Spectroscopy and liftime of mesons with bottom and charm quarks

The understanding of hadronic matter properties in high density and temperature environment is necessary for interpreting relativistic heavy ion collision data. Accordingly the bound state of a bottom and acharm quark B-c is of great theoretical and experimental importance. We have calculated the spectrum of this meson in Bethe-Salpeter model using two reductions. The ground state mass and decay lifetime of B-c predicted by this model are found in excellent agreement with the experimental values observed at Fermi Lab. We evaluate the mass of the pseudo-scalar B-c meson as 6.356 GeV/c(2) and 6.380 GeV/c(2) and the lifetime as 0.47 ps and 0.46 ps respectively in the two reductions, in good agreement with the recently reported mass of 6.40 +/- 0.39 (stat.) +/- 0.13 (syst.) GeV/c(2) and lifetime of 0.46(-0.16)(+0.18) (stat.) +/- 0.03 (syst.) ps by the CDF Collaboration. We evaluate the decay constant of the B-c meson and compare different contributions to its decay width.