An-Najah Staff

In the framework of static and QCD-motivated model potentials for heavy quarkonium, we present a further comprehensive calculation of the mass spectrum of  system and its ground state spin-dependent splittings in the context of the shifted l-expansion technique. We also predict the leptonic constant f_Bc of the lightest pseudoscalar B_c, and  of the vector  states taking into account the one-loop and two-loop QCD corrections. Furthermore, we use the scaling relation to predict the leptonic constant of the nS-states of the  system. Our predicted results are generally in high agreement with some earlier numerical methods. The parameters of each potential are adjusted to obtain best agreement with the experimental spin-averaged data (SAD).

We give a review and present a comprehensive calculation for the leptonic constant f_Bc of the low-lying pseudoscalar and vector states of B_c-meson in the framework of static and QCD-motivated nonrelativistic potential models taking into account the one-loop and two-loop QCD corrections in the short distance coefficient that governs the leptonic constant of B_c quarkonium system. Further, we use the scaling relation to predict the leptonic constant of the nS-states of the  system. Our results are compared with other models to gauge the reliability of the predictions and point out differences.