Energy evolution of T-odd gluon TMDs at small $x$

TL;DR

This paper investigates the energy evolution of T-odd gluon transverse momentum dependent distributions at small x, highlighting their connection to the spin-dependent odderon and proposing experimental studies at RHIC.

Contribution

It introduces the energy evolution of T-odd gluon TMDs at small x and links them to the spin-dependent odderon, proposing azimuthal asymmetries in polarized proton collisions for experimental access.

Findings

Model predictions for azimuthal asymmetries as functions of jet or photon transverse momentum.

Identification of the small-x T-odd gluon TMDs as originating from the spin-dependent odderon.

Proposal to study their evolution through virtual photon-jet production at RHIC.

Abstract

We study the energy or TMD evolution of the three leading twist dipole type T-odd gluon TMDs inside a transversely polarized nucleon, all of which at small $x$ dynamically originate from the spin dependent odderon. Their energy dependence presents a unique opportunity to study the polarization dependent TMD evolution in the small-$x$ region, where the distributions are identical up to a normalization constant at tree level. We further propose to study their evolution via azimuthal asymmetries in virtual photon-jet production in polarized proton-proton collisions at RHIC. We present model predictions for the asymmetries as functions of the large jet or photon transverse momentum and $Q^2$ which set the hard scales in this process.