Longitudinal double spin asymmetry of $\ddot{I}{€}^{\pm }$-tagged jet, $\hat{I}›$, $\overline{\hat{I}}›$, and $K_S^0$ in polarized $p+p$ collisions at $\sqrt{s}=200$ $\mathrm{GeV}$ at STAR

Yi Yu

Understanding the origin of the proton spin is one of the most fundamental and challenging questions in QCD. Much progress has been made since the first surprising result by the EM…