D_s(2317) and D_s(2457) from HQET Sum Rules
  Within the framework of the heavy quark effective theory, QCD sum rules are used to calculate the masses of p-wave (c-bar s) states. The results for 0^+ and 1^+ states with the angular momentum of the light component j_l=1/2 are consistent with the experimental values for D_s(2317) and D_s(2457), respectively. 
Yuan-Ben Dai, Chao-Shang Huang, Chun Liu, Shi-Lin Zhu