Abstract
The charged particle multiplicity as a function of pseudorapidity (n), transverse momentum spectra (p(T)), average transverse momentum (< p(perpendicular to)>), and multiplicity as a function of the number of charged particles have been studied using various cosmic rays and non-cosmic rays Monte Carlo (MC) event generators in pp collisions at root s = 13 TeV. The distributions are investigated for transverse momentum, p(T) > 0.5 GeV, pseudorapidity |n|< 2.5 and requirement of at least one charged particle produced in an event. Additionally, these measurements for reduced phase space region with a requirement of |n|< 0.8 are also performed. We show the models' predictions in contrast with the experimental data from ATLAS and CMS. It has been observed from these measurements that none of the discussed model-based event generators completely predict the experimental results except EPOS, which, in general, has excellent agreement with the data. The cosmic-ray (CR) simulation models can cover the central region of rapidity density distributions. Gribov's Reggeon Field Theory (RFT)-based models treat the diffractive scattering more advanced than the CR models. The model-based observations can be constructive to re-tune some basic parameters and help to study the extrapolation at the highest possible energies. These observations can also help put possible constraints on improving the pQCD and non-pQCD-based hadronic event generators.