Thermal quarks and gluon propagators in two-color dense QCD

TL;DR

This paper investigates Landau gauge gluon propagators in two-color dense QCD at finite temperature and chemical potential, comparing analytic one-loop medium polarization effects with lattice data, especially in the high-density diquark condensate phase.

Contribution

It introduces an analytic one-loop calculation of gluon propagators including medium effects in two-color QCD and compares these results with lattice data across different phases.

Findings

Color singlet diquark condensates protect IR gluon propagators at zero temperature.

Electric screening mass is underestimated at finite temperature by the model.

Analytic results align with lattice data beyond the diquark condensate critical temperature.

Abstract

We study Landau gauge gluon propagators in two-color QCD at finite quark chemical potential ($\mu_q$) and temperature ($T$). We include medium polarization effects at one-loop by quarks into massive gluon propagators, and compared the analytic results with the available lattice data. We particularly focus on the high density phase of color-singlet diquark condensates whose critical temperature is $\sim 100$ MeV with weak dependence on $\mu_q$. At zero temperature the color singlet condensates protect the IR limit of electric and magnetic gluon propagators from the medium screening effects. At finite temperature, this behavior remains true for the magnetic sector, but the electric screening mass should be generated by thermal, and hence gapless, particles which are unbound from the diquark condensates. Treating thermal excitations as quasi-quarks, we found that the electric screening develops too fast compared to the lattice results. Beyond the critical temperature for diquark condensates the analytic results are consistent with the lattice results.