Speaker
Description
Hadronic B decays without a charm quark constitute a powerful probe to search for physics beyond the standard model as well as provide constraints of CP-violation parameters. We report the final measurements from Belle of the branching fraction and CP asymmetry for the decays B0→π0π0, B±→K+K−π± and preliminary results for B→KS0KS0h+(h=K,π) and B±→π+π−π±. All investigations employ the full data sample delivered by the KEKB e+e− collider. The B0→π0π0 measurements enable improved constraints on the angle φ2 of the CKM unitarity triangle. For B±→K+K−π± we measure CP asymmetry as a function of the invariant-mass of the K+K− system, where we find strong evidence for large direct CP-violation as well as a large increase in yield at low mass. This measurement challenges conventional theoretical approaches since the result requires a large enhancement in both tree and loop diagrams in the same small region of phase-space. The three-body decay final states π+π−π± and KS0KS0h+(h=K,π) proceed mostly via flavor-changing neutral currents and are thus sensitive to new physics via enhanced CP-asymmetry due to interference from non-SM amplitudes in loops. The final measurement plays an important role in understanding the B decay dynamics and improving the deviation boundary of sin2φ1 obtained in b→cqqˉ and b→sqqˉ decays.
