Bounds on the slope and curvature of Isgur-Wise function in a QCD   inspired quark model
  The QCD inspired potential model persued by us earlier has been recently modified to incorporate an additional factor 'c' in the linear cum Coulomb potential. While it felicitates the inclusion of standard confinement parameter b = 0.183GeV 2, unlike in previous work, it still falls short of explaining the Isgur-Wise function for the B mesons without adhoc adjustment of the strong coupling constant. In this work, we determine the factor 'c' from the experimental values of decay constants and masses and show that the reality constraint on 'c' yeilds bounds on the strong coupling constant as well on slope and curvature of Isgur-Wise function allowing more flexibility to the model. 
B. J. Hazarika, D. K. Choudhury
hep-ph