Recent results in high-energy longitudinal polarized proton-proton   collisions at 200GeV at RHIC
  We report on recent results of the longitudinal double-spin asymmetry A_LL from the STAR and PHENIX experiments. Data were collected in longitudinally polarized proton-proton collisions at a center-of-mass energy of 200 GeV. The results added new constraints to the polarized gluon distribution function g(x) with the probed x range of 0:02 < x < 0:3. The results lead to the importance of probing small x. 
T. Sakuma (for the RHIC Spin collaboration)