Bayesian approach to determine the initial condition for the Balitsky-Kovchegov equation

2024/07/15 by Carlisle Casuga, Casuga, Carlisle, Mikko Karhunen +3
Mathematics · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #advanced mathematical theories

paper · pdf · doi:10.48550/arxiv.2407.10581

openalex publication_date 2024/07/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30

Abstract

We present posterior distributions of parameters that characterize the nonperturbative initial input for the Balitsky-Kovchegov evolution equation. The BK equation evolves an initial dipole-target scattering amplitude at moderate x_Bj values toward smaller values. We use Bayesian inference to constrain the model parameters against the precise combined reduced cross section data from HERA, and obtain probability distributions for the free parameters. Our results show the data's preference for the anomalous dimension to be γ∼ 1. The distributions provide a rigorous method for propagating uncertainties of the BK initial condition for other CGC calculations. We demonstrate this for inclusive quark production in proton-proton collisions and nuclear modification factor for the total deep inelastic scattering cross section to be measured at the EIC.

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