An Examination of STAR 2012 pi0 Data with Longitudinally Polarized Proton Collisions at 500 GeV
Arts and Sciences
A recent global analysis of the proton spin has provided evidence for positive gluon polarization Δg(x) for the momentum fraction range of 0.05 < x < 0.20. The region x < 0.05 remains relatively poorly constrained, and may provide a significant contribution to the spin of the proton. The STAR detector can bbe used to measure the effects of quark and gluon spins in the proton through the measurement of asymmetries in neutral pion production for different polarization states. The Relativistic Heavy Ion collider at Brookhaven National Laboratory is uniquely able to collide polarized protons. Data from the proton-proton run in 2012 has significantly higher integrated luminosity at a higher center of mass energy of 500 GeV than previous datasets, allowing better access to Δg(x) at low x. The STAR endcap electromagnetic calorimeter, or EEMC, is able to detect neutral pions in the range of pseudorapidity 0.8 < η < 2.0, a region at this energy where Δg(x) for x < 0.05 can be examined. Preliminary work on 2012 data will be shown.
Place, Stephen, "An Examination of STAR 2012 pi0 Data with Longitudinally Polarized Proton Collisions at 500 GeV" (2015). Symposium on Undergraduate Research and Creative Expression (SOURCE). 404.