Sub-leading correction of two-gluon rapidity correlations of strong colour field

TL;DR

This paper calculates two-gluon rapidity correlations within the Color Glass Condensate framework, highlighting the differences between leading and sub-leading order contributions and their dependence on saturation momentum.

Contribution

It introduces the calculation of sub-leading order corrections to two-gluon rapidity correlations in CGC EFT, revealing their quantum nature and momentum dependence.

Findings

Leading order enhances both short- and long-range correlations.

Sub-leading order mainly contributes short-range quantum correlations.

Sub-leading corrections are smaller but non-negligible.

Abstract

In the framework of Color Glass Condensate (CGC) effective field theory (EFT), we calculate two-gluon rapidity correlations in the leading and sub-leading orders of $p_\perp/Q_s$. In the leading order, both short- and long-range rapidity correlations are enhanced. In contrast, the contribution of sub-leading order is mainly short range quantum correlations. It is much smaller than that of the leading one, but is not negligible. Transverse momentum dependence of rapidity correlation shows that the leading order is sensitive to the saturation momentum of two incident particles, but the sub-leading one is not.