학술논문
Search for exotic decays of the Higgs boson to a pair of pseudoscalars in the μμbbττbb and μμbbττbb final states
Document Type
Original Paper
Author
Source
The European Physical Journal C: Particles and Fields. 84(5)
Subject
Language
English
ISSN
1434-6052
Abstract
A search for exotic decays of the Higgs boson (HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV) with a mass of 125HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV to a pair of light pseudoscalars HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV is performed in final states where one pseudoscalar decays to two HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV quarks and the other to a pair of muons or HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV leptons. A data sample of proton–proton collisions at HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV corresponding to an integrated luminosity of 138HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV recorded with the CMS detector is analyzed. No statistically significant excess is observed over the standard model backgrounds. Upper limits are set at 95% confidence level (HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV) on the Higgs boson branching fraction to HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV and to HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV via a pair of HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeVs. The limits depend on the pseudoscalar mass HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV and are observed to be in the range (0.17–3.3) HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV and (1.7–7.7) HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV in the HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV and HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV final states, respectively. In the framework of models with two Higgs doublets and a complex scalar singlet (2HDM+S), the results of the two final states are combined to determine upper limits on the branching fraction HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV at 95% HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV, with HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV being a muon or a HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV lepton. For different types of 2HDM+S, upper bounds on the branching fraction HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV are extracted from the combination of the two channels. In most of the Type II 2HDM+S parameter space, HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV values above 0.23 are excluded at 95% HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV for HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV values between 15 and 60HGeVa1bτs=13TeVfb-1CLμμbbττbb,a1ma1×10-4×10-2μμbbττbbB(H→a1a1→ℓℓbb)CLℓτB(H→a1a1)B(H→a1a1)CLma1GeV.