Global Spline Fit GSF-2025 - An update of the data-driven model of the cosmic-ray flux and its mass composition

The Global Spline Fit (GSF) is a data-driven parameterization of the cosmic-ray flux and corresponding mass composition. It combines direct and indirect measurements of cosmic-ray flux of individual elements from 1 GeV to $10^{11}$ GeV, considering their uncertainties and possible difference in the energy scale of the measurements. At lower energies, the flux is corrected to the local interstellar spectra using the individual data-taking periods of the experiments. The systematic energy scale uncertainty for each experiment is treated as a nuisance parameter and minimized jointly with other model parameters, thus, matching the flux from indirect measurements above the knee to direct measurements below the knee region. Since the original work was presented in 2017, many new measurements have been published by both direct and indirect cosmic-ray experiments. This presentation describes an updated GSF model, referred to as GSF-2025, which includes datasets from the last eight years. We assess the mutual compatibility and demonstrate the impact of the newly added data on the all-particle flux and mass composition over 11 decades in energy. It is shown that a much better understanding of the energy region around the knee is obtained.