Energy staggering parameters in nuclear magnetic rotational bands *

Abstract

The systematics of energy staggering for the magnetic rotational bands with M 1 and E2 transition properties strictly consistent with the features of good candidates of magnetic rotational bands in the A ∼ 80, 110, 130 and 190 mass regions are presented. The regularities exhibited by these bands concerning the staggering parameter which increases with increasing spin are in agreement with the semiclassical description of shears mechanism. In addition, the abnormal behaviours in the backbend regions or close to band termination have also been discussed. Taking the magnetic dipole bands with same configuration in three N = 58 isotones, i.e., 103 Rh, 105 Ag, and 107 In, as examples, the transition from chiral rotation to magnetic rotation with the proton number approaching Z = 50 is presented. Moreover, the self-consistent tilted axis cranking and principle axis cranking relativistic mean-field theories are applied to investigate the rotational mechanism in dipole band of 105 Ag.

Systematic study of magnetic and antimagnetic rotational bands

“…( ) , we can deduce the formula S(I) ∝ 1 − (2I 0 + 1)/2I, which supports the fact that S(I) has an increasing trend with increasing spin [2,323]. Moreover, S(I) decreases as a function of spin in 83,85 Rb, 86 Sr, 135 Te, 133 Pr, 134 Nd, 144 Gd, 191 Pb and 198 Bi.…”

“…However, signature splitting is observed in many bands, such as in 105, 109 Ag, 102,104 Cd, 135 Ce, 142 Eu, 144 Dy, 193,195,196 Hg, and 198 Bi (No judgement on the presence or absence of splitting could however be made in many cases where only 4−5 levels have been observed). This signature splitting of S(I) is usually considered a sign of the collective rotation, which indicates a competition between the shear mechanism and collective motion [323,324]. Additionally, it can be seen that S(I) in most MR bands increases with increasing spin except for the band-crossing regions.…”

“…About 10 of the MR bands show a roughly increasing trend, such as the bands of 116 Sb and 131 La. [3,5,323]. However, signature splitting is observed in many bands, such as in 105, 109 Ag, 102,104 Cd, 135 Ce, 142 Eu, 144 Dy, 193,195,196 Hg, and 198 Bi (No judgement on the presence or absence of splitting could however be made in many cases where only 4−5 levels have been observed).…”

Studying the doublet bands at the borders of the $A \approx 130$ island of chiral candidates: the $^{120}$I case

“…During the past few decades, the relativistic mean field (RMF) theory has been a great success in describing properties of nuclei and many nuclear phenomena [17,[68][69][70][71]. Based on the RMF theory, the tilted axis cranking relativistic mean-field (TAC-RMF) theory has been developed for describing many nuclear rotational phenomenon such as magnetic, antimagnetic and chiral rotation [17,57,62,72,73]. In the TAC-RMF theory, nuclei are characterized by the relativistic fields S(r) and V µ (r) in the Dirac equation in the rotating frame with a constant angular velocity vector Ω as…”

Doublet bands at borders of A ≈ 130 island of chiral candidates: Case study of 120I *

“…To further investigate the configuration of the doublet bands in 120 I, TAC-RMF calculations were performed. In the past few decades, the relativistic mean field (RMF) theory has had great success in describing properties of nuclei and numerous nuclear phenomena [17,[68][69][70][71]. Based on the RMF theory, the tilted axis cranking relativistic mean-field (TAC-RMF) theory was developed to describe numerous nuclear rotational phenomenona, such as magnetic, antimagnetic, and chiral rotation [17,38,57,62,72].…”