Fusion of strings: Consequences at the highest cosmic ray energies

Abstract

Possible consequences at the highest cosmic ray energies of the collective effects, invoked to explain some features of heavy ion data at AGS and SPS (10–20 GeV per nucleon in center of mass system) are discussed. The fusion of the strings produced in the collision, have been introduced in the usual models of soft hadronic and nuclear interactions like DPM/QGSM to explain the strangeness enhancement, found in heavy ion collisions. Two effects of string fusion, namely the reduction of multiplicities and the enhancement of cumulative production, should strongly affect the first interactions in the shower and could be of importance to explain two features of the highest energy cosmic rays: their composition and the energy of the primary.