Single Spin Asymmetry in Open Charm Photoproduction and Decay as a Test of pQCD

Abstract

We analyze the possibility of measuring the single spin asymmetry (SSA) in open charm production by linearly polarized photons in the planned E160/E161 experiments at SLAC using the inclusive spectra of secondary (decay) leptons. In leading order pQCD, the SSA in the azimuthal distribution of the charged decay lepton is predicted to be about 0.2 for SLAC kinematics. Our calculations show that the SSA in the decay lepton distribution is well defined in pQCD: it is stable both perturbatively and parametrically, and practically insensitive to theoretical uncertainties in the charm semileptonic decays. Nonperturbative contributions to the leptonic SSA due to the gluon transverse motion in the target, heavy quark fragmentation and Fermi motion of the $c$-quark inside the $D$-meson are predicted to be about 10%. We conclude that measurements of the azimuthal asymmetry in the secondary lepton distribution would provide a good test of the applicability of pQCD to open charm production at energies of fixed target experiments. Our analysis of the SLAC experimental conditions shows that this SSA can be measured in E160/E161 with an accuracy of about ten percent.

18 pages, 10 figures, RevTeX, references corrected

References in corpus (2)

• Photoproduction of charm near threshold
• Perturbative Stability of the QCD Predictions for Single Spin Asymmetry in Heavy Quark Photoproduction

Cited by in corpus (7)

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• On the Perturbative Stability of the QCD Predictions for the Ratio $R=F_L/F_T$ in Heavy-Quark Leptoproduction
• How to measure the linear polarization of gluons in unpolarized proton using the heavy-quark pair leptoproduction
• Azimuthal Asymmetries in DIS as a Probe of Intrinsic Charm Content of the Proton
• Azimuthal Dependence of the Heavy Quark Initiated Contributions to DIS
• Azimuthal Asymmetries in Heavy Quark Leptoproduction as a Test of pQCD
• Azimuthal Asymmetry and Ratio $R=F_L/F_T$ as Probes of the Charm Content of the Proton