Radiative Weak Annihilation Decays

TL;DR

This paper discusses a class of rare meson decay modes sensitive to a specific quark topology, providing order-of-magnitude estimates of their branching fractions and potential observability at current experiments.

Contribution

It offers a simple calculation of branching fractions for these rare decays and compares them with previous results, highlighting their experimental prospects.

Findings

D_s^+ --> rho^+ gamma may be observable at charm experiments.

D^+ --> K^{*+} gamma and B^+ --> D_s^{*+} gamma could be seen at B factories.

Remaining modes might be detectable at hadron colliders.

Abstract

A class of meson decay modes sensitive to only one quark topology at leading G_F order (annihilation of valence quarks through a W) is described. No experimental observations, nor even upper limits, have been reported for these decays. This work presents a simpleminded (order-of-magnitude) calculation of their branching fractions, and compares to results of previous calculations where available. Although rare, one of these modes (D_s^+ --> rho^+ gamma) might already be observable at charm experiments, two others (D^+ --> K^{*+} gamma, B^+ --> D_s^{*+} gamma) should appear at the B factories, and the rest at hadron colliders.