Kinematical constraint effects in the evolution equations based on angular ordering

TL;DR

This paper investigates how different kinematical constraints affect the CCFM evolution equations and their non-linear extensions, revealing significant modifications to gluon density shapes relevant for collider phenomenology.

Contribution

It introduces a comprehensive analysis of the impact of full kinematical constraints on the CCFM equation and its non-linear extension, highlighting their importance in accurate gluon density modeling.

Findings

Complete kinematical constraints significantly alter gluon density shapes.

Gluon density is suppressed at large hard scales and gluon transverse momentum.

Results are relevant for jet correlation studies at the LHC.

Abstract

We study effects of imposing various forms of the kinematical constraints on the full form of the CCFM equation and its non-linear extension. We find that imposing the constraint in its complete form modifies significantly way the shape of gluon density as compared to forms of the constraint used in the numerical calculations and phenomenological applications. In particular the resulting gluon density is suppressed for large values of hard scale related parameter and kT of gluon. This result might be important in description studies of jet correlations at Large Hadron Collider within CCFM approach.