Bs and Bc mesons in lattice QCD with exact chiral symmetry

Abstract

We determine the masses and decay constants of the pseudoscalar mesons Bs and Bc, and also the masses of the vector mesons Bs^* and Bc^*, in quenched lattice QCD with exact chiral symmetry. For 100 gauge configurations generated with single-plaquette action at beta = 7.2 on the 32^3 x 60 lattice, we compute point-to-point quark propagators for 33 quark masses in the range [0.01, 0.85], and measure the time-correlation functions of pseudoscalar and vector mesons. The inverse lattice spacing and the charm quark bare mass are determined using the mass and decay constant of eta_c(2980). The bare masses of s and b quarks are chosen such that the masses of the corresponding vector mesons are in good agreement with phi(1020), and Upsilon(9460) respectively. Our results are: m_{Bs} = 5385(27)(17) MeV, f_{Bs} = 253(8)(7) MeV, m_{Bc} = 6278(6)(4) MeV, f_{Bc} = 489(4)(3) MeV, m_{Bs^*} = 5424(28)(19) MeV, and m_{Bc^*} = 6315(6)(5) MeV.