Neutron contribution to nuclear deeply virtual Compton scattering asymmetries

作者：Guzey V^*

来源：Physical Review C, 2008, 78(2): 025211.

DOI：10.1103/PhysRevC.78.025211

Using a simple model for nuclear generalized parton distributions (GPDs), we study the role of the neutron contribution to nuclear deeply virtual Compton scattering (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-entiched 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 constrain neutron GPDs in incoherent nuclear DVCS. A similar trend is expected for other DVCS asymmetries.

• 出版日期2008-8