Influence of the exchange potential on the neutron radius ofPb208extracted from sub-Coulomb pickup

Analysis of sub-Coulomb pickup using the realistic nonlocality arising from the exchange term in Hartree-Fock theory is shown to yield a point-nucleon rms radius for the excess neutrons in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ of 6.21 fm, a value of 0.22 fm larger than previously obtained using local potentials. A simple schematic calculation is presented to elucidate the effect of nonlocality and arguments are presented to substantiate the reliability of a more realistic calculation. The implications of this result concerning the Coulomb energy anomaly are briefly discussed.