The coupled-channel analysis of the D and D_s mesons
  The shift of the p-wave $D_s$ meson mass due to coupling to the DK channel is calculated without fitting parameters using the chiral Lagrangian. As a result the original $Q\bar q$ mass 2.490 MeV generically calculated in the relativistic quark models is shifted down to the experimental value 2317 MeV. With the same Lagrangian the shift of the radial excited $1^-$ level is much smaller, while the total width $\Gamma > 100$ MeV and the width ratio is in contradiction with the $D^*(2632)$ state observed by SELEX group. 
Yu. A. Simonov and J. A. Tjon