Semi-inclusive and exclusive measurements with EIC: The advantages of lower energies

TL;DR

This paper discusses how lower-energy electron-ion colliders can provide significant advantages for detailed measurements of nucleon structure, especially in semi-inclusive and exclusive deep inelastic scattering, compared to higher-energy colliders.

Contribution

It demonstrates the benefits of moderate CM energy and symmetric configurations for precise nucleon structure measurements at the EIC.

Findings

Lower energies improve angular and energy resolution of final-state particles.

Moderate CM energy enhances large-x coverage in measurements.

Symmetric E_e/E_p configurations optimize the detection of semi-inclusive and exclusive processes.

Abstract

Exploring the nucleon's sea quark and gluon structure is a prime objective of a future electron-ion collider (EIC). Many of the key questions require accurate differential semi-inclusive (spin/flavor decomposition, orbital motion) and exclusive (spatial distributions of quarks/gluons) DIS measurements in the region 0.01 < x < 0.3 and Q^2 ~ few 10 GeV^2. Such measurements could ideally be performed with a high-luminosity collider of moderate CM energy, s ~ 10^3 GeV^2, and relatively symmetric configuration, e.g. E_e/E_p = 5/30-60 GeV. Specific examples are presented, showing the advantages of this setup (angular/energy distribution of final-state particles, large-x coverage) compared to typical high-energy colliders.