Neutron deformation inHo165

Abstract
Measurements are reported of orientation asymmetries in the forward-angle differential cross sections for pion single-charge-exchange scattering of aligned and unaligned Ho165 nuclei. The extrapolated 0° asymmetry of -0.022±0.024 indicates a quadrupole deformation ratio β2a/β2c=0.84±0.08. This result conflicts with the predictions of the best available Hartree-Fock models.