On the Size of the Chiral Condensate, Generalized Chiral Perturbation Theory and the DIRAC experiment
Abstract
Description
In the near future, the DIRAC collaboration will measure pion-pion scattering lengths with great precision. Those measurements are likely to shed some light on the problem of the size of the chiral quark-antiquark condensate. Although it is usually assumed to be as a large as (-225 MeV)^3, in the last years a more general approach, has been developed to accommodate either a large or a small alternative (-100 MeV)^3. Such a low value would also modify the standard temperature estimate at which the chiral phase transition occurs. In this work we briefly review the basic theoretical ideas related to this issue as well as the experiment that could help to establish any of the two scenarios.
To appear in the "Gribov Memorial Volume" Heavy Ion Physics. Acta Physica Hungarica New Series. Discussion on quark masses from QCD sum rules corrected and new references added
To appear in the "Gribov Memorial Volume" Heavy Ion Physics. Acta Physica Hungarica New Series. Discussion on quark masses from QCD sum rules corrected and new references added