A search for exotic decays of the Higgs boson (H) with a mass of 125 GeV to a pair of light pseudoscalars a(1) is performed in final states where one pseudoscalar decays to two b quarks and the other to a pair of muons or tau leptons. A data sample of proton-proton collisions at root s = 13 TeV corresponding to an integrated luminosity of 138 fb(-1) recorded with the CMS detector is analyzed. No statistically significant excess is observed over the standard model backgrounds. Upper limits are set at 95 onfidence level (CL) on the Higgs boson branching fraction to mu mu bb and to tau tau bb, via a pair of a(1)s. The limits depend on the pseudoscalar mass m(a1) and are observed to be in the range (0.17-3.3) x10(-4) and (1.7-7.7) x10(-2) in the mu mu bb and tau tau bb 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 B(H -> a(1)a(1) -> llbb) at 95% CL, with l being a muon or a tau lepton. For different types of 2HDM+S, upper bounds on the branching fraction B(H -> a(1)a(1)) are extracted from the combination of the two channels. In most of the Type II 2HDM+S parameter space, B(H -> a(1)a(1)) values above 0.23 are excluded at 95% CL for m(a1) values between 15 and 60 GeV.
Search for exotic decays of the Higgs boson to a pair of pseudoscalars in the μμbb and ττbb final states
Meola Sabino
2024-01-01
Abstract
A search for exotic decays of the Higgs boson (H) with a mass of 125 GeV to a pair of light pseudoscalars a(1) is performed in final states where one pseudoscalar decays to two b quarks and the other to a pair of muons or tau leptons. A data sample of proton-proton collisions at root s = 13 TeV corresponding to an integrated luminosity of 138 fb(-1) recorded with the CMS detector is analyzed. No statistically significant excess is observed over the standard model backgrounds. Upper limits are set at 95 onfidence level (CL) on the Higgs boson branching fraction to mu mu bb and to tau tau bb, via a pair of a(1)s. The limits depend on the pseudoscalar mass m(a1) and are observed to be in the range (0.17-3.3) x10(-4) and (1.7-7.7) x10(-2) in the mu mu bb and tau tau bb 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 B(H -> a(1)a(1) -> llbb) at 95% CL, with l being a muon or a tau lepton. For different types of 2HDM+S, upper bounds on the branching fraction B(H -> a(1)a(1)) are extracted from the combination of the two channels. In most of the Type II 2HDM+S parameter space, B(H -> a(1)a(1)) values above 0.23 are excluded at 95% CL for m(a1) values between 15 and 60 GeV.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
