Saturation Correction to Projectile -- some ${\cal{O}}(g^5)$ results within LCPT

TL;DR

This paper provides a detailed calculation of the ${ m O}(g^5)$ saturation correction in projectile gluon production within light cone perturbation theory, extending previous ${ m O}(g^3)$ results for nucleus-nucleus collisions.

Contribution

It introduces the first analytic calculation of a sample graph at ${ m O}(g^5)$, advancing the understanding of saturation effects in high-energy collisions.

Findings

Calculated a sample ${ m O}(g^5)$ graph in LCPT.

Extended saturation correction analysis beyond ${ m O}(g^3)$.

Provided insights into higher-order contributions in gluon production.

Abstract

We revisited the first saturation correction to projectile in nucleus-nucleus collisions \cite{Chirilli:2015tea} within diagrammatic light cone perturbation theory (LCPT). To get an analytic expression for the saturation correction in projectile authors in \cite{Chirilli:2015tea} calculated complete ${\cal{O}}(g^3)$ amplitudes, where the main results are given in transverse coordinate space. However to find the complete first saturation correction in the projectile, one needs to calculate both ${\cal{O}}(g^3)$ and ${\cal{O}}(g^5)$ gluon production amplitudes. We here present a detailed calculation of a sample graph at ${\cal{O}}(g^5)$ in diagrammatic light cone perturbation theory.