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Article
Charged-pion cross sections and double-helicity asymmetries in polarized p plus p collisions at root s=200 GeV
Physical Review D
  • Andrew Adare, University of Colorado, Boulder
  • Alan Dion, Iowa State University
  • John C. Hill, Iowa State University
  • Todd Kempel, Iowa State University
  • John G. Lajoie, Iowa State University
  • Alexandre Lebedev, Iowa State University
  • Craig Ogilvie, Iowa State University
  • H. Pei, Iowa State University
  • Marzia Rosati, Iowa State University
  • C. L. Silva, Iowa State University
  • Feng Wei, Iowa State University
  • et al.
  • PHENIX Collaboration, PHENIX Collaboration
Document Type
Article
Publication Version
Published Version
Publication Date
2-2-2015
DOI
10.1103/PhysRevD.91.032001
Abstract
We present midrapidity charged-pion invariant cross sections, the ratio of the pi(-) to pi(+) cross sections and the charge-separated double-spin asymmetries in polarized p + p collisions at root s = p + 200 GeV. While the cross section measurements are consistent within the errors of next-to-leading-order (NLO) perturbative quantum chromodynamics predictions (pQCD), the same calculations overestimate the ratio of the charged-pion cross sections. This discrepancy arises from the cancellation of the substantial systematic errors associated with the NLO-pQCD predictions in the ratio and highlights the constraints these data will place on flavor-dependent pion fragmentation functions. The charge-separated pion asymmetries presented here sample an x range of similar to 0.03-0.16 and provide unique information on the sign of the gluon-helicity distribution.
Comments

This is an article from Physical Review D 91 (2015): 032001, doi:10.1103/PhysRevD.91.032001. Posted with permission.

Copyright Owner
American Physical Society
Language
en
File Format
application/pdf
Citation Information
Andrew Adare, Alan Dion, John C. Hill, Todd Kempel, et al.. "Charged-pion cross sections and double-helicity asymmetries in polarized p plus p collisions at root s=200 GeV" Physical Review D Vol. 91 Iss. 3 (2015) p. 032001
Available at: http://works.bepress.com/craig-ogilvie/54/