Search for the radiative decays $D^0\to \gamma \bar K_1(1270)^0$ and $D^+\to \gamma K_1(1270)^+$

TL;DR

This study searches for specific radiative decays of D mesons involving axial-vector mesons, setting upper limits on their branching fractions, and providing the first test of the Vector Meson Dominance model in such decays.

Contribution

First experimental limits on $D$ meson radiative decays to axial-vector mesons, testing the Vector Meson Dominance mechanism in charm meson decays.

Findings

No significant signals observed.

Upper limits on branching fractions set.

First test of VMD in these decays.

Abstract

A search for the radiative decays $D^0\to \gamma \bar K_1(1270)^0$ and $D^+\to \gamma K_1(1270)^+$ is conducted using $20.3~\mathrm{fb}^{-1}$ of $e^+e^-$ annihilation data collected at the center-of-mass energy $\sqrt{s}=3.773$ GeV by the BESIII detector operating at the BEPCII collider. No significant signals are observed, and upper limits on the branching fractions of $D^0\to \gamma \bar K_1(1270)^0$ and $D^+\to \gamma K_1(1270)^+$ at 90\% confidence level are determined to be $7.7\times10^{-4}$ and $3.9\times10^{-5}$, respectively. This represents the first test of the Vector Meson Dominance mechanism in the radiative decays of charmed mesons to axial-vector mesons.