A Search for Physics Beyond the Standard Model Using Like-Sign Muon Pairs in Pp Collisions at Sqrt(s) PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download A Search for Physics Beyond the Standard Model Using Like-Sign Muon Pairs in Pp Collisions at Sqrt(s) PDF full book. Access full book title A Search for Physics Beyond the Standard Model Using Like-Sign Muon Pairs in Pp Collisions at Sqrt(s) by Louise Anastasia Skinnari. Download full books in PDF and EPUB format.
Author: Louise Anastasia Skinnari Publisher: ISBN: Category : Languages : en Pages : 424
Book Description
This dissertation presents a search for physics beyond the Standard Model using pairs of muons with equal electric charge. The search is performed in a proton-proton collision data sample collected during 2011 at sqrt(s) = 7 TeV by the ATLAS experiment at the Large Hadron Collider. The total data sample corresponds to an integrated luminosity of 4.7fb-1. Events are selected by requiring pairs of prompt and isolated like-sign muons with transverse momentum greater than 20 GeV. The observed dimuon invariant mass distribution is compared to the Standard Model expectation, searching for any deviation between the observed and predicted yields. No evidence for an excess beyond the Standard Model expectation is observed. The results are interpreted as inclusive cross-section limits on the production of like-sign muon pairs from non-Standard Model sources as function of the dimuon invariant mass. The cross-section limits range between 30 fb and 1.2 fb. The data are also searched for a new narrow resonance which decays to like-sign muon pairs. No evidence for such resonant production is observed and the results are interpreted as upper limits on the mass and production cross section of doubly charged Higgs bosons. Assuming pair-production and a 100% branching ratio to muons, masses below 398 GeV (306 GeV) are excluded assuming coupling to left-handed (right-handed) fermions.
Author: Louise Anastasia Skinnari Publisher: ISBN: Category : Languages : en Pages : 424
Book Description
This dissertation presents a search for physics beyond the Standard Model using pairs of muons with equal electric charge. The search is performed in a proton-proton collision data sample collected during 2011 at sqrt(s) = 7 TeV by the ATLAS experiment at the Large Hadron Collider. The total data sample corresponds to an integrated luminosity of 4.7fb-1. Events are selected by requiring pairs of prompt and isolated like-sign muons with transverse momentum greater than 20 GeV. The observed dimuon invariant mass distribution is compared to the Standard Model expectation, searching for any deviation between the observed and predicted yields. No evidence for an excess beyond the Standard Model expectation is observed. The results are interpreted as inclusive cross-section limits on the production of like-sign muon pairs from non-Standard Model sources as function of the dimuon invariant mass. The cross-section limits range between 30 fb and 1.2 fb. The data are also searched for a new narrow resonance which decays to like-sign muon pairs. No evidence for such resonant production is observed and the results are interpreted as upper limits on the mass and production cross section of doubly charged Higgs bosons. Assuming pair-production and a 100% branching ratio to muons, masses below 398 GeV (306 GeV) are excluded assuming coupling to left-handed (right-handed) fermions.
Author: Publisher: ISBN: Category : Languages : en Pages : 37
Book Description
Our search is presented for physics beyond the standard model in final states with two opposite-sign same-flavor leptons, jets, and missing transverse momentum. The data sample corresponds to an integrated luminosity of 19.4 fb-1 of proton-proton collisions at √s = 8 TeV collected with the CMS detector at the CERN LHC in 2012. The analysis focuses on searches for a kinematic edge in the invariant mass distribution of the oppositesign same-flavor lepton pair and for final states with an on-shell Z boson. Furthermore, the observations are consistent with expectations from standard model processes and are interpreted in terms of upper limits on the production of supersymmetric particles.
Author: Publisher: ISBN: Category : Languages : en Pages : 33
Book Description
A search for physics beyond the standard model in events with at least three leptons and any number of jets is presented. The data sample corresponds to 35 inverse picobarns of integrated luminosity in pp collisions at sqrt(s) = 7 TeV collected by the CMS experiment at the LHC. A number of exclusive multileptonic channels are investigated and standard model backgrounds are suppressed by requiring sufficient missing transverse energy, invariant mass inconsistent with that of the Z boson, or high jet activity. Control samples in data are used to ascertain the robustness of background evaluation techniques and to minimise the reliance on simulation. The observations are consistent with background expectations. These results constrain previously unexplored regions of supersymmetric parameter space.
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
A search is presented for physics beyond the standard model (BSM) in events with a Z boson, jets, and missing transverse energy (MET). This signature is motivated by BSM physics scenarios, including supersymmetry. The study is performed using a sample of proton-proton collision data collected at sqrt(s) = 7 TeV with the CMS experiment at the LHC, corresponding to an integrated luminosity of 4.98 inverse femtobarns. The contributions from the dominant standard model backgrounds are estimated from data using two complementary strategies, the jet-Z balance technique and a method based on modeling MET with data control samples. In the absence of evidence for BSM physics, we set limits on the non-standard-model contributions to event yields in the signal regions and interpret the results in the context of simplified model spectra. Additional information is provided to facilitate tests of other BSM physics models.
Author: Publisher: ISBN: Category : Languages : en Pages : 45
Book Description
A search for new physics is performed based on events with jets and a pair of isolated, same-sign leptons. The results are obtained using a sample of proton-proton collision data collected by the CMS experiment at a centre-of-mass energy of 8 TeV at the LHC, corresponding to an integrated luminosity of 19.5 inverse femtobarns. In order to be sensitive to a wide variety of possible signals beyond the standard model, multiple search regions defined by the missing transverse energy, the hadronic energy, the number of jets and b-quark jets, and the transverse momenta of the leptons in the events are considered. No excess above the standard model background expectation is observed and constraints are set on a number of models for new physics, as well as on the same-sign top-quark pair and quadruple-top-quark production cross sections. As a result, information on event selection efficiencies is also provided, so that the results can be used to confront an even broader class of new physics models.
Author: Tao Han Publisher: World Scientific ISBN: 9814549215 Category : Languages : en Pages : 650
Book Description
These proceedings contain over 100 talks on all aspects of Physics Beyond the Standard Model of the strong and electroweak interactions — ranging from Supersymmetry, Grand Unification, Technicolor, Exotic Particles, and CP Violation to Baryogenesis, Dark Matter, Strings and Black Holes — by leading authorities and the most active researchers in High Energy Physics. The goal of the conference is to provide a completely current summary of the most exciting and aesthetically appealing theoretical ideas, especially with regard to their predictions for yet undiscovered new particles, interactions and consequent phenomena. Particular emphasis is placed on current experimental limits and constraints on new physics, and on expectations and predictions regarding our ability to probe and discriminate between the many possibilities through experiments at present and future colliders in the decade(s) to come.
Author: Robert Wayne Stringer Publisher: ISBN: Category : Gauge fields (Physics) Languages : en Pages : 176
Book Description
Many theoretical models of physics beyond the Standard Model provide a signature of two photons and large missing transverse energy [Special characters omitted.] in the final state. This search was performed using 36 pb[superscript -1] of proton-proton collision data at [Squared root of s] = 7 TeV. The candidate events are determined by comparing the [Special characters omitted.] distribution for events with two photons and at least one hadronic jet with the [Special characters omitted.] T distribution from QCD and electroweak processes that have no true missing transverse energy. 1.2 ± 0.8 background events were expected, with one event observed. This result was interpreted in two theoretical models beyond the Standard Model. The cross section for General Gauge Mediated Supersymmetry Breaking is given an upper limit between 0.3 pb and 1.1 pb. Universal Extra Dimensions has been excluded for all values of 1/ R
Author: Louise Anastasia Skinnari
Author: Louise Anastasia Skinnari
Author: 
Author: 
Author: 
Author: 
Author: Ren-Jie Wang
Author: Tao Han
Author: Albert M. Sirunyan
Author: Marco-Andrea Buchmann
Author: Robert Wayne Stringer