Interpretation of particle yields in pp interactions at √S = 8.8, 12.3 and 17.3 GeV within statistical hadronization model

Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland

^* e-mail: tomek.matulewicz@cern.ch

Published online: 1 March 2023

Abstract

The statistical hadronization model ThermalFist was applied to numerous hadron yields measured in p+p collisions at √S = 8.8, 12.3 and 17.3 GeV, including recently published yields of ϕ-mesons, measured by the NA61/SHINE Collaboration. We consistently used the energy-dependent widths of Breit-Wigner mass distributions of hadronic resonances, as this approach was generally found to provide better agreement with experimental data. The well-established experimental ϕ meson yields are consequently accounted for (although neglecting this particle was found to improve the fit quality). The canonical treatment of particles with open strangeness with the grand canonical approach for non-strange particles gave a moderately reasonable agreement with the measured yields, only when the volume of strange particles was allowed to vary freely. In all the studied cases this volume is found to be greater than the canonical one.