Model studies of $V^0$ production ratios in pp collisions at $\sqrt{\textrm{s}} = 0.2, 0.9$, and 7 TeV

Abstract

This paper has compared $V^0$ ratios between HIJING, Sibyll, and QGSJET model-based event generators. The ratios under study are $\overline{\Lambda }$/$\Lambda$, $\overline{\Lambda }$/$\textrm{K}^{0}_{\textrm{S}}$ and $\Xi ^{-}$/$\Lambda$ as a function of rapidity y, rapidity loss ($\Delta y$) and $p_{\textrm{T}}$ from pp collisions at $\sqrt{\textrm{s}}$ = 0.2, 0.9, and 7 TeV and these simulations are then compared with the STAR and LHCb fiducial phase spaces in different $p_{\textrm{T}}$ regions. Although the models could produce some ratios in a limited $p_{\textrm{T}}$ or y region, none completely predicts the experimental results. The QGSJET has good predictions with the data in most cases, but since the model does not include $\Xi$ particle definition, it does not give any predictions for $\Xi$/$\Lambda$ ratios. The extrapolation to the highest possible energies can be studied by re-tuning some basic parameters based on current and previous measurements. These kinds of systematic comparison studies are also helpful in applying certain constraints on the pQCD and non-pQCD-based hadronic event generators to significantly improve the predictions of Standard Model physics at the RHIC and LHC experimental data for the understanding of underlying physics mechanisms in high energy collisions.