Exploring the Discovery Reach for a 95 GeV Scalar in Future $e^{+}{e}^{-}$ Collisions

Abstract

The observed indications for a new scalar resonance with a mass around 95\,GeV, initially reported by LEP and supported by CMS and ATLAS in di-photon, $\ddot{I}„\ddot{I}„$, and $W^{+}{W}^{-}$ channels, motivate exploring its discovery potential at future electron-positron colliders. This study focuses on the production of the new scalar ($S$) via $e^{+}{e}^{-}\to ZS$ with $Z\to \hat{I}{¼}^{+}\hat{I}{¼}^{-}$ and $S\to b\bar{b}$ and optimizes the signal recognition using the recoil-mass method. By employing deep neural networks for signal-background discrimination, we demonstrate that a 95\,GeV scalar, mixing with the Standard Model Higgs by an angle of $\sim$0.1, can be observed with a 5$\ddot{I}ƒ$ significance at $\sqrt{s}$ = 250\,GeV or 200\,GeV with 5~ab${}^{-1}$ of integrated luminosity.

5 pages, 2 figures, 1 table, Proceeding submitted to XXXII International Workshop on Deep Inelastic Scattering and Related Subjects (DIS2025), 24-28 March, 2025, Cape Town, South Africa