Pion production in p+p interactions and Be+Be collisions at the CERN SPS energies

TL;DR

This paper reports measurements of charged pion production in p+p and Be+Be collisions at CERN SPS energies, comparing results with Pb+Pb collisions to explore the onset of deconfinement in high-energy nuclear interactions.

Contribution

It provides new spectra of charged pions in p+p and Be+Be collisions at various energies, contributing to the understanding of deconfinement onset in nuclear matter.

Findings

Pion spectra in p+p and Be+Be collisions at 20A-158A GeV/c.

Comparison with Pb+Pb collision data at the same energies.

Insights into the energy dependence of hadron production.

Abstract

Evidence for the onset of deconfinement in central Pb+Pb collisions was reported by NA49 in fixed target measurements at beam momentum 30A GeV/c. This observation motivated the NA61/SHINE program started in 2009 at the CERN SPS, which, in particular, aims to study properties of the onset of deconfinement by measurements of hadron production in proton-proton, proton-nucleus and nucleus-nucleus collisions. This contribution presents spectra of charged pions produced in p+p interactions and $^7$Be+$^9$Be collisions at 20A-158A GeV/c beam momentum. The NA61/SHINE results are compared with the corresponding NA49 data from central Pb+Pb collisions at the same beam momenta per nucleon.