Low-m⊥ π+-π− asymmetry enhancement from hadronization of QGP

We show that in sudden hadronization of QGP a non-equilibrium value of the pion phase space occupancy parameter γq>1 is expected in order to accommodate the entropy excess in QGP and the process of gluon fragmentation. When γq is near to its maximum allowed value, pion overabundance is shown to arise at low m⊥, where the charged pion asymmetry is also amplified. These effects are considered and we show that their magnitude suffices to explain pertinent experimental data obtained in 160–200A GeV Pb- and S- induced reactions.