News on mean pion multiplicity from NA61/SHINE

TL;DR

This paper presents preliminary measurements of mean negatively charged pion multiplicities in central Ar+Sc and Be+Be collisions at CERN SPS, using new extrapolation methods and comparisons across experiments to understand particle production.

Contribution

It introduces a new scheme to calculate the mean number of wounded nucleons using the EPOS MC model and applies it to pion multiplicity data from various collision systems.

Findings

Measured rapidity distributions were extrapolated to unmeasured regions.

Comparison of pion-to-wounded nucleon ratios across different collision systems.

Preliminary results for mean negatively charged pion multiplicities in specific collision systems.

Abstract

NA61/SHINE is a large acceptance fixed target experiment at the CERN SPS which studies final hadronic states in interactions between various particles and nuclei. The main topic of this contribution are preliminary results for mean negatively charged pion multiplicities $\langle \pi^{-} \rangle$ from central Ar+Sc and Be+Be collisions. The data were taken recently by the NA61/SHINE collaboration for a wide range of beam momenta. Measured rapidity distributions $\frac{dn}{dy}$ were extrapolated to unmeasured regions to obtain total multiplicities $\langle \pi^{-} \rangle$. A new scheme to calculate the mean number of wounded nucleons $\langle W \rangle$ utilizing the EPOS MC model is described. Using data from other experiments, a comparison of $\frac{\langle \pi \rangle}{\langle W \rangle}$ for different collisions and beam momenta is discussed