Invariant mass analyses of (p, π±) pairs in 58Ni + Cu collisions at 1.97A GeV have been performed and show correlations resulting from the decays of the Δ resonance, the Δ baryon, and possibly the N*(1440) resonance. A reduction in the Δ mass is observed and the mass reduction increases with collision centrality. Events generated by the relativistic cascade model (ARC) also reveal a mass reduction. The mass reduction is related to the size of the reaction volume and the details of Δ production mechanisms in heavy ion collisions.
ASJC Scopus subject areas
- Physics and Astronomy(all)