Bochum 1998 – wissenschaftliches Programm

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HK: Hadronen und Kerne

HK 2: Heavy Ion Reactions I, Ultrarelativistic Energies

HK 2.4: Vortrag

Montag, 16. März 1998, 15:00–15:15, P

Wavelet analysis in search for the Disoriented Chiral Condensate in ultrarelativistic Pb+Pb Collisions — •T.K. Ghosh and H. Löhner — Kernfysisch Versneller Instituut, Groningen

In ultrarelativistic heavy-ion collisions sufficient energy density might be created to approach the phase transition to the quark-gluon plasma. At high temperatures and densities chiral symmetry is approximately realized in QCD, but spontaneously broken in normal nuclear matter by the formation of a chiral condensate. It has been argued [1] that in expanding hot matter transient domains of "disoriented" chiral condensate (DCC) develop. This effect results in anomalous isospin fluctuations which might be able to signal the chiral phase transition. A unique combination of position-sensitive charged-particle and photon detectors was employed in WA98 to allow investigations of these fluctuations in the ratio of charged to neutral pions.

The multiresolution wavelet analysis was applied to simulated data in order to determine the sensitivity of this technique. Subsequently, experimental data have been analyzed to separate a sample of candidate events which are characterized by large non-statistical fluctuations in the charged particle distributions. The corresponding low transverse-momentum photon spectra have been analyzed. We will discuss limits for the formation of DCC domains.

[1] K. Rajagopal, in Quark-Gluon Plasma 2, World Scientific, 1995.