On systematic effects in the numerical solutions of the JIMWLK equation

Autor: Piotr Korcyl, Salvatore Calì, Cyrille Marquet, Piotr Kotko, Krzysztof Cichy, Krzysztof Kutak
Přispěvatelé: Centre de Physique Théorique [Palaiseau] (CPHT), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)
Jazyk: angličtina
Rok vydání: 2021
Předmět:
noise
Physics and Astronomy (miscellaneous)
FOS: Physical sciences
QC770-798
Astrophysics
01 natural sciences
Momentum
Langevin equation
High Energy Physics - Phenomenology (hep-ph)
coupling constant: energy dependence
statistical analysis
Position (vector)
Nuclear and particle physics. Atomic energy. Radioactivity
0103 physical sciences
quantum chromodynamics
Limit (mathematics)
Statistical physics
correlation function
010306 general physics
numerical calculations
Engineering (miscellaneous)
Coupling
Physics
Coupling constant
longitudinal momentum
010308 nuclear & particles physics
ddc:530
530 Physik
gluon: density
3. Good health
Gluon
QB460-466
High Energy Physics - Phenomenology
Nonlinear system
rapidity
[PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph]
nonlinear
heavy ion: colliding beams
Zdroj: European Physical Journal C: Particles and Fields, Vol 81, Iss 7, Pp 1-20 (2021)
Eur.Phys.J.C
Eur.Phys.J.C, 2021, 81, pp.663. ⟨10.1140/epjc/s10052-021-09380-6⟩
European Physical Journal
ISSN: 1434-6052
1434-6044
DOI: 10.1140/epjc/s10052-021-09380-6⟩
Popis: In the high energy limit of hadron collisions, the evolution of the gluon density in the longitudinal momentum fraction can be deduced from the Balitsky hierarchy of equations or, equivalently, from the nonlinear Jalilian-Marian-Iancu-McLerran-Weigert-Leonidov-Kovner (JIMWLK) equation. The solutions of the latter can be studied numerically by using its reformulation in terms of a Langevin equation. In this paper, we present a comprehensive study of systematic effects associated with the numerical framework, in particular the ones related to the inclusion of the running coupling. We consider three proposed ways in which the running of the coupling constant can be included: "square root" and "noise" prescriptions and the recent proposal by Hatta and Iancu. We implement them both in position and momentum spaces and we investigate and quantify the differences in the resulting evolved gluon distributions. We find that the systematic differences associated with the implementation technicalities can be of a similar magnitude as differences in running coupling prescriptions in some cases, or much smaller in other cases.
21 pages, 18 figures, references updated
Databáze: OpenAIRE