Speaker
Description
The longitudinal double-spin asymmetry $A_{LL}$ in spin-polarized $p+p$ collisions provides insight into the gluon contribution to the proton's spin by accessing the gluon helicity distribution $\Delta$g. Prior RHIC 200 GeV measurements show non-zero asymmetries and hence indicate a nonzero contribution of gluon helicity to the proton spin $\Delta$G for the Bjorken-$x$ range $x > 0.05$ in the recent NLO analyses. The 510 GeV PHENIX $\pi_{0}$ and STAR jet data confirms the non-zero asymmetries and extends constraints on $\Delta$G to lower $x$. A measurement of the jet $A_{LL}$ at $\surd$s = 510 GeV in PHENIX will provide an important cross-check. In this talk, I will detail the jet reconstruction techniques tuned for the PHENIX detector and present the status of the measured jet cross section and $A_{LL}$.
