Neutral-Current Weak Interactions at an EIC

TL;DR

This paper presents a simulation study of neutral current structure functions at the future EIC, highlighting new interference structure functions accessible via parity-violating asymmetries and their potential to probe parton distributions and the weak mixing angle.

Contribution

It introduces the measurement of new gamma-Z interference structure functions at the EIC and assesses their uncertainties, including effects of radiative corrections and detector smearing.

Findings

Uncertainty projections for structure functions in electron-proton collisions.

Feasibility of measuring the weak mixing angle at high Q^2.

Inclusion of radiative corrections and detector effects in simulations.

Abstract

A simulation study of measurements of neutral current structure functions of the nucleon at the future high-energy and high-luminosity polarized electron-ion collider (EIC) is presented. A new series of $\gamma-Z$ interference structure functions, $F_1^{\gamma Z}$, $F_3^{\gamma Z}$, $g_1^{\gamma Z}$, $g_5^{\gamma Z}$ become accessible via parity-violating asymmetries in polarized electron-nucleon deep inelastic scattering (DIS). Within the context of the quark-parton model, they provide a unique and, in some cases, yet-unmeasured combination of unpolarized and polarized parton distribution functions. The uncertainty projections for these structure functions using electron-proton collisions are considered for various EIC beam energy configurations. Also presented are uncertainty projections for measurements of the weak mixing angle $\sin^2 \theta_W$ using electron-deuteron collisions which cover a much higher $Q^2$ than that is accessible in fixed target measurements. QED and QCD radiative corrections and effects of detector smearing are included with the calculations.