Download or read book Search for Charged Higgs Bosons Produced in Association with a Top Quark and Decaying Via H 2 tau nu Using Pp Collision Data Recorded at mml written by and published by . This book was released on 2016 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper, charged Higgs bosons produced in association with a single top quark and decaying via H±→[tau][nu] are searched for with the ATLAS experiment at the LHC, using proton-proton collision data at √s=13 TeV corresponding to an integrated luminosity of 3.2 fb-1. The final state is characterised by the presence of a hadronic [tau] decay and missing transverse momentum, as well as a hadronically decaying top quark, resulting in the absence of high-transverse-momentum electrons and muons. The data are found to be consistent with the expected background from Standard Model processes. A statistical analysis leads to 95% confidence-level upper limits on the production cross section times branching fraction, [sigma](pp→[b]tH±)×BR(H±→[tau][nu]) , between 1.9 pb and 15 fb, for charged Higgs boson masses ranging from 200 to 2000 GeV. Finally, the exclusion limits for this search surpass those obtained with the proton-proton collision data recorded at √s=8 TeV.
Download or read book Search for Charged Higgs Bosons Produced in Association with a Top Quark and Decaying Via H u2192 Using Pp Collision Data Recorded at written by and published by . This book was released on 2016 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper, charged Higgs bosons produced in association with a single top quark and decaying via H±→?? are searched for with the ATLAS experiment at the LHC, using proton–proton collision data at √s=13 TeV corresponding to an integrated luminosity of 3.2 fb-1. The final state is characterised by the presence of a hadronic ? decay and missing transverse momentum, as well as a hadronically decaying top quark, resulting in the absence of high-transverse-momentum electrons and muons. The data are found to be consistent with the expected background from Standard Model processes. A statistical analysis leads to 95% confidence-level upper limits on the production cross section times branching fraction, ?(pp→[b]tH±)×BR(H±→??) , between 1.9 pb and 15 fb, for charged Higgs boson masses ranging from 200 to 2000 GeV. Finally, the exclusion limits for this search surpass those obtained with the proton–proton collision data recorded at √s=8 TeV.
Download or read book Search for Charged Higgs Bosons Decaying Via H in Fully Hadronic Final States with the ATLAS Detector at the LHC written by Anna Kopp and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Zusammenfassung: Searches for charged Higgs bosons decaying to a tau lepton and a neutrino in fully hadronic final states are presented in this thesis. The analyses are based on 4.6fb^-1 and 19.5fb^-1 of proton-proton collision data taken with the ATLAS detector at the LHC at center-of-mass energies of 7TeV and 8TeV in 2011 and 2012, respectively.Charged Higgs bosons with masses less than the top quark mass are searched for in events consistent with top-quark pair production and charged Higgs bosons with masses greater than the top quark mass are searched for in associated production with a top quark.In the search based on data taken in 2011, all background contributions are estimated in data-driven ways. Only a minor background contribution is estimated using simulation in the searches based on data taken in 2012; all dominant background contributions are estimated using data-driven methods here as well. An embedding method is used in all searches to assess the dominant and irreducible background contributions containing true hadronically decaying tau leptons and described in detail in this thesis.No significant excess of the data compared to the background expectations due to Standard Model processes is observed. Statistical analyses lead to 95% confidence-level upper limits on the branching ratios B(t->bH^±)xB(H^±->tau^± nu) between 0.23% and 1.3% for charged Higgs boson masses between 80GeV and 160GeV and on the production cross section times branching ratio, sigma(pp->tH^±+X)xB(H^±->tau^± nu) ranging from 0.76pb to 4.5fb for charged Higgs boson masses between 180GeV and 1000GeV. The branching ratio and cross section limits are used to derive constraints on the parameter space of minimal supersymmetric extensions of the Standard Model in various benchmark scenarios. These limits are the so far strictest limits set by the ATLAS collaboration in the search for charged Higgs bosons in fully hadronic final states
Download or read book Search for Charged Higgs Bosons in the tau lepton Final State with 36 1 Fb 1 of Pp Collision Data Recorded at square Root s written by Blake Burghgrave and published by . This book was released on 2018 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes a search for charged Higgs bosons decaying to a tau and a neutrino (H+ [right arrow] [tau]+[nu][sub t] or the charge-conjugate process) in association with a leptonically decaying top quark, using 36.1 fb−1 of pp collision data collected with [square root]s = 13 TeV by the ATLAS detector. The theoretical motivation, including a review of the Standard Model, is given, along with a description of the ATLAS detector and particle reconstruction. A multi-variate analysis approach uses stochastic gradient boosted decision trees to improve the separation between H^[+/-] signal and background. The semi-leptonic channel described in this thesis is used in combination with a fully hadronic channel to search for charged Higgs bosons in a mass range of 90 GeV [less than or equal to] m[sub H^[+/-]] [less than or equal to] 2000 GeV. Finding no significant excess, limits are set at the 95% confidence level on the charged Higgs production cross section times the branching fraction into [tau][nu] ranging from 4.2 pb to 2.5 fb. These limits are interpreted in the hMSSM benchmark scenario as an exclusion at 95% confidence on tan[beta] as a function of m[sub H^[+/-]]. In this scenario, for tan[beta] = 60, the H^[+/-] mass range up to 1100 GeV is excluded, with all values of tan[beta] exclude for m[sub H^[+/-]] [precedes or equivalent to] 160 GeV.
Download or read book Search for Charged Higgs Bosons in Decays of Top Quarks in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2009 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on the first direct search for charged Higgs bosons in decays of top quarks in p{bar p} collisions at √s = 1.96 TeV. The search uses a data sample corresponding to an integrated luminosity of 2.2 fb−1 collected by the CDF II detector at Fermilab, and looks for a resonance in the invariant mass distribution of two jets in the lepton+jets sample of t{bar t} candidates. We observe no evidence of charged Higgs bosons in top quark decays. Hence, 95% upper limits on the top quark decay branching ratio are placed at [Beta](t → H+b)
Download or read book Search for Charged Higgs Bosons in Decays of Top Quarks in Proton Antiproton Collisions at S 1 2 written by and published by . This book was released on 2009 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation we report on the first direct search for charged Higgs bosons in decays of top quarks in p{bar p} collisions at √s = 1.96 TeV. The search uses a data sample with an integrated luminosity of 2.2 fb−1 collected by the CDF II detector at Fermilab and looks for a resonance in the invariant mass distribution of two jets in the lepton+jets sample of t{bar t} candidates. We observe no evidence of charged Higgs bosons in top quark decays; hence 95% C.L. upper limits on the branching ratio are placed at [Beta](t → H+b)
Download or read book Search for Charged Higgs Bosons in Decays of Top Quarks in Proton Antiproton Collisions at u221A s written by and published by . This book was released on 2009 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation we report on the first direct search for charged Higgs bosons in decays of top quarks in p$ar{p}$ collisions at √s = 1.96 TeV. The search uses a data sample with an integrated luminosity of 2.2 fb-1 collected by the CDF II detector at Fermilab and looks for a resonance in the invariant mass distribution of two jets in the lepton+jets sample of t$ar{t}$ candidates. We observe no evidence of charged Higgs bosons in top quark decays; hence 95% C.L. upper limits on the branching ratio are placed at ?(t → H+b) 0.1 to 0.3 for charged Higgs boson masses of 60 to 150 GeV/csup2/sup assuming ?(Hsup+/sup → c$ar{s}$) = 1.0 and ?(t → Wb)+?(t → Hsup+/supb) = 1.0. The upper limits on ?(t → Hsup+
Download or read book A Search for Charged Higgs Boson Decays of the Top Quark Using Hadronic Decays of the Tau Lepton in Proton antiproton Collisions at Square Root S written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Standard Model predicts the existence of one neutral scalar Higgs boson, which is a remnant of the mechanism that breaks the SU(2)[sub L]xU(1)[sub Y] electroweak symmetry and generates masses for the heavy vector bosons and fermions. Many extensions to the Standard Model predict two or more Higgs doublets, resulting in a larger spectrum of Higgs bosons including a charged Higgs boson (H[sup [+-]]). For a light charged Higgs boson mass, the top decay into a charged Higgs boson and bottom quark might occur. This thesis presents results of a direct search for this top quark decay mode via the charged Higgs decay to a tau lepton and tau-neutrino, using the hadronic decays of the tau leptons. The search data consist of 100 pb[sup -1] of Run 1 data collected between 1992-1995 at the CDF detector, from p[anti p] collisions at a center-of-mass energy of 1.8 TeV produced at Fermilab's Tevatron accelerator. A total of seven events are observed in two search channels with an expected background contribution of 7.4[+-]2.0 events coming from fake taus (5.4[+-]1.5), heavy vector boson decays with jets (1.9[+-]1.3) and dibosons(0.08[+-]0.06). Lacking evidence for a signal, we set limits on charged Higgs production at the 95% confidence level in the charged Higgs mass plane versus tan[beta](a parameter of the theory) for a top quark mass of 175 GeV/c[sup 2] and for top production cross sections ([sigma][sub t[anti t]]) of 5.0 and 7.5 pb, assuming the Type-II Two-Higgs-Doublet-Model. For large tan[beta], this analysis excludes a charged Higgs boson of mass below 147(158)GeV/c[sup 2] for [sigma][sub t[anti t]]=5.0(7.5)pb. Using the Standard Model measured top quark cross section from CDF, this limit increases to 168 GeV/c[sup 2] and we also exclude a branching fraction of top decays via this charged Higgs mode of greater than 43% for charged Higgs masses below 168 GeV/c[sup 2].
Download or read book Search for Higgs Bosons Decaying to Aa in the mu mu tau tau Final State in Pp Collisions at arrow written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for the decay to a pair of new particles of either the 125 GeV Higgs boson (h) or a second charge parity (CP)-even Higgs boson (H) is presented. The data set corresponds to an integrated luminosity of 20.3 fb-1 of pp collisions at [arrow]" = 8 TeV recorded by the ATLAS experiment at the LHC in 2012. The search was done in the context of the next-to-minimal supersymmetric standard model, in which the new particles are the lightest neutral pseudoscalar Higgs bosons (a). One of the two a bosons is required to decay to two muons while the other is required to decay to two [tau] leptons. No significant excess is observed above the expected backgrounds in the dimuon invariant mass range from 3.7 to 50 GeV. Upper limits are placed on the production of h 2!aa relative to the standard model gg 2!h production, assuming no coupling of the a boson to quarks. The most stringent limit is placed at 3.5% for ma = 3.75 GeV. Upper limits are also placed on the production cross section of H 2!aa from 2.33 to 0.72 pb, for fixed ma = 5 GeV with mH ranging from 100 to 500 GeV.
Download or read book Search for Charged Higgs Bosons in Decays of Top Quarks in P Anti p Collisions at S written by and published by . This book was released on 2009 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on the first direct search for charged Higgs bosons in decays of top quarks in p{bar p} collisions at √s = 1.96 TeV. The search uses a data sample corresponding to an integrated luminosity of 2.2 fb−1 collected by the CDF II detector at Fermilab, and looks for a resonance in the invariant mass distribution of two jets in the lepton+jets sample of t{bar t} candidates. We observe no evidence of charged Higgs bosons in top quark decays. Hence, 95% upper limits on the top quark decay branching ratio are placed at?(t → Hb)
Download or read book A Search for the Top Quark Decaying to Charged Higgs in P bar P Collisions at radical written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present results of a search for the top quark decaying to a charged. Higgs boson (H) in p[bar p] collisions at [radical]s = 1.8 TeV at the Fermilab Tevatron. Using 4.1 pb[sup [minus]1] of data collected during the 1988--1989 CDF run, we have searched for evidence of t[bar t] production assuming that t[r-arrow] Hb and H[r-arrow] [tau][nu][sub [tau]]. We find no evidence for this decay and are able to exclude regions in the (m[sub t], m[sub H]) plane for different Br(H[r-arrow] [tau][nu][sub [tau]]). We also interpret these results for the two Higgs doublet(THD) model.
Download or read book Search for Charged Higgs Bosons Decaying Into Top and Bottom Quarks with Single lepton Final States Using Pp Collisions Collected at a Centre of mass Energy of 13 TeV by the ATLAS Detector written by Francesco Peri and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Neutral Higgs Bosons Decaying to Tau Pairs Produced in Association with b Quarks in p bar p Collisions at sqrt s written by and published by . This book was released on 2011 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report results from a search for neutral Higgs bosons produced in association with b quarks using data recorded by the D0 experiment at the Fermilab Tevatron Collider and corresponding to an integrated luminosity of 7.3 fb−1. This production mode can be enhanced in several extensions of the standard model (SM) such as in its minimal supersymmetric extension (MSSM) at high tan [beta]. We search for Higgs bosons decaying to tau pairs with one tau decaying to a muon and neutrinos and the other to hadrons. The data are found to be consistent with SM expectations, and we set upper limits on the cross section times branching ratio in the Higgs boson mass range from 90 to 320 GeV/c2. We interpret our result in the MSSM parameter space, excluding tan [beta] values down to 25 for Higgs boson masses below 170 GeV/c2.
Download or read book A Search for the Top Quark Decaying to Charged Higgs in P bar P Collisions at s written by and published by . This book was released on 1993 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present results of a search for the top quark decaying to a charged. Higgs boson (H) in p{bar p} collisions at √s = 1.8 TeV at the Fermilab Tevatron. Using 4.1 pb−1 of data collected during the 1988--1989 CDF run, we have searched for evidence of t{bar t} production assuming that t→ Hb and H→??{sub?}. We find no evidence for this decay and are able to exclude regions in the (m{sub t}, m{sub H}) plane for different Br(H→ {tau}?{sub {tau}}). We also interpret these results for the two Higgs doublet(THD) model.
Download or read book Search for Charged Higgs Bosons Produced Via Vector Boson Fusion and Decaying Into a Pair of W and Z Bosons Using Pp Collisions at s written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for a Charged Higgs Boson in Pp Collisions at u221A s written by and published by . This book was released on 2015 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our search for a charged Higgs boson is performed with a data sample corresponding to an integrated luminosity of 19.7 ± 0.5 fb-1 collected with the CMS detector in proton-proton collisions at √s=8,TeV. The charged Higgs boson is searched for in top quark decays for m H± m t - m b, and in the direct production pp → t(b)Hsup± /supfor m H± m t - m born The H± → ? ± ? ? and H± → tb decay modes in the final states ? h+jets, ?? h, l+jets, and ll’ (l =e, ?) are considered in the search. No signal is observed and 95% confidence level upper limits are set on the charged Higgs boson production. Furthermore, a model-independent upper limit on the product branching fraction B(t→H±b)B(H±→?±??)=1.2-0.15% is obtained in the mass range m H± = 80–160 GeV, while the upper limit on the cross section times branching fraction ?(pp→t(b)H±)B(H±→ ?±??)=0.38-0.025 pb is set in the mass range m H+ = 180–600 GeV. Here, ?(pp → t(b)H±) stands for the cross section sum ?(pp→t¯(b)H+)+?(pp→t(b¯)H-). Assuming B(H±→tb)=1, an upper limit on ?(pp → t(b)H±) of 2.0–0.13 pb is set for m H± = 180–600 GeV. The combination of all considered decay modes and final states is used to set exclusion limits in the m H±-tan ? parameter space in different MSSM benchmark scenarios.
Download or read book Search for a Charged Higgs Boson Produced in the Vector boson Fusion Mode with Decay H u2192 W Z Using pp Collisions at u221A s written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for a charged Higgs boson, H±, decaying to a W± boson and a Z boson is presented. The search is based on 20.3 fb–1 of proton-proton collision data at a center-of-mass energy of 8 TeV recorded with the ATLAS detector at the LHC. The H± boson is assumed to be produced via vector-boson fusion and the decays W± → qq¯' and Z → e+e–/?+?– are considered. The search is performed in a range of charged Higgs boson masses from 200 to 1000 GeV. No evidence for the production of an H± boson is observed. Upper limits of 31–1020 fb at 95% C.L. are placed on the cross section for vector-boson fusion production of an H± boson times its branching fraction to W±Z. The limits are compared with predictions from the Georgi-Machacek Higgs triplet model.
