Topological String in Quantum-Chromodynamical Chiral PhaseTransitions

Abstract

It is pointed out that if in heavy ion collision processes, thequark–gluon plasma SU(2) chiral phase transition really takes placeand the phase transition is a second order. Then the topological string,i.e., the π string, will be formed. The main effect of thisphenomenon is that there will be a number of pions produced by decay ofthe π string in the final state. The pions from the decay of theπ string lead to the same effect of decreasing theHanbury–Brown–Twiss peak in two-pion spectra which is just as that ofthe long-lived hadronic resonances. At relativistic heavy-ion collisionand large hadron collision energies, it is expected that thefactors are about α~0.7−0.9 and α~0.6−0.85,respectively.