Strong decays of heavy-light mesons in a chiral quark model

TL;DR

This paper systematically studies heavy-light meson strong decays using a chiral quark model, achieving good agreement with experimental data and providing predictions for unobserved states to guide future experiments.

Contribution

It introduces a comprehensive analysis of heavy-light meson decays within a chiral quark model, including state mixing schemes and decay mode predictions for unobserved mesons.

Findings

Results agree with experimental data for various meson states.

Favored mixing angle for axial vectors is approximately -55 degrees.

Predictions for decay modes of unobserved states are provided.

Abstract

We carry out a systematic study of the heavy-light meson strong decays in a chiral quark model. For the $S$-wave vectors ($D^*(2007)$, $D^{*\pm}(2010)$), $P$-wave scalars ($D^*_0(2400)$, $B^*_0(5730)$) and tensors ($D^*_2(2460)$, $D^*_{s2}(2573)$), we obtain results in good agreement with the experimental data. For the axial vectors $D_1(2420)$ and $D_1^\prime(2430)$, a state mixing scheme between $1^1P_1$ and $1^3P_1$ is favored with a mixing angle $\phi\simeq-(55\pm 5)^\circ$, which is consistent with previous theoretical predictions. The same mixing scheme also applies to $D_{s1}(2460)$ and $D_{s1}(2536)$ that accounts for the narrow width of the $D_{s1}(2536)$ and its dominant decay into $D^*K$. For $B_1(5725)$ and $B_1^\prime(5732)$, such a mixing explains well the decay width of the former but leads to an even broader $B_1^\prime(5732)$. Predictions for the strange-bottom axial vectors are also made. For the undetermined meson $D^*(2640)$, we find that they fit in well the radially excited state $2^3S_1$ according to its decay mode. The newly observed $D^*_{sJ}(2860)$ strongly favors the $D$-wave excited state $1^3D_3$. For $D^*_{sJ}(2632)$ and $D^*_{sJ}(2690)$, we find they are difficult to fit in any $D_s$ excitations in that mass region, if the experimental data are accurate. Theoretical predictions for decay modes of those unobserved states as multiplets of 2S and 1D waves are also presented, which should be useful for further experimental search for those states.