Spectra and mean multiplicities of π- in central 40Ar+45Sc collisions at 13A, 19A, 30A, 40A, 75A and 150AGeV/c beam momenta measured by the NA61/SHINE spectrometer at the CERN SPS

The physics goal of the strong interaction program of the NA61/SHINE experiment at the CERN Super Proton Synchrotron (SPS) is to study the phase diagram of hadronic 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 differential inclusive spectra of transverse momentum, transverse mass and rapidity of pi(-) mesons produced in central Ar-40+Sc-45 collisions at beam momenta of 13A, 19A, 30A, 40A, 75A and 150A GeV/c. Energy and system size dependence of parameters of these distributions - mean transversemass, the inverse slope parameter of transverse mass spectra, width of the rapidity distribution and mean multiplicity - are presented and discussed. Furthermore, the dependence of the ratio of the mean number of produced pions to the mean number of wounded nucleons on the collision energy was derived. The results are compared to predictions of several models.

Automated summary

The study aims to explore the phase diagram of hadronic matter by examining particle production in collisions of different-sized nuclei, presenting parameters such as mean transverse mass, slope parameter, rapidity distribution width, mean multiplicity, and the ratio of produced pions to wounded nucleons as a function of collision energy. Results are compared to various models to understand the behavior of hadronic matter at different energies and system sizes.