Forward-backward multiplicity correlations in proton-proton collisions from several GeV to LHC energies

Abstract

Forward-backward multiplicity correlations in pp collisions at LHC energies are studied with the quark-gluon string model. Comparison with experimental data and with model calculations for lower energies is performed. The model correctly reproduces the linear slope of the correlations, 〈nB(nF)〉 = a + bcorrnF, in the whole energy interval. Positive correlations arise because of mixing of sub-processes with different mean multiplicities. The increase of bcorr with rising collision energy is linked to the increase of the variety of sub-processes going via the soft and hard multi-Pomeron exchanges. For the events with fixed amount of Pomerons the correlation slope bcorr is shown to be essentially zero.