6533b7dafe1ef96bd126d842

RESEARCH PRODUCT

Color charge correlations in the proton at NLO: Beyond geometry based intuition

Risto PaatelainenHeikki MäntysaariHeikki MäntysaariAdrian DumitruAdrian Dumitru

subject

High Energy Physics - TheoryQuarkprotonitCOLLISIONSNuclear and High Energy PhysicsProtonFLOWQC1-999FOS: Physical sciencesGeometry114 Physical sciences01 natural sciencesMomentumGLUON DISTRIBUTION-FUNCTIONSHigh Energy Physics - Phenomenology (hep-ph)0103 physical sciencesSCATTERINGFIELDNUCLEON010306 general physicscolor charge correlatorsPhysicsprotons010308 nuclear & particles physicsPhysicsQUARKMomentum transferHigh Energy Physics - PhenomenologyDipoleHigh Energy Physics - Theory (hep-th)Impact parameterNucleonColor charge

description

Color charge correlators provide fundamental information about the proton structure. In this Letter, we evaluate numerically two-point color charge correlations in a proton on the light cone including the next-to-leading order corrections due to emission or exchange of a perturbative gluon. The non-perturbative valence quark structure of the proton is modelled in a way consistent with high-$x$ proton structure data. Our results show that the correlator exhibits startlingly non-trivial behavior at large momentum transfer or central impact parameters, and that the color charge correlation depends not only on the impact parameter but also on the relative transverse momentum of the two gluon probes and their relative angle. Furthermore, from the two-point color charge correlator, we compute the dipole scattering amplitude. Its azimuthal dependence differs significantly from a impact parameter dependent McLerran-Venugopalan model based on geometry. Our results also provide initial conditions for Balitsky-Kovchegov evolution of the dipole scattering amplitude. These initial conditions depend not only on the impact parameter and dipole size vectors, but also on their relative angle and on the light-cone momentum fraction $x$ in the target.

10.1016/j.physletb.2021.136560http://www.sciencedirect.com/science/article/pii/S0370269321005001