Reduction of CGC prescription dependence through higher-order and beyond-eikonal corrections

Determine whether the substantial dependence of nuclear SIDIS predictions on the choice of the small-x momentum fraction x_g is reduced by incorporating beyond-eikonal and next-to-leading-order corrections to the Color Glass Condensate framework for Electron-Ion Collider kinematics.

Background

The paper compares large-transverse-momentum semi-inclusive deep inelastic scattering calculated using collinear factorization and the Color Glass Condensate (CGC) framework. For nuclear targets in projected Electron-Ion Collider kinematics, the authors find that the CGC nuclear-to-proton SIDIS ratio changes substantially depending on whether the dipole amplitude is evaluated at x_g=x_B or at a transverse-momentum-dependent prescription x_g(P_t,Q_s). This sensitivity indicates that the eikonal CGC approximation may not be quantitatively robust at the studied, nonasymptotically small values of x_B.

The unresolved issue is whether this prescription dependence is an artifact of restricting the calculation to leading order and leading eikonal accuracy. Resolving it requires calculations including both beyond-eikonal effects, which account for finite longitudinal momentum transfer, and next-to-leading-order corrections to CGC SIDIS.