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

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.