Spectra of heavy mesons in the Bethe-Salpeter approach

We present a calculation of the spectrum of charmonia, bottomonia and Bc-meson states with “ordinary” and exotic quantum numbers. We discuss the merits and limitations of a rainbow-ladder truncation of Dyson-Schwinger and Bethe-Salpeter equations and explore the effects of different shapes of the effective running coupling on ground and excited states in channels with quantum numbers $J\le 3$. We furthermore discuss the status of the $X(3872)$ as a potential (excited) quark-antiquark state and give predictions for the masses of charmonia and bottomonia in the tensor channels with $J= 2, 3$