Online Reconstruction on GPUs for J/ψ TSSA Study at SpinQuest*

The E1039/SpinQuest experiment is a transversely polarized fixed target experiment at Fermi National Accelerator Laboratory aiming to explore the sea quark and gluon Sivers functions via the measurement of the transverse single spin asymmetry (TSSA) for a number of physics processes including J/ψ, ψ' and Drell-Yan production. The experiment employs a 120-GeV extracted proton beam colliding with transversely-polarized NH3 and ND3 cryogenic targets and its spectrometer is optimized to detect the oppositely-charged muon pair output of these processes. In pursuit of these asymmetry measurements, we are developing an advanced graphical processing unit (GPU) based multi-threaded framework that allows for an efficient parallelization of the online data processing flow and track reconstruction along with diagnostics and visualization tools. In this talk, I will report the plans to complete the optimization of the offline track reconstruction in GPU by this early autumn to reach real-time data visualization and monitoring. Moreover, I will present results estimating the anticipated precision of TSSA measurement via J/ψ production from the first SpinQuest production data.