# Direct $CP$ violation for $\bar{B}_s^0 \to \phi {\pi^+}{\pi^-}$ in Perturbative QCD

## TL;DR

This paper investigates direct CP violation in the decay of B_s^0 to 
ho(omega) phi with \u007fpi^+pi^-, highlighting how 
ho-omega mixing enhances CP asymmetry near the omega resonance.

## Contribution

The study introduces a mechanism involving 
ho-omega mixing to significantly enhance CP violation in B_s^0 decay processes.

## Key findings

- Maximum CP violation of 5.98% in B_s^0 decay.
- CP violation is enhanced near the omega resonance.
- Detection prospects for CP violation are discussed.

## Abstract

In perturbative QCD approach, we study the direct $CP$ violation in the decay of $\bar{B}_s^0\to\rho(\omega )\phi\to {\pi^+}{\pi^-}\phi$ via isospin symmetry breaking. An interesting mechanism involving the charge symmetry violating between $\rho$ and $\omega$ is applied to enlarge the $CP$ violating asymmetry. We find that the $CP$ violation can be enhanced by the $\rho-\omega$ mixing mechanism when the invariant masses of the $\pi^+\pi^-$ pairs are in the vicinity of the $\omega$ resonance. For the decay process of $\bar{B}^0_{s}\to\rho(\omega )\phi\to{\pi^+}{\pi^-}\phi$, the maximum $CP$ violation can reach $5.98\%$. The possibility of detecting the $CP$ violation is also presented.