Spectral Function of Quarks in Quark Matter

We have investigated the spectral function of light quarks in infinite quark matter using a simple, albeit selfconsistent model [1]. Relations between the spectral function and the collisional self-energies in the Born approximation were used to calculate the spectral function in an iterative process beyond the quasiparticle approximation. The quark interactions were described by the SU(2) Nambu–Jona-Lasinio (NJL) model [2]. It has the same symmetries as QCD and describes an effective quark-quark interaction with a constant coupling strength. Mean field effects have been neglected in the calculations. This study has been motivated by similar calculations for nucleons in nuclear matter [3]. It was found there that the results are in good agreement with calculations from many-body theory. In particular the model was very successful in describing the influence of short-range correlations on the properties on nuclear matter using a simple pointlike nucleon interaction with constant scattering amplitude.