Forward Neutral Pion Production in p+p and d+Au Collisions at sNN=200GeV
Abstract
Measurements of the production of forward π0 mesons from p+p and d+Au collisions at sNN=200GeV are reported. The p+p yield generally agrees with next-to-leading order perturbative QCD calculations. The d+Au yield per binary collision is suppressed as η increases, decreasing to ∼30% of the p+p yield at ⟨η⟩=4.00, well below shadowing expectations. Exploratory measurements of azimuthal correlations of the forward π0 with charged hadrons at η≈0 show a recoil peak in p+p that is suppressed in d+Au at low pion energy. These observations are qualitatively consistent with a saturation picture of the low-x gluon structure of heavy nuclei.
- Publication:
-
Physical Review Letters
- Pub Date:
- October 2006
- DOI:
- 10.1103/PhysRevLett.97.152302
- arXiv:
- arXiv:nucl-ex/0602011
- Bibcode:
- 2006PhRvL..97o2302A
- Keywords:
-
- 24.85.+p;
- 13.85.Fb;
- 13.85.Ni;
- 25.75.Dw;
- Quarks gluons and QCD in nuclei and nuclear processes;
- Inelastic scattering: two-particle final states;
- Inclusive production with identified hadrons;
- Particle and resonance production;
- Nuclear Experiment;
- High Energy Physics - Experiment
- E-Print:
- 6 pages, 4 figures. Minor changes from review process in Phys. Rev. Lett. Plain text tables of data in STAR publications may be found at http://www.star.bnl.gov/central/publications