Measurements of $\ddot{I}{€}^{\pm }$, $K^{\pm }$, $p$ and $\bar{p}$ spectra in ${}^{40}$Ar+${}^{45}$Sc collisions at 13$A$ to 150$A$ GeV/$c$

Abstract

The NA61/SHINE experiment at the CERN Super Proton Synchrotron studies the onset of deconfinement in strongly interacting matter through a beam energy scan of particle production in collisions of nuclei of varied sizes. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of $\ddot{I}{€}^{\pm }$, $K^{\pm }$, $p$ and $\bar{p}$ produced in ${}^{40}$Ar+${}^{45}$Sc collisions at beam momenta of 13$A$, 19$A$, 30$A$, 40$A$, 75$A$ and 150$A$~\GeVc. The analysis uses the 10\% most central collisions, where the observed forward energy defines centrality. The energy dependence of the $K^{\pm }$/$\ddot{I}{€}^{\pm }$ ratios as well as of inverse slope parameters of the $K^{\pm }$ transverse mass distributions are placed in between those found in inelastic $p$+$p$ and central Pb+Pb collisions. The results obtained here establish a system-size dependence of hadron production properties that so far cannot be explained either within statistical or dynamical models.