ALP and $Z^{\prime }$ boson at the Electron-Ion collider

Abstract

We study the sensitivity of the upcoming electron-ion (EIC) collider to purely electrophilic new physics in the GeV mass range. Within an effective field theory framework, we consider two different scenarios: an axion-like particle (ALP) and a new heavy neutral vector gauge boson $Z^{\prime }$, each couples to electrons only. We analyze electron-proton collisions at $\sqrt{s}=141$ GeV with an integrated luminosity of $100{\mathrm{fb}}^{-1}$, focusing primarily on the tri-electron final state. Additionally, loop-induced ALP-photon couplings driven photon final states are also explored. Incorporating realistic detector effects and systematic uncertainties, we obtain projected exclusion limits on the relevant cross-sections and couplings. We find that the results from EIC can significantly extend the sensitivity to electrophilic axion-like particles and $Z^{\prime }$ bosons in regions of parameter space that remain weakly constrained by existing experiments.

36 pages, 21 figures, 8 tables, version accepted for publication in PRD