Campus Units

Physics and Astronomy

Document Type

Article

Publication Version

Published Version

Publication Date

2-2-2015

Journal or Book Title

Physical Review D

Volume

91

Issue

3

First Page

032001

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

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