Measurement of azimuthal asymmetries associated with deeply virtual Compton scattering on an unpolarized deuterium target

TL;DR

This paper measures azimuthal asymmetries in deeply virtual Compton scattering on unpolarized deuterium, providing insights into the underlying processes and comparing results with proton targets.

Contribution

It presents the first measurement of azimuthal asymmetries in DVCS on an unpolarized deuterium target, extending previous proton studies.

Findings

Beam-charge asymmetry amplitudes are consistent with proton results.

Beam-helicity asymmetry amplitudes are compatible with proton data.

Results support similar underlying mechanisms in deuterium and proton DVCS.

Abstract

Azimuthal asymmetries in exclusive electroproduction of a real photon from an unpolarized deuterium target are measured with respect to beam helicity and charge. They appear in the distribution of these photons in the azimuthal angle phi around the virtual-photon direction, relative to the lepton scattering plane. The extracted asymmetries are attributed to either the deeply virtual Compton scattering process or its interference with the Bethe-Heitler process. They are compared with earlier results on the proton target. In the measured kinematic region, the beam-charge asymmetry amplitudes and the leading amplitudes of the beam-helicity asymmetries on an unpolarized deuteron target are compatible with the results from unpolarized protons.