## Today on arxiv

07/12/2010

As usual I read the daily coming from arxiv for some new papers to talk you about. This morning I have found some interesting ones I would like to say something on. Firstly, I would like to point out to you the paper by Marco Ruggieri and Raoul Gatto (see here). These authors discuss the behavior of QCD in presence of a strong magnetic field. The main tool they consider is the Nambu-Jona-Lasinio model. As you may know, I showed that this is the low-energy limit of QCD (see here and here) but there is also a paper by Kondo (see here) giving the same conclusion even if an expression for the Nambu-Jona-Lasinio constant is not obtained. Gatto and Ruggieri arrive at the important conclusion that a strong magnetic field changes in some way the phase diagram of QCD. I think that this conclusion is strongly supported by the consistency of the model they use. By my side, I think that this area of research is very promising to test my derivation of low-energy QCD.

An important paper as well is the one posted by BESIII Collaboration (see here). This paper gives the most precise measure of the $\eta'\rightarrow\eta\pi\pi$ decay obtained so far due to their larger statistics. They arrive at the important conclusion that for this decay interactions of the decay products is important. This conclusion is really important as implies a production of intermediate resonances as $\sigma$ and a0(980) as already discussed in my preceding post. The reason why this is so important is that this gives a strong support to the view of the $\sigma$ resonance as a glueball and to our current understanding of QCD given above.

Indeed, today there is again a paper of Juan Sanz-Cillero discussing this matter (see here). A more extended discussion has been given in my post here.