Study of identified particle ratios using cosmic rays Monte-Carlo models in pp collisions at s=0.9 and 7 TeV

Abstract

Cosmic rays with high energies can be studied only by measuring the extensive air showers of particles produced in the upper atmosphere. A complete simulation is required to know the primary particle properties, which is possible by studying the modeling of hadronic particle production at the generator level. In this connection, we report the yield ratios π−/π+, K−/K+, p̄/p (same particles ratio), p/π, p/K, and K/π (different particles ratio) with pseudorapidity (η) in pp collisions at s = 0.9 and 7 TeV using models being used for extensive air shower simulation. The ratios were measured at the following transverse momentum (pT) regions; low pT; 0 1.2 GeV/c and at different pseudorapidity (η) range of 3.0 < η < 4.5 and 2.5 < η < 4.5. These results are then compared with the data from the LHCb experiment. The ratio of π−/π+ from various model predictions agrees with the measurements at both energies at almost all pT and η regions. There is a reasonable agreement in K−/K+ and p̄/p ratios of model and experimental data at s = 900 GeV except few pT and η regions, in which the models do not describe the experimental data adequately. However, almost all the models fully describe the K−/K+ and p̄/p ratios at s = 7 TeV except few pT and η regions. Moreover, none of the models completely reproduce the different particle ratios at s = 900 GeV, with Pythia and EPOS producing better results. On the other hand, in most cases, the models’ predictions for the different particle ratios are consistent with experimental data s = 7 TeV. These kinds of studies will certainly help tune the Monte-Carlo generators being used for the studies of the hadron productions at various energies.

Keywords

• Identified particles ratios
• MC models
• pp collisions
• LHC energies