Double Spin Asymmetry of Electrons from Heavy Flavor Decays in p+p   Collisions at sqrt(s)=200 GeV
  We report on the first measurement of double-spin asymmetry, A_LL, of electrons from the decays of hadrons containing heavy flavor in longitudinally polarized p+p collisions at sqrt(s)=200 GeV for p_T= 0.5 to 3.0 GeV/c. The asymmetry was measured at mid-rapidity (|eta|<0.35) with the PHENIX detector at the Relativistic Heavy Ion Collider. The measured asymmetries are consistent with zero within the statistical errors. We obtained a constraint for the polarized gluon distribution in the proton of |Delta g/g(log{_10}x= -1.6^+0.5_-0.4, {mu}=m_T^c)|^2 < 0.033 (1 sigma), based on a leading-order perturbative-quantum-chromodynamics model, using the measured asymmetry. 
A. Adare, S. Afanasiev, C. Aidala, N. N. Ajitanand, Y. Akiba, R.   Akimoto, H. Al-Ta'ani, J. Alexander, K. R. Andrews, A. An...
hep-ex nucl-ex