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Towards softer scales in hot QCD

F. Guerin
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Abstract

An effective theory for the soft field modes in hot QCD has been obtained recently by integrating out the field modes of momenta of order T and g T. The mean hard particle distribution obeys a transport equation with a collision term. The scale that comes out for the soft field is g^2 T ln 1/g . N-gluon soft amplitudes are shown to be a sum of tree diagrams and to obey tree-like Ward identities. These effective amplitudes are used to compute the one-soft loop contribution to the gluon self-energy when the loop momentum is of order g^2 T ln 1/g. It allows to identify a new collision term which, when included into the transport equation, takes into account collisions with gluon exchange of order g^2 T ln 1/g. The infrared behaviour of the collision term exhibits a significant change.

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F. Guerin. 2000-09-07. Towards softer scales in hot QCD. https://doi.org/10.1103/physrevd.63.045017

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