Dileptons, spectral weights, and conductivity in the quark-gluon plasma.

摘要

This thesis re-examines soft dilepton emission from a weakly coupled Quark-Gluon Plasma. It shows that Braaten, Pisarski, and Yuan's result, that the dilepton rate rises as 1/q40 (and the spectral weight scales as 1/q0) at small energy q0 gT is correct, but that the coefficient they found for this behavior is not correct, because their analysis was incomplete. At still smaller scales, the behavior moderates to ∝ 1/q20 for q0 ≲ g4T, consistent with a finite electrical conductivity. An evaluation of the spectral weight in the q0 ∼ g4 T region by kinetic theory techniques is carried out. The spectral weight is then shown to satisfy a sum rule, which makes the determination of electrical conductivity from the Euclidean correlation function very challenging.