Sudakov suppression of the Balitsky-Kovchegov kernel

Abstract

To sum high-energy leading logarithms in a consistent way, one has to impose the strong ordering in both projectile rapidity and dense target rapidity simultaneously, which results in a kinematically improved Balitsky-Kovchegov(BK) equation. We find that beyond this strong ordering region, the important sub-leading double logarithms arise at high order due to the incomplete cancellation between real corrections and virtual corrections in a t-channel calculation. Based on this observation, we further argue that these double logarithms are the Sudakov type ones, and thus can be resummed into an exponential leading to a Sudakov suppressed BK equation.

Dijet photoproduction at low x at next-to-leading order and its back-to-back limit

“…In kinematics with a hierarchy of scales s µ 2 µ 2 b Λ 2 QCD , the necessity arises to simultaneously treat large ln(s/µ 2 ) and ln(µ 2 /µ 2 b ) logarithms. Such a combined low-x and Sudakov resummation is the subject of intensive research, some of which very recent, either JHEP10(2022)184 based on the HEF approach [33][34][35][36][37][38][39][40][41][42][43], BFKL [44,45], BK [46], the CGC [47][48][49][50][51][52], and TMD factorization [53][54][55].…”

QCD theory review

“…[18,19] that inclusion of Sudakov logarithms is necessary in order to describe the LHC jet data at small x but yet before the saturation regime. In the low x domain, the resummation leading to the Sudakov logarithms has been developed in [20][21][22][23][24][25][26] see also [27]. In the paper [28], it has been shown for the first time, that the interplay of saturation effects and the resummation of the Sudakov logarithms is essential to describe the small-x forward-forward dijet data.…”

QCD theory overview

“…[21,22] that inclusion of Sudakov logarithms is necessary in order to describe the LHC jet data at small x but yet before the saturation regime. In the low x domain, the resummation leading to the Sudakov logarithms has been developed in [23][24][25][26][27][28][29] see also [30]. In the paper [31], it has been shown for the first time, that the interplay of saturation effects and the resummation of the Sudakov logarithms is essential to describe the small-x forward-forward dijet data.…”