Measurement of forward-backward multiplicity correlations in lead-lead, proton-lead, and proton-proton collisions with the ATLAS detector

M. Aaboud, G. Aad, B. Abbott, J. Abdallah, O. Abdinov, B. Abeloos, R. Aben, O. S. AbouZeid, N. L. Abraham, H. Abramowicz, H. Abreu, R. Abreu (+2846 others)
2017 Physical Review C  
Two-particle pseudorapidity correlations are measured in √(s_NN) = 2.76 TeV Pb+Pb, √(s_NN) = 5.02 TeV p+Pb, and √(s) = 13 TeV pp collisions at the LHC, with total integrated luminosities of approximately 7 μb^-1, 28 nb^-1, and 65 nb^-1, respectively. The correlation function C_ N(η_1,η_2) is measured as a function of event multiplicity using charged particles in the pseudorapidity range |η|<2.4. The correlation function contains a significant short-range component, which is estimated and
more » ... stimated and subtracted. After removal of the short-range component, the shape of the correlation function is described approximately by 1+〈a_1^2〉η_1η_2 in all collision systems over the full multiplicity range. The values of √(〈a_1^2〉) are consistent between the opposite-charge pairs and same-charge pairs, and for the three collision systems at similar multiplicity. The values of √(〈a_1^2〉) and the magnitude of the short-range component both follow a power-law dependence on the event multiplicity. The η distribution of the short-range component, after symmetrizing the proton and lead directions in p+Pb collisions, is found to be smaller than that in pp collisions with comparable multiplicity.
doi:10.1103/physrevc.95.064914 fatcat:rokixs77rbefzduddzww26m3cu