How to understand the X(2900)?

Abstract

In this work, the S- and P-wave bar{D}^*K^* interactions are studied in a coupled-channel formalism to understand the recently observed X_0(2900) and X_1(2900) at LHCb. The experimental event distributions can be well described, and two states with I(J^P)=0(0^+) and 0(1^-) are yielded in a unified framework. The masses of the 0^+ and 1^- states are consistent with the experimental data, but the width of the 0^+ state is larger than that of the 1^- one. The X_1(2900) can be interpreted as the P-wave excitation of the ground-state X_0(2900) in the hadronic molecular picture. The S- and P-wave multiplets in the bar{D}^*K^* system have many members, so the present peak in the D^-K^+ invariant mass distributions might contain multi substructures.