Geant4 FTF Model Description of the NA61/SHINE Collaboration Data on Strange Particle's Production in pp Interactions

TL;DR

This paper evaluates the Geant4 FTF model's ability to describe strange particle production in proton-proton collisions, adjusting parameters to improve agreement with recent NA61/SHINE experimental data.

Contribution

It introduces specific parameter settings within the Geant4 FTF model that better match experimental data on strange particle yields in pp interactions.

Findings

Good data description achieved with P_{Vec} = 0.6 for mesons with one strange quark.

Enhanced hyperon modeling requires modifications to diquark fragmentation functions.

Parameter tuning improves Monte Carlo simulation accuracy for strange particle production.

Abstract

The latest data by the NA61/SHINE collaboration on inclusive distributions of $K^{*0}$ and $\phi$ meson's, $\Xi^-$ and $\bar \Xi^+$ hyperon's production in ${\rm pp}$ interactions at $P_{lab}$ from 40 up to 158 GeV/c are considered. As it was shown before in experimental papers, Monte Carlo models -- EPOS 1.99, UrQMD 3.4 and Pythia 6, cannot describe reasonably well the data. In the presented paper, the yields of the particles are analyzed within the Geant4 FTF model. The meson yields are proportional to the probability of strange quark-antiquark pair production from the vacuum, and the probability to form a vector meson at a given quark-anti-quark content -- $P_{Vec}$. Detailed calculations presented in our paper show that a good description of the data can be reached for $P_{Vec}$ = 0.6 for a meson with one strange quark or antiquark. For a meson contained strange quark and strange antiquark, $P_{Vec}$ = 0.7. For a combination of non-strange quark and antiquark, $P_{Vec}$ = 0.5. The description of the $\Xi^-$ and $\bar \Xi^+$ hyperons requires a change of the diquark fragmentation function into hyperons and a special treatment (rearrangement) of fragmentation of anti-diquark -- diquark strings with low masses.