Search for the Standard Model Higgs Boson in the Decay Channel $H$ to $Z Z$ to 4 Leptons in $pp$ Collisions at $\sqrt{s}
Title | Search for the Standard Model Higgs Boson in the Decay Channel $H$ to $Z Z$ to 4 Leptons in $pp$ Collisions at $\sqrt{s} PDF eBook |
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Release | 2012 |
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A search for a Higgs boson in the four-lepton decay channel H to ZZ, with each Z boson decaying to an electron or muon pair, is reported. The search covers Higgs boson mass hypotheses in the range 110 mH
Search for a Higgs Boson in the Decay Channel $H$ to ZZ(*) to $q$ Qbar $\ell-̂$ L+ in $pp$ Collisions at $\sqrt{s}
Title | Search for a Higgs Boson in the Decay Channel $H$ to ZZ(*) to $q$ Qbar $\ell-̂$ L+ in $pp$ Collisions at $\sqrt{s} PDF eBook |
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Release | 2012 |
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A search for the standard model Higgs boson decaying into two Z bosons with subsequent decay into a final state containing two quark jets and two leptons, H to ZZ(*) to q q-bar l-l+ is presented. Results are based on data corresponding to an integrated luminosity of 4.6 inverse femtobarns of proton-proton collisions at sqrt(s)=7 TeV, collected with the CMS detector at the LHC. In order to discriminate between signal and background events, kinematic and topological quantities, including the angular spin correlations of the decay products, are employed. Events are further classified according to the probability of the jets to originate from quarks of light or heavy flavor or from gluons. No evidence for the Higgs boson is found, and upper limits on its production cross section are determined for a Higgs boson of mass between 130 and 600 GeV.
Discovery of a Higgs Boson in the H to ZZ to 4 Leptons Channel
Title | Discovery of a Higgs Boson in the H to ZZ to 4 Leptons Channel PDF eBook |
Author | Adish Pradeep Vartak |
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Pages | 206 |
Release | 2014 |
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ISBN | 9781303948466 |
A search for the standard model Higgs boson is presented using data collected in pp collisions at the LHC with the CMS detector. Two distinct Higgs boson decay channels are analyzed. The H --> ZZ --> 2l2[Nu] channel, where l = e or [mu], is analyzed with data collected in 2011 at sqrt(s) = 7 TeV corresponding to an integrated luminosity of 4.6 fb−1. No significant excess of events is observed above the background expectation and the presence of a standard model Higgs boson is excluded in the mass range 270-440 GeV at 95% confidence level. The H --> ZZ --> 4l channel is analyzed with data collected in 2011 and 2012 corresponding to integrated luminosities of 5.1 and 19.7 fb−1 at sqrt(s) = 7 and 8 TeV respectively. A new boson is observed with a local significance of 6.7 standard deviations. The mass of this particle is measured to be 125.6±0.4(stat)±0.2(syst) GeV, and it has a signal strength of 1.04+0.29/-0.25(stat) +0.14/-0.08(syst) relative to the standard model Higgs boson expectation. The width of this particle is measured to be less than 3.6 GeV at 95% confidence level. The spin and parity of this particle is found to be consistent with the standard model Higgs boson.
Search for the Standard Model Higgs Boson in the H ZZ L + L - Qq Decay Channel at CMS
Title | Search for the Standard Model Higgs Boson in the H ZZ L + L - Qq Decay Channel at CMS PDF eBook |
Author | Francesco Pandolfi |
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Pages | 146 |
Release | 2013-09-30 |
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ISBN | 9783319009049 |
Combined Results of Searches for the Standard Model Higgs Boson in Pp Collisions at Sqrt(s)
Title | Combined Results of Searches for the Standard Model Higgs Boson in Pp Collisions at Sqrt(s) PDF eBook |
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Release | 2012 |
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Combined results are reported from searches for the standard model Higgs boson in proton-proton collisions at sqrt(s)=7 TeV in five Higgs boson decay modes: gamma pair, b-quark pair, tau lepton pair, W pair, and Z pair. The explored Higgs boson mass range is 110-600 GeV. The analysed data correspond to an integrated luminosity of 4.6-4.8 inverse femtobarns. The expected excluded mass range in the absence of the standard model Higgs boson is 118-543 GeV at 95% CL. The observed results exclude the standard model Higgs boson in the mass range 127-600 GeV at 95% CL, and in the mass range 129-525 GeV at 99% CL. An excess of events above the expected standard model background is observed at the low end of the explored mass range making the observed limits weaker than expected in the absence of a signal. The largest excess, with a local significance of 3.1 sigma, is observed for a Higgs boson mass hypothesis of 124 GeV. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-600 (110-145) GeV is estimated to be 1.5 sigma (2.1 sigma). More data are required to ascertain the origin of this excess.
Observation and Examination of a Higgs Boson in the ZZ to Four Lepton Channel
Title | Observation and Examination of a Higgs Boson in the ZZ to Four Lepton Channel PDF eBook |
Author | Duncan Kelley Ralph |
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Pages | 123 |
Release | 2014 |
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Results are presented on 5.1 fb- 1 of proton-proton collisions at a center of mass energy of 7 TeV and 19.7 fb- 1 at 8 TeV in a search for decays of the Standard Model (SM) Higgs boson to two Z bosons to four charged leptons. We observe a single excess above background expectation with a significance of 7.4 standard deviations at a mass of 125.6 ±0.4(stat) ±0.2(syst) GeV. This excess has a signal strength parameter ... We examine the transverse momentum spectrum of the new particle and find it to be consistent with the SM expectation, and also determine that the Standard Model JPC = 0++ is favored over the plausible alternative hypotheses.
Search for the Standard Model Higgs Boson Decaying to a $W$ Pair in the Fully Leptonic Final State in $pp$ Collisions at $\sqrt{s}
Title | Search for the Standard Model Higgs Boson Decaying to a $W$ Pair in the Fully Leptonic Final State in $pp$ Collisions at $\sqrt{s} PDF eBook |
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Pages | 113 |
Release | 2012 |
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A search for the standard model Higgs boson decaying to W+W- in pp collisions at sqrt(s) = 7 TeV is reported. The data are collected at the LHC with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. The W+W- candidates are selected in events with two charged leptons and large missing transverse energy. No significant excess of events above the standard model background expectations is observed, and upper limits on the Higgs boson production relative to the standard model Higgs expectation are derived. The standard model Higgs boson is excluded in the mass range 129-270 GeV at 95% confidence level.