Search for Charged Higgs Bosons in Decays of Pair-produced Top Quarks at D0

Search for Charged Higgs Bosons in Decays of Pair-produced Top Quarks at D0

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Published: 2001

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The authors present a search for t → bH+ in t{bar t} candidate events at D0 based on two methods. The first seeks a deficit in signal relative to expectations from the standard model (SM). Such a deficit would imply the presence of a non-SM decay of the top quark. This search involves the full data sample of ≈ 110 pb−1 of p{bar p} collisions at √s = 1.8 TeV, collected with the D0 detector. The second method looks for charged Higgs decays to [tau] leptons (and associated neutrinos), and is based on a 62 pb−1 subset of the aforementioned data sample.


Search for Resonant Pair Production of Higgs Bosons Decaying to Two Bottom Quark-antiquark Pairs in Proton-proton Collisions at 8 TeV.

Search for Resonant Pair Production of Higgs Bosons Decaying to Two Bottom Quark-antiquark Pairs in Proton-proton Collisions at 8 TeV.

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Published: 2015

Total Pages: 23

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A model-independent search for a narrow resonance produced in proton-proton collisions at √s = 8 TeV and decaying to a pair of 125 GeV Higgs bosons that in turn each decays into a bottom quark-antiquark pair is performed by the CMS experiment at the LHC. We analyzed the data so that it corresponded to an integrated luminosity of 17.9 fb-1. No evidence for a signal is observed. Upper limits at a 95% confidence level on the production cross section for such a resonance, in the mass range from 270 to 1100 GeV, are reported. A radion with decay constant of 1 TeV and mass from 300 to 1100 GeV, and a Kaluza-Klein graviton with mass from 380 to 830 GeV are excluded at a 95% confidence level.


Search for Pair Production of Higgs Bosons in the Four Bottom Quark Final State Using Proton-Proton Collisions at √S

Search for Pair Production of Higgs Bosons in the Four Bottom Quark Final State Using Proton-Proton Collisions at √S

Author: Patrick Bryant

Publisher:

Published: 2018

Total Pages: 351

ISBN-13: 9780438756397

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A search for Higgs boson pair production in the four b-jet final state is carried out with up to 36.1/fb of LHC proton-proton collision data collected at √s = 13 TeV with the ATLAS detector in 2015 and 2016. Three benchmark signals are studied: a spin-2 graviton decaying into a Higgs boson pair, a scalar resonance decaying into a Higgs boson pair, and Standard Model non-resonant Higgs boson pair production. This thesis presents a search in events with four individually resolved b-tagged jets. Higgs bosons produced with large momenta are reconstructed as single large radius jets with substructure. The analysis of this topology is presented in CERN-THESIS-2018-118. The two analyses are statistically combined and upper limits on the production cross section of Higgs boson pairs times branching ratio to four b-quarks are set in each model. The combined result searches for resonance masses in the range 260-3000 GeV. No significant excess is observed; the largest deviation of data over prediction is found at a mass of 280 GeV, corresponding to 2.3 standard deviations globally. The observed 95% confidence level upper limit on the non-resonant production is 13 times the Standard Model prediction.


Search for Doubly-charged Higgs Boson Production in the Decay H++ H--{u2192} ?+?+?-?- with 1.1 Fb-1 at D0 Detector

Search for Doubly-charged Higgs Boson Production in the Decay H++ H--{u2192} ?+?+?-?- with 1.1 Fb-1 at D0 Detector

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Published: 2007

Total Pages: 199

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This work presents a search for the pair production of doubly-charged Higgs bosons in the process p{bar p} → H++H-- → ?+?+?-?- using the data corresponding to an integrated luminosity of about 1.1 fb-1. This is the complete dataset of RunIIa taken from April 19, 2002 to February 22, 2006 by the D0 experiment at the Fermilab Tevatron Collider. In the absence of significant excess above standard model background, 95% confidence level mass limits of M(H$±±top{L}$) > 150 GeV and M(H$±±top{R}$) > 126.5 GeV are set for left-handed and right-handed doubly-charged Higgs bosons respectively assuming a 100% branching ratio into muons.


A Search for Double-charged Higgs Bosons at the Tevatron

A Search for Double-charged Higgs Bosons at the Tevatron

Author: Sasha Baraoiant

Publisher:

Published: 2006

Total Pages: 174

ISBN-13:

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We search for the pair production of doubly charged Higgs particles followed by the lepton-flavor violating decay of each Higgs into electron-and-tau and muon-and-tau pairs using 350 pb{sup -1} of data collected by the CDF II experiment at the Fermilab Tevatron. Separate searches investigate cases where three or four final state leptons are detected, and the limits for each exclusive decay mode reflect the combined results of both searches. Assuming the H{sup {+-}{+-}}{sub L} decays exclusively into like sign electron-and-tau pairs, we set a lower limit on its mass of 114 GeV/c2 at the 95 % confidence level. In the case of exclusive muon-and-tau decays, we set a lower mass limit of 112 GeV/c2 also at the 95% confidence level.