This series of winter workshops is devoted to nuclear dynamics, a term referring to a broad range of physics topics that can be explored by bringing the nuclear system far away from its ordinary tranquil state, usually by means of nuclear collisions. As ever more powerful accelerators and increasingly refined detector systems are becoming available, the scope of these studies has steadily expanded. Not only has the accessible domain of the nuclear chart grown explosively, but prospects have appeared for probing fundamental features of strongly interacting systems. A long-standing goal has been to probe the non-perturbative properties of QCD and the expected transition to a deconfined quark-gluon plasma phase. Of somewhat more recent date is the recognition that high-energy nucleus-nucleus collisions may also provide key insights into chiral symmetry. In particular, the collision may produce extended regions of space within which chiral symmetry is temporarily nearly restored and the subsequent non-equilibrium relaxation towards the normal vacuum may then produce large-amplitude coherent oscillations of the pion field. This hypothetical phenomenon, which has been dubbed disoriented chiral condensates, may lead to an enhanced emission of isospin-polarized soft pions.1–6 We shall briefly review the key DCC features and discuss various possible signals for its actual occurrence. For a recent DCC review, see ref. 7.
KeywordsChiral Symmetry Field Fluctuation Linear Sigma Model Dilepton Production Pion Field
Unable to display preview. Download preview PDF.
- 3.J.D. Bjorken, K.L. Kowalski, and C.C. Taylor, SLAC-PUB-6109 (1993).Google Scholar
- 4.J.D. Bjorken, K.L. Kowalski, and C.C. Taylor, hep-ph/9309235.Google Scholar
- 7.J.P. Blaizot and A. Krzywicki, Acta Phys. Polon. 27 (1996) 1687.Google Scholar
- 26.K. Rajagopal, Hirschegg Winter Workshop XXV (1997); hep-ph/9703258.Google Scholar
- 28.D. Boyanovsky, H.J. de Vega, R. Holman, and S. Prem Kumar, PRD56 (1997) 5233.Google Scholar