Charged Particle Ratio Fluctuation as a Signal for QGP

Abstract

In this letter we argue that the event-by-event fluctuations of the ratio of the positively charged and the negatively charged pions provides a signal of quark-gluon plasma. The fact that quarks carry fractional charges is ultimately responsible for this distinct signal.

Comments: 4 pages in latex. Submitted simultaneously with hep-ph/0003169. This revised version to appear in PRL