The newly observed open-charm states in quark model

Comparing the measured properties of the newly observed open-charm states D (2550), D (2600), D (2750), D (2760), D s 1 (2710), D sJ (2860), and D sJ (3040) with our predicted spectroscopy and strong decays in a constituent quark model, we find that (1) the D (2 1 S 0 ) assignment to D (2550) remains open for its too broad width determined by experiment; (2) the D (2600) and D s 1 (2710) can be identified as the 2 3 S 1 –1 3 D 1 mixtures; (3) if the D (2760) and D (2750) are indeed the same resonance, they would be the D (1 3 D 3 ); otherwise, they could be assigned as the D (1 3 D 3 ) and , respectively; (4) the D sJ (2860) could be either the D s 1 (2710)’s partner or the D s (1 3 D 3 ); and (5) both the D s 1 (2 P ) and interpretations for the D sJ (3040) seem likely. The E 1 and M 1 radiative decays of these sates are also studied. Further experimental efforts are needed to test the present quarkonium assignments for these new open-charm states.