Gluon propagator in the infrared

[Lester]

I have read some recent preprints in arxiv recently:

http://arxiv.org/abs/0709.2042

http://arxiv.org/abs/0704.3260

http://arxiv.org/abs/hep-th/0610148

about the behavior of the gluon propagator in the infrared. Recent lattice computations seem to support them (e.g. http://arxiv.org/abs/0710.0412) and the agreement with the spectrum of a pure Yang-Mills theory appears quite striking (e.g. http://arxiv.org/abs/hep-lat/0404008) with a proper choice of the string tension. I was not able to find any obvious fault in the mathematical derivations in these papers. In other times such a very good coincidences with the known results should have excited the community or some rumors should have been going around. Nothing of this happened. So, why?

Lester

 

[mormonator_rm]

I have read some recent preprints in arxiv recently:

http://arxiv.org/abs/0709.2042

http://arxiv.org/abs/0704.3260

http://arxiv.org/abs/hep-th/0610148

about the behavior of the gluon propagator in the infrared. Recent lattice computations seem to support them (e.g. http://arxiv.org/abs/0710.0412) and the agreement with the spectrum of a pure Yang-Mills theory appears quite striking (e.g. http://arxiv.org/abs/hep-lat/0404008) with a proper choice of the string tension. I was not able to find any obvious fault in the mathematical derivations in these papers. In other times such a very good coincidences with the known results should have excited the community or some rumors should have been going around. Nothing of this happened. So, why?

Lester

Hmmm...

First of all, I think these first three papers listed are all slightly different presentations of the same work, and have been posted by the same author. I am not familiar with Marco Frasca, and I am not sure of his affiliation.

I would be more excited about these papers if they were supported by physical experiments, rather than just the fact that they fit well with recent lattice work. Also, I do not personally agree with his idea of the sigma meson being linked so heavily to the glueball masses; it is as if he is saying that the sigma is a sort of "super-light glueball". If that was true, then we would also see a super-light tensor resonance around 1000 to 1050 MeV, according to his same work. This resonance has never been seen, to my knowledge, and if it was seen it was certainly never confirmed. I think a tetraquark-meson mixing model is a much more plausible explanation of the sigma resonance than this.

Furthermore, he is taking all of this in the "infrared limit", which assumes the energy of an individual gluon is very small. Certainly this is his target region, but I cannot see this working well in the relativistic world of light-quark hadrons and glueballs. Maybe it would be okay for extremely massive quarks, but I do not know. I am no expert at this, either, so I hope someone who really knows this stuff comes along to comment.

 

[sir-pinski]

, thank you for bringing up this interesting topic. The behavior of the gluon propagator in the infrared is definitely a hot topic in current research. As you mentioned, recent lattice computations have provided strong evidence for the existence of an infrared fixed point, which is in agreement with the results predicted by the pure Yang-Mills theory. This is indeed a striking coincidence and has caused some excitement in the community.

However, I believe the reason why there hasn't been a lot of buzz or rumors surrounding this topic is because the results are still in the early stages and need to be further confirmed and studied. While the recent preprints and lattice computations provide strong evidence, they are not yet considered definitive proof. There may still be some uncertainties or assumptions in the mathematical derivations that need to be addressed.

In addition, the gluon propagator in the infrared is a complex and challenging topic, and not many researchers have the expertise or resources to delve into it. It may take some time for the results to be fully understood and for the community to fully embrace them.

Furthermore, the current focus of research in high energy physics has shifted towards other topics such as the search for new particles at the Large Hadron Collider (LHC). This could also be a reason why there hasn't been as much attention on the gluon propagator in the infrared.

But I believe that as more research is conducted and more evidence is gathered, the community will start to pay more attention to this topic. It is an exciting development in our understanding of the fundamental forces and could potentially have significant implications for our understanding of the strong force and the behavior of particles at high energies. So, let's keep an eye on this topic and see how it develops in the future.