Spectral functions of confined particles

Abstract

We determine the gluon and ghost spectral functions along with the analytic structure of the associated propagators from numerical data describing gauge correlators at space-like momenta obtained by either solving the Dyson-Schwinger equations or through lattice simulations. Our novel reconstruction technique shows the expected branch cut for the gluon and the ghost propagator, which, in the gluon case, is supplemented with a pair of complex conjugate poles. Possible implications of the existence of these poles are briefly addressed.

Comments: 7 pages, 5 figures. Extended version which includes the analysis of lattice unquenched 2+1+1 Landau gauge data and quenched Rxi gauge data. Matches the published version in PLB