Nucleon spin structure measurements at the EIC : A case for polarized "neutron" beams

The advent of highly polarized beams and targets, nearly four decades ago, opened a frontier in experimental hadronic physics that transformed our understanding of the spin structure of the nucleon and the underlying theory of Quantum Chromodynamics. The electron-ion collider (EIC) will usher in a new era of hadronic physics by replacing nuclear targets with high-energy ion and polarized proton beams. As we embark on the EIC era it is imperative to pursue the development of highly polarized light ion beams, such as deuterium, helium-3 and lithium-6. These ion beams serve as proxies for free neutrons, providing additional information and constraints that cannot be provided by polarized proton beams alone. This talk will discuss the importance of polarized "neutron" beams for the flagship spin structure program planned for the EIC.