Two proton and two neutron photoemission cross sections of ⁶³Cu

The (e,2p) and (e,2n) cross sections and the (e+γ,2p) and (e+γ,2n) yields have been measured for ⁶³Cu in the electron energy range 28–60 MeV. The experimental results have been analyzed using distorted-wave Born approximation E1 and E2 virtual photon spectra in order to derive the E1 and isovector E2 components of the (γ,2p) and (γ,2n) cross sections. In the 2n channel the E1 component exhausts 12.4(11)% of the E1 energy weighted sum, while the isovector E2 component exhausts 52(15)% of its sum. The 2p channel exhausts 1.03(8)% of the energy weighted sum for E1 and we were able to establish an upper limit for the isovector E2 contribution of 0.58% of its sum.