Irregularity inKπ=8−rotational bands ofN=150isotones

Abstract

Motivated by new experimental spectra in transfermium mass region, we have investigated broken-pair high-K multiparticle excited states and their rotational bands for the N = 150 isotones around Z = 100, by using the configuration-constrained pairing-deformation-frequency self-consistent total-Routhian-surface (TRS) model. In order to avoid the spurious phase transition encountered in the Bardeen-Copper-Schrieffer (BCS) pairing, the particle-number-conserving method has been employed for pairing calculations. Pairing correlations are remarkably reduced for the rotations of broken-pair multiparticle states. The present configuration-constrained TRS calculations reproduce reasonably existing experimental data. The abnormal feature in the recently observed K π = 8 − bands of 252 No and 250 Fm would be associated with configuration mixing.

In-beam spectroscopy of heavy elements

“…Calculations of rotational bands built on high-K isomeric states are still seldomly performed in the A ∼ 250 mass region. So far such calculations have been reported only by Sulignano et al [19] and Fu et al [133] in both 250 Fm and 252 No. Sulignano et al performed cranked HFB calculations using the D1S Gogny force.…”

Population and decay of aKπ=8−two-quasineutron isomer inPu244

“…It would be instructive to corroborate this interpretation with a full calculation within the model of Ref. [33].…”

“…In 252 No, a crossing with a side band built on a low-lying 2 − state was put forward as a possible explanation for the anomaly. A more recent theoretical study using a configuration-constrained total-Routhiansurface model suggests that the prominent dips in J (2) moments for both 250 Fm and 252 No are due to configuration mixing with a proton 7/2 [33]. The smooth behavior of the J (2) moment for the 2-qp band in 244 Pu is consistent with this interpretation, as the 7/2 + [633] π configuration moves to higher excitation energies with decreasing Z and would thus be less likely to mix with the two-quasineutron isomer configuration.…”

Configuration-constrained calculations of high-<italic>K </italic>rotational bands in even-even isotones around <italic>N</italic>=100

“…前几年, 本课题组 [24] goliubov对相互作用. 这种方法被成功用于描述原子核 转动带, 尤其是边带 [17,24,25] . 然而, 在计算包含单体势的 2 计算结果与讨论 计算所选用的Skyrme参数是SKM* [32] , pairing强度 通过三点公式质量奇偶差 [33]…”