Scrutinizing the 95-100 GeV di-tau excess in the top associated process

Abstract

Recently, the CMS collaboration has reported a di-tau excess with a local significance of 2.6-3.1$\sigma$ where the invariant mass is $m_{\tau\tau}=$95-100 GeV. This excess can be interpreted as a light scalar boson that couples to the third generation fermions, particularly top and $\tau$. Based on the simplest model that can account for the CMS di-tau excess, we evaluate experimental sensitivities to the additional light resonance, using the results reported by the ATLAS collaboration. We see that a search for the top-quark associated production of the SM Higgs boson that decays into $\tau\bar\tau$ sets a strong model-independent limit. We also find that the CP-even scalar interpretation of the light resonance is excluded by the ATLAS results, while the CP-odd interpretation is not.