Light-quarkonium spectra and orbital-angular-momentum decomposition in a Bethe-Salpeter-equation approach

Understand

We investigate the light quarkonium spectrum using a covariant Dyson-Schwinger-Bethe-Salpeter-equation approach to QCD.

• We discuss splittings among as well as orbital angular momentum properties of various states in detail and analyze common features of mass splittings with regard to properties of the effective interaction.
• In particular, we predict the mass of sbars exotic 1-+ states, and identify orbital angular momentum content in the excitations of the rho meson.
• Comparing our covariant model results, the rho and its second excitation being predominantly S-wave, the first excitation being predominantly D-wave, to corresponding conflicting lattice-QCD studies, we investigate the pion-mass dependence of the orbital-angular-momentum assignment and find a crossing at a scale of $m_\pi$ ~ 1.4 GeV.