The impact of inclusive electron ion collider data on the strong coupling determination in a global PDF fit

Overview

This study investigates the capacity of inclusive electron-proton scattering data from the Electron Ion Collider to constrain the strong coupling constant within a global parton distribution function fitting framework. The analysis employs pseudodata corresponding to experimental scenarios ranging from conservative to optimistic uncertainty projections, enabling quantitative assessment of the EIC's potential contribution to precision determinations of fundamental QCD parameters.

Methods and approach

The research integrates prospective EIC electron-proton scattering pseudodata into the MSHT global PDF fitting methodology. Two scenarios are constructed based on differing experimental uncertainty projections. Simultaneous extraction of proton parton distribution functions and the strong coupling is performed for each case. An additional investigation introduces controlled inconsistencies between EIC pseudodata and existing global fit data to evaluate sensitivity to potential tensions and systematic bias propagation in the extracted coupling value.

Key Findings

The conservative experimental uncertainty scenario yields moderate but non-negligible impact on strong coupling determination. The optimistic uncertainty projection demonstrates substantially more significant constraining power. Injection of explicit data inconsistencies produces observable bias in extracted strong coupling values, underscoring sensitivity to unaccounted theoretical uncertainties and the necessity for expanded error definitions in precision coupling extractions.

Implications

The results establish that EIC inclusive electron-proton scattering data possesses meaningful potential for improving strong coupling precision, contingent upon achieving optimistic experimental uncertainty targets. The magnitude of impact varies substantially across plausible experimental scenarios, indicating that instrumental performance specifications will critically determine the measurement's utility for fundamental parameter extraction. The demonstrated sensitivity to data tensions emphasizes that comprehensive theoretical uncertainty quantification remains essential for robust strong coupling determination, irrespective of individual dataset precision.