Transverse momentum spectra of mesons in p+p collisions at CERN SPS energies from the UrQMD transport model

Vitalii Ozvenchuk,Andrzej Rybicki

doi:10.1051/epjconf/201919905003

Vitalii Ozvenchuk, Andrzej Rybicki

Open Access

https://doi.org/10.1051/epjconf/201919905003

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Abstract

The UrQMD transport model, version 3.4, is used to study the new experimental data on total yields, rapidity distributions and transverse momentum spectra of π±, K±, p and $\bar p$ produced in inelastic p + p interactions at SPS energies, recently published by the NA61/SHINE Collaboration. The comparison of model predictions to these new measurements is presented as a function of collision energy. In addition, we compare with the experimental data the results on kaon-over-pion multiplicity ratio and the inverse slope parameter of negative kaons produced at midrapidity. A complicated pattern of discrepancies between the experimental data and the UrQMD transport model is apparent. We conclude that new experimental data analyzed in this contribution still constitute a challenge for the present version of the model.

Highlights

The NA61/SHINE Collaboration published new, detailed experimental results [1] on inclusive spectra and mean multiplicities of π±, K±, p and pproduced in inelastic p + p interactions at 20, 31, 40, 80 and 158 GeV/c at the CERN Super Proton Synchrotron (SPS)
Recent NA61/SHINE data on particle production in inelastic p + p collisions at CERN SPS energies suggests a step-like structure in the inverse slope parameter of K− at midrapidity, qualitatively similar to that observed in Pb + Pb collisions [4]
We present the results for the rapidity distributions of π+ and K+ as well as for the transverse momentum spectra of K− produced in inelastic p + p interactions at different collision energies obtained from the UrQMD calculations

Summary

Introduction

The NA61/SHINE Collaboration published new, detailed experimental results [1] on inclusive spectra and mean multiplicities of π±, K±, p and pproduced in inelastic p + p interactions at 20, 31, 40, 80 and 158 GeV/c at the CERN Super Proton Synchrotron (SPS) These measurements were meant as a baseline in the study of the properties of the onset of deconfinement and the possibility to observe the critical point of strongly-interacting matter in nucleus-nucleus collisions. The position of the plateau (in collision energy) agrees with that of the ”horn” which was observed previously [3, 4] in central Pb + Pb reactions by the NA49 Collaboration at the CERN SPS and was predicted, within the statistical model of the early stage [5], as a signature of the onset of deconfinement Another important observable is the inverse slope parameter of the pT -distributions of negative kaons. The application of theoretical models in order to study the new p + p experimental data is valuable as it gives a chance to follow in detail whether these similarities between p + p and heavy-ion collisions have a decisive or only a casual importance for our knowledge of deconfined matter

The UrQMD transport model

Results

Summary