Search for the semileptonic decay $D^{0(+)}\to b_1(1235)^{-(0)} e^+\nu_e$

TL;DR

This study searches for the semileptonic decay of D mesons into an axial-vector meson $b_1(1235)$ and an electron-neutrino pair, setting upper limits on the decay probabilities due to no significant signals observed.

Contribution

First search for $D^{0(+)}$ decays into $b_1(1235)$ axial-vector mesons with no prior experimental evidence, establishing upper limits on their branching fractions.

Findings

No significant signals observed for the decays.

Upper limits set on the product branching fractions.

Results constrain theoretical models of charm meson decays.

Abstract

Using $2.93~\mathrm{fb}^{-1}$ of $e^+e^-$ annihilation data collected at a center-of-mass energy $\sqrt{s}=3.773$ GeV with the BESIII detector operating at the BEPCII collider, we search for the semileptonic $D^{0(+)}$ decays into a $b_1(1235)^{-(0)}$ axial-vector meson for the first time. No significant signal is observed for either charge combination. The upper limits on the product branching fractions are ${\mathcal B}_{D^0\to b_1(1235)^- e^+\nu_e}\cdot {\mathcal B}_{b_1(1235)^-\to \omega\pi^-}<1.12\times 10^{-4}$ and ${\mathcal B}_{D^+\to b_1(1235)^0 e^+\nu_e}\cdot {\mathcal B}_{b_1(1235)^0\to \omega\pi^0}<1.75\times 10^{-4}$ at the 90\% confidence level.