The 95 GeV Excess in the Georgi-Machacek Model: Single or Twin Peak Resonance

Abstract

In this work, we investigate the possibility to address the excess observed around 95 GeV in the $\gamma\gamma$, $\tau\tau$, and $b\bar{b}$ channels as a scalar resonance(s) within the Georgi-Machacek (GM) model. In our analysis, we find that the excess can be easily accommodated in the channels ($\gamma\gamma$ and $b\bar{b}$) simultaneously, where the 95 GeV candidate is a single peak resonance (SPR) due to a light CP-even scalar. We found that the excess in the $\tau\tau$ channel can be addressed simultaneously with $\gamma\gamma$ and $b\bar{b}$ only if the 95 GeV candidate is a twin peak resonance (TPR), i.e., another CP-odd scalar in addition to the CP-even scalar. We demonstrate that the nature of the 95 GeV scalar resonance candidate (SPR or TPR) can be probed via the properties of its di-$\tau$ decay.