Measurement of the ZZ production cross section and limits on anomalous neutral triple gauge couplings in proton-proton collisions at √s=7TeV with the ATLAS detector
Physical Review Letters 108:4 (2012)
Abstract:
A measurement of the ZZ production cross section in proton-proton collisions at √s=7TeV using data corresponding to an integrated luminosity of 1.02fb -1 recorded by the ATLAS experiment at the LHC is presented. Twelve events containing two Z boson candidates decaying to electrons and/or muons are observed, with an expected background of 0.3±0.3(stat)- 0.3+0.4(syst) events. The cross section measured in a phase-space region with good detector acceptance and for dilepton masses within the range 66 to 116 GeV is σZZ→" +" -" +" -fid=19.4-5.2+6.3(stat)-0.7+0. 9(syst)±0.7(lumi)fb. The resulting total cross section for on-shell ZZ production, σZZtot=8.5-2.3+2.7(stat)-0.3+0.4(syst)±0.3(lumi)pb, is consistent with the standard model expectation of 6.5-0.2+0.3pb calculated at the next-to-leading order in QCD. Limits on anomalous neutral triple gauge boson couplings are derived. © 2012 CERN. Published by the American Physical Society under the terms of the < uri xlink:href="http://creativecommons. org/licenses/by/3.0/" > Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Search for a low mass Standard Model Higgs boson in the tau-tau decay channel in $p\bar{p}$ collisions at $\sqrt{s}$ = 1.96 TeV
(2012)
Search for a low mass Standard Model Higgs boson in the tau-tau decay channel in $p\bar{p}$ collisions at $\sqrt{s}$ = 1.96 TeV
ArXiv 1201.488 (2012)
Abstract:
We report on a search for the standard model Higgs boson decaying into pairs of tau leptons in $p\bar{p}$ collisions produced by the Tevatron at $\sqrt{s}$ = 1.96 TeV. The analyzed data sample was recorded by the CDFII detector and corresponds to an integrated luminosity of 6.0 fb$^{-1}$. The search is performed in the final state with one tau decaying leptonically and the second one identified through its semi-hadronic decay.Since no significant excess is observed, a 95% credibility level upper limit on the production cross section times branching ratio to the tau-tau final state is set for hypothetical Higgs boson masses between 100 and 150 GeV/$c^2$. For a Higgs boson of 120 GeV/$c^2$ the observed (expected) limit is 14.6 (15.3) the predicted value.Search for a heavy Standard Model Higgs boson in the channel H→ZZ→ℓ+ℓ-qq̄ using the ATLAS detector
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 707:1 (2012) 27-45
Abstract:
A search for a heavy Standard Model Higgs boson decaying via H→ZZ→ℓ+ℓ-qq̄, where ℓ=e, μ, is presented. The search is performed using a data set of pp collisions at √s=7 TeV, corresponding to an integrated luminosity of 1.04 fb-1 collected in 2011 by the ATLAS detector at the CERN LHC collider. No significant excess of events above the estimated background is found. Upper limits at 95% confidence level on the production cross section (relative to that expected from the Standard Model) of a Higgs boson with a mass in the range between 200 and 600 GeV are derived. Within this mass range, there is at present insufficient sensitivity to exclude a Standard Model Higgs boson. For a Higgs boson with a mass of 360 GeV, where the sensitivity is maximal, the observed and expected cross section upper limits are factors of 1.7 and 2.7, respectively, larger than the Standard Model prediction. © 2011 CERN.Search for Lorentz invariance and CPT violation with muon antineutrinos in the MINOS Near Detector
(2012)