Analysis of the Exotic Higgs Decay at Circular Electron Positron Collider

Abstract

In many beyond Standard Model (SM) theories such as the Next-to-Minimal Supersymmetric Standard Model (NMSSM), it is predicted that the SM-like Higgs boson can decayinto SM particles through non-standard couplings or decay into non-SM particles directly. The precision of the branching ratios and couplings of the Higgs boson that have been measured at the LHC still allows a sizable fraction of invisible or exotic decays. It was estimated that the precision of the LHC measurements of the Higgs couplings will not be better than $5\%$. Theproposed future collider in China —Circular Electron Positron Collider (CEPC) can measure the couplings and branching ratios to percent levels or even sub-percent levels. We will present the studies on several promising channelsat CEPC: Invisible channel ($H \to$ invisible), semi-visible channel ($H \to b\overline{b}+$ invisible), and visible channel ($H \to bb\overline{b}\overline{b}$).