22-28 July 2010
Palais des Congrès de Paris
Europe/Paris timezone

Measurements of Charmless B Decays at Belle

23 Jul 2010, 14:32
Salle 242A ()

Salle 242A

Parallel Session Talk 06 - CP violation, CKM and Rare Decays 06 - CP violation, CKM and Rare Decays


Min-Zu Wang (Physics Department-National Taiwan University (NTU))


We report the first observation of inclusive B -> X_s eta decays using a large sample of B-anti{B} pairs accumulated at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e^+e^- collider. The X_s system is a charmless inclusive state with unit strangeness, and is reconstructed using a pseudo-inclusive technique from a kaon and up to four pions, of which at most one pion is neutral. We measure a partial branching fraction for M_{X_s} < 2.6 GeV/c2 to be (25.5 +- 2.7 (stat) +- 1.6(syst) ^{+3.8}_{-14.1} (model)) x 10^{-5}. A significant fraction of this signal occurs in the region M_{X_s} > 1.8 GeV/c2, which is beyond the range of all previously measured exclusive contributions to B -> X_s eta. We also present measurements of the branching fraction and time-dependent CP violation parameters of B0 -> a_1^{+-}(1260) pi^{-+} decays, an updated measurement of the branching fraction and direct CP asymmetry for B --> pi0 pi0 and the results of a search for the charmless decays B^+ --> rho^+ omega, B^+ --> phi pi^+ and B0 --> phi pi0. We present improved measurements of the charmless decay B --> phi phi K. We update the branching fractions of B^{+-} --> phi phi K^{+-} and B0 --> phi phi K0 decays, and the measurement of related decays such as B^{+-,0} --> phi (K^+ K^-) K^{+-,0} and B^{+-,0} --> (K^+ K^-) (K^+ K^-) K^{+-,0}. In addition, we also study the charmonium decays related to the B --> phi phi K such as J/psi --> phi (K^+ K^-) and eta_c--> phi phi.

Primary author

Presentation Materials