Deformation effects in low-momentum distributions of heavy nuclei

Momentum distributions (MD) of deep hole proton states in ²³⁸U are studied paying particular attention to the influence of deformation. Two essentially different mean-field models, Woods–Saxon (WS) and Skyrme–Hartree–Fock with the SkM* force, are used. Noticeable deviations between the WS and SkM* results are found. They are mainly due to the difference in the effective nucleon mass. In particular, SkM* gives much weaker deformation effects at low momenta than WS. It is shown that, in spite of the deformation mixing, MD at low momenta can serve for identification of K^π = 1/2⁺ hole states originating from s_1/2 spherical subshells. Moreover, following the WS calculations, the deformation results in additional K^π = 1/2⁺ states with strong l = 0 contributions. A possibility of probing such states in knock-out experiments is discussed.