Eur. Phys. J. Plus (2023) 138: 645
https://doi.org/10.1140/epjp/s13360-023-04269-7

Regular Article

Study of baryon number transport using model simulations in pp collisions at LHC energies

¹ Centre for Cosmology, Particle Physics and Phenomenology (CP3), Université Catholique de Louvain, 1348, Louvain-la-Neuve, Belgium
² Department of Physics, Quaid-i-Azam University, 44000, Islamabad, Pakistan
³ Department of Physics, Riphah International University, 44000, Islamabad, Pakistan
⁴ Department of Modern Physics, University of Science and Technology of China, 230026, Hefei, China
⁵ Department of Mathematics and Sciences, Prince Sultan University, 11586, Riyadh, Saudi Arabia
⁶ Department of Physics, Susquehanna University, 17870, Selinsgrove, PA, USA

^a usman.ashraf@cern.ch

Received: 12 September 2022
Accepted: 7 July 2023
Published online: 24 July 2023

Abstract

We report on the excitation function of anti-baryon to baryon ratios ($\overline{p}/p$, $\overline{\mathrm{\Lambda }}$/$\mathrm{\Lambda }$ and ${\overline{\mathrm{\Xi }}}^{+}$/ ${\mathrm{\Xi }}^{-}$) in pp collisions at $\sqrt{\text{s}}$ = 0.9, 2.76, 7 TeV from DPMJET-III, Pythia 8, EPOS 1.99, and EPOS-LHC model simulations. The computed ratios obtained from model simulations are then compared to the experimental results given by the ALICE experiment. To study the predictions of these models at $\sqrt{\text{s}}$= 13.6 TeV, at which LHC is taking Run-3 data in pp collisions, we also computed these ratios at 13.6 TeV. The anti-baryon to baryon ratios are extremely important for the study of baryon number transport mechanism. These ratios help to determine the carriers of baryon number and in the extraction of baryon structure information. We find that these ratios are independent of both the transverse momentum ($p_{\text{T}}$) and the rapidity (y). Even though all models show a good agreement with experimental data, the ratios extracted from DPMJET-III model closely describes the data at all energies. We found that these ratios converge to unity for various model predictions from 0.9 to 13.6 TeV. It is also observed that DPMJET-III and EPOS-LHC models exhibits an increase of the ratio with strangeness content for the given energy and this effect is more prominent in $\overline{\mathrm{\Lambda }}$/$\mathrm{\Lambda }$ and ${\overline{\mathrm{\Xi }}}^{+}$/ ${\mathrm{\Xi }}^{-}$ ratios. For all species, the ratio increases with the increase in energy similar to the experimental data. At lower energies, an excess production of baryons over anti-baryons is observed. However, this effect vanishes at higher energies due to the baryon–anti-baryon pair production, and the baryon–anti-baryon yield becomes equal. We additionally compute the asymmetry, ($A\equiv \frac{N_p-N_{\overline{p}}}{N_p+N_{\overline{p}}}$) for protons from various model simulations. The asymmetry shows a decreasing trend with an increase in energy from 0.9 to 7 TeV for all energies. This trend is confirmed by model predictions at $\sqrt{\text{s}}$ = 13.6 TeV, which will help to put possible constraints on model calculations at $\sqrt{\text{s}}$ = 13.6 TeV once the Run-3 data for LHC becomes available.