Jul 22 – 29, 2015
Europe/Vienna timezone

Study of B -> K pi pi gamma decays

Jul 25, 2015, 12:50 PM


talk Flavour Physics and Fundamental Symmetries Flavour Physics and Fundamental Symmetries


Gerald Eigen (University of Bergen)


We present a measurement of the time-dependent CP asymmetry in the radiative-penguin decay B0 -> K_S pi+ pi- gamma, using a sample of 471 million BBbar events recorded with the BaBar detector at the PEP-II e+e- collider at SLAC. We obtain the CP-violating parameters S and C in the decay, and, using new theoretical input, extract from them the time-dependent mixing-induced CP asymmetry, S_rho0KS, related to the hadronic CP eigenstate rho^0 K_S. This observable provides information on the photon polarization in the underlying b -> s gamma transition. The extraction of S_rho0Ks is done assuming isospin symmetry, using a study of B+ -> K+ pi+ pi- gamma decays. In this mode, we measure intermediate amplitudes of different resonances decaying to K pi pi through the intermediate states rho^0 K^+, K^*0 pi^+ and K pi (S wave) pi^+. In addition to the need for this information for the extraction of S_rho0KS, it provides information on the B -> K pi pi system, which is useful for other studies of the photon polarization.

Primary author

Gerald Eigen (University of Bergen)

Presentation materials