Wavelet Perspective of the Disoriented Chiral Condensate (DCC) (with Z. Huang, R. Thews and X. N. Wang); selected publications related to this topic: Z. Huang, I. Sarcevic, R. Thews and X. N. Wang, Phys. Rev. D54, 750 (1996); Z. Huang, I. Sarcevic, R. Thews and X. N. Wang, AZPH-TH/96-27, to appear in Proceedings of DPF'96.
QCD has an approximate global SU(2)_L * SU(2)_R chiral symmetry which at zero temperature is spontaneously broken in a way analogous to Higgs mechanism. The relevant order parameter is a four-component vector Phi =(sigma, phi) which in the physical vacuum, points in the sigma direction. At high temperatures, , the chiral symmetry is restored. Disoriented Chiral Condensate (DCC) is a medium where Psi is coherently misaligned. Namely, the vacuum orientation can be tilted into one of the pion directions, i.e. the chiral condensate points in different direction from that in the ground state. We have introduced a novel method for studying the formation of DCC in high energy heavy-ion collisions utilizing a discrete wavelet transformation. Due to its salient feature of space-scale locality, the discrete wavelet proves to be very effective in probing physics simultaneously at different locations in phase space and at different scales. We show that the probability distributions of the neutral pion fraction for various rapidity-bin sizes have distinctive shapes in the case of a DCC and exhibit a delay in approaching the Gaussian distribution required by the Central Limit Theorem. We find the wavelet power spectrum for a DCC to exhibit a strong dependence on the scale while an equilibrium system and the standard dynamical models such as HIJING have a flat spectrum.