Abstract
Transverse single-spin asymmetries to probe the transverse-spin structure of the proton have been measured for neutral pions and nonidentified charged hadrons from polarized proton-proton collisions at midrapidity and . The data cover a transverse momentum () range for neutral pions and for charged hadrons, at a Feynman- value of approximately zero. The asymmetries seen in this previously unexplored kinematic region are consistent with zero within errors of a few percent. In addition, the inclusive charged hadron cross section at midrapidity from is presented and compared to next-to-leading order perturbative QCD (pQCD) calculations. Successful description of the unpolarized cross section above suggests that pQCD is applicable in the interpretation of the asymmetry results in the relevant kinematic range.
- Received 17 July 2005
DOI:https://doi.org/10.1103/PhysRevLett.95.202001
©2005 American Physical Society