Azimuthal Asymmetries in Heavy Quark Leptoproduction as a Test of pQCD

Abstract

We analyze the perturbative and parametric stability of the QCD predictions for the azimuthal asymmetries in heavy quark leptoproduction. At leading order, the $\cos \varphi$ asymmetry vanishes whereas the $\cos 2\varphi$ one is of leading twist and predicted to be about 15% at energies sufficiently above the production threshold. We calculate the NLO soft-gluon corrections to $\varphi$-dependent leptoproduction to the next-to-leading logarithmic accuracy. The soft-gluon approximation provides a good description of the available exact NLO results at $Q^2\lesssim m^2$. Our analysis shows that, contrary to the production cross sections, the $\cos 2\varphi$ asymmetry is practically insensitive to soft radiation for $Q^2\lesssim m^2$ at energies of the fixed target experiments. We conclude that the $\cos 2\varphi$ asymmetry is well defined in pQCD: it is stable both perturbatively and parametrically, and insensitive (in the case of bottom production) to nonperturbative contributions. Measurements of the azimuthal asymmetries would provide an excellent test of pQCD applicability to heavy flavor production.

arXiv comment13 pages, 9 figures, revtex, minor corrections, to appear in Nucl.Phys.B

References in corpus (20)

• Global QCD Analysis of Parton Structure of the Nucleon: CTEQ5 Parton Distributions
• The Resummation of Soft Gluon in Hadronic Collisions
• Evolution of Color Exchange in QCD Hard Scattering
• Sudakov Factorization and Resummation
• Resummation of Threshold Corrections for Single-Particle Inclusive Cross Sections
• Rates for Inclusive Deep-Inelastic Electroproduction of Charm Quarks at HERA
• Structure functions and low x physics
• Reanalysis of the EMC charm production data with extrinsic and intrinsic charm at NLO
• Heavy-quark correlations in deep-inelastic electroproduction
• kt Effects in Direct-Photon Production
• The Perturbative Resummed Series for Top Quark Production in Hadron Reactions
• Heavy Quark Correlations in Photon-Hadron Collisions
• High-order corrections and subleading logarithms for top quark production
• Soft Gluon Resummation for Heavy Quark Electroproduction
• Resummation for heavy quark and jet cross sections
• Perturbative Stability of the QCD Predictions for Single Spin Asymmetry in Heavy Quark Photoproduction
• Single Spin Asymmetry in Heavy Flavor Photoproduction as a Test of pQCD
• Soft Gluon Resummation for Polarized Deep-inelastic Production of Heavy Quarks
• Effects of threshold resummation
• Single Spin Asymmetry in Open Charm Photoproduction and Decay as a Test of pQCD

Cited by in corpus (9)

• The Ratio $R=F_L/F_T$ in DIS as a Probe of the Charm Content of the Proton
• On the Perturbative Stability of the QCD Predictions for the Ratio $R=F_L/F_T$ in Heavy-Quark Leptoproduction
• Azimuthal Asymmetries in DIS as a Probe of Intrinsic Charm Content of the Proton
• How to measure the linear polarization of gluons in unpolarized proton using the heavy-quark pair leptoproduction
• Azimuthal Dependence of the Heavy Quark Initiated Contributions to DIS
• The ratio $R=\mathrm{d}{\sigma }_L/\mathrm{d}{\sigma }_T$ in heavy-quark pair leptoproduction as a probe of linearly polarized gluons in unpolarized proton
• QCD predictions for the azimuthal asymmetry in charm leptoproduction for the COMPASS kinematics
• How to measure the linear polarization of gluons in unpolarized proton using the heavy-quark pair production
• Azimuthal Asymmetry and Ratio $R=F_L/F_T$ as Probes of the Charm Content of the Proton