Extraction of the strong coupling with HERA and EIC inclusive data

TL;DR

This paper assesses how well current and future deep inelastic scattering data can determine the strong coupling constant, highlighting the potential for high precision with combined HERA and EIC measurements in a NNLO QCD framework.

Contribution

It demonstrates the potential for achieving world-leading precision in measuring ppa_S using combined HERA and EIC data within a NNLO QCD analysis.

Findings

Potential for high-precision ppa_S measurement with combined data

Simulated EIC data significantly improve current constraints

Uncertainties from missing higher orders remain a concern

Abstract

Sensitivity to the strong coupling $\alpha_S(M^2_Z)$ is investigated using existing Deep Inelastic Scattering data from HERA in combination with projected future measurements from the Electron Ion Collider (EIC) in a next-to-next-to-leading order QCD analysis. A potentially world-leading level of precision is achievable when combining simulated inclusive neutral current EIC data with inclusive charged and neutral current measurements from HERA, with or without the addition of HERA inclusive jet and dijet data. The result can be obtained with substantially less than one year of projected EIC data at the lower end of the EIC centre-of-mass energy range. Some questions remain over the magnitude of uncertainties due to missing higher orders in the theoretical framework.