Charged-pion cross sections and double-helicity asymmetries in polarizedp+pcollisions ats=200 GeV
Citations Over TimeTop 10% of 2015 papers
Abstract
We present midrapidity charged-pion invariant cross sections, the ratio of the ${\ensuremath{\pi}}^{\ensuremath{-}}$ to ${\ensuremath{\pi}}^{+}$ cross sections and the charge-separated double-spin asymmetries in polarized $p+p$ collisions at $\sqrt{s}=200\text{ }\mathrm{GeV}$. 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 $\ensuremath{\sim}0.03--0.16$ and provide unique information on the sign of the gluon-helicity distribution.
Related Papers
- → All non-maximally-helicity-violating one-loop seven-gluon amplitudes inN=4super-Yang-Mills theory(2005)152 cited
- → All Next-to-Maximally-Helicity-Violating One-Loop Gluon Amplitudes in N=4 Super-Yang-Mills Theory(2005)21 cited
- → The Non-Maximally-Helicity-Violating One-Loop Seven-Gluon Amplitudes in N=4 Super-Yang-Mills Theory(2004)1 cited
- → Effect of triple gluon coupling in semi-inclusive polarized scattering processes(1983)