Neutral-Current Electroweak Physics and SMEFT Studies at the EIC

TL;DR

This paper evaluates the potential of the EIC to perform precision electroweak measurements and BSM searches using neutral-current scattering asymmetries, incorporating realistic systematics and SMEFT analysis.

Contribution

It introduces an updated analysis framework for EIC electroweak studies, including new detector design, simultaneous fitting techniques, and weak mixing angle running effects.

Findings

EIC can probe BSM operators at scales comparable to or exceeding LHC bounds.

The analysis accounts for systematic errors from both theory and experiment.

The study demonstrates the EIC's capability to measure the weak mixing angle with high precision.

Abstract

We study the potential for precision electroweak (EW) measurements and beyond-the-Standard Model (BSM) searches using cross-section asymmetries in neutral-current (NC) deep inelastic scattering at the electron-ion collider (EIC). Our analysis uses a complete and realistic accounting of systematic errors from both theory and experiment and considers the potential of both proton and deuteron beams for a wide range of energies and luminosities. We also consider what can be learned from a possible future positron beam and a potential ten-fold luminosity upgrade of the EIC beyond its initial decade of running. We use the SM effective field theory (SMEFT) framework to parameterize BSM effects and focus on semi-leptonic four-fermion operators, whereas for our precision EW study, we determine how well the EIC can measure the weak mixing angle. New features of our study include the use of an up-to-date detector design of EIC Comprehensive Chromodynamics Experiment (ECCE) and accurate running conditions of the EIC, the simultaneous fitting of beam polarization uncertainties and Wilson coefficients to improve the sensitivity to SMEFT operators, and the inclusion of the weak mixing angle running in our fit template. We find that the EIC can probe BSM operators at scales competitive with and in many cases exceeding LHC Drell-Yan bounds while simultaneously not suffering from degeneracies between Wilson coefficients.