Determination of the Beam-Spin Asymmetry of Deuteron Photodisintegration in the Energy Region $E_{\gamma }=1.1-2.3$ GeV

Abstract

The beam-spin asymmetry, $\Sigma$, for the reaction $\gamma d\to pn$ has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, ${\theta }_{c.m.}$, between $25^{\circ }$ and $160^{\circ }$. These are the first measurements of beam-spin asymmetries at ${\theta }_{c.m.}=90^{\circ }$ for photon-beam energies above 1.6 GeV, and the first measurements for angles other than ${\theta }_{c.m.}=90^{\circ }$. The angular and energy dependence of $\Sigma$ is expected to aid in the development of QCD-based models to understand the mechanisms of deuteron photodisintegration in the transition region between hadronic and partonic degrees of freedom, where both effective field theories and perturbative QCD cannot make reliable predictions.

18 pages

References in corpus (3)

• Angular dependence of recoil proton polarization in high-energy γd \to p n
• Azimuthal Dependence of the Heavy Quark Initiated Contributions to DIS
• Hard Break-Up of Two-Nucleons from the 3He Nucleus

Cited by in corpus (2)

• Deuteron photodisintegration by polarized photons in the region of the $d^{\ast }(2380)$
• Hard Photodisintegration of 3He into pd pair