Particles, Astrophysics, and Nuclear Physics Seminar
Magnetic Quasi-Particles in Hot QCD
Centre de Physique Théorique
Les Universités à Marseille, Luminy
Quasi-particles are almost free excitations in condensed matter systems. They can be either elementary or collective. In hot QCD the best known quasi-particles are the gluons. Because of deconfinement the electric color flux does disorder an electric flux loop as shown by lattice simulation. The quasi-particle picture is found to stay valid down to almost the deconfinement temperature.
The Wilson loop monitors color magnetic activity in the plasma. Its behavior from simulations is consistent, on the few percent level with a magnetic quasi-particle picture. These magnetic quasi-particles are collective excitations, and non-perturbative in terms of magnetic gluons. Their diluteness is controlled by the measured small ratio of string tension in units of the lowest glue ball mass. Implications for the pressure are discussed.
Monday, October 10, 2005
Gant Science Complex