Determining $\pi^0$ $A_{LL}$ from STAR 2012 Endcap Calorimeter Data

The Solenoidal Tracker at RHIC (STAR) located at Brookhaven National Laboratory uses longitudinally polarized proton-proton collisions to study the gluon contribution to the spin of the proton. One such method, using data from the 2012 longitudinally polarized proton-proton collisions ( $\sqrt{s}$ = 510 GeV), studies the production of neutral pions ( $\pi^0$ ) from these collisions. The asymmetry of the spin-dependent neutral pion production, $A_{LL}$, can be determined by analyzing the photons produced from $\pi^0$ decays, as detected in the Endcap Electromagnetic Calorimeter (EEMC). The EEMC, positioned in an intermediate pseudorapidity range of 1 $<$ $\eta$ $<$ 2, is able to measure the energy and position of an incoming photon’s electromagnetic shower. From these measurements the two-photon invariant mass spectrum can be reconstructed. These spectra are then fitted using a skewed Gaussian plus a background function to determine the total number of $\pi^0$ s. The $\pi^0$ asymmetry is calculated from the number of $\pi^0$ s produced in collisions of protons with different spin alignments. The status of the analysis of the 2012 data set to measure the $\pi^0$ $A_{LL}$ will be presented.