Neutron contribution to nuclear DVCS asymmetries

Journal Article · Tue Jan 22 00:00:00 EST 2008

OSTI ID:922244

Guzey, Vadim

Using a simple model for nuclear GPDs, we study the role of the neutron contribution to nuclear DVCS observables. As an example, we use the beam-spin asymmetry $$A_{LU}^A$$ measured in coherent and incoherent DVCS on a wide range of nuclear targets in the HERMES and JLab kinematics. We find that at small values of the momentum transfer $$t$$, $$A_{LU}^A$$ is dominated by the coherent-enriched contribution, which enhances $$A_{LU}^A$$ compared to the free proton asymmetry $$A_{LU}^p$$, $$A_{LU}^A(\phi)/A_{LU}^p(\phi)=1.8-2.2$$. At large values of $$t$$, the nuclear asymmetry is dominated by the incoherent contribution and $$A_{LU}^A/(\phi)A_{LU}^p(\phi)=0.66-0.74$$. The deviation of $$A_{LU}^A(\phi)/A_{LU}^p(\phi)$$ from unity at large $$t$$ is a result of the neutron contribution, which gives a possibility to constain neutron GPDs in incoherent nuclear DVCS. A similar trend is expected for other DVCS asymmetries.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 922244
• Report Number(s): JLAB-THY-08-767; DOE/OR/23177-0275
• Country of Publication: United States
• Language: English