Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC


Chatrchyan S., Khachatryan V., Sirunyan A. M., Tumasyan A., Adam W., Aguilo E., ...More

PHYSICS LETTERS B, vol.716, no.1, pp.30-61, 2012 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 716 Issue: 1
  • Publication Date: 2012
  • Doi Number: 10.1016/j.physletb.2012.08.021
  • Journal Name: PHYSICS LETTERS B
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.30-61
  • Keywords: CMS, Physics, Higgs, MODEL HIGGS-BOSON, STANDARD MODEL, PP COLLISIONS, ELECTROWEAK CORRECTIONS, PARTON DISTRIBUTIONS, BROKEN SYMMETRIES, QCD CORRECTIONS, SEARCH, COLLIDERS, SPECTRUM
  • Çukurova University Affiliated: Yes

Abstract

Results are presented from searches for the standard model Higgs boson in proton-proton collisions at root s = 7 and 8 TeV in the Compact Muon Solenoid experiment at the LHC, using data samples corresponding to integrated luminosities of up to 5.1 fb(-1) at 7 TeV and 5.3 fb(-1) at 8 TeV. The search is performed in five decay modes: gamma gamma, ZZ, W+W-, tau(+)tau(-), and b (b) over bar. An excess of events is observed above the expected background, with a local significance of 5.0 standard deviations, at a mass near 125 GeV, signalling the production of a new particle. The expected significance for a standard model Higgs boson of that mass is 5.8 standard deviations. The excess is most significant in the two decay modes with the best mass resolution, gamma gamma and ZZ; a fit to these signals gives a mass of 125.3 +/- 0.4(stat.) +/- 0.5(syst.) GeV. The decay to two photons indicates that the new particle is a boson with spin different from one. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.