Pseudorapidity dependence of the pT spectra of charged hadrons in pp collisions at √S=0.9 and 2.36 TeV

We report the predictions of different Monte Carlo event generators including HUING, Pythia, and QGSJETII in comparison with the experimental data measured by the CMS Collaboration at CERN in proton-proton (pp) collisions at center-of-mass energy root s = 0.9 and 2.36 TeV. The CMS experimental transverse momentum (p(T) or p(perpendicular to)) spectra of charged hadrons were measured for pseudorapidity range 0 <= eta <= 2.4 with bin width of eta = 0.2 (for p(T) from 0.1 to 2 GeV/c) and a single bin of eta for vertical bar eta vertical bar< 2.4 (for p(T) from 0.1 to 4 GeV/c). Pythia reproduced the p(T) spectra with reasonable agreement for most of the p(T) range. It depicts better results in the case of the vertical bar eta vertical bar < 2.4 than HUING and QGSJETII which could reproduce the spectra in a limited p(T) range. Furthermore, to analyze the p(T) spectra of charged hadrons measured by the CMS Collaboration, we used a three-component function (structured from the Boltzmann distribution) and the q-dual function (from the q-dual statistics) to extract parameter values relevant for the study of bulk properties of hadronic matter at high energy. We have also applied the two analytic functions over the model predictions. The values extracted by the functions from the RUING and Pythia models are closer to the experimental data than the QGSJETII model. Although the models could reproduce the p(T) spectra of all charged particles in some of the p(T) range but none of them could reproduce the distributions over the entire p(T )range and in all the pseudorapidity regions.

Automated summary

This study compares the predictions of different Monte Carlo event generators (including HUING, Pythia, and QGSJETII) with experimental data obtained from the CMS Collaboration at CERN. Results show that Pythia reproduces the experimental data more accurately in most cases, while HUING and QGSJETII can only reproduce the data within a limited range. Additionally, parameter values relevant to the study of bulk properties of hadronic matter at high energy were extracted using two analytic functions, and it was found that the values extracted from the RUING and Pythia models are closer to the experimental data than those extracted from the QGSJETII model.