Download or read book Search for New Physics in a Final State with Same sign Dileptons Jets and Missing Transverse Energy at 7 TeV Center of Mass Energy written by Frank Golf and published by . This book was released on 2012 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on a search for new physics in a final state with two same sign leptons, missing transverse energy, and significant hadronic activity at a center of mass energy sqrt(s) = 7 TeV. The data were collected with the CMS detector at the CERN LHC and correspond to an integrated luminosity of 0.98 inverse femtobarns. Data-driven methods are developed to estimate the dominant Standard Model backgrounds. No evidence for new physics is observed. The dominant background to the analysis comes from failures of lepton identification in Standard Model ttbar events. The ttbar production cross section in the dilepton final state is measured using 3.1 inverse picobarns of data. The cross section is measured to be 194 ± 72 (stat) ± 24 (syst) ± 21 (lumi) pb. An algorithm is developed that uses tracking information to improve the reconstruction of missing transverse energy. The reconstruction of missing transverse energy is commissioned using the first collisions recorded at 0.9, 2.36 and 7 TeV data. Events with abnormally large values of missing transverse energy are identified as arising from anomalous signals in the calorimeters. Tools are developed to identify and remove these anomalous signals.
Download or read book Search for New Physics in a Final State with Same Sign Dileptons Jets and Missing Transverse Energy at 7 TeV Center of Mass Energy written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on a search for new physics in a final state with two same sign leptons, missing transverse energy, and significant hadronic activity at a center of mass energy $\sqrt{s}$ = 7 TeV. The data were collected with the CMS detector at the CERN LHC and correspond to an integrated luminosity of 0.98 $\mathrm{fb}^{-1}$. Data--driven methods are developed to estimate the dominant Standard Model backgrounds. No evidence for new physics is observed. The dominant background to the analysis comes from failures of lepton identification in Standard Model $t\bar{t}$ events. The $t\bar{t}$ production cross section in the dilepton final state is measured using 3.1 $\mathrm{fb}^{-1}$ of data. The cross section is measured to be 194 $\pm$ 72 (stat) $\pm$ 24 (syst) $\pm$ 21 (lumi) pb. An algorithm is developed that uses tracking information to improve the reconstruction of missing transverse energy. The reconstruction of missing transverse energy is commissioned using the first collisio ns recorded at 0.9, 2.36 and 7 TeV data. Events with abnormally large values of missing transverse energy are identified as arising from anomalous signals in the calorimeters. Tools are developed to identify and remove these anomalous signals.
Download or read book A Search for New Physics in Events with Oppositely Charged Dileptons Jets and Missing Transverse Energy in Proton proton Collisions at 7 TeV Center of Mass Energy written by Derek Michael Barge and published by . This book was released on 2014 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search is presented for physics beyond the standard model (BSM) in final states with a pair of opposite-sign isolated leptons accompanied by jets and missing transverse energy. The search uses LHC data recorded at a center-of-mass energy of 7 TeV with the CMS detector, corresponding to an integrated luminosity of approximately 5 inverse femto-barns. The search strategy probes models of dilepton production with heavy, colored objects that decay to final states including invisible particles, leading to very large hadronic activity and missing transverse energy. No evidence for an event yield in excess of the standard model expectations is found. Upper limits on the BSM contributions to the signal regions are deduced from the results, which are used to exclude a region of the parameter space of the constrained minimal supersymmetric extension of the standard model. Additional information related to detector efficiencies and response is provided to allow testing specific models of BSM physics not explicitly considered.
Download or read book A Search for New Physics in Final States With Two Opposite SignSame Flavor Leptons Jets and Missing Transverse Energy InProton Proton Collisions with a Center of Mass Energy of 13 TeV written by Charles Vincent Welke and published by . This book was released on 2016 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search is performed in final states with Z$\rightarrow\ell\ell$, jets, and missing transverse momentum using data collected with the CMS detector at the CERN LHC in 2015 corresponding to an integrated luminosity of 2.3~\fbinv of pp collisions at $\sqrt{s}=13$\TeV. Signal regions are defined to maximize sensitivity to new physics including one to search where ATLAS reported a 3.0~$\sigma$ excess at 8~TeV. The observations in all regions are consistent with the predicted standard model backgrounds, and the results are interpreted in the context of simplified models of supersymmetry.
Download or read book Research Directions For The Decade Snowmass 1990 Proceedings Of The 1990 Summer Study On High Energy Physics written by Berger Edmond L and published by World Scientific. This book was released on 1992-09-16 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the advent of the Superconducting Super Collider and other new technologies, coupled with the development of particle astrophysics and other non-accelerator based physics, research in high energy particle physics in the nineties promises to break into new and exciting frontiers. To chart the directions and opportunities for this new decade, the 1990 Summer Study on High Energy Physics was organized in Snowmass, Colorado. Like previous Snowmass Summer Studies, it plays a key role in shaping research directions and in drawing the particle physics community together.This book of the proceedings examines the full spectrum of important scientific issues and opportunities in high energy particle physics in the decade of the 1990's, including research at existing and anitcipated hadron-hadron, e+e-, and ep colliders; research at fixed-target facilities; the scientific potential of possible new facilities such as B factories; particle astrophysics and non-accelerator based physics; and accelerator and detector initiatives. It also discusses the physics and technical aspects of the initial Superconducting Super Collider experimental program.This volume, therefore, offers a captivating glimpse into the future of high energy physics, and makes essential reading for all physicists interested in assessing the exciting new research opportunities the future technologies would bring.
Download or read book Search for an MSUGRA Signature in the Electron Jets Missing Transverse Energy Final State in p bar p Collisions at Center of mass Energy written by and published by . This book was released on 2001 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for New Physics with a Same sign Dilepton Pair at a Center of mass Energy of 13 TeV at the CMS Detector written by Christopher Alexandre George and published by . This book was released on 2016 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: An inclusive search for new physics is performed with a 13 TeV dataset from the CMS detector (May--November 2015, corresponding to 2.32/fb) using events with at least two leptons with the same electrical charge, missing transverse energy, and significant hadronic activity. No significant excesses are reported above the Standard Model background predictions. Constraints are set on a number of new physics models. As motivation, a thorough pedagogical review of the Standard Model and its shortcomings is presented in the first two chapters.
Download or read book Search for New Physics in All hadronic Events with AlphaT in 8 TeV Data with CMS written by Yossof Eshaq and published by . This book was released on 2015 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: "An inclusive search for supersymmetric processes that produce final states with jets and missing transverse energy is performed in pp collisions at a center-of-mass energy of [the square root of] s = 8 TeV. The data sample corresponds to an integrated luminosity of 19.5 fb−1 collected by the CMS experiment at the LHC. In this search, a dimensionless kinematic variable, [alpha]T, is used to discriminate between events with genuine and misreconstructed missing transverse energy. The search is based on an examination of the number of reconstructed jets per event, the scalar sum of transverse energies of these jets, and the number of these jets identified as originating from bottom quarks. The results are interpreted in two simplified models with direct stop production"--Page v.
Download or read book Search for New Physics with the MT2 Variable in All jets Final States Produced in Pp 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 new physics is performed using events that contain one or more jets, no isolated leptons, and a large transverse momentum imbalance, as measured through the MT2 variable, which is an extension of the transverse mass in events with two invisible particles. The results are based on a sample of proton-proton collisions collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, and that corresponds to an integrated luminosity of 2.3 inverse femtobarns. The observed event yields in the data are consistent with predictions for the standard model backgrounds. The results are interpreted using simplified models of supersymmetry and are expressed in terms of limits on the masses of potential new colored particles. Assuming that the lightest neutralino is stable and has a mass less than about 500 GeV, gluino masses up to 1550-1750 GeV are excluded at 95% confidence level, depending on the gluino decay mechanism. For the scenario of direct production of squark-antisquark pairs, top squarks with masses up to 800 GeV are excluded, assuming a 100% branching fraction for the decay to a top quark and neutralino. Similarly, bottom squark masses are excluded up to 880 GeV, and masses of light-flavor squarks are excluded up to 600-1260 GeV, depending on the degree of degeneracy of the squark masses.
Download or read book Search for New Physics in the Jets Missing ET Topology written by and published by . This book was released on 2006 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although the standard model of particle physics agrees perfectly with experimental data, it is unlikely the final theory describing particles and their interactions. New phenomena has been searched in the jets and missing transverse energy topology. Such phenomena may be due to the pair production of leptoquarks decaying into a quark and a neutrino or the pair production of stops decaying into a charm and a neutralino which is assumed to be the lightest supersymmetric particle. These searches have been performed with the D0 detector at hadronic collider TeVatron with a center of mass energy of 1.96 TeV. This kind of search needs a good understanding of the jet energy calibration. The determination of the relative jet energy scale has allowed them to reduce the systematic uncertainties on the jet energy measurement when comparing the data and the simulation. Moreover a new method has been developed in order to correct simulated jets for the differences observed in the jet energy scale, the jet energy resolution and the jet reconstruction efficiency between the data and the simulation. The data analysis, performed with an integrated luminosity of 310 pb−1, has not observed any excess. This result is interpreted in terms of limit on the mass of the particles: leptoquarks with a mass smaller than 136 GeV and stops with a mass smaller than 131 GeV, for a neutralino mass equal to 46 GeV, are excluded with 95% confidence level.
Download or read book Search for New Phenomena in Jets Plus Missing Transverse Energy Final States at the LHC written by Roger Caminal Armadans and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for New Physics in Events with High Jet Multiplicity and Low Missing Transverse Momentum 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 dedicated search is presented for new phenomena in inclusive eight- and ten-jet final states with low missing transverse momentum, with and without identification of jets originating from b quarks. The analysis is based on data from proton-proton collisions corresponding to an integrated luminosity of 19.6 inverse femtobarns collected with the CMS detector at the LHC at sqrt(s) = 8 TeV. The dominant multijet background expectations are obtained from low jet multiplicity control samples. Data agree well with the standard model background predictions, and limits are set in several benchmark models. Colorons (axigluons) with masses between 0.6 and 0.75 (up to 1.15) TeV are excluded at 95% confidence level. Similar exclusion limits for gluinos in R-parity violating supersymmetric scenarios are from 0.6 up to 1.1TeV. These results comprise the first experimental probe of the coloron and axigluon models in multijet final states.
Download or read book Electroweak Interactions and Unified Theories written by J. Thanh Van Tran and published by Atlantica Séguier Frontières. This book was released on 1988 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Final States with Two Leptons and Missing Transverse Energy in P Anti p Collisions with a Center of mass Energy of 1 96 TeV written by Marc Hohlfeld and published by . This book was released on 2004 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for New Physics in Final States with Low Transverse Energy Photon and Missing Transverse Energy in Proton proton Collisions at sqrt s written by and published by . This book was released on 2015 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for new physics in the [gamma]+ET nal state is performed using pp collision data corresponding to an integrated luminosity of 7.3 fb-1 collected at √s = 8 TeV using low threshold triggers in a phase space region de ned by ET > 45 GeV and ET > 40 GeV.
Download or read book Search for New Physics in Events with Same sign Dileptons and b Jets in pp Collisions at sqrt s written by and published by . This book was released on 2012 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for New Phenomena in Final States with an Energetic Jet and Large Missing Transverse Momentum in Pp Collisions at sqrt s mathrm written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb-1 of \(\sqrt{s{\mathrm{}}} = 8\) TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT>120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between EmissT>150 GeV and EmissT>700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. Limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presented.
