Diagrammatic approach to soft nonAbelian dynamics at high temperature

Mar, 1999
21 pages
Published in:
  • Nucl.Phys.B 566 (2000) 402-422
e-Print:
Report number:
  • NBI-HE-99-04

Citations per year

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Abstract:
The dynamics of soft (pg2T|\vec{p}|\sim g^2 T) non-Abelian gauge fields at finite temperature is non-perturbative. The effective theory for the soft scale is determined by diagrams with external momenta p_0\lsim g^2 T, pg2T|\vec{p}|\sim g^2 T and loop momenta larger than g2Tg^2 T. We consider the polarization tensor beyond the hard thermal loop approximation, which accounts for loop momenta of order TT. There are higher loop diagrams, involving also the scale gTgT, which are as important as the hard thermal loops. These higher loop contributions are characteristic for non-Abelian gauge theories and their calculation is simplified by using the hard thermal loop effective theory. Remarkably, the effective one-loop polarization tensor is found to be gauge fixing independent and transverse at leading order in gg. The transversality indicates that this approach leads to a gauge invariant effective theory.
Note:
  • 23 pages, latex, 4 figures, uses axodraw.sty; discussion of higher loop contributions and of their relation to the Boltzmann equation (Sect. 5) added, several references added, to appear in Nucl. Phys. B
  • 11.10.Wx
  • 11.15.-q
  • gauge field theory: nonabelian
  • finite temperature
  • polarization: tensor
  • Feynman graph: higher-order