The bottom-charmed meson spectrum from a QCD approach based on Tamm--Dancoff approximation

Abstract

The bottom-charmed meson spectrum is studied in this work via an effective version of the Coulomb gauge QCD Hamiltonian. The Tamm-Dancoff approximation is employed to estimate the energies of the low-lying and radial-excited \(B_c\) states with quantum numbers \(J^P = 0^{-}, 0^{+}, 1^{-}, 1^{+}, 2^{+}, 2^{-}\). In particular, we analyze the effects of incorporating an effective transverse hyperfine interaction and spin mixing. The Regge trajectories and hyperfine splitting of both \(S\)- and \(P\)-wave states are also examined. The numerical results are compared with available experimental data and theoretical predictions of other models.