Search for the Decay B0 -> D*0 gamma

TL;DR

This paper reports a search for the rare decay B0 -> D*0 gamma, setting an upper limit on its branching ratio, which supports the Standard Model prediction that such decays are dominated by short-distance processes.

Contribution

The study provides experimental limits on the B0 -> D*0 gamma decay, offering evidence against anomalous enhancements and confirming the dominance of the b -> s gamma mechanism in the Standard Model.

Findings

Upper limit on Br(B0->D*0 gamma) < 5.0 x 10^-5 at 90% CL

Evidence that anomalous enhancement is absent in W-exchange processes

Supports the Standard Model prediction of short-distance dominance

Abstract

We report results of a search for the rare radiative decay B0 -> D*0 gamma. Using 9.7 million BB meson pairs collected with the CLEO detector at the Cornell Electron Storage Ring, we limit Br(B0->D*0 gamma) < 5.0 * 10^-5 at 90% CL. This provides evidence that anomalous enhancement is absent in W-exchange processes and that weak radiative B decays are dominated by the short-distance b -> s gamma mechanism in the Standard Model.