Search for exotic decays of the Higgs boson to a pair of pseudoscalars in the $$\upmu \upmu \text{ b } \text{ b } $$ and $$\uptau \uptau \text{ b } \text{ b } $$ final states

Abstract A search for exotic decays of the Higgs boson ( $$\text {H}$$ H ) with a mass of 125 $$\,\text {Ge}\hspace{-.08em}\text {V}$$ Ge V to a pair of light pseudoscalars $$\text {a}_{1} $$ a 1 is performed in final states where one pseudoscalar decays to two $${\textrm{b}}$$ b quarks and the other to a pair of muons or $$\tau $$ τ leptons. A data sample of proton–proton collisions at $$\sqrt{s}=13\,\text {Te}\hspace{-.08em}\text {V} $$ s = 13 Te V corresponding to an integrated luminosity of 138 $$\,\text {fb}^{-1}$$ 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% confidence level ( $$\text {CL}$$ CL ) on the Higgs boson branching fraction to $$\upmu \upmu \text{ b } \text{ b } $$ μ μ b b and to $$\uptau \uptau \text{ b } \text{ b },$$ τ τ b b , via a pair of $$\text {a}_{1} $$ a 1 s. The limits depend on the pseudoscalar mass $$m_{\text {a}_{1}}$$ m a 1 and are observed to be in the range (0.17–3.3) $$\times 10^{-4}$$ × 10 - 4 and (1.7–7.7) $$\times 10^{-2}$$ × 10 - 2 in the $$\upmu \upmu \text{ b } \text{ b } $$ μ μ b b and $$\uptau \uptau \text{ b } \text{ b } $$ τ τ b b 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 $${\mathcal {B}}(\text {H} \rightarrow \text {a}_{1} \text {a}_{1} \rightarrow \ell \ell \text{ b } \text{ b})$$ B ( H → a 1 a 1 → ℓ ℓ b b ) at 95% $$\text {CL}$$ CL , with $$\ell $$

Hali tarjima qilinmagan