Equation of State for Hadronic Matter Produced in High-Energy Collisions

Abstract

Conflicting inclusive data from the CERN intersecting storage rings, treated with Landau's original hydrodynamical differential equations for an arbitrary equation of state ($p=H\epsilon$) describing the created hadronic matter fluid, lead to two different physical pictures. A recent Pisa-Stony Brook experiment suggests $p=0.3\mathrm{}\epsilon$; $p=\frac{\epsilon }{3}$ implies scale invariance, suggesting we are near an asymptotic region governed by scaling. However, earlier experiments imply that the dynamics may be quite different ($p\approx \frac{1}{2}\epsilon$,), with viscous hadronic "fluid" being produced.