Search for the rare decay B0bar --> D*0 gamma

TL;DR

This paper reports a search for the rare decay B0bar --> D*0 gamma using data from the BABAR detector, finding no significant signal and setting an upper limit on its branching fraction.

Contribution

The study provides the first upper limit on the branching fraction of B0bar --> D*0 gamma, constraining theoretical models of W-exchange processes.

Findings

No significant signal observed.

Upper limit on branching fraction set at 2.5 x 10^{-5}.

Results constrain theoretical predictions.

Abstract

We report on a search for the rare decay B0bar --> D*0 gamma, which in the standard model is dominated by W-exchange. The analysis is based on a data sample comprising 87.8 x 10^6 BBbar pairs collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. No significant signal is observed, and an upper limit on the branching fraction of 2.5 x 10^{-5} at the 90% confidence level is obtained.