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

Abstract

Abstract Recently, the CMS collaboration has reported a di-tau excess with a local significance of 2.6–3.1 $$\sigma $$ σ where the invariant mass is $$m_{\tau \tau } =95$$ m τ τ = 95 –100 GeV. This excess can be interpreted as a light scalar boson that couples to the third generation fermions, particularly top and $$\tau $$ τ . 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 $$\tau {\bar{\tau }}$$ τ τ ¯ 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.