Possible evidence for deconfinement in hadron collisions

Abstract

The collision of hadrons at very high energies produces an entity whose energy density is extremely large resulting in the emission of a large number of hadrons. Though the entity may not have transited into the deconfined parton phase, the very high energy density may cause more than one charged hadron to be emitted at any instant. This yields a new multiplicity distribution, termed the GS distribution which fits the data as well as the popular negative binomial distribution. Neither the GS nor the NB distribution alone agrees with the data beyond 200 GeV, but a weighted sum of GS and NB distributions fits the experimental results exceedingly well. Since the negative binomial distribution arises from the branching of partons, we interpret the increase with energy of the negative binomial component in the weighted sum as the onset of a deconfined phase. The rising cross section for the negative binomial component parallels very closely the inclusive cross section for hadron jets which also is considered a consequence of parton branching.