Author: Trisha FarooquePublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Search for Heavy Resonances Decaying to Top Quark Pairs in the Boosted All-Hadronic Decay Channel
Author: Trisha FarooqueSearch for Heavy Resonance Decays Into Top-quark Pairs Using a Lepton-plus-jets Final State in Proton-proton Collisions at √s
Author: Kyle KrowpmanPublisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 0
Book Description
This thesis presents two studies in a search for new heavy resonances with 139 fb-1 of proton-proton collisions delivered by the Large Hadron Collider at √s = 13 TeV as measured by the ATLAS detector. In many Standard Model extensions, the top quark plays an important role in the dynamics of electroweak symmetry breaking, and so the studies presented here focus on heavy resonance searches in the top-antitop decay channel and their combination with searches for heavy resonances decaying into other final states. The first study detailed in this thesis is a search for new heavy resonances in a semileptonically decaying top-antitop final state where no significant excesses of data were observed with respect to the background prediction. That being so, exclusion limits at the 95% confidence level were placed on possible resonant masses for a Z′ in a leptophobic topcolor-assisted technicolor model and for a bulk Randall-Sundrum graviton at 4.2 TeV and 1.0 TeV, respectively. This top-antitop search was combined with searches in orthogonal final states performed by the ATLAS Collaboration from which limit contours were placed at the 95% confidence level in the space of couplings to Standard Model particles for the Heavy Vector Triplet model.
Search for a Heavy Resonance Decaying to a Top Quark and a Vector-like Top Quark at $\sqrt{s}$
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
A search is presented for massive spin-1 Z' resonances decaying to a top quark and a heavy vector-like top quark partner T. The search is based on a 2.6 inverse femtobarns sample of proton-proton collisions at 13 TeV collected with the CMS detector at the LHC. The analysis is optimized for final states in which the T quark decays to a W boson and a bottom quark. The focus is on all-jet final states in which both the W boson and the top quark decay into quarks that evolve into jets. The decay products of the top quark and of the W boson are assumed to be highly Lorentz-boosted and cannot be reconstructed as separate jets, but are instead reconstructed as merged, wide jets. Techniques for the identification of jet substructure and jet flavour are used to distinguish signal from background events. Several models for Z' bosons decaying to T quarks are excluded at 95% confidence level, with upper limits on the cross section ranging from 0.13 to 10 pb, depending on the chosen hypotheses. This is the first search for a neutral spin-1 heavy resonance decaying to a top quark and a vector-like T quark in the all-hadronic final state.
Search for $\mathrm{ T \bar{t} }$ Resonances in Highly-boosted Lepton+jets and Fully Hadronic Final States in Proton-proton Collisions at $ \sqrt{s}
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
A search for the production of heavy resonances decaying into top quark-antiquark pairs is presented. The analysis is performed in the lepton+jets and fully hadronic channels using data collected in proton-proton collisions at $\sqrt{s}$ =13 TeV using the CMS detector at the LHC, corresponding to an integrated luminosity of 2.6 inverse femtobarns. The selection is optimized for massive resonances, where the top quarks have large Lorentz boosts. No evidence for resonant ttbar production is found in the data, and upper limits on the production cross section of heavy resonances are set. The exclusion limits for resonances with masses above 2 TeV are significantly improved compared to those of previous analyses at $\sqrt{s}$ = 8 TeV.
Search for Resonances Decaying Into Top Quark Pairs Using Fully Hadronic Decays in Pp Collisions with ATLAS at Sqrt(s)
Author: Gregor KasieczkaSearch for Resonances Decaying Into Top Quark Pairs Using Fully Hadronic Decays in Pp Collisions with ATLAS at √s _327 7 TeV
Author: Gregor KasieczkaNew Results And Actual Problems In Particle & Astroparticle Physics And Cosmology - Proceedings Of Xxixth International Workshop On High Energy Physics
Author: Roman Anatolievich RyutinPublisher: World Scientific
ISBN: 9814578754
Category : Science
Languages : en
Pages : 234
Book Description
This unique volume contains the materials of the XXIXth International Workshop on High Energy Physics. The content of the volume is much wider than just high-energy physics and actually concerns all the most fundamental areas of modern physics research: high-energy physics proper, gravitation and cosmology. Presentations embrace both theory and experiment.
A Search for Massive Resonances Decaying to Top Quark Pairs and Jet Trigger Performance Studies with the ATLAS Detector at the Large Hadron Collider
Author: Search for Pair-produced Resonances Decaying to Top Quarks and Jets in Proton-proton Collisions at 8 TeV with the CMS Detector at the LHC
Author: Gala Nicolas KaufmanPublisher:
ISBN:
Category :
Languages : en
Pages : 394
Book Description
We present a search for pair production of new physics resonances decaying into a top quark and a light parton in final states with two leptons, interpreting the results in the context of an R-parity violating supersymmetric model. We use 19.5 fb[-]1 of data collected by the CMS experiment at the LHC from proton-proton collisions at s = 8 TeV in 2012. The experimental signature consists of two leptons (e or [MICRO SIGN]), two jets identified as originating from the decay of a b quark, and two jets identified as coming from light flavor quarks or gluons. We reconstruct and analyze potential resonant decays. The dominant standard model background is top quark pair production with additional jets from initialor final-state radiation. We perform an extended unbinned maximum likelihood fit to the transverse momenta of the two leading light jets and the reconstructed resonance mass. The observation is consistent with the standard model expectation, and we set upper limits on the signal cross section for R-parity violating bottom squarks with masses between 250 and 600 GeV. We exclude R-parity violating bottom squark pair production at the 95% confidence level between 250 GeV and 326 GeV.
A Search for New Diboson Resonances in the Boosted Semi-leptonic Final State at √s
Author: Ryne Michael CarbonePublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Models of a neutral, narrow scalar boson (spin-0), charged and neutral vector bosons (spin-1) coupling to the Standard Model gauge bosons, and a neutral Randall-Sundrum bulk graviton (spin-2) are considered. The search significantly improves the limits produced in recent searches.