Document Type

Article

Publication Date

2026

DOI

10.1016/j.physletb.2026.140470

Publication Title

Physics Letters B

Volume

877

Pages

140470

Abstract

We study the small-x asymptotics of unpolarized generalized parton distributions (GPDs) and generalized transverse momentum distributions (GTMDs). Unlike the previous works in the literature, we consider the case of non-zero (but small) skewness while allowing for non-linear contributions to the evolution equations. We first show that unpolarized GPDs and GTMDs at small x are related to the eikonal dipole amplitude N, whose small-x evolution is given by the BK/JIMWLK evolution equations, and to the odderon amplitude 𝒪, whose evolution is also known in the literature. We then show that the effect of non-zero skewness ξ ≠ 0 is to modify the value of the evolution parameter (rapidity) in the arguments for the dipole amplitudes N and 𝒪 from Y = ln(1/𝑥) to Y = ln min {1 /|x|, 1 /|ξ|}.

Rights

© 2026 The Authors. Funded by SCOAP³.

This is an open access article under the Creative Commons Attribution 4.0 International (CC BY 4.0) license.

Data Availability

No data was used for the research described in the article.

Original Publication Citation

Kovchegov, Y. V., Santiago, M. G., & Sun, H. (2026). Unpolarized GPDs at small x and non-zero skewness. Physics Letters B, 877, Article 140470. https://doi.org/10.1016/j.physletb.2026.140470 

ORCID

0000-0003-0770-6279 (Santiago)

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