First Look at SpinQuest Studies with Polarized Targets

SpinQuest is a high-luminosity Drell-Yan experiment utilizing transversely polarized ammonia (NH$_3$) and deuterated ammonia (ND$_3$) targets to measure the Sivers function for light sea quarks in nucleons.~A non-vanishing sea quark Sivers function is evidence of their orbital angular momentum. The experiment also intends to measure transverse single-spin asymmetries (TSSA) in the production of $J/\psi$ particles, which are sensitive to the gluon Sivers function. Such studies are viable via a polarized target system deploying a split-pair 5~T superconducting magnet and a powerful cooling system based on the $^4$He evaporation refrigerator. The latter operates at 1~K through high-powered evaporation facilitated by a roots stack with a pumping rate of $\sim $17,000 liters per hour. With such a setup, the expected average target polarization of $\sim$ 80\% (32\%) for NH$_3$ (ND$_3$) will be achieved based on the dynamic nuclear polarization technique. In this talk, a brief overview of the polarized target system, as well as the dedicated efforts to benchmark the $J/\psi$ TSSA from the first SpinQuest data-taking period, will be presented.