Long Range Energy-energy Correlator at the LHC

Abstract

We study the forward-backward azimuthal angular correlations of hadrons in association with multi-particle production in the central rapidity region in proton-proton collisions at the LHC. We apply the nucleon energy-energy correlator framework, where the spinning gluon distribution introduces a nontrivial $\cos (2\varphi )$ asymmetries. We will demonstrate that the fundamental helicity structure of QCD amplitudes predicts a unique power counting rule: $\cos (2\varphi )$ asymmetry starts at $O({\alpha }_s^2)$ order for dijet, $O({\alpha }_s)$ for three jet and $O(1)$ for four (and more) jet productions. Our results will help us to understand the long standing puzzle of nearside ridge behavior observed in high multiplicity events of $pp$ collisions at the LHC.

Comments: 10 pages, 5 figures