Download or read book A Search for Associated Chargino neutralino Production in Proton antiproton Collisions at S square Root written by Martin Charles Griffiths and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Search for the Associated Production of Charginos and Neutralinos in Proton Antiproton Collisions at s written by Olav Michael Kåre Mundal and published by . This book was released on 2009 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Chargino Neutralino Production in p bar p Collisions at sqrt s 1 8 TeV written by and published by . This book was released on 1996 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have searched for the existence of the chargino-neutralino (X$~±\atop{1}$X$~0\atop{2}$) pair production predicted by the Minimal Supersymmetric Standard Model(MSSM).
Download or read book J psi Production in Proton antiproton Collisions at square Root S written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Chargino neutralino Production in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2007 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the results of a search for associated production of the chargino and neutralino supersymmetric particles using up to 1.1 fb−1 of integrated luminosity collected by the CDF II experiment at the Tevatron p{bar p} collider at a center-of-mass energy of 1.96 TeV. The search is conducted by analyzing events with a large transverse momentum imbalance and either three charged leptons or two charged leptons of the same electric charge. The numbers of observed events are found to be consistent with standard model expectations. Upper limits on the production cross section are derived in different theoretical models. In one of these models a lower limit on the mass of the chargino is set at 129 GeV/c2 at the 95% confidence level.
Download or read book Search for the Direct Production of Charginos Neutralinos and Staus in Final States with at Least Two Hadronically Decaying Taus and Missing Transverse Momentum in Pp Collisions at sqrt s written by and published by . This book was released on 2014 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present results of a search for the electroweak associated production of charginos and next-to-lightest neutralinos, pairs of charginos or pairs of tau sleptons. These processes are characterised by final states with at least two hadronically decaying tau leptons, missing transverse momentum and low jet activity. The analysis is based on an integrated luminosity of 20.3 fb−1 of proton-proton collisions at √s = 8TeV recorded with the ATLAS experiment at the Large Hadron Collider. We observed no significant excess with respect to the predictions from Standard Model processes. Limits are set at 95% confidence level on the masses of the lighter chargino and next-to-lightest neutralino for various hypotheses for the lightest neutralino mass in simplified models. In the scenario of direct production of chargino pairs, with each chargino decaying into the lightest neutralino via an intermediate tau slepton, chargino masses up to 345 GeV are excluded for a massless lightest neutralino. For associated production of mass-degenerate charginos and next-tolightest neutralinos, both decaying into the lightest neutralino via an intermediate tau slepton, masses up to 410 GeV are excluded for a massless lightest neutralino.
Download or read book Search for Chargino neutralino Production in P Anti p Collisions at S written by and published by . This book was released on 2007 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the results of a search for associated production of the chargino and neutralino supersymmetric particles using up to 1.1 fb−1 of integrated luminosity collected by the CDF II experiment at the Tevatron p{bar p} collider at a center-of-mass energy of 1.96 TeV. The search is conducted by analyzing events with a large transverse momentum imbalance and either three charged leptons or two charged leptons of the same electric charge. The numbers of observed events are found to be consistent with standard model expectations. Upper limits on the production cross section are derived in different theoretical models. In one of these models a lower limit on the mass of the chargino is set at 129 GeV/c2 at the 95% confidence level.
Download or read book A Measurement of the Tt Production Cross Section in Proton antiproton Collisions at square Root S written by Markus Klute and published by . This book was released on 2004 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Anomalous Kinematics of Top Dilepton Events in Proton antiproton Collisions at square Root S written by Andrew Gennadievich Ivanov and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Search for Disappearing Tracks in Proton proton Collisions at Sqrt s written by Jessica Danielle Brinson and published by . This book was released on 2015 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a search for evidence of new supersymmetric particles in proton-proton collision data collected by the Compact Muon Solenoid at the Large Hadron Collider located in Geneva, Switzerland. The data was collected in 2012 at a center of mass energy of 8 TeV and corresponds to an integrated luminosity of 19.5 inverse femtobarns. The search examines events that produce the experimental signature of a disappearing track. Disappearing tracks are identifed as those with little or no associated calorimeter energy deposits and with several missing hits in the outer layers of the tracker. This search is motived by anomaly-mediated supersymmetry which postulates that a long-lived chargino decaying to a neutralino and pion with low momentum could give rise to a disappearing track. The sources of background in this search arise from leptons which fail to be reconstructed and false trajectories determined by the track reconstruction algorithm. The number of observed events is in agreement with the background expectation, and limits are set on the cross section of direct electroweak chargino production in terms of the chargino mass and mean proper lifetime. At 95 % confidence level, anomaly-mediated supersymmetry breaking models with a chargino mass less than 260 GeV, corresponding to a mean proper lifetime of 0.2 ns, are excluded.
Download or read book Lambda0 and Antilambda0 Production in Proton Antiproton Collisions at Square Root S written by Dennis Keith Wesson and published by . This book was released on 1990 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Pair Production of Supersymmetric Top Quarks in Dilepton Events at the Tevatron written by William Johnson and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We search for pair production of the supersymmetric partner of the top quark, the stop quark, decaying to a b-quark and a chargino with a subsequent decay into a neutralino, lepton, and neutrino. Using 2.7 fb−1 of [square root]s=1.96 TeV proton on antiproton collision data collected by the CDF II experiment, we reconstruct the mass of candidate stop events and fit the observed mass spectrum to a combination of standard model processes and stop signal. No evidence of stop pair production is found, therefore we set 95% C.L. limits on the masses of the stop and the neutralino for several values of the chargino mass and the branching ratio B(X̃±/1[right arrow]X̃01l±v).
Download or read book Search for Chargino and Neutralino Production in Final States with Two Same sign Leptons Jets and Missing Transverse Momentum at Sqrt s written by 勞卓義 and published by . This book was released on 2019 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct Photon Center of mass Angular Distribution in Proton antiproton Collisions at square Root s written by Leslie F. Nakae and published by . This book was released on 1992 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book UA5 written by and published by . This book was released on 1987 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
