Charged-Current Elastic Scattering at the Electron-Ion Collider

TL;DR

This paper explores the potential for measuring charged-current elastic scattering at the Electron-Ion Collider to better understand the nucleon's axial form factor, highlighting experimental challenges and possible solutions.

Contribution

It proposes a novel measurement approach for the axial form factor using polarized electron-proton collisions at the EIC, emphasizing the need for specialized instrumentation.

Findings

Measurement of the axial form factor via target-spin asymmetry is feasible with dedicated detectors.

Charged-current elastic scattering measurement at the EIC is very challenging but potentially achievable.

The study underscores the importance of specialized instrumentation for such measurements.

Abstract

We discuss the measurement of the charged-current elastic scattering process $e^-p\rightarrow\nu_e n$ at the Electron-Ion Collider (EIC). This process provides sensitivity to the poorly constrained axial form factor of the nucleon, which encodes the spatial distribution of weak charge. Collisions of electrons with polarized protons enable measuring the axial form factor via the $e^{-\!}\,\vec{p} \to \nu_e\,n$ target-spin asymmetry for the first time. We conclude that a measurement of charged-current elastic scattering at the EIC will, perhaps unsurprisingly, prove very challenging. However, with dedicated instrumentation at a second EIC detector, the measurement may be possible.