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FIZIKA B 13 (2004) 2, 383-396
 
DISORIENTED CHIRAL CONDENSATE AND CHARGE-NEUTRAL PARTICLE FLUCTUATIONS
IN HEAVY-ION COLLISIONS
MLADEN MARTINIS and VESNA MIKUTA-MARTINIS
Theoretical Physics Division, Ruđer Bošković Institute, P.O.B. 1016,
11001 Zagreb,CROATIA
E-mail addresses: martinis@rudjer.irb.hr
, vmikuta@rudjer.irb.hr
Received 2 September 2003; Accepted 30 August 2004
Online 14 November 2004
The possibility of large charge and isospin fluctuations of the disoriented chiral
condensate type (DCC-type) in high-energy heavy-ion collisions is studied within the
framework of an unitary eikonal model. The factorization property of the scattering
amplitude in the impact-parameter space of the leading two-nucleon system is used to study
semiclassical production of pions in the central region. A classical source function of a
pion field in the impact-parameter space was related to the semiclassical solutions of the
equation of motion of the nonlinear s-model coupled to quark
degrees of freedom. A multi-pion exchange potential between two quarks is derived. It is
shown that in the limit of soft chiral pion bremsstrahlung, the anomalously large
fluctuations in the ratio of neutral to charged pions are obtained without involving DCC
formation. We also show that the DCC-type fluctuations should be suppressed if a large
number of pions was produced via r-type clusters.
PACS numbers: 25.75.+ r, 12.38.Mh, 13.85.Tp, 24.60.Ky
UDC 539.12
Keywords: heavy-ion collisions, disoriented chiral condensate, chiral pion
bremsstrahlung
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