Hadron loops effect on mass shifts of the charmed and charmed-strange   spectra
  The hadron loop effect is conjectured to be important in understanding discrepancies between the observed states in experiments and the theoretical expectations of non-relativistic potential model. We present that, in an easily operable procedure, the hadron loop effect could shift the poles downwards to reduce the differences and provide better descriptions of both the masses and the total widths, at least, of the radial quantum number $n=1$ charmed and charmed-strange states. The $1^1P_1-1^3P_1$ mixing phenomena could be naturally explained due to their couplings with common channels. The newly observed $D$ states are also addressed, but there are still some problems remaining unclear. 
Zhi-Yong Zhou, Zhiguang Xiao
hep-ph hep-ex nucl-th