Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-Zero Magnetic Screening Mass in QED and QCD at One Loop Level in
  Non-Equilibrium   Using the Schwinger-Keldysh closed time path integral formalism we show that
the magnetic screening mass in QED and QCD at one loop level is non-zero as
long as the single particle distribution function f(\vec{k}) is non-isotropic,
{i.e.} it depends on the direction of the momentum. For isotropic distribution
functions such as those corresponding to thermal equilibrium the magnetic
screening mass at one loop level is found to be zero which is consistent with
finite temperature field theory. The non-zero magnetic screening mass in
non-isotropic non-equlibrium situations has fundamental importance in that it
acts as a natural cut-off to remove infrared divergences in the magnetic
sector. Thus it allows one to avoid infrared problems which previously made it
difficult to use a transport theory approach using perturbative QCD or QED
scattering kernels to study the thermalization of a QED or QCD plasma.

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The categories of this paper are: alg-geom
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
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The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-ex
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The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
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The categories of this paper are: eess
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The categories of this paper are: comp-gas
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The categories of this paper are: bayes-an
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The categories of this paper are: stat
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The categories of this paper are: funct-an
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The categories of this paper are: ao-sci
9
The categories of this paper are: nlin