Speaker
Description
We promote our leading order analysis [1] determining the initial condition of the Balitsky-Kovchegov (BK) evolution equation to the next-to-leading order treatment, using both the NLO BK equation and NLO impact factors. The initial condition, to be described by the posterior distribution obtained via Bayesian optimization, is constrained by the total cross section and charm quark production measurements from HERA. The determined posterior distribution [2] is a necessary input for all NLO calculations in the CGC framework, and enables one to rigorously propagate uncertainties from this non-perturbative input to calculated cross sections. The HERA data are found to provide tight constraints for the initial condition. A successful description of all HERA data is obtained only with initial condition parametrizations that feature a steep dipole-target scattering amplitude at moderately small dipoles.
References:
[1] Casuga, C., Karhunen, M., Mäntysaari, H., Phys.Rev.D 109 (2024) 054018 arXiv: 2311.10491.
[2] Casuga, C., Hänninen, H., Mäntysaari, H., in preparation
