Identification of $D^*_2(3000)$ as the $D_2^*(2^3P_2)$ and exploring potential of undiscovered $2^+$ mesons via $B$ decays

TL;DR

This paper identifies the $D^*_2(3000)$ as the $D_2^*(2^3P_2)$ state using $B$ decay data and explores the potential to discover other unobserved $2^+$ charmed mesons through $B$ meson decays.

Contribution

It provides a theoretical assignment of the $D^*_2(3000)$ resonance and assesses the detectability of other $2^+$ mesons in $B$ decays using the Bethe-Salpeter equation approach.

Findings

$D^*_2(3000)$ matches $D_2^*(2^3P_2)$ predictions.

Other candidate states have negligible branching ratios in $B$ decays.

Potential to observe unconfirmed $2^+$ mesons in $B$ decays.

Abstract

Following the discovery of the $D^*_2(3000)$, its mass and full width have been extensively studied. Yet its nature remains undetermined to date. Since it was discovered through nonleptonic decay of $B$ meson and the corresponding cascade process, we therefore in this paper investigate the nonleptonic and semileptonic decays of $B$ meson to $J^P = 2^+$ charmed mesons using the Bethe-Salpeter equation approach. Our calculations on nonleptonic $B$ decays reveal that the unconfirmed resonance $D^*_2(3000)$ aligns well with $D^*_2(2^3P_2)$ predictions. Other candidates, including $D^*_2(1^3F_2)$, $D^*_2(3^3P_2)$, and $D^*_2(2^3F_2)$, are excluded due to their very small branching ratios in $B$ decays. Considering that the $D^*_2(1F)$, $D^*_2(3P)$, and $D^*_2(2F)$ have not yet been experimentally observed, we investigate the feasibility of their detection in $B$-meson decays.