Search for the Radiative Penguin Decays B+ -> rho+ gamma, B0 -> rho0 gamma, and B0 -> omega gamma

TL;DR

This paper reports a search for specific rare B meson radiative decays, setting upper limits on their branching fractions and constraining CKM matrix element ratios, with no evidence of these decays observed.

Contribution

The study provides the first experimental upper limits on B --> rho gamma and B0 --> omega gamma decays, constraining theoretical models and CKM parameters.

Findings

No evidence for the decays was observed.

Upper limits on branching fractions were established.

Constraints on CKM matrix element ratios were derived.

Abstract

A search for the decays B --> rho(770) gamma and B0 --> omega(782)gamma is performed on a sample of 211x10^6 Y(4S)->BBbar events collected by the BABAR detector at the PEP-II asymmetric-energy e+e- storage ring. No evidence for the decays is seen. We set the following limits on the individual branching fractions: BF(B --> rho+ gamma)<1.8 x 10^-6, BF(B --> rho0 gamma)<0.4 x 10^-6, and BF(B --> omega gamma)<1.0 x 10^-6 at the 90% confidence level (C.L.). We use the quark model to limit the combined branching fraction BFbar[B --> (rho/omega) gamma]<1.2 x 10^-6, from which we determine a constraint on the ratio of Cabibbo-Kobayashi-Maskawa matrix elements |V_td|/|V_ts|.