Higgs to $\ddot{I}„\ddot{I}„$ analysis in the future $e^{+}{e}^{-}$ Higgs factories

Abstract

The Circular Electron Positron Collider and International Linear Collider are two electron positron Higgs factories. They are designed to operate at center-of-mass energy of 240 and 250 GeV and accumulate 5.6 and 2 $a{b}^{-1}$ of integrated luminosity. Using CEPC official samples, the signal strength for Higgs to $\ddot{I}„\ddot{I}„$ events are analyzed. The combined accuracy of the signal strength for $H\to \ddot{I}„\ddot{I}„$ at CEPC achieves 0.8\%. Extrapolating this analysis to the ILC setup, we conclude the ILC can reach a relative accuracy of 1.1\% or 1.2\%, corresponding to two benchmark settings of the beam polarization.