The Weizsäcker-Williams distribution of linearly polarized gluons (and its fluctuations) at small x

Abstract

The conventional and linearly polarized Weizsäcker-Williams gluon distributions at small x are defined from the two-point function of the gluon field in light-cone gauge. They appear in the cross section for dijet production in deep inelastic scattering at high energy. We determine these functions in the small-x limit from solutions of the JIMWLK evolution equations and show that they exhibit approximate geometric scaling. Also, we discuss the functional distributions of these WW gluon distributions over the JIMWLK ensemble at rapidity $Y\sim 1/{\alpha }_s$. These are determined by a 2d Liouville action for the logarithm of the covariant gauge function $g^2\mathrm{tr}{A}^{+}(q)A^{+}(-q)$. For transverse momenta on the order of the saturation scale we observe large variations across configurations (evolution trajectories) of the linearly polarized distribution up to several times its average, and even to negative values.

10 pages, 3 figures; Proceedings of the XLVII International Symposium on Multiparticle Dynamics, Tlaxcala City, Mexico, September 11--15, 2017; to be published in EPJ-Conferences

References in corpus (7)

• Universality of Unintegrated Gluon Distributions at small x
• Relations between generalized and transverse momentum dependent parton distributions
• Direct Probes of Linearly Polarized Gluons inside Unpolarized Hadrons
• Transverse-momentum-dependent gluon distributions from JIMWLK evolution
• Associated production of a dilepton and a ${\rm Y}(J/\psi )$ at the LHC as a probe of gluon transverse momentum dependent distributions
• Cos(4 phi) azimuthal anisotropy in small-x DIS dijet production beyond the leading power TMD limit
• Fluctuations of the gluon distribution from the small-x effective action

Cited by in corpus (4)

• Measuring the Weizsaecker-Williams distribution of linearly polarized gluons at an EIC through dijet azimuthal asymmetries
• Event engineering studies for heavy flavor production and hadronization in high multiplicity hadron-hadron and hadron-nucleus collisions
• Sub-femtometer scale color charge correlations in the proton
• The ratio $R=\mathrm{d}{\sigma }_L/\mathrm{d}{\sigma }_T$ in heavy-quark pair leptoproduction as a probe of linearly polarized gluons in unpolarized proton