Study of the excited 1^- charm and charm\u2013strange mesons

Abstract

We give a systematical study on the recently reported excited charm and charm–strange mesons with potential 1^- spin–parity, including the D^*_{s1}(2700)^+, D^*_{s1}(2860)^+, D^*(2600)^0, D^*(2650)^0, D^*_1(2680)^0 and D^*_1(2760)^0. The main strong decay properties are obtained in the framework of Bethe–Salpeter (BS) methods. Our results reveal that the two 1^- charm–strange mesons can be well described by the further 2^3!S_1–1^3!D_1 mixing scheme with a mixing angle of (8.7^{+3.9}_{-3.2})^circ . The predicted decay ratio frac{mathcal {B}(D^*K)}{mathcal {B}(D~K)} for D^*_{s1}(2860) is 0.62^{+0.22}_{-0.12}. D^*(2600)^0 can also be explained as the 2^3!S_1 predominant state with a mixing angle of -(7.5^{+4.0}_{-3.3})^circ . Considering the mass range, D^*(2650)^0 and D^*_1(2680)^0 are more likely to be the 2^3!S_1 predominant states, although the total widths under the two 2^3!S_1 and 1^3!D_1 assignments have no great conflict with the current experimental data. The calculated width for the LHCb D^*_1(2760)^0 seems to be about 100 MeV larger than the experimental measurement if taking it as 1^3!D_1 or 1^3!D_1 dominant state cbar{u}. The comparisons with other calculations and several important decay ratios are also presented. For the identification of these 1^- charm mesons, further experimental information, such as frac{mathcal {B}(Dpi )}{mathcal {B}(D^*pi )}, is necessary.