Large Direct CP Violation in B^0 -> pi^+ pi^- and an Enhanced Branching Ratio for B^0 -> pi^0 pi^0

Abstract

Recent measurements of B^0 -> pi pi decays reveal two features that are in conflict with conventional calculations: the channel B^0 (Bbar^0) -> pi^+ pi^- shows a large direct CP-violating asymmetry, and the channel B^0 (B^0) -> pi^0 pi^0 has an unexpectedly high branching ratio. We show that both features can be understood in terms of strong-interaction mixing of pi pi and D Dbar channels in the isospin-zero state, an effect that is important because of the large experimentally observed ratio Gamma(B^0 / Bbar^0 -> D^+ D^-) / Gamma (B^0 / Bbar^0 -> pi^+ pi^-) approx. 50. Our dynamical model correlates the branching ratios and the CP-violating parameters C and S, for the decays B^0 (Bbar^0) -> pi^+ pi^-, B^0 (Bbar^0) -> pi^0 pi^0, B^0 (Bbar^0) -> D^+ D^- and B^0 (Bbar^0) -> D^0 Dbar^0.

10 pages, 2 figures, 1 table; v2: Misprint corrected in Eq. (12), second line: -a_m replaced by +a_m. To appear in Phys. Lett. B

Cited by in corpus (12)

• CP Violation and the CKM Matrix: Assessing the Impact of the Asymmetric B Factories
• Final State Interactions in Hadronic B Decays
• Charmless $B\to PP$ decays using flavor SU(3) symmetry
• Non-factorizable Contributions to $B\to \pi \pi$ Decays
• Evidence for Direct CP Violation in B0 -> K+- pi-+ Decays
• Observation of B0->pi0pi0
• Reducing the Error on alpha in B-> pi pi, rho rho, rho pi
• Charmless Final State Interaction in B-> pi pi decays
• Direct CP Violation in B-+ -> pi-+ omega, pi-+ rho0, pi0 rho-+, and in B-bar0(B0) -> pi-+ rho+- With an Enhanced Branching Ratio for pi0 rho0
• Strong Phases in the Decays B to pi pi
• CP Violation in the Decays B -> K Kbar in the Presence of D Dbar <-> K Kbar Mixing
• Constraining Charming Penguins in Charmless B Decays