Probing proton spin structure via heavy flavor production in PHENIX

The measurement of spin asymmetries in polarized p+p collisions provides an opportunity to probe the spin structure of nucleons. With transversely and longitudinally polarized proton beams at RHIC, we can measure both double longitudinal spin asymmetry A_LL and single transverse spin asymmetry A_N. At the RHIC energy, heavy quark (charm and beauty) production is dominated by gluon–gluon interactions, so measurements of A_LL and A_N will allow us to directly probe the polarized gluon distribution and gluon's Sivers functions, respectively. PHENIX experiment collected 3.5 pb⁻¹ (beam polarization ∼50%) and 10 pb⁻¹ (beam polarization ∼60%) data from year 2005 and 2006 runs, respectively. In this analysis, the J/Ψ have been measured through the J/Ψ → μ⁺μ⁻ channel at forward rapidities, and about 30 000 J/Ψ candidates are reconstructed from Lvl2 triggered data production. We present the latest results of J/ΨA_LL and A_N measurements at forward rapidities from the PHENIX experiment.