Re: Gluon propagator in the infrared

I was just thinking: Is the DS approach nonperturbative? Doesnt the
theory become strongly coupled in the IR such that concepts like
propagator hardly are defined?

I would rather believe the lattice calculations, which are
nonperturbative.

jon.les...@xxxxxxxxxx schrieb:

There is today a rather strange situation about the behavior of the
gluon propagator in the infrared. Some people using Dyson-Schwinger
(DS) equation claim that this should go to zero in the limit of
momentum going to zero while lattice computations are now starting to
contradict this view. More clearly one has the renormalized coupling
constant that goes to zero in the limit of momentum going to zero,
indicating a free theory in the infrared while DS equation gives an
infrared fixed point.

It is interesting to note that no gluebal spectrum ever came out from
DS computations while one should expect that the propagator has to
contain this information. This would be an acid test for this kind of
approach.

Is there any expert out there about this matter to give some insights
on this delicate matter?

Jon

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