The Quark-Gluon Plasma, its 'thermomether', and a path to Technicolor

by Maria Paola Lombardo (LNF)

Tuesday 29 Apr 2014, 15:00 → 16:30 Europe/Rome

131 (INFN edificio C)

When matter is heated up to and above 2 x 10^12 K it becomes a plasma of quarks and gluons - this state of matter briefly existed about 10 microseconds after the Big Bang and it is re-created in the collisions of ultrarelativistic heavy nuclei. Despite a rich theoretical and experimental activity the Quark-Gluon Plasma remains to some extent misterious, reflecting our still incomplete understanding of the phases of strong interations. After a short outline of the main experimental and theoretical studies, with emphasys on the lattice approach, the talk will concentrate on the analysis of heavy quarkonia. A very well known diagnostic tool -- which warrants quarkonia the role of 'thermometer' of the QGP -- the analysis of quarkonia has reserved to us a few surprises, developing into a field of its own. The lattice results will be discussed vis-a-vis the experimental findings from SPS to RHIC and the LHC. In the last part of the talk I will set the study of the Quark-Gluon Plasma within the general framework of the phases of strong interactions in an extended space spanned by the temperature and the matter content. Here, the thermal QCD transition turns out to be connected with the cold essential singularity typical of Technicolor-like models and I will present on overview of the contemporary results and challenges of this rapidly evolving field.