Search for Higgs boson decays into two neutral scalars with unequal masses in final states with b quarks and tau leptons in proton-proton collisions at $\sqrt{s}$ = 13 TeV

TL;DR

This paper reports a search for Higgs boson decays into two neutral scalars with different masses, focusing on final states with b quarks and tau leptons, using CMS data at 13 TeV, setting upper limits on the decay rates.

Contribution

The study introduces a search for Higgs decays into two unequal-mass neutral scalars with specific final states, providing new upper limits on these rare decay processes.

Findings

No significant excess over the standard model was observed.

Upper limits on the production cross section times branching ratios range from 0.9 to 36.8 pb.

Constraints depend on the mass hypotheses and decay scenarios.

Abstract

A search for Higgs boson (H) decays into a pair of neutral scalars $\phi_1$ and $\phi_2$, with $\phi_2$ heavier than $\phi_1$, is performed in final states with b quarks and tau leptons. Depending on the masses of the neutral scalars, $\phi_2$ can undergo a cascade decay into $\phi_1\phi_1$. For both the cascade and non-cascade scenarios, one $\phi_1$ is required to decay to a pair of tau leptons. Proton-proton collision data corresponding to an integrated luminosity of 138 fb$^{-1}$ collected with the CMS detector at the LHC at $\sqrt{s}$ = 13 TeV are analyzed. No statistically significant excess over the standard model expectation is observed. Upper limits are set on the products $\sigma \mathcal{B}$(H $\to$ $\phi_1\phi_2$ $\to$ 3$\phi_1$ $\to$ 2$\tau$4b) and $\sigma \mathcal{B}$(H $\to$ $\phi_1\phi_2$) $\mathcal{B}$($\phi_1$ $\to$ 2$\tau$) $\mathcal{B}$($\phi_2$ $\to$ 2b) where $\sigma$ is the Higgs boson production cross section. The observed upper limits range between 0.9 and 36.8 pb at 95% confidence level, depending on the mass hypothesis and decay scenario.