Evidence for Higgs boson decays to a low-mass dilepton system and a photon in pp collisions at root s=13 TeV with the ATLAS detector


Aad G., Abbott B., Abbott D. C., Abud A. A., Abeling K., Abhayasinghe D. K., ...Daha Fazla

PHYSICS LETTERS B, cilt.819, 2021 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 819
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1016/j.physletb.2021.136412
  • Dergi Adı: PHYSICS LETTERS B
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, INSPEC, zbMATH, Directory of Open Access Journals
  • İstanbul Üniversitesi Adresli: Evet

Özet

A search for the Higgs boson decaying into a photon and a pair of electrons or muons with an invariant mass m(ll) < 30 GeV is presented. The analysis is performed using 139 fb(-1) of proton-proton collision data, produced by the LHC at a centre-of-mass energy of 13 TeV and collected by the ATLAS experiment. Evidence for the H -> ll(gamma) process is found with a significance of 3.2 over the background-only hypothesis, compared to an expected significance of 2.1 for the Standard Model prediction. The best-fit value of the signal-strength parameter, defined as the ratio of the observed signal yield to the one expected in the Standard Model, is mu = 1.5 +/- 0.5. The Higgs boson production cross-section times the H -> ll(gamma) branching ratio for m(ll) < 30 GeV is determined to be 8.7(-2.7)(+2.8) fb. (C) 2021 The Author. Published by Elsevier B.V.