Double helicity asymmetry in inclusive Mid-rapidity neutral pion production for polarized p+p collisions ''S IND.NN' POT. 1/2' = 200GeV - Adler, S S; Dietzsch, Olácio; Leite, Marco Aurelio Lisboa; Silva, Cesar Luiz da; Takagui, Emi Márcia (Physical Review Letters, 2004)