Semileptonic Decays of $B^{**}_{s}$ mesons into $D_{s1}$ and   $D^{*}_{s2}$ in HQET
  In the framework of the heavy quark effective theory, the leading order Isgur-Wise functions relevant to semileptonic decays of the orbitally $P$-wave excited $B_{s}$ meson states $B^{**}_{s}$, including the newly found narrow $B_{s1}(5830)$ and $B^{*}_{s2}(5840)$ states, into the ($D_{s1}(2536)$, $D^{*}_{s2}(2573)$) doublet are calculated from QCD sum rules. With these universal form factors, the decay rates and branching ratios are also estimated. 
Long-Fei Gan, Ming-Qiu Huang
hep-ph