$CP$-violating observables of four-body $B_{(s)}\to (\pi \pi )(K\bar{K})$ decays in perturbative QCD

Da-Cheng Yan, Yan Yan, Zhou Rui

In this work, we investigate six helicity amplitudes of the four-body $B_{(s)}\to (\pi \pi )(K\bar{K})$ decays in the perturbative QCD (PQCD) approach. The $\pi \pi$ invariant mass spectrum…