Radiative corrections to the pressure and the one-loop polarization tensor of massless modes in SU(2) Yang-Mills thermodynamics

Schwarz, Markus; Hofmann, Ralf; Giacosa, Francesco

Radiative corrections to the pressure and the one-loop polarization tensor of massless modes in SU(2) Yang-Mills thermodynamics

Authors

Schwarz, Markus

Hofmann, Ralf

Giacosa, Francesco

Description

We compute the one-loop polarization tensor $Π$ for the on-shell, massless mode in a thermalized SU(2) Yang-Mills theory being in its deconfining phase. Postulating that SU(2)$_{\tiny{CMB}}\stackrel{\tiny{today}}=U(1)_Y$, we discuss $Π$'s effect on the low-momentum part of the black-body spectrum at temperatures $\sim 2... 4$ $T_{\tiny{CMB}}$ where $T_{\tiny{CMB}}\sim 2.73 $K. A table-top experiment is proposed to test the above postulate. As an application, we point out a possible connection with the stability of dilute, cold, and old innergalactic atomic hydrogen clouds. We also compute the two-loop correction to the pressure arising from the instantaneous massless mode in unitary-Coulomb gauge, which formerly was neglected, and present improved estimates for subdominant corrections.
25 pages, 17 figs, v4: consequences of a modification of the evolution equation for the effectice coupling implemented, no qualitative change of the physics