Measurements of ${\pi }^{\pm }$, $K^{\pm }$, p and $\overline{p}$ spectra in ${}^{40}{\text{Ar+}}^{45}\text{Sc}$ collisions at 13A to 150A $\text{ Ge }\text{ V }/c$

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 ${\pi }^{\pm },K^{\pm },p$ and $\overline{p}$ producedin ${}^{40}$Ar+${}^{45}$Sc collisions at beam momenta of 13A, 19A, 30A, 40A, 75A and 150A GeV/c. The analysis uses the 10% most central collisions, where the observed forward energy defines centrality. The energy dependence of the $K^{\pm }/{\pi }^{\pm }$ 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.