Gluon Polarisation in the Nucleon and Longitudinal Double Spin Asymmetries from Open Charm Muoproduction

Abstract

The gluon polarisation in the nucleon has been determined by detecting charm production via D0 meson decay to charged K and pi in polarised muon scattering off a longitudinally polarised deuteron target. The data were taken by the COMPASS Collaboration at CERN between 2002 and 2006 and corresponds to an integrated luminosity of 2.8 fb^-1. The dominant underlying process of charm production is the photon-gluon fusion to a cc-bar pair. A leading order QCD approach gives an average gluon polarisation of (Delta g/g)_x= -0.49 +- 0.27(stat) +- 0.11(syst) at a scale mu^2 ~ 13 (GeV/c)^2 and at an average gluon momentum fraction (x) ~ 0.11. The longitudinal cross-section asymmetry for D0 production is presented in bins of the transverse momentum and the energy of the D0 meson.

arXiv commentOnly Meta data changed (title), 16 pages, 3 figures

References in corpus (21)

• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• The COMPASS Experiment at CERN
• Precise determination of the spin structure function ${\mathbf{g}}_1$ of the proton, deuteron and neutron
• LEPTO 6.5 - A Monte Carlo Generator for Deep Inelastic Lepton-Nucleon Scattering
• The Deuteron Spin-dependent Structure Function g1d and its First Moment
• Inclusive cross section and double helicity asymmetry for π^0 production in p+p collisions at sqrt(s)=200 GeV: Implications for the polarized gluon distribution in the proton
• Measurement of the Deuteron Spin Structure Function g_1^d(x) for 1 (GeV/c)^2 < Q^2 < 40 (GeV/c)^2
• The Spin Structure of the Proton
• Longitudinal double-spin asymmetry and cross section for inclusive jet production in polarized proton collisions at sqrt(s) = 200 GeV
• Reanalysis of the EMC charm production data with extrinsic and intrinsic charm at NLO
• Measurement of the Spin Asymmetry in the Photoproduction of Pairs of High-pT Hadrons at HERMES
• Gluon polarization in the nucleon from quasi-real photoproduction of high-pT hadron pairs
• Measurement of the Spin Structure of the Deuteron in the DIS Region
• Measurement of the $x$- and $Q^2$-Dependence of the Asymmetry $A_1$ on the Nucleon
• Spin asymmetry A_1^d and the spin-dependent structure function g_1^d of the deuteron at low values of x and Q^2
• AROMA 2.2 - A Monte Carlo Generator for Heavy Flavour Events in $ep$ Collisions
• Transverse Polarization of Lambda and Lambda-bar Hyperons in Quasireal Photoproduction
• Extraction Of Delta g/g From Hermes Data On Inclusive Charged Hadrons
• Simultaneous Determination of Signal and Background Asymmetries
• Measurement of Delta G/G from high transverse momentum hadron pairs in COMPASS

Cited by in corpus (21)

• The Spin Structure of the Nucleon
• The Spin Structure of the Nucleon
• What can break the Wandzura--Wilczek relation?
• Physics of Gluon Helicity Contribution to Proton Spin
• Leading and Next-to-Leading Order Gluon Polarisation in the Nucleon and Longitudinal Double Spin Asymmetries from Open Charm Muoproduction
• Leading-Order Determination of the Gluon Polarization from high-$p_T$ Hadron Electroproduction
• Cross section and double helicity asymmetry for eta mesons and their comparison to neutral pion production in p+p collisions at sqrt(s)=200 GeV
• Leading order determination of the gluon polarisation from DIS events with high-p_T hadron pairs
• Gluon Helicity Delta G from a Universality Class of Operators on a Lattice
• Understanding the proton's spin structure
• Conceptual design of the Spin Physics Detector
• Helicity Parton Distributions at a Future Electron-Ion Collider: A Quantitative Appraisal
• Analysis of the double-spin asymmetry A_LT in inelastic nucleon-nucleon collisions
• The proton spin puzzle: where are we today ?
• Next-to-Leading Order QCD Corrections to Heavy Quark Correlations in Longitudinally Polarized Hadron-Hadron Collisions
• Spin structure of the nucleon: QCD evolution, lattice results and models
• QCD predictions for the azimuthal asymmetry in charm leptoproduction for the COMPASS kinematics
• Longitudinally Polarized Photoproduction of Heavy Flavors at Next-to-Leading Order of QCD
• Gluon polarization in the proton
• D* and D Meson Production in Muon Nucleon Interactions at 160 GeV/c
• $\Deltag/g$ results from the Open Charm production at COMPASS