Coupling constants of bottom (charmed) mesons with pion from three point   QCD sum rules
  In this article, the three point QCD sum rules is used to compute the strong coupling constants of vertices containing the strange bottomed ( charmed ) mesons with pion. The coupling constants are calculated, when both the bottom ( charm ) and pion states are off-shell. A comparison of the obtained results of coupling constants with the existing predictions is also made. Key words: strong coupling constant, meson, QCD sum rules, bottom, charm. 
M. Janbazi, N. Ghahramany and E. Pourjafarabadi
hep-ph