgs et de la supersymetrie - Conditions de declenchement pour phenomenes rares dans l'experience DO

    Energy Technology Data Exchange (ETDEWEB)

    Duperrin, A

    2007-04-15

    This document presents a summary of my research work during the past 7 years for the preparation of the D0 experiment at Fermilab and the analysis of the data collected at the Tevatron hadron collider. It mainly focuses on 2 topics: trigger and direct search for new phenomena, particularly on supersymmetry and standard model Higgs boson searches. This document is divided into 5 chapters: 1) the phenomenology of the standard model and beyond, 2) the phenomenology of pp-bar events, 3) the Tevatron and D0 detector, 4) the trigger system and data acquisition, and 5) data analysis: search for supersymmetry and Higgs boson.

  12. Study of beauty photoproduction with the ZEUS experiment at the electron-proton collider HERA

    Energy Technology Data Exchange (ETDEWEB)

    Yaguees Molina, Ana Gloria

    2008-02-22

    This thesis presents a measurement of beauty photoproduction in ep interactions at the HERA collider working at a center of mass energy of {radical}(s)=318 GeV. Two goals are followed in this thesis: first the development of a reliable algorithm (secondary vertex b-tagging) to identify jets originating from b quarks by exploiting exclusively the full micro-vertex-detector potential and the properties of the b quark, and second the determination of its performance by obtaining first measurements of inclusive beauty dijet photoproduction. The main result presented here is based on a data set collected in 2004 corresponding to an integrated luminosity of 35 pb{sup -1}. Events containing at least two jets, each having an identified secondary vertex, are selected. The fraction of events containing b-quarks is extracted using the characteristic distributions of reconstructed decay length and invariant mass of the secondary vertex. The jets are required to be within the pseudorapidity region vertical stroke {eta} vertical stroke <1.5 with transverse momenta p{sub T}>7(6) GeV/c respectively. No requirements are imposed on the b decay final state so that the measurement is kept inclusive. Total and differential cross sections as a function of transverse momentum d{sigma}/dp{sub T} and pseudorapidity d{sigma}/d{eta} of the b-jet are measured. Furthermore, the results on d{sigma}/dp{sub T} were extrapolated to obtain a measurement at the b-quark level. Motivated by the results of this exploratory analysis of beauty quark production using secondary vertex b-tagging and profiting from improvements of the ZEUS tracking software since this first analysis, a more precise measurement became possible. The new analysis, still ongoing, is based on the data set collected in 2005 by the ZEUS detector and profits of higher statistics (L=132.6 pb{sup -1}) as well as of an improved detector alignment and calibration and a better understanding of the tracking/vertexing procedures which

  13. Study of beauty photoproduction with the ZEUS experiment at the electron-proton collider HERA

    International Nuclear Information System (INIS)

    Yaguees Molina, Ana Gloria

    2008-01-01

    This thesis presents a measurement of beauty photoproduction in ep interactions at the HERA collider working at a center of mass energy of √(s)=318 GeV. Two goals are followed in this thesis: first the development of a reliable algorithm (secondary vertex b-tagging) to identify jets originating from b quarks by exploiting exclusively the full micro-vertex-detector potential and the properties of the b quark, and second the determination of its performance by obtaining first measurements of inclusive beauty dijet photoproduction. The main result presented here is based on a data set collected in 2004 corresponding to an integrated luminosity of 35 pb -1 . Events containing at least two jets, each having an identified secondary vertex, are selected. The fraction of events containing b-quarks is extracted using the characteristic distributions of reconstructed decay length and invariant mass of the secondary vertex. The jets are required to be within the pseudorapidity region vertical stroke η vertical stroke T >7(6) GeV/c respectively. No requirements are imposed on the b decay final state so that the measurement is kept inclusive. Total and differential cross sections as a function of transverse momentum dσ/dp T and pseudorapidity dσ/dη of the b-jet are measured. Furthermore, the results on dσ/dp T were extrapolated to obtain a measurement at the b-quark level. Motivated by the results of this exploratory analysis of beauty quark production using secondary vertex b-tagging and profiting from improvements of the ZEUS tracking software since this first analysis, a more precise measurement became possible. The new analysis, still ongoing, is based on the data set collected in 2005 by the ZEUS detector and profits of higher statistics (L=132.6 pb -1 ) as well as of an improved detector alignment and calibration and a better understanding of the tracking/vertexing procedures which contribute significantly to the reduction of the uncertainties of the measurements

  14. Collider and Detector Protection at Beam Accidents

    Science.gov (United States)

    Rakhno, I. L.; Mokhov, N. V.; Drozhdin, A. I.

    2003-12-01

    Dealing with beam loss due to abort kicker prefire is considered for hadron colliders. The prefires occured at Tevatron (Fermilab) during Run I and Run II are analyzed and a protection system implemented is described. The effect of accidental beam loss in the Large Hadron Collider (LHC) at CERN on machine and detector components is studied via realistic Monte Carlo calculations. The simulations show that beam loss at an unsynchronized beam abort would result in severe heating of conventional and superconducting magnets and possible damage to the collider detector elements. A proposed set of collimators would reduce energy deposition effects to acceptable levels. Special attention is paid to reducing peak temperature rise within the septum magnet and minimizing quench region length downstream of the LHC beam abort straight section.

  15. Seismic studies for Fermilab future collider projects

    International Nuclear Information System (INIS)

    Lauh, J.; Shiltsev, V.

    1997-11-01

    Ground motion can cause significant beam emittance growth and orbit oscillations in large hadron colliders due to a vibration of numerous focusing magnets. Larger accelerator ring circumference leads to smaller revolution frequency and, e.g. for the Fermilab Very Large Hadron Collider(VLHC) 50-150 Hz vibrations are of particular interest as they are resonant with the beam betatron frequency. Seismic measurements at an existing large accelerator under operation can help to estimate the vibrations generated by the technical systems in future machines. Comparison of noisy and quiet microseismic conditions might be useful for proper choice of technical solutions for future colliders. This article presents results of wide-band seismic measurements at the Fermilab site, namely, in the tunnel of the Tevatron and on the surface nearby, and in two deep tunnels in the Illinois dolomite which is though to be a possible geological environment of the future accelerators

  16. Collider and Detector Protection at Beam Accidents

    International Nuclear Information System (INIS)

    Rakhno, I.L.; Mokhov, N.V.; Drozhdin, A.I.

    2003-01-01

    Dealing with beam loss due to abort kicker prefire is considered for hadron colliders. The prefires occurred at Tevatron (Fermilab) during Run I and Run II are analyzed and a protection system implemented is described. The effect of accidental beam loss in the Large Hadron Collider (LHC) at CERN on machine and detector components is studied via realistic Monte Carlo calculations. The simulations show that beam loss at an unsynchronized beam abort would result in severe heating of conventional and superconducting magnets and possible damage to the collider detector elements. A proposed set of collimators would reduce energy deposition effects to acceptable levels. Special attention is paid to reducing peak temperature rise within the septum magnet and minimizing quench region length downstream of the LHC beam abort straight section

  17. Collider and detector protection at beam accidents

    International Nuclear Information System (INIS)

    Rakhno, I.L.; Mokhov, N.V.; Drozhdin, A.I.

    2003-01-01

    Dealing with beam loss due to abort kicker prefire is considered for hadron colliders. The prefires occurred at Tevatron (Fermilab) during Run I and Run II are analyzed and a protection system implemented is described. The effect of accidental beam loss in the Large Hadron Collider (LHC) at CERN on machine and detector components is studied via realistic Monte Carlo calculations. The simulations show that beam loss at an unsynchronized beam abort would result in severe heating of conventional and superconducting magnets and possible damage to the collider detector elements. A proposed set of collimators would reduce energy deposition effects to acceptable levels. Special attention is paid to reducing peak temperature rise within the septum magnet and minimizing quench region length downstream of the LHC beam abort straight section

  18. Energy calibration of the jets in the experiment D0; Etalonnage de l'energie des jets dans l'experience D0

    Energy Technology Data Exchange (ETDEWEB)

    Coss, J

    2003-12-15

    This thesis have been performed in the D0 group of the Nuclear Physics Institute at Lyon. This work is about the calibration of the jets in the D0 experiment located on the proton-antiproton collider Tevatron. I studied the Jet Offset Correction and we have proposed a new method to calibrate the b-jets. We have calculated the response of the calorimeter for these jets in the 'photon + b - jets' events. (author)

  19. Study and optimal correction of a systematic skew quadrupole field in the Tevatron

    International Nuclear Information System (INIS)

    Snopok, Pavel; Johnstone, Carol; Berz, Martin; Ovsyannikov, Dmitry A.; Ovsyannikov, Alexander D.

    2006-01-01

    Increasing demands for luminosity in existing and future colliders have made lattice design and error tolerance and correction critical to achieving performance goals. The current state of the Tevatron collider is an example, with a strong skew quadrupole error present in the operational lattice. This work studies the high-order performance of the Tevatron and the strong nonlinear behavior introduced when a significant skew quadrupole error is combined with conventional sextupole correction, a behavior still clearly evident after optimal tuning of available skew quadrupole circuits. An optimization study is performed using different skew quadrupole families, and, importantly, local and global correction of the linear skew terms in maps generated by the code COSY INFINITY [M. Berz, COSY INFINITY version 8.1 user's guide and reference manual, Department of Physics and Astronomy MSUHEP-20704, Michigan State University (2002). URL http://cosy.pa.msu.edu/cosymanu/index.html]. Two correction schemes with one family locally correcting each arc and eight independent correctors in the straight sections for global correction are proposed and shown to dramatically improve linearity and performance of the baseline Tevatron lattice

  20. Near-Threshold Production of W±, Z0, and H0 at a Fixed-Target Experiment at the Future Ultrahigh-Energy Proton Colliders

    Directory of Open Access Journals (Sweden)

    J. P. Lansberg

    2015-01-01

    Full Text Available We outline the opportunities to study the production of the Standard Model bosons, W±, Z0, and H0, at “low” energies at fixed-target experiments based on possible future ultrahigh-energy proton colliders, that is, the High-Energy LHC, the Super proton-proton Collider, and the Future Circular Collider hadron-hadron. These can be indeed made in conjunction with the proposed future colliders designed to reach up to s=100 TeV by using bent crystals to extract part of the halo of the beam which would then impinge on a fixed target. Without disturbing the collider operation, this technique allows for the extraction of a substantial amount of particles in addition to serving for a beam-cleaning purpose. With this method, high-luminosity fixed-target studies at centre-of-mass energies above the W±, Z0, and H0 masses, s≃170–300 GeV, are possible. We also discuss the possibility offered by an internal gas target, which can also be used as luminosity monitor by studying the beam transverse shape.

  1. First results from bent crystal extraction at the Fermilab Tevatron

    International Nuclear Information System (INIS)

    1996-07-01

    First results from Fermilab Experiment 953 are presented. E853 is an experiment to test the feasibility and efficiency of extracting a low intensity beam from the halo of the Tevatron using channeling in a bent silicon crystal. The motivation for the experiment is to apply crystal extraction to trans-TeV accelerators like the LHC. Extensive simulation work has been carried out. Two accelerator operating modes have been developed for crystal studies, ''kick'' mode and diffusion mode. Results from the first successful extraction in kick mode are presented

  2. 4. topical workshop on proton-antiproton collider physics

    International Nuclear Information System (INIS)

    Haenni, H.; Schacher, J.

    1984-01-01

    The most exciting topic at this Workshop was clearly the experimental hint for new unexpected phenomena, reported by the UA1 and UA2 Collaborations: At the CERN SPS Collider (vs = 540 GeV), a few events were observed with high missing transverse energy in association with an isolated electromagnetic cluster or one or more hard jets (UA1) or an isolated electron and one or two hard jets (UA2). Due to the enhanced data sample, the discovery of the intermediate vector bosons W and Z in 1983 was undoubtedly confirmed, and the nice agreement of their properties with the predictions of the electroweak theory was shown. In addition, many new results on experimental and theoretical jet physics were presented. The Tevatron Collider project and its planned experiments at Fermilab were discussed, and there were contributions about the possible future developments in theory (compositeness, supersymmetry) as well as in experimental high energy physics (Supercollider, Juratron). See hints under the relevant topics. (orig./HSI)

  3. Stop Lepton Associated Production at Hadron Colliders

    CERN Document Server

    Alves, A; Plehn, Tilman

    2003-01-01

    At hadron colliders, the search for R-parity violating supersymmetry can probe scalar masses beyond what is covered by pair production processes. We evaluate the next-to-leading order SUSY-QCD corrections to the associated stop or sbottom production with a lepton through R-parity violating interactions. We show that higher order corrections render the theoretical predictions more stable with respect to variations of the renormalization and factorization scales and that the total cross section is enhanced by a factor up to 70% at the Tevatron and 50% at the LHC. We investigate in detail how the heavy supersymmetric states decouple from the next-to-leading order process, which gives rise to a theory with an additional scalar leptoquark. In this scenario the inclusion of higher order QCD corrections increases the Tevatron reach on leptoquark masses by up to 40 GeV and the LHC reach by up to 200 GeV.

  4. Tevatron HTS power lead test

    International Nuclear Information System (INIS)

    Feher, S.; Carcagno, R.; Orris, D.; Pischalnikov, Y.; Sylvester, C.; Tartaglia, M.; Tompkins, J.C.

    2004-01-01

    Two pairs of ASC 6 kA power leads developed for the Tevatron were successfully tested at Fermilab at over-current conditions. Stable operation was achieved while operating at a current of 9.56 kA for five hours and while continuously ramping between 0-9.56 kA at a ramp rate of 200 A/s for one hour. The minimum required liquid nitrogen flow rate was measured to be 1.5 g/s at 10 kA. After ramping up to 10 kA at 200A/s, it took only 15 minutes to stabilize the upper copper section of the lead with a flow of 1.8 g/s of liquid nitrogen vapor. Testing under extreme operating conditions--270-370 kPa liquid nitrogen vapor pressure and over 0.1 T external magnetic field--demonstrated that the HTS part of the lead can safely operate in the current sharing mode and that this design has large operating margin

  5. Linear Colliders

    International Nuclear Information System (INIS)

    Alcaraz, J.

    2001-01-01

    After several years of study e''+ e''- linear colliders in the TeV range have emerged as the major and optimal high-energy physics projects for the post-LHC era. These notes summarize the present status form the main accelerator and detector features to their physics potential. The LHC era. These notes summarize the present status, from the main accelerator and detector features to their physics potential. The LHC is expected to provide first discoveries in the new energy domain, whereas an e''+ e''- linear collider in the 500 GeV-1 TeV will be able to complement it to an unprecedented level of precision in any possible areas: Higgs, signals beyond the SM and electroweak measurements. It is evident that the Linear Collider program will constitute a major step in the understanding of the nature of the new physics beyond the Standard Model. (Author) 22 refs

  6. Using the circulating beam in the Fermilab antiproton accumulator for experiments

    International Nuclear Information System (INIS)

    MacLachlan, J.A.

    1988-01-01

    The Fermilab Accumulator is a storage ring optimized for stacking and stochastic cooling 8 GeV antiprotons for the Tevatron collider. Minor modifications have been made to provide for beam in the energy range 8.0-2.9 GeV of luminosity /approximately/10 31 cm -2 s/sup - 1/ with a hydrogen jet internal target. Experience to date consists of machine studies and detector engineering run with protons. 7 refs

  7. Analysing the control software of the Compact Muon Solenoid Experiment at the Large Hadron Collider

    NARCIS (Netherlands)

    Hwong, Y.L.; Kusters, V.J.J.; Willemse, T.A.C.; Arbab, F.; Sirjani, M.

    2012-01-01

    The control software of the CERN Compact Muon Solenoid experiment contains over 30,000 finite state machines. These state machines are organised hierarchically: commands are sent down the hierarchy and state changes are sent upwards. The sheer size of the system makes it virtually impossible to

  8. A full acceptance experiment at the CERN large hadron collider (LHC)

    International Nuclear Information System (INIS)

    Eggert, K.; Morsch, A.; Taylor, C.

    1996-01-01

    The physics of full acceptance detector at the LHC is reviewed. A possible experimental layout situated in IP4 is presented. The interface between the experiment and the machine lattice is described with particular attention given to the measurement of elastic and diffractive protons. (author)

  9. Deterioration of the Skew Quadrupole Moment in Tevatron Dipoles Over Time

    CERN Document Server

    Syphers, Michael J

    2005-01-01

    During the 20 years since it was first commissioned, the Fermilab Tevatron has developed strong coupling between the two transverse degrees of freedom. A circuit of skew quadrupole magnets is used to correct for coupling and, though capable, its required strength has increased since 1983 by more than an order of magnitude. In more recent years changes to the Tevatron for colliding beams operation have altered the skew quadrupole corrector distribution and strong local coupling become evident, often encumbering routine operation during the present physics run. Detailed magnet measurements were performed on each individual magnet during construction, and in early 2003 it was realized that measurements could be performed on the magnets in situ which could determine coil movements within the iron yoke since the early 1980's. It was discovered that the superconducting coils had become vertically displaced relative to their yokes since their construction. The ensuing systematic skew quadrupole field introduced by t...

  10. PHENIX Conceptual Design Report. An experiment to be performed at the Brookhaven National Laboratory Relativistic Heavy Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Nagamiya, Shoji; Aronson, Samuel H.; Young, Glenn R.; Paffrath, Leo

    1993-01-29

    The PHENIX Conceptual Design Report (CDR) describes the detector design of the PHENIX experiment for Day-1 operation at the Relativistic Heavy Ion Collider (RHIC). The CDR presents the physics capabilities, technical details, cost estimate, construction schedule, funding profile, management structure, and possible upgrade paths of the PHENIX experiment. The primary goals of the PHENIX experiment are to detect the quark-gluon plasma (QGP) and to measure its properties. Many of the potential signatures for the QGP are measured as a function of a well-defined common variable to see if any or all of these signatures show a simultaneous anomaly due to the formation of the QGP. In addition, basic quantum chromodynamics phenomena, collision dynamics, and thermodynamic features of the initial states of the collision are studied. To achieve these goals, the PHENIX experiment measures lepton pairs (dielectrons and dimuons) to study various properties of vector mesons, such as the mass, the width, and the degree of yield suppression due to the formation of the QGP. The effect of thermal radiation on the continuum is studied in different regions of rapidity and mass. The e{mu} coincidence is measured to study charm production, and aids in understanding the shape of the continuum dilepton spectrum. Photons are measured to study direct emission of single photons and to study {pi}{sup 0} and {eta} production. Charged hadrons are identified to study the spectrum shape, production of antinuclei, the {phi} meson (via K{sup +}K{sup {minus}} decay), jets, and two-boson correlations. The measurements are made down to small cross sections to allow the study of high p{sub T} spectra, and J/{psi} and {Upsilon} production. The PHENIX collaboration consists of over 300 scientists, engineers, and graduate students from 43 institutions in 10 countries. This large international collaboration is supported by US resources and significant foreign resources.

  11. Physics at hadron colliders: Experimental view

    International Nuclear Information System (INIS)

    Siegrist, J.L.

    1987-08-01

    The physics of the hadron-hadron collider experiment is considered from an experimental point of view. The problems encountered in determination of how well the standard model describes collider results are discussed. 53 refs., 58 figs

  12. Tau physics at p bar p colliders

    International Nuclear Information System (INIS)

    Konigsberg, J.

    1993-01-01

    Tau detection techniques in hadron colliders are discussed together with the measurements and searches performed so far. We also underline the importance tau physics has in present and future collider experiments

  13. LINEAR COLLIDER PHYSICS RESOURCE BOOK FOR SNOWMASS 2001.

    Energy Technology Data Exchange (ETDEWEB)

    ABE,T.; DAWSON,S.; HEINEMEYER,S.; MARCIANO,W.; PAIGE,F.; TURCOT,A.S.; ET AL

    2001-05-03

    The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decade or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e{sup +}e{sup {minus}} linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e{sup +}e{sup {minus}} linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e{sup +}e{sup {minus}} linear collider; in any scenario that is now discussed, physics will benefit from the new information that e{sup +}e{sup {minus}} experiments can provide.

  14. Linear Collider Physics Resource Book for Snowmass 2001

    Energy Technology Data Exchange (ETDEWEB)

    Peskin, Michael E

    2001-06-05

    The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decade or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e{sup +}e{sup -} linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e{sup +}e{sup -} linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e{sup +}e{sup -} linear collider; in any scenario that is now discussed, physics will benefit from the new information that e{sup +}e{sup -} experiments can provide.

  15. The development of colliders

    International Nuclear Information System (INIS)

    Sessler, A.M.

    1993-02-01

    Don Kerst, Gersh Budker, and Bruno Touschek were the individuals, and the motivating force, which brought about the development of colliders, while the laboratories at which it happened were Stanford, MURA, the Cambridge Electron Accelerator, Orsay, Frascati, CERN, and Novosibirsk. These laboratories supported, during many years, this rather speculative activity. Of course, many hundreds of physicists contributed to the development of colliders but the men who started it, set it in the right direction, and forcefully made it happen, were Don, Gersh, and Bruno. Don was instrumental in the development of proton-proton colliders, while Bruno and Gersh spearheaded the development of electron-positron colliders. In this brief review of the history, I will sketch the development of the concepts, the experiments, and the technological developments which made possible the development of colliders. It may look as if the emphasis is on theoretical concepts, but that is really not the case, for in this field -- the physics of beams -- the theory and experiment go hand in hand; theoretical understanding and advances are almost always motivated by the need to explain experimental results or the desire to construct better experimental devices

  16. Future colliders

    International Nuclear Information System (INIS)

    Palmer, R.B.; Gallardo, J.C.

    1996-10-01

    The high energy physics advantages, disadvantages and luminosity requirements of hadron (pp, pp), of lepton (e + e - , μ + μ - ) and photon-photon colliders are considered. Technical arguments for increased energy in each type of machine are presented. Their relative size, and the implications of size on cost are discussed

  17. Collider Physics

    Indian Academy of Sciences (India)

    This is summary of the activities of the working group on collider physics in the IXth Workshop on High Energy Physics Phenomenology (WHEPP-9) held at the Institute of Physics, Bhubaneswar, India in January 2006. Some of the work subsequently done on these problems by the subgroups formed during the workshop is ...

  18. Fourth workshop on experiments and detectors for a relativistic heavy ion collider

    International Nuclear Information System (INIS)

    Fatyga, M.; Moskowitz, B.

    1990-01-01

    This report contains papers on the following topics: physics at RHIC; flavor flow from quark-gluon plasma; space-time quark-gluon cascade; jets in relativistic heavy ion collisions; parton distributions in hard nuclear collisions; experimental working groups, two-arm electron/photon spectrometer collaboration; total and elastic pp cross sections; a 4π tracking TPC magnetic spectrometer; hadron spectroscopy; efficiency and background simulations for J/ψ detection in the RHIC dimuon experiment; the collision regions beam crossing geometries; Monte Carlo simulations of interactions and detectors; proton-nucleus interactions; the physics of strong electromagnetic fields in collisions of relativistic heavy ions; a real time expert system for experimental high energy/nuclear physics; the development of silicon multiplicity detectors; a pad readout detector for CRID/tracking; RHIC TPC R ampersand D progress and goals; development of analog memories for RHIC detector front-end electronic systems; calorimeter/absorber optimization for a RHIC dimuon experiment; construction of a highly segmented high resolution TOF system; progress report on a fast, particle-identifying trigger based on ring-imaging and highly integrated electronics for a TPC detector

  19. Characterising dark matter searches at colliders and direct detection experiments: Vector mediators

    International Nuclear Information System (INIS)

    Buchmueller, Oliver; Dolan, Matthew J.; Malik, Sarah A.; McCabe, Christopher

    2015-01-01

    We introduce a Minimal Simplified Dark Matter (MSDM) framework to quantitatively characterise dark matter (DM) searches at the LHC. We study two MSDM models where the DM is a Dirac fermion which interacts with a vector and axial-vector mediator. The models are characterised by four parameters: m DM , M med, g DM and g q , the DM and mediator masses, and the mediator couplings to DM and quarks respectively. The MSDM models accurately capture the full event kinematics, and the dependence on all masses and couplings can be systematically studied. The interpretation of mono-jet searches in this framework can be used to establish an equal-footing comparison with direct detection experiments. For theories with a vector mediator, LHC mono-jet searches possess better sensitivity than direct detection searches for light DM masses (≲5 GeV). For axial-vector mediators, LHC and direct detection searches generally probe orthogonal directions in the parameter space. We explore the projected limits of these searches from the ultimate reach of the LHC and multi-ton xenon direct detection experiments, and find that the complementarity of the searches remains. In conclusion, we provide a comparison of limits in the MSDM and effective field theory (EFT) frameworks to highlight the deficiencies of the EFT framework, particularly when exploring the complementarity of mono-jet and direct detection searches

  20. Event processing time prediction at the CMS experiment of the Large Hadron Collider

    International Nuclear Information System (INIS)

    Cury, Samir; Gutsche, Oliver; Kcira, Dorian

    2014-01-01

    The physics event reconstruction is one of the biggest challenges for the computing of the LHC experiments. Among the different tasks that computing systems of the CMS experiment performs, the reconstruction takes most of the available CPU resources. The reconstruction time of single collisions varies according to event complexity. Measurements were done in order to determine this correlation quantitatively, creating means to predict it based on the data-taking conditions of the input samples. Currently the data processing system splits tasks in groups with the same number of collisions and does not account for variations in the processing time. These variations can be large and can lead to a considerable increase in the time it takes for CMS workflows to finish. The goal of this study was to use estimates on processing time to more efficiently split the workflow into jobs. By considering the CPU time needed for each job the spread of the job-length distribution in a workflow is reduced.

  1. Fourth workshop on experiments and detectors for a relativistic heavy ion collider

    Energy Technology Data Exchange (ETDEWEB)

    Fatyga, M.; Moskowitz, B. (eds.)

    1990-01-01

    This report contains papers on the following topics: physics at RHIC; flavor flow from quark-gluon plasma; space-time quark-gluon cascade; jets in relativistic heavy ion collisions; parton distributions in hard nuclear collisions; experimental working groups, two-arm electron/photon spectrometer collaboration; total and elastic pp cross sections; a 4{pi} tracking TPC magnetic spectrometer; hadron spectroscopy; efficiency and background simulations for J/{psi} detection in the RHIC dimuon experiment; the collision regions beam crossing geometries; Monte Carlo simulations of interactions and detectors; proton-nucleus interactions; the physics of strong electromagnetic fields in collisions of relativistic heavy ions; a real time expert system for experimental high energy/nuclear physics; the development of silicon multiplicity detectors; a pad readout detector for CRID/tracking; RHIC TPC R D progress and goals; development of analog memories for RHIC detector front-end electronic systems; calorimeter/absorber optimization for a RHIC dimuon experiment; construction of a highly segmented high resolution TOF system; progress report on a fast, particle-identifying trigger based on ring-imaging and highly integrated electronics for a TPC detector.

  2. Results from colliding magnetized plasma jet experiments executed at the Trident laser facility

    Science.gov (United States)

    Manuel, M. J.-E.; Rasmus, A. M.; Kurnaz, C. C.; Klein, S. R.; Davis, J. S.; Drake, R. P.; Montgomery, D. S.; Hsu, S. C.; Adams, C. S.; Pollock, B. B.

    2015-11-01

    The interaction of high-velocity plasma flows in a background magnetic field has applications in pulsed-power and fusion schemes, as well as astrophysical environments, such as accretion systems and stellar mass ejections into the magnetosphere. Experiments recently executed at the Trident Laser Facility at the Los Alamos National Laboratory investigated the effects of an expanding aluminum plasma flow into a uniform 4.5-Tesla magnetic field created using a solenoid designed and manufactured at the University of Michigan. Opposing-target experiments demonstrate interesting collisional behavior between the two magnetized flows. Preliminary interferometry and Faraday rotation measurements will be presented and discussed. This work is funded by the U.S Department of Energy, through the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, grant number DE-NA0001840. Support for this work was provided by NASA through Einstein Postdoctoral Fellowship grant number PF3-140111 awarded by the Chandra X-ray Center, which is operated by the Astrophysical Observatory for NASA under contract NAS8-03060.

  3. Measurement of the Top Quark Mass using Dilepton Events and a Neutrino Weighting Algorithm with the D0 Experiment at the Tevatron (Run II)

    International Nuclear Information System (INIS)

    Meyer, Joerg; Bonn U

    2007-01-01

    measurement of the top quark mass by the D0 experiment at Fermilab in the dilepton final states. The comparison of the measured top quark masses in different final states allows an important consistency check of the Standard Model. Inconsistent results would be a clear hint of a misinterpretation of the analyzed data set. With the exception of the Higgs boson, all particles predicted by the Standard Model have been found. The search for the Higgs boson is one of the main focuses in high energy physics. The theory section will discuss the close relationship between the physics of the Higgs boson and the top quark

  4. Measurement of the Top Quark Mass using Dilepton Events and a Neutrino Weighting Algorithm with the D0 Experiment at the Tevatron (Run II)

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Joerg [Univ. of Bonn (Germany)

    2007-01-01

    measurement of the top quark mass by the D0 experiment at Fermilab in the dilepton final states. The comparison of the measured top quark masses in different final states allows an important consistency check of the Standard Model. Inconsistent results would be a clear hint of a misinterpretation of the analyzed data set. With the exception of the Higgs boson, all particles predicted by the Standard Model have been found. The search for the Higgs boson is one of the main focuses in high energy physics. The theory section will discuss the close relationship between the physics of the Higgs boson and the top quark.

  5. 2nd CERN-Fermilab Hadron Collider Physics Summer School, June 6-15, 2007, CERN

    CERN Multimedia

    2007-01-01

    The school web site is http://cern.ch/hcpss with links to the academic programme and the application procedure. The APPLICATION DEADLINE IS 9 MARCH 2007. The results of the selection process will be announced shortly thereafter. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The first school in the series, held last summer at Fermilab, covered extensively the physics at the Tevatron collider experiments. The second school, to be held at CERN, will focus on the technology and physics of the LHC experiments. Emphasis will be placed on the first years of data-taking at the LHC and on the discovery potential of the programme. The series of lectures will be supported by in-depth discussion sessions and will include the theory and phenomenology of hadron collisions, discovery physics topics, detector and analysis techniques and tools...

  6. Peer-To-Peer Architectures in Distributed Data Management Systems for Large Hadron Collider Experiments

    CERN Document Server

    Lo Presti, Giuseppe; Lo Re, G; Orsini, L

    2005-01-01

    The main goal of the presented research is to investigate Peer-to-Peer architectures and to leverage distributed services to support networked autonomous systems. The research work focuses on development and demonstration of technologies suitable for providing autonomy and flexibility in the context of distributed network management and distributed data acquisition. A network management system enables the network administrator to monitor a computer network and properly handle any failure that can arise within the network. An online data acquisition (DAQ) system for high-energy physics experiments has to collect, combine, filter, and store for later analysis a huge amount of data, describing subatomic particles collision events. Both domains have tight constraints which are discussed and tackled in this work. New emerging paradigms have been investigated to design novel middleware architectures for such distributed systems, particularly the Active Networks paradigm and the Peer-to-Peer paradigm. A network man...

  7. Search for the Higgs Boson and for Anomalous Quartic Gauge Boson Couplings in the WW Channel with Dielectron Events with the D0 Experiment at the Tevatron; Recherche du boson de Higgs et de couplages de jauge quartiques anormaux dans le canal WW en électrons dans l'expérience D0 au Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Chapon, Emilien [Pierre and Marie Curie Univ., Paris (France)

    2013-01-01

    Le paysage de la physique des particules a subi des changements majeurs entre le début de cette thèse, en septembre 2010, et sa n en juin 2013. On peut notamment qualier l'année 2012 de date-clé dans l'histoire de la physique des particules. En 2012, une nouvelle particule a été découverte au LHC [1, 2], dont la majeure partie de la communauté s'accorde aujourd'hui à dire qu'il s'agit très probablement du boson de Higgs. Cet événement est intervenu peu après une sorte de passage de relais entre le Tevatron, arrêté le 30 septembre 2011, et le LHC, dont les toutes premières collisions sont intervenues le 23 novembre 2009.

  8. The Fermilab anti pp collider

    International Nuclear Information System (INIS)

    Harrison, M.

    1984-01-01

    The goal of the Tevatron I project is to achieve anti pp collisions in the centre-of-mass energy range up to 2 TeV with a luminosity of at least 10 30 cm -2 sec -1 . The project involves adapting the Tevatron to function as a storage ring and modifying the lattice to provide low-beta interaction points; changes to the Main Ring to allow anti p transfers and the installation of experimental equipment; and the construction of a anti p source. Major experimental areas will be located in the socalled BO and DO straight sections together with smaller, more specialized experiments in several of the other interacting regions. (orig./HSI)

  9. Combination of Tevatron searches for the standard model Higgs boson in the W+W- decay mode

    NARCIS (Netherlands)

    Aaltonen, T.; et al., [Unknown; Ancu, L.S.; de Jong, S.J.; Filthaut, F.; Galea, C.F.; Hegeman, J.G.; Houben, P.; Meijer, M.M.; Svoisky, P.; van den Berg, P.J.

    2010-01-01

    We combine searches by the CDF and D0 Collaborations for a Higgs boson decaying to W+W-. The data correspond to an integrated total luminosity of 4.8 (CDF) and 5.4 (D0) fb(-1) of p (p) over bar collisions at root s = 1.96 TeV at the Fermilab Tevatron collider. No excess is observed above background

  10. Participation in the ARGUS experiment at the DORIS collider at DESY, Hamburg, Germany

    International Nuclear Information System (INIS)

    Darden, C.

    1986-01-01

    Progress reported for 1985 includes publishing final results for investigation of F mesons. Particle decays were sought including a gamma line at 9.46 GeV. One such decay was Upsilon(1S)→γH 0 . A search for fractionally charged particles is reported. The muon pair branching ratio was determined for decays of the Upsilon(2S). Six anti-deuterons were seen in a data sample of over 720,000 electron-positron annihilation events. A clear D 0 signal was seen in the K + K - channel. Results were obtained for the radiative transitions from the Upsilon(2S) to the 1 3 P states of the banti-b system. Fifteen events were also seen which were interpreted to be the color suppressed decay of a B meson to J/psi. A new upper limit was set for the mass of the tau neutrino. A CAMAC booster was used to reduce dead time in the experiment. New preamplifiers raised the vertex drift chambers enough above the electromagnetic noise of the storage ring that it was no longer a problem. The performance of the inner compensation coils, storage ring, and main drift chamber are reported, as well as the time of flight, shower, and muon counters

  11. Search for heavy fermions with the ATLAS experiment at the LHC collider

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00359999; Santiago, José; Onofre, António

    In the present thesis a search for new heavy fermions using LHC data collected in 2012 by the ATLAS experiment is presented. In particular, a search for pair and single production of vector-like quarks with electric charge 2/3 ($T$) and -1/3 ($B$) decaying to a $Z$ boson is discussed. For this search the analysis was divided in two channels, depending on the lepton multiplicity, and both channels were combined at the end for the final results. Since no evidence for signal was found, limits on the mass of the vector-like quarks were evaluated. The observed (expected) limit on the mass of an $SU(2)$ singlet $T$ quark is 655~GeV (625~GeV), while the observed (expected) limit on the mass of a $T$ quark in a $(T,B)$ doublet is 735~GeV (720~GeV). The observed (expected) limit on the mass of an $SU(2)$ singlet $B$ quark is 685~GeV (670~GeV), while the observed (expected) limit on the mass of a $B$ quark in a $(B,Y)$ doublet is 755~GeV (755~GeV). The impact of a heavy gluon in the searches for pair production of vect...

  12. The upgraded Pixel Detector of the ATLAS experiment for Run-2 at the Large Hadron Collider

    CERN Document Server

    Giordani, MarioPaolo; The ATLAS collaboration

    2016-01-01

    Run-2 of the LHC is providing new challenges to track and vertex reconstruction with higher energies, denser jets and higher rates. Therefore the ATLAS experiment has constructed the first 4-layer Pixel detector in HEP, installing a new Pixel layer, also called Insertable B-Layer (IBL). IBL is a fourth layer of pixel detectors, and has been installed in May 2014 at a radius of 3.3 cm between the existing Pixel Detector and a new smaller radius beam-pipe. The new detector, built to cope with high radiation and expected occupancy, is the first large scale application of 3D detectors and CMOS 130nm technology. In addition the Pixel detector was refurbished with a new service quarter panel to recover about 3% of defective modules lost during run-1 and a new optical readout system to readout the data at higher speed while reducing the occupancy when running with increased luminosity. The commissioning and performance of the 4-layer Pixel Detector, in particular the IBL, will be presented, using collision data.

  13. SUSY Without Prejudice at Linear Colliders

    International Nuclear Information System (INIS)

    Rizzo, T.

    2008-01-01

    We explore the physics of the general CP-conserving MSSM with Minimal Flavor Violation, the pMSSM. The 19 soft SUSY breaking parameters are chosen so to satisfy all existing experimental and theoretical constraints assuming that the WIMP is the lightest neutralino. We scan this parameter space twice using both flat and log priors and compare the results which yield similar conclusions. Constraints from both LEP and the Tevatron play an important role in obtaining our final model samples. Implications for future TeV-scale e + e - linear colliders (LC) are discussed

  14. Top quark mass measurement at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes da Costa, Joao; /Harvard U.

    2004-12-01

    The authors report on the latest experimental measurements of the top quark mass by the CDF and D0 Collaborations at the Fermilab Tevatron. They present a new top mass measurement using the t{bar t} events collected by the D0 Collaboration in Run I between 1994 and 1996. This result is combined with previous measurements to yield a new world top mass average. They also describe several preliminary results using up to 193 pb{sup -1} of t{bar t} events produced in {bar p}p collisions at {radical}s = 1.96 TeV during the Run II of the Tevatron.

  15. Evading the top-quark mass bound at the Fermilab Tevatron: New signals for the top quark

    International Nuclear Information System (INIS)

    Mukhopadhyaya, B.; Nandi, S.

    1991-01-01

    If an SU(2)-singlet charge-2/3 quark exists, current data allow a wide range for the parameters of the 4x4 mixing matrix in which the usual ''hard-lepton'' signal of the top quark is suppressed. For a light Higgs boson, the top quark decays predominantly via the flavor-changing Yukawa interaction, thus evading the Fermilab Tevatron bounds on its mass. For a heavier Higgs boson, flavor-changing neutral-current decays become important, giving rise to anomalous Z-pair production, testable at the upgraded Tevetron, at the CERN Large Hardon Collider, and at the Superconducting Super Collider

  16. Recherche du boson de Higgs dans l'état final dimuonique et étude de l'asymétrie de production de la paire top antitop avec l'expérience DO auprès du Tevatron; Higgs boson search in the dimuonique final state and study of the top pair antitop production asymmetry with the DO experiment at the Tevatron.

    Energy Technology Data Exchange (ETDEWEB)

    Fauré, Alexandre [University of Paris-Sud, Orsay (France)

    2014-06-03

    Two high energy particle physics analyses are presented in this PhD report using events with two leptons oppositely charged and with missing transverse energy. These events are selected using 9.7 fb-1 of total pp collisions data collected with the DØ detector at the TeVatron at √s=1.96 TeV.The first analysis is the research of the Higgs boson decaying in the H→WW→μνμν channel. No significant excess above the background prediction is observed.Upper limits on Higgs boson production cross-section are computed in the standard model framework but also in the 4th generation of fermions and in the fermiophobic coupling to Higgs boson hypotheses. In order to validate the research methodology, the W boson pair production cross-section is measured.The second analysis is the measurement of the forward-backward asymmetry of the tt pair production. This is the first measurement in the dileptonic channel at DØ experiment. In this context, a new tt pair kinematic reconstruction is used (matrix element method) to give a raw measurement of the forward-backward asymmetry. Thanks to a dedicated calibration method, we give a final measurement of AFB=18.0 ± 6.0 (stat) ± 3.3 (syst).

  17. Top and Higgs at the Tevatron: Measurements, searches, prospects

    International Nuclear Information System (INIS)

    Konigsberg, J.

    2000-01-01

    In this paper we summarize the status of Top Quark Physics and of searches for the Standard Model Higgs at the Tevatron. Results from both the CDF and D0 experiments are discussed and the prospects for the upcoming Run 2, in the year 2001, are outlined. Much work has been performed on these topics and due to the nature of these proceedings only a brief explanation can be offered here. For more details the reader should turn to the excellent sources listed in the reference section

  18. QCD for collider experiments

    OpenAIRE

    Trócsányi, Z.

    2016-01-01

    These lectures are intended to provide the theoretical basis of describing high- energy particle collisions at a level appropriate to graduate students in experimental high energy physics. They are supposed to be familiar with quantum electrodynamics, the concept of Feynman rules, Feynman graphs and compu- tation of the cross section in quantum field theory. These lectures are intended to provide the theoretical basis of describing high-energy particle collisions at a level appropriate to...

  19. Comparison of discovery limits for extra Z bosons at future colliders

    International Nuclear Information System (INIS)

    Godfrey, S.

    1995-01-01

    We study and compare the discovery potential for heavy neutral gauge bosons (Z') at various e + e - and pp (-) colliders that are planned or have been proposed. Typical discovery limits are for the Fermilab Tevatron ∼1 TeV, Di-Tevatron ∼2 TeV, CERN LHC ∼4 TeV, LSGNA (a 60 TeV pp collider) ∼13 TeV while the e + e - discovery limits are 2--10x √s with the large variation reflecting the model dependence of the limits. While both types of colliders have comparable discovery limits the hadron colliders are generally less dependent on the specific Z' model and provide more robust limits since the signal has little background. In contrast, discovery limits for e + e - limits are more model dependent and, because they are based on indirect inferences of deviations from standard model predictions, they are more sensitive to systematic errors

  20. Searching for doubly-charged Higgs bosons at future colliders

    International Nuclear Information System (INIS)

    Gunion, J.F.; Pitts, K.T.

    1996-10-01

    Doubly-charged Higgs bosons (Δ -- /Δ ++ ) appear in several extensions to the Standard Model and can be relatively light. We review the theoretical motivation for these states and present a study of the discovery reach in future runs of the Fermilab Tevatron for pair-produced doubly-charged Higgs bosons decaying to like-sign lepton pairs. We also comment on the discovery potential at other future colliders. 16 refs., 3 figs., 1 tab

  1. Higgs-photon associated production at hadron colliders

    International Nuclear Information System (INIS)

    Abbasabadi, A.; Repko, W.W.

    1997-01-01

    The authors present cross sections for the reactions p anti p → Hγ and pp → Hγ arising from the subprocess q anti q → Hγ. The calculation includes the complete one-loop contribution from all light quarks and is the main source of Higgs-photon associated production in hadron colliders. At Tevatron energies, the cross section is typically 0.1 fb or less, while at LHC energies it can exceed 1.0fb

  2. Photon final states at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Campanelli, Mario; /University Coll. London

    2008-04-01

    The authors present here several recent measurements involving associate production of photons and jets at the Tevatron. In particular, inclusive photon + met from D0, and photon + b-jets and photon + b-jet + leptons + MET from CDF are described in some detail. These measurements offer a good test of QCD predictions in rather complex final states.

  3. In celebration of the fixed target program with the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey A. Appel et al.

    2001-12-28

    The Tevatron is the world's first large superconducting accelerator. With its construction, we gained the dual opportunities to advance the state of the art in accelerator technology with the machine itself and in particle physics with the experiments that became possible in a higher energy regime. There have been 43 experiments in the Tevatron fixed target program. Many of these are better described as experimental programs, each with a broad range of physics goals and results, and more than 100 collaborating physicists and engineers. The results of this program are three-fold: (1) new technologies in accelerators, beams and detectors which advanced the state of the art; (2) new experimental results published in the refereed physics journals; and (3) newly trained scientists who are both the next generation of particle physicists and an important part of the scientific, technical and educational backbone of the country as a whole. In this book they compile these results. There are sections from each experiment including what their physics goals and results were, what papers were published, and which students have received degrees. Summaries of these results from the program as a whole are quite interesting, but the physics results from this program are too broad to summarize globally. The most important of the results appear in later sections of this booklet.

  4. An investigation of triply heavy baryon production at hadron colliders

    CERN Document Server

    Gomshi Nobary, M A

    2006-01-01

    The triply heavy baryons have a rather diverse mass range. While some of them possess considerable production rates at existing facilities, others need to be produced at future high energy colliders. Here we study the direct fragmentation production of the Ωccc and Ωbbb baryons as the prototypes of triply heavy baryons at the hadron colliders with different . We present and compare the transverse momentum distributions of the differential cross sections, distributions of total cross sections and the integrated total cross sections of these states at the RHIC, the Tevatron Run II and the CERN LHC.

  5. An investigation of triply heavy baryon production at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Gomshi Nobary, M.A. [Department of Physics, Faculty of Science, Razi University, Kermanshah (Iran, Islamic Republic of) and Center for Theoretical Physics and Mathematics, AEOI, Roosbeh Building, PO Box 11365-8486, Tehran (Iran, Islamic Republic of)]. E-mail: mnobary@razi.ac.ir; Sepahvand, R. [Department of Physics, Faculty of Science, Razi University, Kermanshah (Iran, Islamic Republic of)

    2006-05-01

    The triply heavy baryons have a rather diverse mass range. While some of them possess considerable production rates at existing facilities, others need to be produced at future high energy colliders. Here we study the direct fragmentation production of the {omega}{sub ccc} and {omega}{sub bbb} baryons as the prototypes of triply heavy baryons at the hadron colliders with different s. We present and compare the transverse momentum distributions of the differential cross sections, p{sub T}{sup min} distributions of total cross sections and the integrated total cross sections of these states at the RHIC, the Tevatron Run II and the CERN LHC.

  6. Supersymmetric Higgs pair discovery prospects at hadron colliders

    CERN Document Server

    Belyaev, A; Éboli, Oscar J P; Mizukoshi, J K; Novaes, S F

    2000-01-01

    We study the potential of hadron colliders in the search for the pair production of neutral Higgs bosons in the framework of the Minimal Supersymmetric Standard Model. Using analytical expressions for the relevant amplitudes, we perform a detailed signal and background analysis, working out efficient kinematical cuts for the extraction of the signal. The important role of squark loop contributions to the signal is emphasised. If the signal is sufficiently enhanced by these contributions, it could even be observable at the next run of the upgraded Tevatron collider in the near future. At the LHC the pair production of light and heavy Higgs bosons might be detectable simultaneously.

  7. Common mode noise on the main Tevatron bus and associated beam emittance growth

    International Nuclear Information System (INIS)

    Zhang, P.; Johnson, R.P.; Kuchnir, M.; Siergiej, D.; Wolff, D.

    1991-05-01

    Overlap of betatron tune frequencies with the power supply noise spectrum can cause transverse beam emittance growth in a storage ring. We have studied this effect for tunes near the integer, where the betatron frequency is low. By injecting noise onto the main power supply bus, it was determined that common mode noise was the dominant source of emittance growth. A noise suppression feed-back loop was then used to reduce the noise and the emittance growth. These experiments are described as are investigations of the common mode propagation along the Tevatron bus and measurements of the fields generated by common mode excitation of isolated Tevatron magnets. 3 refs., 4 figs

  8. Search for Kaluza-Klein gravitons of the Randall-Sundrum model in the dimuon channel with the D0 detector at Tevatron; Etude de la production de graviton de Kaluza-Klein dans ses desintegrations en paires de muons dans le modele de Randall-Sundrum aupres de l'experience D0 au Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Lahrichi, N

    2004-07-01

    In this thesis we have put the first constraints on the fundamental parameters of the Randall-Sundrum model of extra dimensions, k/M{sub Pl} which is proportional to the coupling of the graviton to the standard model fields and M{sub G} which is the mass of the first excited state of the Kaluza-Klein graviton. The analysis performed on Monte Carlo sample of the signal allowed to find an error in the PYTHIA generator. The elaboration of an independent generator dedicated for this special analysis helped to find out and correct the error. The data sample used for the analysis covers the period running from november 2002 up to july 2003 taken by the D0 collaboration at Tevatron, which corresponds to an accumulated luminosity of 107,8 pb{sup -1}. The search for the graviton in the dimuon channel allowed to measure the Z production cross-section multiplied by the branching ratio in dimuons. (author)

  9. The study of the possibility to use CAMEX chips in collider experiments with short bunch crossing time

    International Nuclear Information System (INIS)

    Aulchenko, V.M.; Chilingarov, A.G.; Serbo, V.V.; Titov, V.M.

    1993-01-01

    The study of the possibility to use CAMEX chips in several systems of the detector KEDR at the e + e - collider VEPP-4M was performed. The relatively short bunch crossing time at VEPP-4M 60 ns leads to some problems with the use of CAMEX in the standard mode. The different ways to overcome these difficulties are investigated and compared. (orig.)

  10. Probing the Higgs sector of high-scale SUSY-breaking models at the Tevatron

    International Nuclear Information System (INIS)

    Carena, Marcela; Liu, Tao

    2010-12-01

    A canonical signature of the Minimal Supersymmetric Standard Model (MSSM) is the presence of a neutral Higgs boson with mass bounded from above by about 135 GeV and Standard Model (SM)-like couplings to the electroweak gauge bosons. In this note we investigate the reach of the Tevatron collider for the MSSM Higgs sector parameter space associated with a variety of high-scale minimal models of supersymmetry (SUSY)-breaking, including the Constrained MSSM (CMSSM), minimal Gauge Mediated SUSY-breaking (mGMSB), and minimal Anomaly Mediated SUSY-breaking (mAMSB). We find that the Tevatron can provide strong constraints on these models via Higgs boson searches. Considering a simple projection for the efficiency improvements in the Tevatron analyses, we find that with an integrated luminosity of 16 fb -1 per detector and an efficiency improvement of 20% compared to the present situation, these models could be probed essentially over their entire ranges of validity. With 40% analysis improvements and 16 fb -1 , our projection shows that evidence at the 3σ level for the light Higgs boson could be expected in extended regions of parameter space. (orig.)

  11. Probing the Higgs sector of high-scale SUSY-breaking models at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Carena, Marcela [Fermi National Accelerator Laboratory, Batavia, IL (United States); Chicago Univ., Chicago, IL (United States). Enrico Fermi Inst.; Draper, Patrick [Chicago Univ., Chicago, IL (United States). Enrico Fermi Inst.; Heinemeyer, Sven [Instituto de Fisica de Cantabria (CSIC-UC), Santander (Spain); Liu, Tao [Chicago Univ., Chicago, IL (United States). Enrico Fermi Inst.; California Univ., Santa Barbara, CA (United States). Dept. of Physics; Wagner, Carlos E.M. [Chicago Univ., Chicago, IL (United States). Enrico Fermi Inst.; Argonne National Laboratory, Argonne, IL (United States). HEP Div.; Chicago Univ., Chicago, IL (United States). KICP and Dept. of Physics; Weiglein, Georg [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-12-15

    A canonical signature of the Minimal Supersymmetric Standard Model (MSSM) is the presence of a neutral Higgs boson with mass bounded from above by about 135 GeV and Standard Model (SM)-like couplings to the electroweak gauge bosons. In this note we investigate the reach of the Tevatron collider for the MSSM Higgs sector parameter space associated with a variety of high-scale minimal models of supersymmetry (SUSY)-breaking, including the Constrained MSSM (CMSSM), minimal Gauge Mediated SUSY-breaking (mGMSB), and minimal Anomaly Mediated SUSY-breaking (mAMSB). We find that the Tevatron can provide strong constraints on these models via Higgs boson searches. Considering a simple projection for the efficiency improvements in the Tevatron analyses, we find that with an integrated luminosity of 16 fb{sup -1} per detector and an efficiency improvement of 20% compared to the present situation, these models could be probed essentially over their entire ranges of validity. With 40% analysis improvements and 16 fb{sup -1}, our projection shows that evidence at the 3{sigma} level for the light Higgs boson could be expected in extended regions of parameter space. (orig.)

  12. The impact of PDF and alphas uncertainties on Higgs Production in gluon fusion at hadron colliders

    NARCIS (Netherlands)

    Demartin, Federico; Forte, Stefano; Mariani, Elisa; Rojo, Juan; Vicini, Alessandro

    2010-01-01

    We present a systematic study of uncertainties due to parton distributions and the strong coupling on the gluon-fusion production cross section of the Standard Model Higgs at the Tevatron and LHC colliders. We compare procedures and results when three recent sets of PDFs are used, CTEQ6.6, MSTW08

  13. Higgs-boson production with one bottom-quark jet at hadron colliders

    International Nuclear Information System (INIS)

    Dawson, S.; Jackson, C.B.; Reina, L.; Wackeroth, D.

    2005-01-01

    We present total rates and kinematic distributions for the associated production of a single bottom quark and a Higgs boson at the Fermilab Tevatron and CERN Large Hardon Collider. We include next-to-leading order QCD corrections and compare the results obtained in the four and five flavor number schemes for parton distribution functions

  14. Operation of the CDF Silicon Vertex Detector with colliding beams at Fermilab

    International Nuclear Information System (INIS)

    Bedeschi, F.; Bolognesi, V.; Dell'Agnello, S.; Galeotti, S.; Grieco, G.; Mariotti, M.; Menzione, A.; Punzi, G.; Raffaelli, F.; Ristori, L.; Tartarelli, F.; Turini, N.; Wenzel, H.; Zetti, F.; Bailey, M.W.; Garfinkel, A.F.; Kruse, M.C.; Shaw, N.M.; Carithers, W.C.; Ely, R.; Haber, C.; Holland, S.; Kleinfelder, S.; Merrick, T.; Schneider, O.; Wester, W.; Wong, M.; Yao, W.; Carter, H.; Flaugher, B.; Nelson, C.; Segler, S.; Shaw, T.; Tkaczyk, S.; Turner, K.; Wesson, T.R.; Barnett, B.; Boswell, C.; Skarha, J.; Snider, F.D.; Spies, A.; Tseng, J.; Vejcik, S.; Amidei, D.; Derwent, P.F.; Song, T.Y.; Dunn, A.; Gold, M.; Matthews, J.; Bacchetta, N.; Azzi, P.; Bisello, D.; Busetto, G.; Castro, A.; Loreti, M.; Pescara, L.; Tipton, P.; Watts, G.

    1992-10-01

    In this paper we briefly describe the main features of the CDF Silicon Vertex Detector (SVX) and discuss its performance during actual colliding beam operation at the Fermilab Tevatron. Details on S/N ratio, alignment, resolution and efficiency are given

  15. Determination of the muonic branching ratio of the W boson and its total width via cross-section measurements at the Tevatron and LHC

    Energy Technology Data Exchange (ETDEWEB)

    Camarda, Stefano [CERN, Geneva (Switzerland); Cuth, Jakub; Schott, Matthias [Johannes Gutenberg University, Mainz (Germany)

    2016-11-15

    The total W-boson decay width Γ{sub W} is an important observable which allows testing of the standard model. The current world average value is based on direct measurements of final state kinematic properties of W-boson decays, and has a relative uncertainty of 2%. The indirect determination of Γ{sub W} via the cross-section measurements of vector-boson production can lead to a similar accuracy. The same methodology leads also to a determination of the leptonic branching ratio. This approach has been successfully pursued by the CDF and D0 experiments at the Tevatron collider, as well as by the CMS collaboration at the LHC. In this paper we present for the first time a combination of the available measurements at hadron colliders, accounting for the correlations of the associated systematic uncertainties. Our combination leads to values of BR(W → μν) = (10.72 ± 0.16)% and Γ{sub W} = 2113 ± 31 MeV, respectively, both compatible with the current world averages. (orig.)

  16. Observation of Central Exclusive Diphoton Production at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Brucken, Jens Erik [Univ. of Helsinki (Finland); Helsinki Inst. of Physics (Finland)

    2013-01-01

    We have observed exclusive γγ production in proton-antiproton collisions at the Tevatron at √ s = 1.96 TeV. We use data corresponding to 1.11 ± 0.07 fb-1 integrated luminosity taken by the Run II Collider Detector at Fermilab, with a trigger requiring two electromagnetic showers, each with transverse energy ET > 2 GeV, and vetoing on hits in the forward beam shower counters. We select events with two electromagnetic showers, each with transverse energy ET > 2.5 GeV and pseudorapidity |η| < 1.0, with no other particles detected in -7.4 < η < +7.4. The two showers have similar ET and an azimuthal angle separation Δφ ~ π; we find 34 events with exactly two matching charged particle tracks, agreeing with expectations for the QED process p¯p → p+e+e- + ¯p by two photon exchange; and we find 43 events with no tracks. The latter are candidates for the exclusive process p¯p → p + γγ + ¯p by double pomeron exchange. We use the strip and wire chambers at the longitudinal shower maximum position within the calorimeter to measure a possible exclusive background from IP + IP → π0π0, and conclude that it is consistent with zero and is < 15 events at 95% C.L. The measured cross section is σγγ,excl(|η| < 1, ET (γ) > 2.5 GeV) = 2.48 +0.40 -0.35(stat) +0.40 -0.51(syst) pb and in agreement with the theoretical predictions. This process is closely related to exclusive Higgs boson production pp → p + H + p at the Large Hadron Collider. The observation of the exclusive production of diphotons shows that exclusive Higgs production can happen and could be observed with a proper experimental setup.

  17. W/Z + Jets and W/Z + Heavy Flavor Jets at the Tevatron

    International Nuclear Information System (INIS)

    Salto, Oriol

    2009-01-01

    The precision measurements of Boson + jets production performed with the Tevatron data have provided an excellent opportunity to test perturbative QCD calculations and the predictions from the new matrix elements techniques. In this contribution, the latest results by CDF and DO experiments are discussed

  18. W/Z + Jets and W/Z + Heavy Flavor Jets at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Salto, Oriol [Institut de Fisica d' Altes Energies, Universitat Autonoma de Barcelona, E-08193 Bellaterra, Barcelona (Spain)

    2009-01-15

    The precision measurements of Boson + jets production performed with the Tevatron data have provided an excellent opportunity to test perturbative QCD calculations and the predictions from the new matrix elements techniques. In this contribution, the latest results by CDF and DO experiments are discussed.

  19. Search prospects of light stabilized radions at Tevatron and LHC

    CERN Document Server

    Mahanta, U

    2000-01-01

    In this paper we use the conformal anomaly in QCD to derive the radion coupling to gluons in the Randall-Sundrum model and use it to compute the radion production cross section at hadron colliders by gluon fusion. We find that for the vacuum expectation value of the radion field, =1 TeV the radion production cross section by gluon fusion at LHC would exceed that of the standard model (SM) Higgs boson by a factor that lies between 7 and 8 over most of the mass range. The radion production cross-section decreases as 1/(/sup 2/) and for greater than 3 TeV, the Higgs production cross-section exceeds that of the radion production. The decay modes of the radion are similar to that of the SM Higgs boson. But the striking feature is the enhancement of radion to 2-photon and radion to 2-gluon branching ratio over the SM case. Utilizing this, we then discuss the possible search strategies of such scalars at the Tevatron and LHC. Using the gamma gamma decay mode one can explore /exclude a radion mass up to 1 TeV at the...

  20. The search for the Higgs at the Tevatron; La recherche du Higgs au Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Lucotte, A

    2004-07-01

    The Tevatron has undergone an impressive technical renovation program whose final aim is to reach an integrated luminosity of 15 fb{sup -1} per experiment. Both CDF and DO detectors have been upgraded in the fields of detection, triggering, track reconstruction and particle identification. In the framework of the standard model, theoretical studies show that for a luminosity of only 2 fb{sup -1} (that is the first step of the renovation program) CDF and DO could barely extend the domain already excluded by LEP for the existence of the Higgs boson. On the other hand for a luminosity of 15 fb{sup -1}, a standard Higgs boson could be excluded up to 180 GeV/c{sup 2} and discovered up to 125 GeV/c{sup 2}. Moreover, a 3*{sigma} result could be obtained in the decay channels H {yields} bb-bar and H {yields} W{sup +}W{sup -} up to 180 GeV/c{sup 2}. In the framework of the minimal supersymmetric standard model (MSSM), at least 20 fb{sup -1} are required for the discovery of the Higgs boson in the energy range: 80 {<=} m{sub A} {<=} 380 GeV/c{sup 2}. (A.C.)

  1. Large Hadron Collider manual

    CERN Document Server

    Lavender, Gemma

    2018-01-01

    What is the universe made of? How did it start? This Manual tells the story of how physicists are seeking answers to these questions using the world’s largest particle smasher – the Large Hadron Collider – at the CERN laboratory on the Franco-Swiss border. Beginning with the first tentative steps taken to build the machine, the digestible text, supported by color photographs of the hardware involved, along with annotated schematic diagrams of the physics experiments, covers the particle accelerator’s greatest discoveries – from both the perspective of the writer and the scientists who work there. The Large Hadron Collider Manual is a full, comprehensive guide to the most famous, record-breaking physics experiment in the world, which continues to capture the public imagination as it provides new insight into the fundamental laws of nature.

  2. The vacuum chamber in the interaction region of particle colliders a historical study and developments implementations in the LHCb experiment at CERN

    CERN Document Server

    Knaster, J R; Gamez-Mejias, L

    2004-01-01

    The history of particle colliders begins in the early 60's when an idea previously patented by R. Wideroe in 1953 is constructed. The design of the vacuum chamber in their experimental area became essential as it was the rst physical barrier that the particles to be detected needed to traverse. The interaction of the products of the collisions with the vacuum chamber structural materials, hindered the identification of the significative events. This Thesis analyses the historical evolution of the experimental vacuum chambers and summarizes the technical criteria that are to be fulfilled. The Large Hadron Collider (LHC) presently under construction at CERN is the last generation of particle colliders. Four big experiments will be in operation (ATLAS, CMS, ALICE and LHCb) in the LHC with diferent physics objectives. In particular, LHCb will be devoted to the study of CP violation and the design of its vacuum chamber is the scope of this Thesis. Physics simulations with an initial design consisting of a conical ...

  3. Probing the Standard Model with Higgs signal rates from the Tevatron, the LHC and a future ILC

    International Nuclear Information System (INIS)

    Bechtle, P.; Staal, O.

    2014-03-01

    We explore the room for possible deviations from the Standard Model (SM) Higgs boson coupling structure in a systematic study of Higgs coupling scale factor (κ) benchmark scenarios using the latest signal rate measurements from the Tevatron and LHC experiments. We employ a profile likelihood method based on a χ 2 test performed with HiggsSignals, which takes into account detailed information on signal efficiencies and major correlations of theoretical and experimental uncertainties. All considered scenarios allow for additional non-standard Higgs boson decay modes, and various assumptions for constraining the total decay width are discussed. No significant deviations from the SM Higgs boson coupling structure are found in any of the investigated benchmark scenarios. We derive upper limits on an additional (undetectable) Higgs decay mode under the assumption that the Higgs couplings to weak gauge bosons do not exceed the SM prediction. We furthermore discuss the capabilities of future facilities for probing deviations from the SM Higgs couplings, comparing the high luminosity upgrade of the LHC with a future International Linear Collider (ILC), where for the latter various energy and luminosity scenarios are considered. At the ILC model-independent measurements of the coupling structure can be performed, and we provide estimates of the precision that can be achieved.

  4. Colliding nuclei

    International Nuclear Information System (INIS)

    Balian, Roger; Remaud, Bernard; Suraud, E.; Durand, Dominique; Tamain, Bernard; Gobbi, A.; Cugnon, J.; Drapier, Olivier; Govaerts, Jan; Prieels, Rene

    1995-09-01

    This 14. international school Joliot-Curie of nuclear physic deals with nuclei in collision at high energy. Nine lectures are included in the proceedings of this summer school: 1 - From statistical mechanics outside equilibrium to transport equations (Balian, R.); 2 - Modeling of heavy ions reactions (Remaud, B.); 3 - Kinetic equations in heavy ions physics (Suraud, E.); 4 - Colliding nuclei near the Fermi energy (Durand, D.; Tamain, B.); 5 - From the Fermi to the relativistic energy domain: which observable? For which physics? (Gobbi, A.); 6 - Collisions at relativistic and ultra relativistic energies, Theoretical aspects (Cugnon, J.); 7 - Quark-gluon plasma: experimental signatures (Drapier, O.); 8 - Electroweak interaction: a window on physics beyond the standard model (Govaerts, J.); 9 - Symmetry tests in β nuclear process: polarization techniques (Prieels, R.)

  5. Tevatron B0 low beta tuning report

    International Nuclear Information System (INIS)

    Johnson, D.E.

    1982-01-01

    A detailed study of the low beta insertion for the B0 experimental area has been carried out and is described below. This insertion is similar to the Type C low beta previously report, anti p Note 169, although some changes have been made to the quadrupole lengths and positions. This insertion is designated Type E. The purpose of the study was to see if it is possible to turn the insertion on in a smooth and continuous manner and tune the insertion to a value of β* of less than one meter while maintaining the overall tune of the j Tevatron to a constant value. This was found to be possible. An examination of chromaticity corrections for the Tevatron with the low beta insertion on in various configurations was also undertaken

  6. Stable massive particles at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fairbairn, M.; /Stockholm U.; Kraan, A.C.; /Pennsylvania U.; Milstead, D.A.; /Stockholm U.; Sjostrand, T.; /Lund U.; Skands, P.; /Fermilab; Sloan, T.; /Lancaster U.

    2006-11-01

    We review the theoretical motivations and experimental status of searches for stable massive particles (SMPs) which could be sufficiently long-lived as to be directly detected at collider experiments. The discovery of such particles would address a number of important questions in modern physics including the origin and composition of dark matter in the universe and the unification of the fundamental forces. This review describes the techniques used in SMP-searches at collider experiments and the limits so far obtained on the production of SMPs which possess various colour, electric and magnetic charge quantum numbers. We also describe theoretical scenarios which predict SMPs, the phenomenology needed to model their production at colliders and interactions with matter. In addition, the interplay between collider searches and open questions in cosmology such as dark matter composition are addressed.

  7. A disoriented chiral condensate search at the Fermilab Tevatron

    International Nuclear Information System (INIS)

    Convery, M.E.

    1997-05-01

    MiniMax (Fermilab T-864) was a small test/experiment at the Tevatron designed to search for disoriented chiral condensates (DCC) in the forward direction. Relativistic quantum field theory treats the vacuum as a medium, with bulk properties characterized by long-range order parameters. This has led to suggestions that regions of open-quotes disoriented vacuumclose quotes might be formed in high-energy collision processes. In particular, the approximate chiral symmetry of QCD could lead to regions of vacuum which have chiral order parameters disoriented to directions which have non-zero isospin, i.e. disoriented chiral condensates. A signature of DCC is the resulting distribution of the fraction of produced pions which are neutral. The MiniMax detector at the C0 collision region of the Tevatron was a telescope of 24 multi-wire proportional chambers (MWPC's) with a lead converter behind the eighth MWPC, allowing the detection of charged particles and photon conversions in an acceptance approximately a circle of radius 0.6 in pseudorapidity-azimuthal-angle space, centered on pseudorapidity η ∼ 4. An electromagnetic calorimeter was located behind the MWPC telescope, and hadronic calorimeters and scintillator were located in the upstream anti-proton direction to tag diffractive events

  8. Fermilab tevatron five refrigerator system tests

    International Nuclear Information System (INIS)

    Rode, C.; Ferry, R.; Leiniger, M.; Makara, J.; Misek, J.; Mizicko, D.; Richied, D.; Theilacker, J.

    1982-01-01

    The Fermilab Tevatron refrigeration system is described with the layout illustrated. The compressor control loops, the refrigerator control loops, and magnet control loops (two per refrigerator) are described and each illustrated. The mobile purifier is described. A five refrigerator test is presented, using two compressor buildings, satellite refrigerator concept test and the test current to the writing. The configuration of the five refrigerator test is diagramed

  9. Jet Production at the Tevatron

    International Nuclear Information System (INIS)

    Nang, F.

    1997-06-01

    Inclusive jet cross section and dijet angular distribution results from the CDF and D0 collaborations are presented. The possibility that compositeness might be evident at high transverse energies is explored by both experiments. Using the angular distributions, the CDF analysis excludes at the 95% CL regions with Λ + - + < 2.0 TeV for the same model

  10. Top Quark Properties at Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Lysák, Roman [Prague, Inst. Phys.

    2017-11-27

    The latest CDF and D0 experiment measurements of the top quark properties except the top quark mass are presented. The final combination of the CDF and D0 forward-backward asymmetry measurements is shown together with the D0 measurements of the inclusive top quark pair cross-section as well as the top quark polarization.

  11. Recent top physics results from the D0 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, Oleg [Gottingen U., II. Phys. Inst.

    2012-09-01

    We review recent measurements of the properties of the top quark by the D0 experiment: the decay width of the top quark, the CKM matrix element $V_{tb}$, the helicity of the $W$ boson, anomalous couplings at the $Wtb$ vertex, violation of invariance under Lorentz transformations, and the asymmetry of $\\ttbar$ production due to the strong colour charge. The measurements are performed using data samples of up to 5.4 \\fb\\ acquired by the D0 experiment in Run II of the Fermilab Tevatron $p\\bar p$ collider at a centre-of-mass energy of $\\sqrt s=1.96 \\TeV$.

  12. Mesure de la section efficace de production de paires de quarks top dans le canal μ + jets + τ + b-jet(s) + Energie transverse manquante auprès de l'expérience DØ du Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Jammes, Jerome [Blaise Pascal Univ., Aubiere (France)

    2011-09-09

    The purpose of high energy physics is to improve our knowledge about the fundamental structure of matter, in particular about particles that constitute the world. One of these is the top quark, that was discovered in 1995 by the CDF and D0 collaborations at the Tevatron protons-antiprotons collider. One of the primary aim of the Tevatron has been then the fine study of the top quark properties, in particular the top-antitop production cross section. Different analysis have been performed in the leptons (μ,e,τ) + jets, dileptons, and all hadronic channels to determine accurately the values of these parameters, and thus to test the validity of the Standard Model. The main goal of this thesis is to verify one of the theoretical predictions of the Standard Model of particle physics, the top-antitop production cross section, at the Tevatron collider.

  13. Results on QCD Physics from the CDF-II Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Pagliarone, C.; /Cassino U. /INFN, Pisa

    2006-12-01

    In this paper the authors review a selection of recent results obtained, in the area of QCD physics, from the CDF-II experiment that studies p{bar p} collisions at {radical}s = 1.96 TeV provided by the Fermilab Tevatron Collider. All results shown correspond to analysis performed using the Tevatron Run II data samples. In particular they will illustrate the progress achieved and the status of the studies on the following QCD processes: jet inclusive production, using different jet clustering algorithm, W({yields} e{nu}{sub e}) + jets and Z({yields} e{sup +}e{sup -}) + jets production, {gamma} + b-jet production, dijet production in double pomeron exchange and finally exclusive e{sup +}e{sup -} and {gamma}{gamma} production. No deviations from the Standard Model have been observed so far.

  14. Supersymmetry results at the Tevatron

    International Nuclear Information System (INIS)

    Badaud, Frederique

    2007-01-01

    The results for searches for Supersymmetry by the CDF and D0 collaborations in pp-bar collisions at √s=1.96 TeV are presented here. Searches for chargino/neutralino and the lightest stop, as well as scenarios with R-parity violation are focused here. The integrated luminosity analyzed ranges from 300 to 800 pb -1 depending on the search. Further informations can be found on the public web pages of the two experiments. (author)

  15. Collider Physics an Experimental Introduction

    International Nuclear Information System (INIS)

    Elvezio Pagliarone, Carmine

    2011-01-01

    This paper reviews shortly a small part of the contents of a set of lectures, presented at the XIV International School of Particles and Fields in Morelia, state of Michoacan, Mexico, during November 2010. The main goal of those lectures was to introduce students to some of the basic ideas and tools required for experimental and phenomenological analysis of collider data. In particular, after an introduction to the scientific motivations, that drives the construction of powerful accelerator complexes, and the need of reaching high center of mass energies and luminosities, some basic concept about collider particle detectors will be discussed. A status about the present running colliders and collider experiments as well as future plans and research and development is also given.

  16. The rise of colliding beams

    International Nuclear Information System (INIS)

    Richter, B.

    1992-06-01

    It is a particular pleasure for me to have this opportunity to review for you the rise of colliding beams as the standard technology for high-energy-physics accelerators. My own career in science has been intimately tied up in the transition from the old fixed-target technique to colliding-beam work. I have led a kind of double life both as a machine builder and as an experimenter, taking part in building and using the first of the colliding-beam machines, the Princeton-Stanford Electron-Electron Collider, and building the most recent advance in the technology, the Stanford Linear Collider. The beginning was in 1958, and in the 34 years since there has been a succession of both electron and proton colliders that have increased the available center-of-mass energy for hard collisions by more than a factor of 1000. For the historians here, I regret to say that very little of this story can be found in the conventional literature. Standard operating procedure for the accelerator physics community has been publication in conference proceedings, which can be obtained with some difficulty, but even more of the critical papers are in internal laboratory reports that were circulated informally and that may not even have been preserved. In this presentation I shall review what happened based on my personal experiences and what literature is available. I can speak from considerable experience on the electron colliders, for that is the topic in which I was most intimately involved. On proton colliders my perspective is more than of an observer than of a participant, but I have dug into the literature and have been close to many of the participants

  17. Unlocking the secrets of the kaon–nucleon/nuclei interactions at low-energies: The SIDDHARTA(-2) and the AMADEUS experiments at the DAΦNE collider

    International Nuclear Information System (INIS)

    Curceanu, C.; Bazzi, M.; Beer, G.; Berucci, C.; Bombelli, L.; Bragadireanu, A.M.; Cargnelli, M.; Clozza, A.; D'Uffizi, A.; Fiorini, C.; Frizzi, T.; Ghio, F.; Guaraldo, C.; Hayano, R.S.; Iliescu, M.; Ishiwatari, T.; Iwasaki, M.; Kienle, P.; Levi Sandri, P.; Longoni, A.

    2013-01-01

    The DAΦNE electron–positron collider at the Laboratori Nazionali di Frascati of INFN has made available a unique quality low-energy negative kaons “beam”, which is being used to unlock the secrets of the kaon–nucleon/nuclei interactions at low energies by the SIDDHARTA(-2) and the AMADEUS experiments. SIDDHARTA has already performed unprecedented precision measurements of kaonic atoms, and is being presently upgraded, as SIDDHARTA-2, to approach new frontiers. The AMADEUS experiment already started a data taking with a dedicated carbon target, plans to perform in the coming years precision measurements on kaon–nuclei interactions at low-energies, in particular to study the possible formation of kaonic nuclei and the Λ(1405). The two experiments are briefly presented in this paper

  18. The Stanford Linear Collider

    International Nuclear Information System (INIS)

    Emma, P.

    1995-01-01

    The Stanford Linear Collider (SLC) is the first and only high-energy e + e - linear collider in the world. Its most remarkable features are high intensity, submicron sized, polarized (e - ) beams at a single interaction point. The main challenges posed by these unique characteristics include machine-wide emittance preservation, consistent high intensity operation, polarized electron production and transport, and the achievement of a high degree of beam stability on all time scales. In addition to serving as an important machine for the study of Z 0 boson production and decay using polarized beams, the SLC is also an indispensable source of hands-on experience for future linear colliders. Each new year of operation has been highlighted with a marked improvement in performance. The most significant improvements for the 1994-95 run include new low impedance vacuum chambers for the damping rings, an upgrade to the optics and diagnostics of the final focus systems, and a higher degree of polarization from the electron source. As a result, the average luminosity has nearly doubled over the previous year with peaks approaching 10 30 cm -2 s -1 and an 80% electron polarization at the interaction point. These developments as well as the remaining identifiable performance limitations will be discussed

  19. Searches for supersymmetry at high-energy colliders

    International Nuclear Information System (INIS)

    Feng, Jonathan L.; Grivaz, Jean-Francois; Nachtman, Jane

    2010-01-01

    This review summarizes the state of the art in searches for supersymmetry at colliders on the eve of the Large Hadron Collider era. Supersymmetry is unique among extensions of the standard model in being motivated by naturalness, dark matter, and force unification, both with and without gravity. At the same time, weak-scale supersymmetry encompasses a wide range of experimental signals that are also found in many other frameworks. Motivations for supersymmetry are recalled and the various models and their distinctive features are reviewed. Searches for neutral and charged Higgs bosons and standard-model superpartners at the high energy frontier are summarized comprehensively, considering both canonical and noncanonical supersymmetric models, and including results from the LEP collider at CERN, HERA at DESY, and the Fermilab Tevatron.

  20. Standard Model Higgs Searches at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Knoepfel, Kyle J.

    2012-06-01

    We present results from the search for a standard model Higgs boson using data corresponding up to 10 fb{sup -1} of proton-antiproton collision data produced by the Fermilab Tevatron at a center-of-mass energy of 1.96 TeV. The data were recorded by the CDF and D0 detectors between March 2001 and September of 2011. A broad excess is observed between 105 < m{sub H} < 145 GeV/c{sup 2} with a global significance of 2.2 standard deviations relative to the background-only hypothesis.

  1. Calculating luminosity for a coupled Tevatron lattice

    International Nuclear Information System (INIS)

    Holt, J.A.; Martens, M.A.; Michelotti, L.; Goderre, G.

    1995-05-01

    The traditional formula for calculating luminosity assumes an uncoupled lattice and makes use of one-degree-of-freedom lattice functions, β H and β v , for relating transverse beam widths to emittances. Strong coupling requires changing this approach. It is simplest to employ directly the linear normal form coordinates of the one turn map. An equilibrium distribution in phase space is expressed as a function of the Jacobian's eigenvectors and beam size parameters or emittances. Using the equilibrium distributions an expression for the luminosity was derived and applied to the Tevatron lattice, which was coupled due to a quadrupole roll

  2. Gluino-pair production at the Tevatron

    International Nuclear Information System (INIS)

    Beenakker, W.; Spira, M.; Zerwas, P.M.

    1995-05-01

    The next-to-leading order QCD corrections to the production of gluino pairs at the Tevatron are presented in this paper. Similar to the production of squark-antisquark pairs, the dependence of the cross section on the renormalization/factorization scale is reduced considerably by including the higher-order corrections. The cross section increases with respect to the lowest-order calculation which, in previous experimental analyses, had been evaluated at the scale of the invariant energy of the partonic subprocesses. (orig.)

  3. Top-quark mass measurements: Alternative techniques (LHC + Tevatron)

    CERN Document Server

    Adomeit, Stefanie; The ATLAS collaboration

    2014-01-01

    Measurements of the top-quark mass employing alternative techniques are presented, performed by the D0 and CDF collaborations at the Tevatron as well as the ATLAS and CMS experiments at the LHC. The alternative methods presented include measurements using the lifetime of $B$-hadrons, the transverse momentum of charged leptons and the endpoints of kinematic distributions in top quark anti-quark pair ($t\\bar{t}$) final states. The extraction of the top-quark pole mass from the $t\\bar{t}$ production cross-section and the normalized differential $t\\bar{t}$ + 1-jet cross-section are discussed as well as the top-quark mass extraction using fixed-order QCD predictions at detector level. Finally, a measurement of the top-quark mass using events enhanced in single top t-channel production is presented.

  4. New Measurements of Upsilon Spin Alignment at the Tevatron

    Directory of Open Access Journals (Sweden)

    Jones Matthew

    2012-06-01

    Full Text Available We describe a new analysis of γ(nS → μ+μ− decays collected in pp¯ $par p$ collisions with the CDF II detector at the Fermilab Tevatron. This analysis measures the angular distributions of the final state muons in the γ rest frame, providing new information about γ production polarization. We find the angular distributions to be nearly isotropic up to γ pT of 40 GeV/c, consistent with previous measurements by CDF, but inconsistent with results obtained by the D0 experiment. The results are compared with recent NLO calculations based on color-singlet matrix elements and non-relativistic QCD with color-octet matrix elements.

  5. Experiences and future plans of movable mask system for the high current collider KEK B-factory

    International Nuclear Information System (INIS)

    Suetsugu, Yusuke; Kageyama, Tatsuya; Takeuchi, Yasunao; Kanazawa, Ken-ichi; Satoh, Kotarou; Sanami, Toshiya; Hirayama, Hideo

    2002-01-01

    The movable mask is a special device for an accelerator that cuts off spent particles near the beam orbit and reduces background of the detector. For the KEKB, an electron/positron collider with two rings, sixteen movable masks had been installed for each ring. The originally designed masks, however, revealed severe troubles of heating, arcing and vacuum leaks at the stored beam currents of several hundreds mA. Several kinds of improved masks had been designed employing RF technologies and were installed to the ring step by step. The latest masks are working well except for the grooves on the mask head. Here the problems of movable masks so far are summarized and the structures of the latest movable masks and their status are presented. (author)

  6. A Demonstration Experiment for the Forecast of Magnetic Field and Field Errors in the Large Hadron Collider

    CERN Document Server

    Sammut, N J; Bottura, L; Deferne, G; Lamont, M; Miles, J; Sanfilippo, S; Strzelczyk, M; Venturini-Delsolaro, W; Xydi, P

    2008-01-01

    In order to reduce the burden on the beam-based feedback, the Large Hadron Collider control system is equipped with the Field Description for the LHC (FiDeL) which provides a forecast of the magnetic field and the multipole field errors. FiDeL has recently been extensively tested at CERN to determine main field tracking, multipole forecasting and compensation accuracy. This paper describes the rationale behind the tests, the procedures employed to power the main magnets and their correctors, and finally, we present the results obtained. We also give an indication of the prediction accuracy that the system can deliver during the operation of the LHC and we discuss the implications that these will have on the machine performance.

  7. The Large Hadron Collider of CERN and the roadmap toward higher performance

    CERN Document Server

    Rossi, L

    2012-01-01

    The Large Hadron Collider is exploring the new frontier of particle physics. It is the largest and most ambitious scientific instrument ever built and 100 years after the Rutherford experiment it continues that tradition of “smashing atoms” to unveil the secret of the infinitely small. LHC makes use of all what we learnt in 40 years of hadron colliders, in particular of ISR and Sp-pbarS at CERN and Tevatron at Fermilab, and it is based on Superconductivity, discovered also 100 years ago. Designing, developing the technology, building and finally commissioning the LHC took more than twenty years. While LHC is now successfully running, we are already preparing the future for the next step. First, by increasing of a factor five the LHC luminosity in ten years from now, and then by increasing its energy by a factor two or more, on the horizon of the next twenty years. These LHC upgrades, in luminosity and energy, will be the super-exploitation of the CERN infrastructure and is the best investment that the HEP...

  8. Drell-Yan and diphoton production at hadron colliders and low scale gravity model

    International Nuclear Information System (INIS)

    Cheung, Kingman; Landsberg, Greg

    2000-01-01

    In the model of Arkani-Hamed, Dimopoulos, and Dvali where gravity is allowed to propagate in the extra dimensions of very large size, virtual graviton exchange between the standard model particles can give rise to signatures that can be tested in collider experiments. We study these effects in dilepton and diphoton production at hadron colliders. Specifically, we examine the double differential cross section in the invariant mass and scattering angle, which is found to be useful in separating the gravity effects from the standard model. In this work, sensitivity obtained using the double differential cross section is higher than that in previous studies based on single differential distributions. Assuming no excess of events over the standard model predictions, we obtain the following 95% confidence level lower limits on the effective Planck scale: 0.9-1.5 TeV in the Fermilab Tevatron run I, 1.3-2.5 TeV in run IIa, 1.7-3.5 TeV in run IIb, and 6.5-12.8 TeV at the CERN LHC. The range of numbers corresponds to the number of extra dimensions n=7-2. (c) 2000 The American Physical Society

  9. The Large Hadron Collider the greatest adventure in town and ten reasons why it matters, as illustrated by the ATLAS experiment

    CERN Document Server

    Millington, Andrew J; MacPherson, Rob; Nordberg, Markus

    2016-01-01

    When the discovery of the Higgs Boson at CERN hit the headlines in 2012, the world was stunned by this achievement of modern science. Less well appreciated, however, were the many ways in which this benefited wider society. The Large Hadron Collider — The Greatest Adventure in Town charts a path through the cultural, economic and medical gains of modern particle physics. It illustrates these messages through the ATLAS experiment at CERN, one of the two big experiments which found the Higgs particle. Moving clear of in-depth physics analysis, it draws on the unparalleled curiosity about particle physics aroused by the Higgs discovery, and relates it to developments familiar in the modern world, including the Internet, its successor "The Grid", and the latest cancer treatments. In this book, advances made from developing the 27 kilometre particle accelerator and its detectors are presented with the benefit of first hand interviews and are extensively illustrated throughout. Interviewees are leading physicis...

  10. The Evolution of the Control System for the Electromagnetic Calorimeter of the Compact Muon Solenoid Experiment at the Large Hadron Collider

    CERN Multimedia

    Holme, Oliver; Dissertori, Günther; Lustermann, Werner; Zelepoukine, Serguei

    2011-01-01

    This paper discusses the evolution of the Detector Control System (DCS) designed and implemented for the Electromagnetic Calorimeter (ECAL) of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) as well as the operational experience acquired during the LHC physics data taking periods of 2010 and 2011. The current implementation in terms of functionality and planned hardware upgrades are presented. Furthermore, a project for reducing the long-term software maintenance, including a year-long detailed analysis of the existing applications, is put forward and the current outcomes which have informed the design decisions for the next CMS ECAL DCS software generation are described. The main goals for the new version are to minimize external dependencies enabling smooth migration to new hardware and software platforms and to maintain the existing functionality whilst substantially reducing support and maintenance effort through homogenization, simplification and standardization of the contr...

  11. Signatures of massive sgoldstinos at hadron colliders

    International Nuclear Information System (INIS)

    Perazzi, Elena; Ridolfi, Giovanni; Zwirner, Fabio

    2000-01-01

    In supersymmetric extensions of the Standard Model with a very light gravitino, the effective theory at the weak scale should contain not only the goldstino G-tilde, but also its supersymmetric partners, the sgoldstinos. In the simplest case, the goldstino is a gauge-singlet and its superpartners are two neutral spin-0 particles, S and P. We study possible signals of massive sgoldstinos at hadron colliders, focusing on those that are most relevant for the Tevatron. We show that inclusive production of sgoldstinos, followed by their decay into two photons, can lead to observable signals or to stringent combined bounds on the gravitino and sgoldstino masses. Sgoldstino decays into two gluon jets may provide a useful complementary signature

  12. The behavior of the Tevatron at energies greater than 1000 GeV

    International Nuclear Information System (INIS)

    Pogorelko, O.

    1991-04-01

    If, as appears likely, the top quark lies at the upper range of the mass reach of the Tevatron, then increasing the energy of the collider operation could prove to be a crucial factor in the future program together with projected luminosity enhancements. While a significant amount of data exists on individual magnets up to an energy of 1000 GeV, there are no detailed measurements above this value. We focus on the operating range beyond 1000 GeV in an attempt to see whether there is any realistic opportunity to extend the energy range of the Tevatron into this regime. The proposed modifications to the Tevatron Cryogenic System will provide sufficient cooling to lower the operating temperature of the 1000 superconducting magnets from the present 4.6--4.8K (1-φ inlet temperature) down to a range of 3.6--3.8K. At this temperature the short sample quench current for the dipole magnets should increase from the present value of ∼4000A (900 GeV) up to a level approaching 4800A (1100 GeV.) Increasing the peak current in the dipoles produces some important questions related to possible mechanical effects including catastrophic failure, the change of magnetic field quality, and quench protection problems resulting from the increased stored energy. In this note we shall examine these effects and comment on the existing data on low temperature operation. We have only considered the dipole magnets since the quadrupoles should not limit performance. We have not looked at the interaction region magnets which involve different considerations

  13. Importance of two-dimensional effects for the generation of ultra high pressures obtained in laser colliding foil experiments

    Energy Technology Data Exchange (ETDEWEB)

    Faral, B.; Fabbro, R. (Laboratoire d' Utilisation des Lasers Intenses, Ecole Polytechnique, 91128 Palaiseau Cedex, (France)); Virmont, J. (Laboratoire de Physique des Milieux Ionises, Ecole Polytechnique, 91128 Palaiseau Cedex, (France)); Cottet, F.; Romain, J.P. (Laboratoire d' Energetique et de Detonique, Ecole Nationale Superieure de Mecanique et d' Aerotechnique, 86034 Poitiers, (France)); Pepin, H. (Institut National de la Recherche Scientifique Energie, Montreal, (Canada))

    1990-02-01

    A 12 {mu}m polyester foil is accelerated by a 0.26 {mu}m wavelength laser and collides with a 15 {mu}m thick molybdenum foil. The accelerating pressure is 45 Mbar (laser intensity{approx}3-- 4{times}10{sup 14} W/cm{sup 2}) and gives to the polyester foil a velocity of about 160 km/sec. The measurement of the shock pressure induced in the impacted foil is made with an improved step technique. When the initial spacing between the two foils is too large compared to the focal spot radius, i.e., larger than 20--30 {mu}m, the different experimental results cannot be reproduced with one-dimensional simulations; this is only possible by using a two-dimensional Lagrangian code that has been developed and that takes into account the strong deformation of the accelerated foil. Finally, even with the low level of x-ray heating due to the ablation plasma, multihundred megabar pressures can be obtained within a very short time.

  14. Importance of two-dimensional effects for the generation of ultra high pressures obtained in laser colliding foil experiments

    International Nuclear Information System (INIS)

    Faral, B.; Fabbro, R.; Virmont, J.; Cottet, F.; Romain, J.P.; Pepin, H.

    1990-01-01

    A 12 μm polyester foil is accelerated by a 0.26 μm wavelength laser and collides with a 15 μm thick molybdenum foil. The accelerating pressure is 45 Mbar (laser intensity∼3-- 4x10 14 W/cm 2 ) and gives to the polyester foil a velocity of about 160 km/sec. The measurement of the shock pressure induced in the impacted foil is made with an improved step technique. When the initial spacing between the two foils is too large compared to the focal spot radius, i.e., larger than 20--30 μm, the different experimental results cannot be reproduced with one-dimensional simulations; this is only possible by using a two-dimensional Lagrangian code that has been developed and that takes into account the strong deformation of the accelerated foil. Finally, even with the low level of x-ray heating due to the ablation plasma, multihundred megabar pressures can be obtained within a very short time

  15. A dedicated LHC collider Beauty experiment for precision measurements of CP-violation. LHC-B letter of intent; TOPICAL

    International Nuclear Information System (INIS)

    Crosetto, Dario B.

    1996-01-01

    The LHC-B Collaboration proposes to build a forward collider detector dedicated to the study of CP violation and other rare phenomena in the decays of Beauty particles. The forward geometry results in an average 80 GeV momentum of reconstructed B-mesons and, with multiple, efficient and redundant triggers, yields large event samples. B-hadron decay products are efficiently identified by Ring-Imaging Cerenkov Counters, rendering a wide range of multi-particle final states accessible and providing precise measurements of all angles,(alpha),(beta) and(gamma) of the unitarity triangle. The LHC-B microvertex detector capabilities facilitate multi-vertex event reconstruction and proper-time measurements with an expected few-percent uncertainty, permitting measurements of B(sub s)-mixing well beyond the largest conceivable values of x(sub S). LHC-B would be fully operational at the startup of LHC and requires only a modest luminosity to reveal its full performance potential

  16. Challenges for MSSM Higgs searches at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Carena, Marcela S.; /Fermilab; Menon, A.; /Argonne /Chicago U., EFI; Wagner, C.E.M.; /Argonne /Chicago U., EFI /KICP, Chicago /Chicago U.

    2007-04-01

    In this article we analyze the impact of B-physics and Higgs physics at LEP on standard and non-standard Higgs bosons searches at the Tevatron and the LHC, within the framework of minimal flavor violating supersymmetric models. The B-physics constraints we consider come from the experimental measurements of the rare B-decays b {yields} s{gamma} and B{sub u} {yields} {tau}{nu} and the experimental limit on the B{sub s} {yields} {mu}{sup +}{mu}{sup -} branching ratio. We show that these constraints are severe for large values of the trilinear soft breaking parameter A{sub t}, rendering the non-standard Higgs searches at hadron colliders less promising. On the contrary these bounds are relaxed for small values of A{sub t} and large values of the Higgsino mass parameter {mu}, enhancing the prospects for the direct detection of non-standard Higgs bosons at both colliders. We also consider the available ATLAS and CMS projected sensitivities in the standard model Higgs search channels, and we discuss the LHC's ability in probing the whole MSSM parameter space. In addition we also consider the expected Tevatron collider sensitivities in the standard model Higgs h {yields} b{bar b} channel to show that it may be able to find 3 {sigma} evidence in the B-physics allowed regions for small or moderate values of the stop mixing parameter.

  17. Forward-Backward Asymmetry of Top Quark Pair Productionn at the Fermilab Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Ziqing [Texas A & M Univ., College Station, TX (United States)

    2015-12-01

    This dissertation presents the final measurements of the forward-backward asymmetry (AFB) of top quark-antiquark pair events (t t-) at the Collider Detector at Fermilab (CDF) experiment. The t t- events are produced in proton{anti-proton collisions with a center of mass energy of 1:96 TeV during the Run II of the Fermilab Tevatron. The measurements are performed with the full CDF Run II data (9.1 fb-1) in the final state that contain two charged leptons (electrons or muons, the dilepton final state), and are designed to con rm or deny the evidence-level excess in the AFB measurements in the final state with a single lepton and hadronic jets (lepton+jets final state) as well as the excess in the preliminary measurements in the dilepton final state with the first half of the CDF Run II data. New measurements include the leptonic AFB (AlFB), the lepton-pair AFB (All FB) and the reconstructed top AFB (At t FB). Each are combined with the previous results from the lepton+jets final state measured at the CDF experiment. The inclusive Al FB, All FB, and At t FB measured in the dilepton final state are 0.072 ± 0.060, 0.076 ± 0.081, and 0.12 ± 0.13, to be compared with the Standard Model (SM) predictions of 0.038 ± 0.003, 0.048 ± 0.004, and 0.010 ± 0.006, respectively. The CDF combination of AlFB and At t FB are 0.090+0:028 -0.026, and 0.160 ± 0.045, respectively. The overall results are consistent with the SM predictions.

  18. Non-perturbative QCD Effects and the Top Mass at the Tevatron

    CERN Document Server

    Wicke, Daniel

    2008-01-01

    The modelling of non-perturbative effects is an important part of modern collider physics simulations. In hadron collisions there is some indication that the modelling of the interactions of the beam remnants, the underlying event, may require non-trivial colour reconnection effects to be present. We recently introduced a universally applicable toy model of such reconnections, based on hadronising strings. This model, which has one free parameter, has been implemented in the Pythia event generator. We then considered several parameter sets (`tunes'), constrained by fits to Tevatron minimum-bias data, and determined the sensitivity of a simplified top mass analysis to these effects, in exclusive semi-leptonic top events at the Tevatron. A first attempt at isolating the genuine non-perturbative effects gave an estimate of order +-0.5GeV from non-perturbative uncertainties. The results presented here are an update to the original study and include recent bug fixes of Pythia that influenced the tunings investigat...

  19. Beam beam tune shifts for 36 bunch operation in the Tevatron

    International Nuclear Information System (INIS)

    Bagley, P.

    1996-10-01

    We are preparing to upgrade the Tevatron Collider from 6 to 36 bunch operation. The 36 bunches are in 3 ''trains'' of 12 bunches. The spacing between bunches within a train is 21 RF buckets (53.106 MHz) and 139 empty buckets separate the trains. Because the 36 bunches are not evenly spaced around the machine, the different bunches within a train pass the opposing bunches at different points in the ring and so feel different beam beam effects. Through most of the machine the beams have helical separation, so these are mainly long range beam beam effects. As a first, very simple step, we've looked at the differences in the tunes of the different anti-proton (anti p) bunches. During the 36 bunch studies in Fall 1995, we used a new tune measurement system to measure these in several different machine conditions. We compare these measurements to calculations of the tunes for a anti p with zero transverse and longitudinal oscillation amplitudes. We discuss experimental problems, and the assumptions, approximations, and effects included in the calculations. Our main intent is to gain confidence that we can accurately model beam beam effects in the Tevatron

  20. SVX II a silicon vertex detector for run II of the tevatron

    International Nuclear Information System (INIS)

    Bortoletto, D.

    1994-11-01

    A microstrip silicon detector SVX II has been proposed for the upgrade of the vertex detector of the CDF experiment to be installed for run II of the Tevatron in 1998. Three barrels of four layers of double sided detectors will cover the interaction region. The requirement of the silicon tracker and the specification of the sensors are discussed together with the proposed R ampersand D to verify the performance of the prototypes detectors produced by Sintef, Micron and Hamamatsu

  1. Berkeley mini-collider

    International Nuclear Information System (INIS)

    Schroeder, L.S.

    1984-06-01

    The Berkeley Mini-Collider, a heavy-ion collider being planned to provide uranium-uranium collisions at T/sub cm/ less than or equal to 4 GeV/nucleon, is described. The central physics to be studied at these energies and our early ideas for a collider detector are presented

  2. Very high energy colliders

    International Nuclear Information System (INIS)

    Richter, B.

    1986-03-01

    The luminosity and energy requirements are considered for both proton colliders and electron-positron colliders. Some of the basic design equations for high energy linear electron colliders are summarized, as well as design constraints. A few examples are given of parameters for very high energy machines. 4 refs., 6 figs

  3. Beam-induced damage to the Tevatron components and what has been done about it

    International Nuclear Information System (INIS)

    Mokhov, N.V.; Czarapata, P.C.; Drozhdin, A.I.; Still, D.A.; Samulyak, R.V.

    2007-01-01

    A beam-induced damage to the Tevatron collimators happened in December 2003 was induced by a failure in the CDF Roman Pot detector positioning during the collider run. Possible scenarios of this failure resulted in an excessive halo generation and superconducting magnet quench have been studied via realistic simulations using the STRUCT and MARS14 codes. It is shown that the interaction of a misbehaved proton beam with the collimators result in a rapid local heating and a possible damage. A detailed consideration is given to the ablation process for the collimator material taking place in high vacuum. It is shown that ablation of tungsten (primary collimator) and stainless steel (secondary collimator) jaws results in creation of a groove in the jaw surface as was observed after the December's accident. The actions undertaken to avoid such an accident in future are described in detail. (author)

  4. Beam-induced damage to the Tevatron components and what has been done about it

    International Nuclear Information System (INIS)

    Mokhov, N.V.; Czarapata, P.C.; Drozhdin, A.I.; Still, D.A.; Samulyak, R.V.

    2006-01-01

    A beam-induced damage to the Tevatron collimators happened in December 2003 was induced by a failure in the CDF Roman Pot detector positioning during the collider run. Possible scenarios of this failure resulted in an excessive halo generation and superconducting magnet quench have been studied via realistic simulations using the STRUCT and MARS14 codes. It is shown that the interaction of a misbehaved proton beam with the collimators result in a rapid local heating and a possible damage. A detailed consideration is given to the ablation process for the collimator material taking place in high vacuum. It is shown that ablation of tungsten (primary collimator) and stainless steel (secondary collimator) jaws results in creation of a groove in the jaw surface as was observed after the December's accident. The actions undertaken to avoid such an accident in future are described in detail

  5. Colored resonances at the Tevatron: phenomenology and discovery potential in multijets

    International Nuclear Information System (INIS)

    Kilic, Can; Okui, Takemichi; Sundrum, Raman

    2008-01-01

    There exist several classes of theories beyond the Standard Model which contain massive spin-1 color octets, generically called ''colorons''. Indeed we argue that colorons inevitably appear in the spectrum whenever new colored particles feel an additional confining force. Colorons are distinctive at hadron colliders as this is the only environment in which they can be resonantly produced. In the simplest models we show that the coloron naturally decays to multijets via secondary resonances, which can be consistent with all existing bounds, even for colorons as light as a few hundred GeV. We perform representative case studies and show that a search in the four-jet channel at the Tevatron has strong signal significance, while the LHC faces formidable challenges for such a search.

  6. Top anti-top Asymmetries at the Tevatron and the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Yvonne Reinhild [DESY

    2012-11-01

    The heaviest known elementary particle today, the top quark, has been discovered in 1995 by the CDF and D0 collaborations at the Tevatron proton antiproton collider at Fermilab. Recently, the CDF and D0 collaborations have studied the forward-backward asymmetry in ttbar events, resulting in measured values larger than the standard model prediction. With the start of the LHC at CERN in 2010, a new top quark factory has opened and asymmetry measurements in ttbar have also been performed in a proton proton environment with higher collision energy. No deviations from the standard model have been noticed so far in the measurements of ATLAS and CMS. This article discusses recent results of asymmetry measurements in ttbar events of the ATLAS, CDF, CMS and D0 collaborations.

  7. B-meson production in the Parton Reggeization approach at Tevatron and the LHC

    International Nuclear Information System (INIS)

    Karpishkov, A.V.; Saleev, V.A.; Nefedov, M.A.; Shipilova, A.V.; Samara State Aerospace Univ.; Hamburg Univ.

    2014-11-01

    We study the inclusive hadroproduction of B 0 , B + , and B 0 s mesons at leading order in the parton Reggeization approach using the universal fragmentation functions extracted from the combined e + e - annihilation data from CERN LEP1 and SLAC SLC colliders. We have described B-meson transverse momentum distributions measured in the central region of rapidity by the CDF Collaboration at Fermilab Tevatron and CMS Collaboration at LHC within uncertainties and without free parameters, applying Kimber-Martin-Ryskin unintegrated gluon distribution function in a proton. The forward B-meson production (2.0< y<4.5) measured by the LHCb Collaboration also has been studied and expected disagreement between our theoretical predictions and data has been obtained.

  8. Diphoton production at Tevatron in the quasi-multiple-Regge-kinematics approach

    Energy Technology Data Exchange (ETDEWEB)

    Saleev, V.A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Samarskij Gosudarstvennyj Univ., Samara (Russian Federation)

    2009-12-15

    We study the production of prompt diphotons in the central region of rapidity within the frame- work of the quasi-multi-Regge-kinematics approach applying the hypothesis of quark and gluon Reggeization. We describe accurately and without free parameters the experimental data which were obtained by the CDF Collaboration at the Tevatron Collider. It is shown that the main contribution to studied process is given by the direct fusion of two Reggeized gluons into a photon pair, which is described by the effective Reggeon-Reggeon to particle-particle vertex. The contribution from the annihilation of Reggeized quark-antiquark pair into a diphoton is also considered. At the stage of numerical calculations we use the Kimber-Martin-Ryskin prescription for unintegrated quark and gluon distribution functions, with the Martin-Roberts-Stirling-Thorne collinear parton densities for a proton as input. (orig.)

  9. Report of the SUGRA Working Group for Run II of the Tevatron

    CERN Document Server

    Barger, V.; Flattum, E.; Falk, T.; Abel, S.; Accomando, E.; Anderson, G.; Arnowitt, R.; Azzi, P.; Baer, H.; Bagger, J.; Beenakker, W.; Belyaev, A.; Berger, E.; Berger, M.; Brhlik, M.; Blazek, T.; Blessing, S.; Bokhari, W.; Bruner, N.; Carena, M.; Chakraborty, D.; Chang, D.; Chankowski, P.; Chen, C.H.; Cheng, H.C.; Chertok, M.; Cho, G.C.; Claes, D.; Demina, R.; Done, J.; Duflot, L.; Dutta, Bhaskar; Eboli, O.J.P.; Eno, S.; Feng, J.; Ganis, G.; Gold, M.; Gregores, E.M.; Hagiwara, K.; Han, T.; Harris, B.; Hikasa, K.; Holck, C.; Kao, C.; Kato, Y.; Klasen, M.; Keung, W.Y.; Kramer, M.; Lammel, S.; Li, T.J.; Lykken, J.D.; Magro, M.; Mani, S.; Matchev, K.T.; Mangano, M.; Mercadante, P.; Mrenna, S.; Nachtman, J.; Nath, P.; Nojiri, M.M.; Nomerotski, A.; Norman, D.; Oishi, R.; Ono, K.; Paige, F.; Paterno, M.; Parke, S.; Pierce, D.; Pilaftsis, A.; Plehn, T.; Pompos, A.; Polonksy, N.; Pokorski, S.; Quintana, P.; Roco, M.; Saltzberg, D.; Savoy-Navarro, A.; Seiya, Y.; Smith, C.; Spira, M.; Spiropulu, M.; Sullivan, Z.; Szalapski, R.; Tannenbaum, B.; Tait, T.; Wackeroth, D.; Wang, Y.; White, J.; Williams, H.H.; Worcester, M.; Worm, S.; Zhang, R.J.; Zielinski, M.

    2000-01-01

    We present an analysis of the discovery reach for supersymmetric particles at the upgraded Tevatron collider, assuming that SUSY breaking results in universal soft breaking parameters at the grand unification scale, and that the lightest supersymmetric particle is stable and neutral. We first present a review of the literature, including the issues of unification, renormalization group evolution of the supersymmetry breaking parameters and the effect of radiative corrections on the effective low energy couplings and masses of the theory. We consider the experimental bounds coming from direct searches and those arising indirectly from precision data, cosmology and the requirement of vacuum stability. The issues of flavor and CP-violation are also addressed. The main subject of this study is to update sparticle production cross sections, make improved estimates of backgrounds, delineate the discovery reach in the supergravity framework, and examine how this might vary when assumptions about universality of soft...

  10. Neutrino results from the Fermilab Tevatron

    International Nuclear Information System (INIS)

    Shaevitz, M.H.; Arroyo, C.; Bachmann, K.T.; Bazarko, A.O.; Blair, R.E.; Bolton, T.A.; Foudas, C.; King, B.J.; Lefmann, W.C.; Leung, W.C.; Mishra, S.R.; Oltman, E.; Quintas, P.Z.; Rabinowitz, S.A.; Sciulli, F.; Seligman, W.G.; Merritt, F.S.; Oreglia, M.J.; Schumm, B.A.; Bernstein, R.H.; Borcherding, F.; Fisk, H.E.; Lamm, M.J.; Marsh, W.; Merritt, K.W.B.; Schellman, H.; Yovanovitch, D.D.; Bodek, A.; Budd, H.S.; De Barbaro, P.; Salcumoto, W.K.; Kinnel, T.S.; Sandler, P.H.; Smith, W.H.

    1995-01-01

    Results from the high-energy, high-statistics studies of neutrino nucleon interactions by the CCFR collaboration at the Fermilab Tevatron are described. Using a data sample of over 3.7million events with energies up to 600GeV, precision measurements are presented for the weak mixing angle, sin 2 θ w , the structure functions, F 2 (x,Q 2 ) and xF 3 (x,Q 2 ), aud the strange quark distribution, xs(x,Q 2 ). Comparisons of these measurements to those obtained in other processes are made in the context of global electroweak and QCD tests. Prospects for the next generation measurements by the NuTeV collaboration at Fermilab are also presented. ((orig.))

  11. 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...

  12. CERN's Large Hadron Collider project

    Science.gov (United States)

    Fearnley, Tom A.

    1997-03-01

    The paper gives a brief overview of CERN's Large Hadron Collider (LHC) project. After an outline of the physics motivation, we describe the LHC machine, interaction rates, experimental challenges, and some important physics channels to be studied. Finally we discuss the four experiments planned at the LHC: ATLAS, CMS, ALICE and LHC-B.

  13. CERN's Large Hadron Collider project

    International Nuclear Information System (INIS)

    Fearnley, Tom A.

    1997-01-01

    The paper gives a brief overview of CERN's Large Hadron Collider (LHC) project. After an outline of the physics motivation, we describe the LHC machine, interaction rates, experimental challenges, and some important physics channels to be studied. Finally we discuss the four experiments planned at the LHC: ATLAS, CMS, ALICE and LHC-B

  14. Physics beyond Colliders Kickoff Workshop

    CERN Document Server

    2016-01-01

    The aim of the workshop is to explore the opportunities offered by the CERN accelerator complex and infrastructure to get new insights into some of today's outstanding questions in particle physics through projects complementary to high-energy colliders and other initiatives in the world. The focus is on fundamental physics questions that are similar in spirit to those addressed by high-energy colliders, but that may require different types of experiments. The kickoff workshop is intended to stimulate new ideas for such projects, for which we encourage the submission of abstracts.

  15. Workshop on Physics Beyond Colliders

    CERN Document Server

    2016-01-01

    The aim of the workshop is to explore the opportunities offered by the CERN accelerator complex and infrastructure to get new insights into some of today's outstanding questions in particle physics through projects complementary to high-energy colliders and other initiatives in the world. The focus is on fundamental physics questions that are similar in spirit to those addressed by high-energy colliders, but that may require different types of experiments. The kick-off workshop is intended to stimulate new ideas for such projects, for which we encourage the submission of abstracts.

  16. Diffraction and Total Cross-Section at the Tevatron and the LHC

    CERN Document Server

    Deile, M; Aurola, A; Avati, V; Berardi, V; Bottigli, U; Bozzo, M; Brucken, E; Buzzo, A; Calicchio, M; Capurro, F; Catanesi, M G; Ciocci, M A; Cuneo, S; Da Vià, C; Dimovasili, E; Eggert, K; Eraluoto, M; Ferro, F; Giachero, A; Guillaud, J P; Hasi, J; Haug, F; Heino, J; Hilden, T; Jarron, P; Kalliopuska, J; Kaspar, J; Kempa, J; Kenney, C; Kok, A; Kundrát, V; Kurvinen, K; Lami, S; Lamsa, J; Latino, G; Lauhakangas, R; Lippmaa, J; Lokajícek, M; Lo Vetere, M; Macina, D; Macri, M; Meucci, M; Minutoli, S; Morelli, A; Musico, P; Negri, M; Niewiadomski, H; Noschis, E; Ojala, J; Oljemark, F; Orava, R; Oriunno, M; Österberg, K; Paoletti, R; Parker, S; Perrot, Anne Laure; Radermacher, E; Radicioni, E; Robutti, E; Ropelewski, Leszek; Ruggiero, G; Saarikko, H; Sanguinetti, G; Santroni, A; Saramad, S; Sauli, Fabio; Scribano, A; Sette, G; Smotlacha, J; Snoeys, W; Taylor, C; Toppinen, A; Turini, N; Van Remortel, N; Verardo, L; Verdier, A; Watts, S; Whitmore, J

    2006-01-01

    At the Tevatron, the total p_bar-p cross-section has been measured by CDF at 546 GeV and 1.8 TeV, and by E710/E811 at 1.8 TeV. The two results at 1.8 TeV disagree by 2.6 standard deviations, introducing big uncertainties into extrapolations to higher energies. At the LHC, the TOTEM collaboration is preparing to resolve the ambiguity by measuring the total p-p cross-section with a precision of about 1 %. Like at the Tevatron experiments, the luminosity-independent method based on the Optical Theorem will be used. The Tevatron experiments have also performed a vast range of studies about soft and hard diffractive events, partly with antiproton tagging by Roman Pots, partly with rapidity gap tagging. At the LHC, the combined CMS/TOTEM experiments will carry out their diffractive programme with an unprecedented rapidity coverage and Roman Pot spectrometers on both sides of the interaction point. The physics menu comprises detailed studies of soft diffractive differential cross-sections, diffractive structure func...

  17. Developments in perturbative QCD? challenges from collider physics

    Energy Technology Data Exchange (ETDEWEB)

    Zeppenfeld, Dieter [Valencia Univ. (Spain). Dept. de Fisica Teorica]. E-mail: dieter@phenom.physics.wisc.edu

    1996-07-01

    The search for new phenomena at hadron colliders requires a good understanding of QCD processes. The analysis of multi-jet signatures in the top quark search at the Tevatron is one example, forward jet tagging and rapidity gap techniques in the analysis of weak boson scattering events at the LH C will be another important application. These topics are discussed in the context of multi-parton/multi-jet QCD processes. Also described are some of the calculation tools, like amplitude techniques and automatic code generation for tree level processes. (author)

  18. Developments in perturbative QCD? challenges from collider physics

    International Nuclear Information System (INIS)

    Zeppenfeld, Dieter

    1996-01-01

    The search for new phenomena at hadron colliders requires a good understanding of QCD processes. The analysis of multi-jet signatures in the top quark search at the Tevatron is one example, forward jet tagging and rapidity gap techniques in the analysis of weak boson scattering events at the LH C will be another important application. These topics are discussed in the context of multi-parton/multi-jet QCD processes. Also described are some of the calculation tools, like amplitude techniques and automatic code generation for tree level processes. (author)

  19. Advanced forward calorimetry for present and future colliders

    International Nuclear Information System (INIS)

    DiBitonto, D.; McIntyre, P.M.; Atac, M.

    1987-01-01

    We propose to develop a compact, high density calorimeter to instrument the very forward region. The design is based on a warm liquid medium such as tetramethylpentane (TMP) or neopentane which is better suited to the expected high background conditions than conventional gas media. The calorimeter will be assembled in sealed units, which can then be placed compactly into a variety of configurations. The accompanying hybrid electronic readout is designed to operate at either 100 MHz or 1 GHz, depending on the specific collider application (Tevatron or SSC)

  20. Fixed target beauty physics from Tevatron to SSC (E771)

    International Nuclear Information System (INIS)

    Lau, K.

    1992-01-01

    The E771 beauty experiment at Fermilab is described. The Super Fixed Target Beauty Facility (SFT) proposal to perform fixed target beauty physics at the SSC is a natural evolution. The unique features of SFT include crystal channeling extraction from the SSC main ring, which allows the experiment to operate concurrently with the collider experiments. The slow extraction rate (≅2x10 8 protons/s) does not limit the lifetime of the stored beams. The proposed beauty spectrometer and its capability in CP violation studies are described. (author) 19 refs.; 2 figs.; 2 tabs