Extracting and using photon polarization information in radiative B decays

Abstract

We discuss the uses of conversion electron pairs for extracting photon polarization information in weak radiative B decays. Both cases of leptons produced through a virtual and real photon are considered. Measurements of the angular correlation between the $(K\pi )$ and $(e^{+}{e}^{-})$ decay planes in $B\to K^{\ast }(\to K\pi ){\gamma }^{(\ast )}(\to e^{+}{e}^{-})$ decays can be used to determine the helicity amplitudes in the radiative $B\to K^{\ast }\gamma$ decay. A large right-handed helicity amplitude in $\bar{B}$ decays is a signal of new physics. The time-dependent CP asymmetry in the $B^0$ decay angular correlation is shown to measure $\sin 2\beta$ and $\cos 2\beta$ with little hadronic uncertainty.

Comments: 15 pages ReVTeX with 1 included figure; 2 references added