Polarized Nuclear DVCS at the EIC

Abstract

The Electron-Ion Collider (EIC) will enable a series of measurements at unprecedented energies and luminosities, providing new opportunities to investigate the microscopic structure of nucleons and nuclei at small $x_B$. Exclusive processes such as Deeply Virtual Compton Scattering (DVCS) offer unique access to the three-dimensional structure of hadrons through Generalized Parton Distributions (GPDs), while polarized electron and ion beams further enable detailed studies of spin-dependent structure. A model for coherent DVCS on polarized ${}^3$Heis developed and applied to simulations of for $9\times 166$-GeV $e^3$He collisions at the EIC. Using this framework, the statistical precision achievable is estimated for measurements of beam-spin asymmetries and for the extraction of the Compton Form Factors (CFFs) ${\mathcal{H}}_{{}^3\mathrm{He}}$ and ${\tilde{\mathcal{H}}}_{{}^3\mathrm{He}}$. Early EIC data are found to enable precise differential measurements of the unpolarized CFF ${\mathcal{H}}_{{}^3\mathrm{He}}$ and to provide significant constraints on its real and imaginary components. By contrast, meaningful constraints on the polarized CFF ${\tilde{\mathcal{H}}}_{{}^3\mathrm{He}}$ require substantially larger integrated luminosities. The kinematics of the recoil ${}^3$He nucleus are also examined, and the far-forward detector capabilities at the EIC required to tag the intact nucleus and perform fully exclusive measurements of coherent nuclear DVCS are discussed.