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arXiv · 1811.05818

On the origin of forward-backward multiplicity correlations in $pp$ collisions at ultrarelativistic energies

L. V. Bravina·J. Bleibel·E. E. Zabrodin
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Abstract

We study multiplicity correlations of hadrons in forward and backward hemispheres in $pp$ inelastic interactions at energies 200GeV $\leq \sqrt{s} \leq$ 13TeV within the microscopic quark-gluon string model. The model correctly describes (i) the almost linear dependence of average multiplicity in one hemisphere on the particle multiplicity in other hemisphere in the center-of-mass frame; (ii) the increase of the slope parameter $b_{corr}$ with rising collision energy; (iii) the quick falloff of the correlation strength with increase of the midrapidity gap; (iv) saturation of the forward-backward correlations at very high multiplicities. Investigation of the sub-processes on partonic level reveals that these features can be attributed to short-range partonic correlations within a single string and superposition of several sub-processes containing different numbers of soft and hard Pomerons with different mean multiplicities. If the number of Pomerons in the event is fixed, no forward-backward correlations are observed. Predictions are made for the top LHC energy $\sqrt{s} = 13$TeV.

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L. V. Bravina, J. Bleibel, E. E. Zabrodin. 2018-11-14. On the origin of forward-backward multiplicity correlations in $pp$ collisions at ultrarelativistic energies. https://doi.org/10.1016/j.physletb.2018.10.053

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