Download or read book Search for Supersymmetry Using Multileptonic Signatures in Proton Proton Collisions with the CMS Detector at the LHC written by Daniel Cedric Tröndle and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Supersymmetry in Proton proton Collisions at 7 TeV in Events with a Single Lepton B tagged Jets and Missing Transverse Momentum at the LHC Using Data Collected from the CMS Detector written by Wing Howard To and published by . This book was released on 2013 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes a search for supersymmetry (SUSY) at the Large Hadron Collider using data collected in Run 2011 at center of mass energy of 7 TeV by the Compact Muon Solenoid detector with an integrated luminosity of 4.98 $fb{-1}$. First, the Large Hadron Collider is briefly described along with the Compact Muon Solenoid detector. Second, the Standard Model of particle physics is described which leads to the motivations for supersymmetry and its description. Finally, a search for supersymmetry in events with a single lepton, 2 b-tagged jets and missing transverse energy is documented in detail. The results are used to predict the yields from the standard model in bins missing transverse energy (\met) and total transverse hadronic energy (HT). Limits are set using these results using a minimal supergravity SUSY model and simplified model spectra SUSY model.
Download or read book Search for Supersymmetry in Hadronic Final States written by Hannsjörg Artur Weber and published by Springer. This book was released on 2015-06-11 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: The project reported here was a search for new super symmetric particles in proton-proton collisions at the LHC. It has produced some of the world’s best exclusion limits on such new particles. Furthermore, dedicated simulation studies and data analyses have also yielded essential input to the upgrade activities of the CMS collaboration, both for the Phase-1 pixel detector upgrade and for the R&D studies in pursuit of a Phase-2 end cap calorimeter upgrade.
Download or read book Search for Supersymmetry in Pp Collisions with All hadronic Final States Using the alpha T Variable with the CMS Detector at the LHC written by Bryn Lugh Shorney Mathias and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Supersymmetry in Hadronic Final States written by Hannsjörg Artur Weber and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The project reported here was a search for new supersymmetric particles in proton-proton collisions at the LHC. It has produced some of the world's best exclusion limits on such new particles. Furthermore, dedicated simulation studies and data analyses have also yielded essential input to the upgrade activities of the CMS collaboration, both for the Phase-1 pixel detector upgrade and for the R&D studies in pursuit of a Phase-2 endcap calorimeter upgrade.
Download or read book Search for Supersymmetry in Pp Collisions with All hadronic Final States Using the T Variable with the CMS Detector at the LHC written by Bryn Lugh Shorney Mathias and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Supersymmetry in Proton proton Collisions at a Center of mass Energy of 13 Tev with a Customized Top Quark Tagger in the All hadronic Final State written by Hua Wei and published by . This book was released on 2017 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a search for direct and gluino-mediated production of supersymmetric scalar top-quark pairs in the all-hadronic final state using top tagging. The result of search is based on a 13 TeV proton-proton sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 36 fb-1. The results of the search are interpreted in several Simplified Models (SMS).
Download or read book Search for Supersymmetry in pp Collisions at s 8 TeV with a Photon Lepton and Missing Transverse Energy written by Yutaro Iiyama and published by Springer. This book was released on 2017-06-14 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Ph.D. thesis is a search for physics beyond the standard model (SM) of particle physics, which successfully describes the interactions and properties of all known elementary particles. However, no particle exists in the SM that can account for the dark matter, which makes up about one quarter of the energy-mass content of the universe. Understanding the nature of dark matter is one goal of the CERN Large Hadron Collider (LHC). The extension of the SM with supersymmetry (SUSY) is considered a promising possibilities to explain dark matter. The nominated thesis describes a search for SUSY using data collected by the CMS experiment at the LHC. It utilizes a final state consisting of a photon, a lepton, and a large momentum imbalance probing a class of SUSY models that has not yet been studied extensively. The thesis stands out not only due to its content that is explained with clarity but also because the author performed more or less all aspects of the thesis analysis by himself, from data skimming to limit calculations, which is extremely rare, especially nowadays in the large LHC collaborations.
Download or read book Supersymmetry Search in Multilepton Final States with Taus Using the CMS Detector at the LHC written by Sho Maruyama and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents a search for SUperSYmmetry (SUSY) in multilepton final states with a data set corresponding to 34.9 pb−1 collected in 2010 with the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) running at a center-of-mass energy of 7 TeV. The analysis channels contain combinations of at least three leptons: electrons, muons, and hadronically decaying taus that are reconstructed using a particle-flow technique. The minimal SUperGRAvity (mSUGRA) model and co-Next-to-the-Lightest-SUSY-Particle (co-NLSP) scenario in the Gauge-Mediated SUSY Breaking (GMSB) model are considered. To identify SUSY signal events, signal and Standard Model (SM) background processes are studied with full detector simulation and systematics uncertainties are evaluated. Relevant SM backgrounds include Z boson + jets, diboson, tt, and QCD processes. The separation between the signal and background is performed using a cut-based selection. Good agreement between simulated samples and data is obtained, in particular for the significant Z boson + jets background. With the chosen event selection, we observe three events in data, consistent with the SM predic- tion within statistical fluctuations. Therefore, we set exclusion limits on both models using Bayesian statistics. For the SUSY parameters of m0 = 60 GeV, A0 = 0, tan[beta] = 3, and [mu]> 0, chargino masses below 163 GeV are excluded in the mSUGRA model. In GMSB, gluino masses up to 1040 GeV are excluded in co-NLSP scenario.
Download or read book Search for Supersymmetry in the All hadronic Final State Using Top Quark Tagging in Pp Collisions at Sqrt s written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search is presented for supersymmetry in all-hadronic events with missing transverse momentum based on tagging of top quarks. The data sample corresponds to an integrated luminosity of 2.3 inverse femtobarns of proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the CMS detector at the LHC. Search regions are defined using the properties of reconstructed jets, the presence of bottom and top quark candidates, and an imbalance in transverse momentum. With no statistically significant excess of events observed beyond the expected contributions from the standard model, we set exclusion limits at 95% confidence level on the masses of new particles in the context of simplified models of direct and gluino-mediated top squark production. For direct top squark production with decays to a top quark and a neutralino, top squark masses up to 740 GeV and neutralino masses up to 240 GeV are excluded. Gluino masses up to 1550 GeV and neutralino masses up to 900 GeV are excluded for models of gluino pair production where each gluino decays to a top-antitop quark pair and a neutralino.
Download or read book Search for Supersymmetry in P p Collisions at s written by Kin Ho Lo and published by . This book was released on 2018 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The thesis describes a search for new physics in form of supersymmetry in hadronic final states and missing transverse energy (ET) using a dataset of 35.9 fb−1 collected during the 2016 proton-proton runs by the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC). The search uses robust kinematic variables to suppress backgrounds while maintaining good acceptance to a broad range of signal models and employs data-driven techniques to accurately determine backgrounds and systematic uncertainties. No evidence for Beyond Standard Model (BSM) physics is observed and simplified models are used to interpret the results. For gluino mediated models, the gluino mass up to 1850 GeV and the lightest symmetric particle (LSP) up to 1100 GeV are excluded. For light squark mediated models, the light squark mass up to 1350 GeV (700 GeV) and the LSP up to 650 GeV (400 GeV), assuming no degeneracy in the light squark masses (a degeneracy in light squark masses). For sbottom mediated models, the sbottom mass is excluded to 1075 GeV and the LSP mass up to 550 GeV. For stop mediated models, the stop mass is excluded up to 1075 GeV with the LSP mass up to 400 GeV."--Page x.
Download or read book Search for Supersymmetry in the Vector boson Fusion Topology in Proton proton Collisions at Sqrt s written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Our first search for supersymmetry in the vector-boson fusion topology is presented. The search targets final states with at least two leptons, large missing transverse momentum, and two jets with a large separation in rapidity. The data sample corresponds to an integrated luminosity of 19.7 fb-1 of proton-proton collisions at [arrow]" = 8 TeV collected with the CMS detector at the CERN LHC. The observed dijet invariant mass spectrum is found to be consistent with the expected standard model prediction. Upper limits are set on the cross sections for chargino and neutralino production with two associated jets, assuming the supersymmetric partner of the [tau] lepton to be the lightest slepton and the lightest slepton to be lighter than the charginos. For a compressed-mass-spectrum scenario in which the mass difference between the lightest supersymmetric particle X~01 and the next lightest, mass-degenerate, gaugino particles X~02 and X~"1 is 50 GeV, a mass lower limit of 170 GeV is set for these latter two particles.
Download or read book Search for Supersymmetry in the One Lepton Channel at the LHC written by Arun Preston Luthra and published by . This book was released on 2013 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for supersymmetry was performed in events with one electron or muon, jets, and missing transverse momentum. The dataset was the first 5.0 fb [superscript -1] of [Square root of s] = 7 TeV proton-proton events from the Large Hadron Collider, as measured by the CMS detector in 2011. A data-driven method was used to estimate the background at high values of the transverse mass, where the suppression of the Standard Model backgrounds allows for relatively loose cuts on the jet activity. No excess above the expected background was observed, so a limit was set in the m0- m[subscript 1/2] plane of the CMSSM at tan [Beta] = 10, A0 = 0, and sgn(mu) = +1.
Download or read book Search for Supersymmetry in the Jets Met TAUS Final State Using the CMS Detector at the LHC written by Roy Joaquin Montalvo and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation results are presented from a search for the pair production of heavy colored particles (gluinos, squarks) in R-parity conserving supersymmetric models, in which the lightest supersymmetric particle is a stable and neutral object. The search was performed for events with at least two tau leptons, two highly energetic jets and large missing transverse momentum in the final state on a data sample of proton-proton collisions at sqrt(s) = 7 TeV. The data sample was collected by the Compact Muon Solenoid detector at the Large Hadron Collider in 2011, and it corresponds to an integrated luminosity of 5fb -1. The tau isolation variable was optimized for this search. The number of events corresponding to standard model processes in the final selection was estimated to be 7.49 plus - minus 0.74 using background estimation techniques based on data. Nine observed events are found to be in agreement with the standard model prediction, and exclusion limits on gluino mass are obtained in the context of supersymmetric models at the 95% confidence level. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/149247
Download or read book A Search for Supersymmetry in Events with Jets and Missing Momentum Using Data Collected by the CMS Detector at 13 TeV written by Sam Daniel Mullin and published by . This book was released on 2016 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: As successful as the Standard Model of particle physics has been it still has several major shortcomings which range from unanswered theoretical questions to a lack of any explanation for observed phenomena such as dark matter. One proposed theory for physics beyond the Standard Model which provides solutions for some of these issues is supersymmetry. This dissertation presents a search for supersymmetry using 2.3 fb -1 of proton-proton collision data. This data was collected at a center-of-mass energy of 13 TeV by the CMS detector at the LHC during 2015. This search focuses on top squark pair production where the produced stops both decay to an all hadronic final state. These decays are characterized by multiple jets and missing transverse momentum. A baseline search region is defined to be sensitive to signal processes which occur at rates many orders of magnitude lower than Standard Model processes. The sensitivity to various signal models is improved by dividing this baseline region into distinct categories. Events with an unreconstructed lepton from leptonic W boson decays constitute the primary background. There are also significant contributions from events where a Z boson decays invisibly to neutrinos especially in bins with higher missing transverse momentum. Events with multijet production where one jet has been severely mis-measured as well as those with a pair of top quarks and an invisibly decaying Z boson also have a small presence in the search region. The contributions from these processes to the search region is estimated using data control regions. No statistically significant deviations from the predicted background yields are observed. The results are interpreted in terms of exclusion limits using the Simplified Model Spectrum framework. Stop and neutralino masses are probed up to 780 GeV and 260 GeV respectively.
Download or read book Search for Supersymmetry in Events with One Lepton and Multiple Jets in Proton proton Collisions at Sqrt s written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for supersymmetry is performed in events with a single electron or muon in proton-proton collisions at a center-of-mass energy of 13 TeV. The data were recorded by the CMS experiment at the LHC and correspond to an integrated luminosity of 2.3 inverse femtobarns. Several exclusive search regions are defined based on the number of jets and b-tagged jets, the scalar sum of the jet transverse momenta, and the scalar sum of the missing transverse momentum and the transverse momentum of the lepton. The observed event yields in data are consistent with the expected backgrounds from standard model processes. The results are interpreted using two simplified models of supersymmetric particle spectra, both of which describe gluino pair production. In the first model, each gluino decays via a three-body process to top quarks and a neutralino, which is associated with the observed missing transverse momentum in the event. Gluinos with masses up to 1.6 TeV are excluded for neutralino masses below 600 GeV. In the second model, each gluino decays via a three-body process to two light quarks and a chargino, which subsequently decays to a W boson and a neutralino. The mass of the chargino is taken to be midway between the gluino and neutralino masses. In this model, gluinos with masses below 1.4 TeV are excluded for neutralino masses below 700 GeV.
Download or read book Search for Supersymmetry in Pp Collisions at Sqrt s written by and published by . This book was released on 2011 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are reported from a search for physics beyond the standard model in proton-proton collisions at a center-of-mass energy of 7 TeV, focusing on the signature with a single, isolated, high-transverse-momentum lepton (electron or muon), energetic jets, and large missing transverse momentum. The data sample comprises an integrated luminosity of 36 inverse picobarns, recorded by the CMS experiment at the LHC. The search is motivated by models of new physics, including supersymmetry. The observed event yields are consistent with standard model backgrounds predicted using control samples obtained from the data. The characteristics of the event sample are consistent with those expected for the production of t t-bar and W +jets events. The results are interpreted in terms of limits on the parameter space for the constrained minimal supersymmetric extension of the standard model.
