[SEMINARI]: Dr. Kalashnikov: Infrared Properties of Hot Gauge Theories

[Arcadi Santamaria]

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                              S E M I N A R I

            [Image]    Departament de Física Teòrica     [Image]
                          Universitat de València
                      46100 Burjassot (València) Spain

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                    Infrared Properties of Hot Gauge Theories

                              Oleg Kalashnikov

                           (Lebedev Inst., Moscow)

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                     Aula de Seminaris de Física Teòrica
                Thursday 25 of February of 1999 at 12:00 AM
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                                    Resum

  The infrared limits of the gluon polarization tensor are analyzed in hot
  non-Abelian theories using perturbative and nonperturbative calculations.
The calculations performed within the lowest one-loop order lead to the very
  important result: to the infrared fictitious pole of the gluon propagator
   which spoils the selfconsistency within any perturbative scheme. Within
    nonperturbative calculations there are two different possibilities to
eliminate this difficulty: the nonanalytical logarithmic behaviour for small
  momenta and the finite limit of the order of g^2 T that is the so-called
  gluon magnetic mass. Both possibilities are analyzed. The next-to-leading
  order calculations are reviewed to present the nonperturbative screening
   potential within hot non-Abelian QCD and the Debye mass. The screening
  potential being calculating nonperturbatively does not correspond to the
   usual attractive QCD-Debye one and instead of that it is repulsive and
 power-behaved like 1/r^6 at large distance. The more exact calculations of
                 the Debye mass are also reviewed briefly.

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