Hunting for Direct CP Violation in     B ¯    s   0   ⟶   π   +     π   −     K   ∗ 0

Sheng-Tao Li,Gang Lü,Xin Liu

doi:10.1155/2022/3136459

Abstract

In perturbative QCD approach, based on the first order of isospin symmetry breaking, we study the direct CP violation in the decay of B ¯ s 0 ⟶ ρ ω K ∗ 0 ⟶ π + π − K ∗ 0 . An interesting mechanism is applied to enlarge the C P violating asymmetry involving the charge symmetry breaking between ρ and ω . We find that the CP violation is large by the ρ − ω mixing mechanism when the invariant masses of the π + π − pairs are in the vicinity of the ω resonance. For the decay process of B ¯ s 0 ⟶ ρ ω K ∗ 0 ⟶ π + π − K ∗ 0 , the maximum CP violation can reach − 59.12 % . Furthermore, taking ρ − ω mixing into account, we calculate the branching ratio for B ¯ s 0 ⟶ ρ ω K ∗ 0 . We also discuss the possibility of observing the predicted C P violation asymmetry at the LHC.

Highlights

Charge-parity (CP) violation is an open problem, even though it has been known in the neutral kaon systems for more than five decades [1]
We have investigated the CP violating asymmetry, ACP, for the B0s ⟶ ρ0ðωÞK∗0 ⟶ π+π−K∗0 of the three-body decay process in the perturbative QCD
It is found that the CP violation can be enhanced via ρ − ω mixing for the decay channel B0s ⟶ ρ0ðωÞK∗0 ⟶ π+π−K∗0 when the invariant mass of π+π− pair is in the vicinity of the mω resonance within perturbative QCD scheme

Summary

Introduction

Charge-parity (CP) violation is an open problem, even though it has been known in the neutral kaon systems for more than five decades [1]. The LHCb collaboration has measured sizable direct CP asymmetries in the phase space of the three-body decay channels of B± ⟶ π±π+π− and B± ⟶ K±π+π− [7,8,9] These processes are valuable for studying the mechanism of multibody heavy meson decays. Advances in High Energy Physics and penguin diagrams, where ρ-ω mixing was used for this purpose in the past few years and focused on the naive factorization and QCD factorization approaches This mechanism was applied to generalize the pQCD approach to the three-body nonleptonic decays in B0,± ⟶ π0,±π+π− and Bc ⟶ D+ðsÞπ+ π−, where even larger CP violation may be possible [31, 32]. The related functions defined in the text are given in the Appendix

The Framework

À5t2 2

Input Parameters

The Numerical Results of CP Violation and Branching Ratio

Summary and Conclusion