Prospect for measurement of the CP-violating phase ${\varphi }_s$ in the $B_s\to J/\psi \varphi$ channel at a future Z factory

Xiaomei Li, Manqi Ruan, Mingrui Zhao

The CP-violating phase ${\varphi }_s$, the \Bs decay width (${\Gamma }_s$), and the \Bs decay width difference ($\Delta {\Gamma }_s$) are sensitive probes to new physics and can constrain the heavy quark expansi…