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

¹ Department of Physics, University of Oslo, PB 1048 Blindern, N-0316 Oslo, Norway
² Max-Planck-Institut für Intelligente Systeme, Heisenbergstr. 3, D-70569 Stuttgart, Germany
³ Institut für Augewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen, Germany
⁴ Skobeltsyn Institute of Nuclear Physics, Moscow State University, RU-119991 Moscow, Russia
⁵ National Research Nuclear University “MEPhI” (Moscow Engineering Physics Institute), Kashirskoe highway 31, Moscow, RU-115409, Russia

^a e-mail: larissa.bravina@fys.uio.no

Published online: 5 December 2017

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, 〈n_B(n_F)〉 = a + b_corrn_F, in the whole energy interval. Positive correlations arise because of mixing of sub-processes with different mean multiplicities. The increase of b_corr 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 b_corr is shown to be essentially zero.