On the Damping Rate of a Moving Fermion in Hot Gauge Theories

Angular Intricacies in Hot Gauge Field Theories

“…By the way, this elucidates also the intriguing point made in the third reference of [8], after equation (3.32), which was then left as an issue. There, the discontinuity in p 0 of the angular integral W 2 was taken to be disc W 2 (P,…”

“…That is, in contradistinction with the RP scheme, a picture emerges out of the PR scheme, where effective vertices potentially mass singular behaviours, melt with partial effective propagators own potentially mass singular behaviours into structural patterns which rule the overall compensation of actual mass/collinear singularities, [8,10].…”

“…In the past few years, another resummation scheme of the leading order thermal fluctuations has been proposed by the present author, and seems to avoid all of the infrared problems met by the standard RP , [8]. In loop calculations (where both resummation schemes are being used as effective perturbation theories, ruling the leading thermal fluctuations) the former only differs the standard RP , the sequence along which are performed an integration over a looping energy p 0 , on the one hand, and a sum over the number N of HT L-self energy insertions, on the other hand.…”

“…While HT L n-point vertices are purely perturbative objects, effective propagators are not, giving rise to pole residues and dispersion laws that cannot be obtained out of pure thermal perturbation theory. In the infrared limit, in particular, those effective propagators are known to give rise to series in the coupling constant that are no longer Taylor's but Laurent's series [8]. In any higher number of loops calculations, this simple, still crucial difference, allows one to foresee easily, why, in the RP case and not in the PR one, some enhancement mechanisms may occur (and effectively will!)…”

Bloch-Nordsieck estimates of high-temperature QED

“…be as large and even larger than the renormalized T=0-part, Π R (k 2 ), [13,14]. However, this leading thermal piece of Π HT L (k 0 , k), is also proportional to k 2 and therefore does not contribute either, to the second term on the right hand side of Eq.…”