High-spin spectroscopy and quasiparticle alignments in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mi mathvariant="normal">Ce</mml:mi><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>124</mml:mn><mml:mo>,</mml:mo><mml:mn>125</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math>
Abstract
Rotational bands have been studied to high spins in the neutron-deficient $^{124,125}\mathrm{Ce}$ nuclei. The nuclei were populated using the $^{64}\mathrm{Zn}(^{64}\mathrm{Zn},2p2n)^{124}\mathrm{Ce}$ and $^{64}\mathrm{Zn}(^{64}\mathrm{Zn},2pn)^{125}\mathrm{Ce}$ reactions, with a beam energy of $260\phantom{\rule{0.3em}{0ex}}\text{MeV}$. High-fold $\ensuremath{\gamma}$-ray coincidence data were collected using the Gammasphere germanium-detector array. The Microball charged-particle detector array was used to provide channel selection. The previously established level structures of both $^{124,125}\mathrm{Ce}$ have been extended to high spins $(\ensuremath{\sim}30\ensuremath{\hbar})$. In addition, several new bands have been identified. The alignments of pairs of ${h}_{11∕2}$ neutrons and protons are observed in both nuclei. The alignments are compared to the predictions of Woods-Saxon cranked shell model calculations and to the systematics of ${h}_{11∕2}$ quasiparticle alignments in neighboring nuclei. The apparent ability of the cranked shell model to explain the ${h}_{11∕2}$ neutron alignments in $^{124,125}\mathrm{Ce}$ highlights the previously reported discrepancies between experiment and theory for the $^{128}\mathrm{Ce}$ isotope and, to a lesser extent, $^{126}\mathrm{Ce}$.