Search for the Standard Model Higgs boson decaying into bb¯ produced in association with top quarks decaying hadronically in pp collisions at √s = 8 TeV with the ATLAS detector


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The ATLAS collaboration A., Aad G., Abbott B., Abdallah J., Abdinov O., Abeloos B., ...More

Journal of High Energy Physics, vol.2016, no.5, 2016 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 2016 Issue: 5
  • Publication Date: 2016
  • Doi Number: 10.1007/jhep05(2016)160
  • Journal Name: Journal of High Energy Physics
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: Hadron-Hadron scattering (experiments)
  • Ankara University Affiliated: Yes

Abstract

A search for Higgs boson production in association with a pair of top quarks (tt¯ H) is performed, where the Higgs boson decays to bb¯, and both top quarks decay hadronically. The data used correspond to an integrated luminosity of 20.3 fb−1 of pp collisions at √s = 8 TeV collected with the ATLAS detector at the Large Hadron Collider. The search selects events with at least six energetic jets and uses a boosted decision tree algorithm to discriminate between signal and Standard Model background. The dominant multijet background is estimated using a dedicated data-driven technique. For a Higgs boson mass of 125 GeV, an upper limit of 6.4 (5.4) times the Standard Model cross section is observed (expected) at 95% confidence level. The best-fit value for the signal strength is μ = 1.6 ± 2.6 times the Standard Model expectation for mH = 125 GeV. Combining all tt¯ H searches carried out by ATLAS at √s = 8 and 7 TeV, an observed (expected) upper limit of 3.1 (1.4) times the Standard Model expectation is obtained at 95% confidence level, with a signal strength μ = 1.7 ± 0.8.