Searches for Additional Scalars at Future $e^{+}{e}^{-}$ Colliders

Abstract

We present growing excesses consistent with a 95 GeV scalar. We provide a comprehensive analysis of the Two Higgs Doublet Model and an additional singlet (2HDM+S) at future $e^{+}{e}^{-}$ collider. In particular, we provide a precise mass reconstruction measurement for the scalar, $m_S$, using the recoil mass method through $e^{+}{e}^{-}\to ZS$ where $Z\to \hat{I}{¼}_{+}\hat{I}{¼}_{-}$ and $S\to b\bar{b}$ at $\sqrt{s}=250$~GeV and $\sqrt{s}=200$~GeV. Furthermore, we employ Deep Neural Network to analyze the properties and behaviour of the scalar particle with a mass most importantly to provide enhanced resolution for the separation between beyond the Standard Model (SM) signal and SM background in the region 95 - 96 GeV in the $S\to b\bar{b}$ for $\hat{I}{¼}_{+}\hat{I}{¼}_{-}$ channel. A 95 GeV scalar can be observed with $5\ddot{I}ƒ$ significance at $15(10)$ fb${}^{-1}$ integrated luminosity for $\sqrt{s}=250(200)$~GeV. This strengthens the discovery of the potential of the future $e^{+}{e}^{-}$ collider.

5 pages, 4 figures