Eur. Phys. J. C (2008) 58: 223-244
https://doi.org/10.1140/epjc/s10052-008-0721-4

Regular Article - Theoretical Physics

Enhanced direct CP violation and branching ratios in bottom hadron decays

Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing, 100875, China

^* e-mail: ganglv@mail.bnu.edu.cn

Received: 10 March 2008
Revised: 14 July 2008
Published online: 24 September 2008

Abstract

In the framework of factorization we study direct CP violation in the decays of bottom hadrons containing a strange quark or a charm quark, H _b →f ρ ⁰(ω)→f π ⁺ π ⁻ (H _b is the bottom hadron and f is the product hadron) including the effect of ρ–ω mixing. We find that the CP violating asymmetry can be enhanced greatly via the ρ–ω mixing mechanism when the invariant mass of the π ⁺ π ⁻ pair is in the vicinity of the ω resonance. For the processes associated with b→d transitions, e.g. , , B _c ⁻ →D ⁻ π ⁺ π ⁻, B _c ⁻ →D ^*− π ⁺ π ⁻, Ξ _b ⁰ →Λ π ⁺ π ⁻, and Ω _b ⁻ →Ξ ⁻ π ⁺ π ⁻, the maximum CP violating asymmetries can reach about −84%, while for the processes associated with b→s transitions, e.g. , , B _c ⁻ →D _s ⁻ π ⁺ π ⁻, B _c ⁻ →D _s ^*− π ⁺ π ⁻, Ξ _b ⁻ →Ξ ⁻ π ⁺ π ⁻, and Ω _b ⁻ →Ω ⁻ π ⁺ π ⁻, the CP violating asymmetries can be enhanced to about 95%. Furthermore, taking ρ–ω mixing into account we calculate the b-hadron decay branching ratios. We also discuss the possibility to observe the predicted CP violating asymmetries at the LHC.