Models prediction of hadrons production ratios in pp collisions at s = 7 TeV

Abstract

The pseudorapidity [Formula: see text] dependence of charged-particles ratios in three transverse momentum [Formula: see text] regions, obtained by hadron production models, in proton–proton collisions at 7 TeV are compared with the measurements of LHCb detector. Compared to the experimental data, the [Formula: see text] ratios are independent of [Formula: see text] and [Formula: see text] and are very well predicted by all models (DPMJETIII, EPOS1.99, EPOS-LHC, HIJING1.383, QGSJETII-04 and Sibyll2.3c). All models predict the [Formula: see text] ratio at low [Formula: see text] for [Formula: see text], but underestimate afterward while reproducing the experimental data at medium and high [Formula: see text] very well. The [Formula: see text] ratio is described by the models very well at high [Formula: see text] in the low and medium [Formula: see text] region. At high [Formula: see text], models predict the experimental data well, except Sibyll2.3c that slightly overestimates. The [Formula: see text] ratio is predicted by EPOS1.99, HIJING and Sibyll at low [Formula: see text] and EPOS-LHC, EPOS1.99 and Sibyll predicted at high [Formula: see text] for low [Formula: see text]. For medium [Formula: see text], EPOS1.99 and Sibyll predict very well for [Formula: see text] while EPOS-LHC and HIJING models reproduce the data for [Formula: see text]. All models underpredict the [Formula: see text] ratio for [Formula: see text]. For the [Formula: see text] and [Formula: see text] ratios, only Sibyll and EPOS1.99 models could reproduce some regions of [Formula: see text] and [Formula: see text]. None of the models satisfactorily predict all the ratios. the same particle ratios are well described by most of the models while the discrepancies occur mostly in predicting the different particles ratios.