Download or read book Search for Supersymmetry in Events with at Least One Photon and Missing Transverse Momentum in Proton proton Collisions at a Center of mass Energy of 13 TeV at the CMS Experiment written by Johannes Schulz and published by . This book was released on 2018* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Supersymmetry in Events with at Least One Photon Missing Transverse Momentum and Large Transverse Event Activity in Proton proton Collisions at 13TeV with the CMS Detector in 2016 written by Maximilian Knut Kiesel and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 the Monophoton Final State at CMS at a Center of Mass Energy of 13 TeV written by De-Lin Xiong and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mission of the CMS experiment at the LHC is to investigate and discover unknown physics in proton-proton collision events. This thesis presents a search for new physics in final states containing a photon and missing transverse momentum in proton-proton collisions at $\\\\sqrt{s}$ = 13 TeV, using the data collected in Run II (2016, 2017 and 2018) by the CMS experiment at the LHC, corresponding to an integrated luminosity of 137 $\\\\text{fb}^{-1}$. The standard model (SM) background in monophoton events can be a problem for sensitivity to new physics. The sensitivity to new physics scenarios can potentially be enhanced by other event properties. A new strategy that can potentially enhance the new physics sensitivity is the track multiplicity from the small mass splitting supersymmetry (SUSY). SUSY with small mass splittings indicates the masses difference between the SUSY particles is small ($\\\\tilde{q}, squark \\\\approx \\\\tilde{\\\\chi}$, dark matter particle). The track multiplicity in monophoton dataset with different bins of track $p_T$ will be studied, and compared with expectation.
Download or read book Search for Supersymmetry with a Photon a Lepton and Missing Transverse Momentum in Pp Collisions at sqrt s written by and published by . This book was released on 2016 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our search for supersymmetry involving events with at least one photon, one electron or muon, and large missing transverse momentum has been performed by the CMS experiment. The data sample corresponds to an integrated luminosity of 19.7 fb-1 of pp collisions at √ s = 8 TeV, produced at the CERN LHC. No excess of events is observed beyond expectations from standard model processes. The result of the search is interpreted in the context of a general model of gauge-mediated supersymmetry breaking, where the charged and neutral winos are the next-to-lightest supersymmetric particles. Within this model, winos with a mass up to 360 GeV are excluded at the 95% confidence level. Also, two simplified models inspired by gauge-mediated supersymmetry breaking are also examined, and used to derive upper limits on the production cross sections of specific supersymmetric processes.
Download or read book Search for Supersymmetry in Events with Photons and Missing Transverse Energy in Pp Collisions at 13 TeV written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of a search for new physics in final states with photons and missing transverse energy are reported. The study is based on a sample of proton-proton collisions collected at a center-of-mass energy of 13 TeV with the CMS detector in 2015, corresponding to an integrated luminosity of 2.3 inverse femtobarns. Final states with two photons and significant missing transverse energy are used to search for supersymmetric particles in models of supersymmetry (SUSY) with general gauge-mediated (GGM) supersymmetry breaking. No excess is observed with respect to the standard model expectation, and the results are used to set limits on gluino pair production and squark pair production in the GGM SUSY framework. Gluino masses below 1.65 TeV and squark masses below 1.37 TeV are excluded at a 95% confidence level.
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 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 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 Search for Supersymmetry in Pp Collisions at sqrt s written by and published by . This book was released on 2016 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are reported from a search for supersymmetric particles in proton-proton collisions in the final state with a single, high transverse momentum lepton; multiple jets, including at least one b-tagged jet; and large missing transverse momentum. The data sample corresponds to an integrated luminosity of 2.3 fb–1 at √s = 13 TeV, recorded by the CMS experiment at the LHC. The search focuses on processes leading to high jet multiplicities, such as gluino pair production with g̃/sup → tt¯X̃/supsup01. The quantity MJ, defined as the sum of the masses of the large-radius jets in the event, is used in conjunction with other kinematic variables to provide discrimination between signal and background and as a key part of the background estimation method. The observed event yields in the signal regions in data are consistent with those expected for standard model backgrounds, estimated from control regions in data. Exclusion limits are obtained for a simplified model corresponding to gluino pair production with three-body decays into top quarks and neutralinos. Gluinos with a mass below 1600 GeV are excluded at a 95% confidence level for scenarios with low Xsup̃/supsup01 mass, and neutralinos with a mass below 800 GeV are excluded for a gluino mass of about 1300 GeV. Lastly, for models with two-body gluino decays producing on-shell top squarks, the excluded region is only weakly sensitive to the top squark mass.
Download or read book Search for Supersymmetry with Photons in Pp 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: Two searches for physics beyond the standard model in events containing photons are presented. Our data sample used corresponds to an integrated luminosity of 19.7 fb-1 of proton-proton collisions at √s=8 TeV, collected with the CMS experiment at the CERN LHC. The analyses pursue different inclusive search strategies. One analysis requires at least one photon, at least two jets, and a large amount of transverse momentum imbalance, while the other selects events with at least two photons and at least one jet, and uses the razor variables to search for signal events. The background expected from standard model processes is evaluated mainly from data. These results are interpreted in the context of general gauge-mediated supersymmetry, with the next-to-lightest supersymmetric particle either a bino- or wino-like neutralino, and within simplified model scenarios. Upper limits at the 95% confidence level are obtained for cross sections as functions of the masses of the intermediate supersymmetric particles.
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+)
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 A Search for Supersymmetry in Events with a Z Boson Jets and Missing Transverse Energy in Pp Collisions with Sqrt s written by Tova Ray Holmes and published by . This book was released on 2016 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for new phenomena in final states containing a Z boson decaying to electrons or muons, jets, and large missing transverse momentum is presented. This search uses proton--proton collision data collected during 2015 and 2016 at a center of mass energy sqrt(s)=13 TeV by the ATLAS detector at the Large Hadron Collider, which correspond to an integrated luminosity of 14.7 fb-1. The search targets the pair production of supersymmetric particles, squarks or gluinos, which decay via jets and a Z boson to the lightest Supersymmetric particle, which does not interact with the ATLAS detector. Results are interpreted in simplified models of gluino-pair (squark-pair) production, and provide sensitivity to gluinos (squarks) with masses as large as 1.3 (1.0) TeV.
Download or read book Search for Stealth Supersymmetry in Events with Jets Either Photons Or Leptons and Low Missing Transverse Momentum in Pp Collisions at 8 TeV written by and published by . This book was released on 2015 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of a search for new physics in final states with jets, either photons or leptons, and low missing transverse momentum are reported. The study is based on a sample of proton-proton collisions collected at a center-of-mass energy View the MathML source with the CMS detector in 2012. The integrated luminosity of the sample is 19.7 fb-1. Many models of new physics predict the production of events with jets, electroweak gauge bosons, and little or no missing transverse momentum. Examples include stealth models of supersymmetry (SUSY), which predict a hidden sector at the electroweak energy scale in which SUSY is approximately conserved. Furthermore, the data are used to search for stealth SUSY signatures in final states with either two photons or an oppositely charged electron and muon. No excess is observed with respect to the standard model expectation, and the results are used to set limits on squark pair production in the stealth SUSY framework.
Download or read book Search for Supersymmetry in the Multijet and Missing Transverse Momentum Final State in Pp Collisions at 13 TeV 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 new physics is performed based on all-hadronic events with large missing transverse momentum produced in proton-proton collisions at sqrt(s)=13 TeV. The data sample, corresponding to an integrated luminosity of 2.3 inverse femtobarns, was collected with the CMS detector at the CERN LHC in 2015. The data are examined in search regions of jet multiplicity, tagged bottom quark jet multiplicity, missing transverse momentum, and the scalar sum of jet transverse momenta. The observed numbers of events in all search regions are found to be consistent with the expectations from standard model processes. Exclusion limits are presented for simplified supersymmetric models of gluino pair production. Depending on the assumed gluino decay mechanism, and for a massless, weakly interacting, lightest neutralino, lower limits on the gluino mass from 1440 to 1600 GeV are obtained, significantly extending previous limits.
Download or read book Search for Supersymmetry in Events with B Jets and Missing Transverse Momentum at the LHC written by and published by . This book was released on 2011 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for supersymmetry is presented using a sample of events with b jets and missing transverse momentum. The search uses a data sample of proton-proton collisions at a centre-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 35 inverse picobarns, collected with the CMS detector. A total of 0.33 +0.43 -0.33 (stat.) +/- 0.13 (syst.) events is predicted, using control samples in the data, to arise from standard model processes, and one event is observed in the data. Upper limits are set at the 95% confidence level on the cross sections of benchmark supersymmetric models.
