Neutron deformation in 165Ho.

Measurements are reported of orientation asymmetries in the forward-angle differential cross sections for pion single-charge-exchange scattering of aligned and unaligned {sup 165}Ho nuclei. The extrapolated 0{degree} asymmetry of {minus}0.022{plus minus}0.024 indicates a quadrupole deformation ratio {beta}{sub 2}{sup {ital a}}/{beta}{sub 2}{sup {ital c}}=0.84{plus minus}0.08. This result conflicts with the predictions of the best available Hartree-Fock models.