Scaling properties of the mean multiplicity and pseudorapidity density in $e^{-}+e^{+}$, $e^{\pm}$+p, p($\bar{\mathrm{p}}$)+p, p+A and A+A(B) collisions

Understand

The pseudorapidity density (dN/deta) for p+p, p+A and A+A(B) collisions, and the mean multiplicity <Nch> for ee, ep, and p+p collisions, are studied for an inclusive range of beam energies (Root_s).

• Characteristic scaling patterns are observed for both dN/deta and <Nch>, consistent with a thermal particle production mechanism for the bulk of the soft particles produced in all of these systems.
• They also validate an essential role for quark participants in these collisions.
• The scaled values for dN/deta and <Nch> are observed to factorize into contributions which depend on log(Root_s) and the number of nucleon or quark participant pairs (Npp).