Download or read book A Search for Supersymmetry Via Chargino Neutralino Production in Low p T Dimuon with the Collider Detector at Fermilab written by and published by . This book was released on 2007 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have searched for evidence of supersymmetry with 1 $fb^-1$ with collected with low-$p_T$ dimuon triggers of the Collider Detector on Tevatron Run II, at Fermilab. We looked for trilepton events in $p\bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV. In the Minimal Supersymmetric Standard Model (MSSM) we expect chargino-neutralino pair production, with subsequent decay into three isolated leptons. We observe one event of three isolated muons, a possible hint of supersymmetry.
Download or read book A Search for Supersymmetry Via Chargino neutralino Production in Low particle Transverse Momentum Dimuon Channel with the Collider Detector at Fermilab written by Vladimir Rekovic and published by . This book was released on 2007 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Search for Chargino neutralino Production at the Fermilab Tevatron Collider written by and published by . This book was released on 1997 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have searched for evidence of supersymmetry with the Collider Detector at Fermilab using trilepton events in p{anti p} collisions at √s = 1.8 TeV. In the Minimal Supersymmetric Standard Model (MSSM), we expect trilepton events from chargino-neutralino ({tilde {xi}}{sup {+-}}1{tilde {xi}}°2) pair production, with subsequent decay into leptons. In all possible combinations of electron and muon channels, we observe no candidate events in 107 pb−1 of data. We present limits on chargino and neutralino production within the framework of a supergravity inspired MSSM: [sigma]{sub {tilde {xi}}{sup {+-}}1{tilde {xi}}°2} · BR({tilde {xi}}{sup {+-}}1{tilde {xi}}°2 → 3l + X) 0.34 pb and M{sub {tilde {xi}}{sup {+-}}1} 81.5 GeV/c2 for tan [beta] = 2, [mu] = -600 GeV/c2 and M{sub {tilde q}} = M{sub {tilde g}}. We also present limits on a SU(5) x U(1) supergravity model and a 4 and 1/2 parameter Minimal SUGRA model.
Download or read book A Search for Chargino neutralino Production at the Fermilab Tevatron Collider written by Benn Tannenbaum and published by . This book was released on 1997 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Chargino neutralino Production at the Collider Detector at Fermilab written by John Strologas and published by . This book was released on 2006 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The chargino-neutralino production is one of the most promising SUSY processes that could be observed at the Tevatron. Cross sections of the order of 0.1 pb have not been excluded yet under the mSUGRA scenario, whereas the trilepton signature of the process is not contaminated by significant standard model backgrounds. We report on the status of CDF search for chargino-neutralino production at the Tevatron by presenting the results of five multilepton subanalyses as well as the result of their combination which leads to our current lower limit on the chargino mass of 127 GeV/c{sup 2} and upper limit on the production cross section times branching ratio to leptons of 0.25 pb at 95% confidence level.
Download or read book Search for Associated Chargino Neutralino Production in Proton Antiproton Collisions at 1 96 TeV written by Ulla Blumenschein and published by . This book was released on 2005 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: The search for a fundamental theory of matter and forces in the universe has ever since attracted the interest of physicists. The large success of the gauge theories in the description of low-energy phenomena nourishes the hope that gauge symmetries are the clue to a unified description of all fundamental processes at high energy scales. Particle collision experiments of the past decades have probed the structure of matter with increasing resolution. The phenomena observed in collision experiments at current energy scales are described with a large precision by the Standard Model of particle physics. Nevertheless, many open questions in the Standard Model suggest that it is an effective low-energy theory of a more fundamental theory: the numbers of free parameters of the model, the numbers of generations, the hierarchy between the electroweak scale and the Planck scale, the pending integration of gravity and the evolution of the strengths of the fundamental forces at large energy regimes. In addition, recent cosmological data suggest that the density of ordinary matter which is described by the Standard Model, corresponds only to a small fraction of the matter density in the universe. Many of the above mentioned problems are addressed by an extension of the Standard Model that is based on an additional internal symmetry, the Supersymmetry (SUSY) of fermions and bosons. It predicts the existence of a partner for each known fundamental particle with the same quantum numbers but different spin. Supersymmetry must be broken at the energy regime of present collider experiments which leads to different masses of Standard Model particles and their super-partners. Low-mass supersymmetric partners are expected to be produced at a sufficient rate at present or future collider experiments. In the analysis performed in this thesis, it is assumed that SUSY particles decay into their Standard Model partners and the stable lightest supersymmetric particle, which is only weakly interacting, carrying away energy and momentum and leading to detector signatures with large missing energy. Supersymmetric particles have been searched for at the electron-positron collider LEP up to the kinematic limit. No evidence for these particles has been observed which results in lower limits on their masses. Additional constraints stem from precision measurements of quantities, which are sensitive to corrections from SUSY particles and from the search for dark matter in cosmological experiments. The search for SUSY particles beyond the reach of LEP is continued at larger energy regimes at present and future hadron colliders. In its second phase of data taking (Run II), the center-of-mass energy of the proton-antiproton collider Tevatron at Fermilab has been raised and the luminosity has been increased considerably. The D0 experiment, one of the two Tevatron experiments, has been upgraded accordingly. The Tevatron collider allows to probe a substantial SUSY mass range beyond the LEP limits. The search will be continued at the Large Hadron Collider (LHC) which is presently being constructed at the European Research laboratory for particle physics CERN in Geneva. At hadron colliders the supersymmetric partners of quarks and gluons are copiously produced in strong interactions, provided they are light enough. Within most of the established SUSY models, these particles are too heavy to be produced at a sufficient rate at the Tevatron collider and the production of the lighter super-partners of the Higgs and gauge bosons, the charginos and neutralinos, becomes an important source of SUSY particles. Decays of these particles result in final states with leptons or hadrons and large missing energy. Leptonic final states can be separated more easily from the large background of hadronic Standard Model processes. A search for the associated production of the lightest chargino and the second lightest neutralino has been performed in final states with two electrons, an additional lepton and large missing transverse energy using data collected with the D0 detector from April 2002 to July 2004. The results are interpreted stand-alone and in combination with other leptonic channels in the framework of constraint supersymmetric models.
Download or read book Study of a Like sign Dilepton Search for Chargino neutralino Production at CDF written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We propose a like-sign dilepton search for chargino-neutralino production in p p collisions at ps = 1:8 TeV, which complements the previously published trilepton search by the CDF detector using Fermilab Run I data. Monte Carlo predictions for the signal and background eciencies indicate a signicant increase in sensitivity to chargino-neutralino production compared to the traditional trilepton analysis alone.
Download or read book Supersymmetry Searches at the Collider Detector at Fermilab written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This article presents the current experimental results of searches for Supersymmetry (SUSY) at the Collider Detector at Fermilab (CDF), using over 110 pb−1 of proton-antiproton collision data with (square root)s = 1800 GeV collected during the period 1992-1995. Since no signal was found, limits on the production of supersymmetric particles are derived. The prospects for supersymmetry searches at Run II of the Tevatron, that began in March 2001, are also discussed here.
Download or read book Search for Chargino and Neutralino at Run II of the Tevatron Collider written by Anadi Canepa and published by . This book was released on 2006 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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{sup -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.
Download or read book The Search for Supersymmetry in Hadronic Final States Using Boosted Object Reconstruction written by Giordon Stark and published by Springer Nature. This book was released on 2020-03-13 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis represents one of the most comprehensive and in-depth studies of the use of Lorentz-boosted hadronic final state systems in the search for signals of Supersymmetry conducted to date at the Large Hadron Collider. A thorough assessment is performed of the observables that provide enhanced sensitivity to new physics signals otherwise hidden under an enormous background of top quark pairs produced by Standard Model processes. This is complemented by an ingenious analysis optimization procedure that allowed for extending the reach of this analysis by hundreds of GeV in mass of these hypothetical new particles. Lastly, the combination of both deep, thoughtful physics analysis with the development of high-speed electronics for identifying and selecting these same objects is not only unique, but also revolutionary. The Global Feature Extraction system that the author played a critical role in bringing to fruition represents the first dedicated hardware device for selecting these Lorentz-boosted hadronic systems in real-time using state-of-the-art processing chips and embedded systems.
Download or read book Search for Supersymmetry at the Tevatron Using the Trilepton Signature written by and published by . This book was released on 2008 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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-anti-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 [plus minus] 1.1 background events from standard model processes and 11.4 [plus minus] 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.
Download or read book Search for Super Symmetry at the Tevatron Using the Trilepton Signature written by and published by . This book was released on 2008 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 (square root)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.
Download or read book Search for Chargino neutralino Pair Production with Dzero Detector at the Tevatron written by Zhongmin Wang and published by . This book was released on 2004 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Production of Supersymmetric Particles Charginos and Neutralinos from Electron and Gamma Beam Collisions written by Solomon Alemu Obolu and published by . This book was released on 2009 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electroweak Physics at the Large Hadron Collider with the ATLAS Detector written by Elodie Resseguie and published by Springer. This book was released on 2021-11-05 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis discusses searches for electroweakly produced supersymmetric partners of the gauge and the Higgs bosons (gauginos and higgsinos) decaying to multiple leptons, using pp collisions at sqrt(s) = 13 TeV. The thesis presents an in-depth study of multiple searches, as well as the first 13 TeV cross section measurement for the dominant background in these searches, WZ production. Two searches were performed using 36.1/fb of data: the gaugino search, which makes use of a novel kinematic variable, and the higgsino search, which produced the first higgsino limits at the LHC. A search using 139/fb of data makes use of a new technique developed in this thesis to cross check an excess of data above the background expectation in a search using a Recursive Jigsaw Reconstruction technique. None of the searches showed a significant excess of data, and limits were expanded with respect to previous results. These searches will benefit from the addition of luminosity during HL-LHC; however, the current detector will not be able to withstand the increase in radiation. Electronics for the detector upgrade are tested and irradiated to ensure their performance.
Download or read book Chargino and Neutralino Studies for Future Colliders written by Tianjun Li and published by . This book was released on 2000 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Supersymmetry in Events with Soft Leptons Low Jet Multiplicity and Missing Transverse Energy in Proton u2013 proton Collisions at sqrt s written by and published by . This book was released on 2016 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are presented from a search for supersymmetric particles in scenarios with a compressed mass spectrum. The data sample corresponds to 19.7 inverse femtobarns of proton-proton collisions recorded by the CMS experiment at √s = 8 TeV. The search targets top squark ($ ilde{t}$ pair production in scenarios with mass differences ?m = m($ ilde{t}$ – m($ ilde{i}$10) below the W-boson mass and with top-squark decays in the four-body mode ($ ilde{t}$ → blv$ ilde{i}$10), where the ($ ilde{i}$10) is assumed to be the lightest supersymmetric particle (LSP). The signature includes a high transverse momentum (pT) jet associated with initial-state radiation, one or two low-pT leptons, and significant missing transverse energy. The event yields observed in data are consistent with the expected background contributions from standard model processes. Limits are set on the cross section for top squark pair production as a function of the $ ilde{t}$ and LSP masses. Assuming a 100% branching fraction for the four-body decay mode, top-squark masses below 316 GeV are excluded for ?m = 25 GeV at 95% CL. Furthermore, the dilepton data are also interpreted under the assumption of chargino-neutralino production, with subsequent decays to sleptons or sneutrinos. Assuming a difference between the common $ ilde{i}$1+/$ ilde{i}$2+ mass and the LSP mass of 20 GeV and a ?-enriched decay scenario, masses in the range m( $ ilde{i}$1+)
