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Physical Society Colloquium
Dr. Ralf Rapp
Department of Physics and Astronomy After a few general remarks on the physics issues to be investigated in the collisions of heavy ions at (ultra-) relativistic energies we focus on the theoretical description of more specific signals from strong interaction matter related to electromagnetic observables (photons and dilepton pairs). The key object to be studied is the electromagnetic current correlator which in the low-mass region is saturated by the light vector mesons. We discuss their modifications in a hot and dense hadronic medium and show that the ensuing effects are important for understanding recent dilepton data taken in Pb-Pb collisions at the CERN-SpS. In particular we address possible implications for the identification of the Quark-Gluon Plasma, where chiral symmetry (which is spontaneously broken in the QCD vacuum) is restored, and quarks and gluons are liberated from their hadronic bound states.
Tuesday, May 30th 2000, 15:30 |