$J/\psi$ Spin Alignment in 120 GeV $p$-Fe Interactions at Fermilab}

The $J/\psi$ is a charmonium bound state with spin 1 and has large branching ratio towards dilepton decay. The angular distribution of such decay particles from $J/\psi$ is affected by its spin alignment. The $J/\psi$ spin alignment, in turn, gives constraints to test and understand various production mechanisms. The SeaQuest, a fixed target experiment at Fermilab, has completed its data taking. The spectrometer of the experiment was designed to measure high energy muons, and uses a 500 cm long solid Iron (Fe) block as beam dump. While interactions in the target served the primary goal of probing the flavor structure of the nucleon, a wealth of data from interaction with the iron beam dump provides ample opportunity to study charmonium production as well. In this talk, we discuss the measurement of the spin alignment of $J/\psi$ produced in 120 GeV $p$-Fe interactions at the SeaQuest experiment.