Measurements of $\ddot{I}{€}^{\pm }$, $K^{\pm }$, $p$ and $\bar{p}$ spectra in ${}^7$Be+${}^9$Be collisions at beam momenta from 19$A$ to 150$A$ GeV/$c$ with the NA61/SHINE spectrometer at the CERN SPS

Abstract

The NA61/SHINE experiment at the CERN Super Proton Synchrotron (SPS) studies the onset of deconfinement in hadron matter by a scan of particle production in collisions of nuclei with various sizes at a set of energies covering the SPS energy range. 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 the 20$\%$ most $central$ ${}^7$Be+${}^9$Be collisions at beam momenta of 19$A$, 30$A$, 40$A$, 75$A$ and 150$A$ GeV/$c$. 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 close to those found in inelastic $p$+$p$ reactions. The new results are compared to the world data on $p$+$p$ and Pb+Pb collisions as well as to predictions of the EPOS, UrQMD, AMPT, PHSD and SMASH models.

52 pages, 38 figures