Search for the Radiative Decay B --> phi gamma

TL;DR

This paper reports a search for the rare decay B0 --> phi gamma using a large data sample, but finds no significant signal and sets an upper limit on its branching fraction.

Contribution

First search for B0 --> phi gamma decay using BABAR data, establishing an upper limit on its branching fraction.

Findings

No significant signal observed.

Upper limit on BR(B0 --> phi gamma) set at 8.5x10^-7.

Provides constraints for theoretical models.

Abstract

We perform a search for the exclusive radiative decay B0 --> phi gamma, which is dominated by b d annihilation, in a sample of 124 million BB events collected with the BABAR detector at the PEP-II asymmetric-energy e+e- storage ring at SLAC. No significant signal is seen. We set an upper limit on the branching fraction BR(B0 --> phi gamma < 8.5x10-7) at the 90% confidence level.