Investigating the $P$-wave $D{K}^{\ast }$ Molecular Interpretation of the $D_{s1}(2700)$ via Its Strong Decays

Abstract

In this work, we investigate the possibility of interpreting the $D_{s1}(2700)$ as a $P$-wave $D{K}^{\ast }$ hadronic molecular state through a systematic study of its strong decay properties. Using the effective Lagrangian approach, we calculate the strong decay widths of the $D_{s1}(2700)$ into the two-body final states $DK$, $D^{\ast }K$, $D_s\eta$, and $D_s^{\ast }\eta$, as well as the three-body $D\pi K$ channel. The coupling of the $D_{s1}(2700)$ to its constituents, $D{K}^{\ast }$, is constrained by the available experimental measurement of $R_{D_{s1}}=\Gamma (D_{s1}(2700)\to D^{\ast }K)/\Gamma (D_{s1}(2700)\to DK)=0.91\pm 0.13\pm 0.12$. With the resulting coupling, the total decay width can be readily obtained and is found to be in good agreement with the experimental measurement, providing strong support for interpreting the $D_{s1}(2700)$ as a $P$-wave $D{K}^{\ast }$ molecular state. The experimentally unobserved $D_{s1}(2700)\to D_s^{\ast }\eta$ decay channel provides a further test of this interpretation, as its predicted sizable decay width differs significantly from the conventional quark model prediction.