High-spin states of the neutron-rich odd nuclei ${}^{159,161,163}\mathrm{Dy}$ have been studied using the incomplete fusion reactions ${}^{158,160}\mathrm{Gd}{(}^7\mathrm{Li},(p,d,t)xn).\mathrm{}$ In ${}^{159}\mathrm{Dy},$ the band crossing in the ${11/2}^{-}\left[505\right]$ band has been observed for the first time. Moreover, 11 $E1\mathrm{}$ transitions connecting both signatures of the ${3/2}^{-}\left[521\right]$ band to the ${5/2}^{+}\left[642\right]$ band have been observed in this nucleus; the deduced $B\left(E1\mathrm{}\right)/B\left(E2\mathrm{}\right)\mathrm{}$ ratios as well as the $B\left(M1\mathrm{}\right)/B\left(E2\mathrm{}\right)\mathrm{}$ ratios for transitions within the ${3/2}^{-}\left[521\right]$ band show a pronounced signature dependence. In ${}^{161}\mathrm{Dy}$ and ${}^{163}\mathrm{Dy},$ rotational bands have been extended to significantly higher spin values. In ${}^{161}\mathrm{Dy},$ the sequences built on the neutron ${5/2}^{-}\left[523\right]$ and ${3/2}^{-}\left[521\right]$ states have been followed up to spin ${49/2}^{-}$ and ${33/2}^{-},$ respectively, and in both cases upbends have been observed around $ħ\omega \approx 0.26$ MeV. In addition, a new band most probably built on the ${11/2}^{-}\left[505\right]$ single-particle state has been identified in this isotope. In ${}^{163}\mathrm{Dy},$ both the ${5/2}^{-}\left[523\right]$ ground state band and the structure built on the ${5/2}^{+}\left[642\right]$ neutron orbit have been extended up to the ${45/2}^{-}$ and ${49/2}^{+}$ states, respectively. However, no band crossing has been observed in this nucleus. The properties of the observed bands in ${}^{159,161,163}\mathrm{Dy}$ are discussed and compared to calculations performed within the projected shell model.

• Received 5 December 2002

DOI:https://doi.org/10.1103/PhysRevC.67.034302