Search for Higgs boson decays into a pair of light bosons in the bbμμ final state in pp collision at √s=13TeV with the ATLAS detector

Collaboration, ATLAS and Barton, A.E. and Bertram, I.A. and Borissov, G. and Bouhova -Thacker, E.V. and Burke, S. and Cao, Y. and Catmore, J.R. and Dewhurst, A. and Fox, H. and Grimm, K. and Henderson, R.C.W. and Hunter, R.F.H. and Janssen, J. and Jones, R.W.L. and Kartvelishvili, V. and Kim, Y.K. and Long, R.E. and Love, P.A. and Ma, Y. and Meng, X.T. and Muenstermann, D. and Price, D. and Ruan, X. and Saito, T. and Sen, S. and Smizanska, M. and Solovyev, V. and Sopczak, A. and Tee, A.S. and Walder, J. and Wharton, A.M. and Whitmore, B.W. and Yamazaki, Y. and Ye, S. (2019) Search for Higgs boson decays into a pair of light bosons in the bbμμ final state in pp collision at √s=13TeV with the ATLAS detector. Physics Letters B, 790. pp. 1-21. ISSN 0370-2693

Abstract

A search for decays of the Higgs boson into a pair of new spin -zero particles, H→aa, where the a -bosons decay into a b -quark pair and a muon pair, is presented. The search uses 36.1 fb−1 of proton–proton collision data at s=13 TeV recorded by the ATLAS experiment at the LHC in 2015 and 2016. No significant deviation from the Standard Model prediction is observed. Upper limits at 95% confidence level are placed on the branching ratio (σH/σSM)×B(H→aa→bbμμ), ranging from 1.2×10−4 to 8.4×10−4 in the a -boson mass range of 20–60 GeV. Model -independent limits are set on the visible production cross -section times the branching ratio to the bbμμ final state for new physics, σvis(X)×B(X→bbμμ), ranging from 0.1 fb to 0.73 fb for mμμ between 18 and 62 GeV. © 2018 The Author