A study of Spin-One Bottomonium in the Functional Formalism in Feynman Gauge

The spin-one bottomonium Bethe-Salpeter equation (BSE) is solved in a class of nontrivial linear covariant gauges. The considered approximation is based on a self-consistent ladder-rainbow truncation employing an effective coupling extracted from lattice simulations. Our first numerical results obtained in Feynman gauge indicate that only a minimal amount of phenomenological input is required. We also address the issue of infrared divergences that arise in the functional formalism for nontrivial values of the gauge-fixing parameter.