Transverse single-spin asymmetries of midrapidity pi(0) and eta mesons in polarized p plus p collisions at root s=200 GeV
Abstract
We present a measurement of the transverse single-spin asymmetry for pi(0) and eta mesons in p(up arrow) + p collisions in the pseudorapidity range vertical bar eta vertical bar < 0.35 and at a center-of-mass energy of 200 GeV with the PHENIX detector at the Relativistic Heavy Ion Collider. In comparison with previous measurements in this kinematic region, these results have factor-of-3-smaller uncertainties.
As hadrons, pi(0) and eta mesons are sensitive to both initial- and final-state nonperturbative effects for a mix of parton flavors. Comparisons of the differences in their transverse single-spin asymmetries have the potential to disentangle the possible effects of strangeness, isospin, or mass.
These results can constrain the twist-3 trigluon collinear correlation function as well as the gluon Sivers function.