Cross section and double helicity asymmetry forηmesons and their comparison toπ0production inp+pcollisions ats=200 GeV

A. Adare, S. Afanasiev, C. Aidala, N. N. Ajitanand, Y. Akiba, H. Al-Bataineh, J. Alexander, K. Aoki, L. Aphecetche, R. Armendariz, S. H. Aronson, J. Asai (+420 others)
2011 Physical Review D  
Measurements of double-helicity asymmetries for inclusive hadron production in polarized p+p collisions are sensitive to helicity--dependent parton distribution functions, in particular to the gluon helicity distribution, Delta(g). This study focuses on the extraction of the double-helicity asymmetry in eta production: polarized p+p --> eta + X, the eta cross section, and the eta/pi^0 cross section ratio. The cross section and ratio measurements provide essential input for the extraction of
more » ... mentation functions that are needed to access the helicity-dependent parton distribution functions.
doi:10.1103/physrevd.83.032001 fatcat:hhbr2asqbngv5fp6sp2ejtumdq