A1 Journal article (refereed)
Inferring the initial condition for the Balitsky-Kovchegov equation (2024)

Casuga, C., Karhunen, M., & Mäntysaari, H. (2024). Inferring the initial condition for the Balitsky-Kovchegov equation. Physical Review D, 109(5), Article 054018. https://doi.org/10.1103/PhysRevD.109.054018

JYU authors or editors

Publication details

All authors or editors: Casuga, Carlisle; Karhunen, Mikko; Mäntysaari, Heikki

Journal or series: Physical Review D

ISSN: 2470-0010

eISSN: 2470-0029

Publication year: 2024

Publication date: 11/03/2024

Volume: 109

Issue number: 5

Article number: 054018

Publisher: American Physical Society (APS)

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1103/PhysRevD.109.054018

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/95088

Publication is parallel published:  https://doi.org/10.48550/arXiv.2311.10491

Abstract

We apply Bayesian inference to determine the posterior likelihood distribution for the parameters describing the initial condition of the small-x Balitsky-Kovchegov evolution equation at leading logarithmic accuracy. The HERA structure function data is found to constrain most of the model parameters well. In particular, we find that the HERA data prefers an anomalous dimension γ≈1 unlike in previous fits where γ>1 which led to e.g. the unintegrated gluon distribution and the quark-target cross sections not being positive definite. The determined posterior distribution can be used to propagate the uncertainties in the non-perturbative initial condition when calculating any other observable in the Color Glass Condensate framework. We demonstrate this explicitly for the inclusive quark production cross section in proton-proton collisions and by calculating predictions for the nuclear modification factor for the F2 structure function in the EIC and LHeC/FCC-he kinematics.

Keywords: quarks; particle physics

Contributing organizations

Related projects

Ministry reporting: Yes

Reporting Year: 2024

Preliminary JUFO rating: 2