The properties of the high spin states of the neutron-rich 98-102Sr and 100-104Zr isotopes have been st udied using the projected shell model. In particular, the upbending phenomenon is investigated for these isotopes...The properties of the high spin states of the neutron-rich 98-102Sr and 100-104Zr isotopes have been st udied using the projected shell model. In particular, the upbending phenomenon is investigated for these isotopes along the yrast line. The results show that the occurrence of upbending phenomenon is attributed to the band crossing between ground state band and 2-qp neutron band having configuration 2vh11/2[-3/2, 5/2], K = 1. Furthermore, the neutron two-quasi-particle structure of side bands in 98SR-102Zr is discussed in this paper.展开更多
Within the framework of the microscopic-macroscopic model,using total Routhian surface calculations in the three-dimensional space(β2,γ,andβ4),a systematic investigation of mirror-pair nuclei^(74)Kr-^(74)Sr,^(78)Sr...Within the framework of the microscopic-macroscopic model,using total Routhian surface calculations in the three-dimensional space(β2,γ,andβ4),a systematic investigation of mirror-pair nuclei^(74)Kr-^(74)Sr,^(78)Sr-78Zr,and^(82)Zr-^(82)Mo is conducted to predict the mirror symmetry violation in their rotational properties.The empirical Pfactor,energy ratio R4/2,energies of the first excited state E_(2_(1)^(+)),and binding energies Ebind of these mirror partner nuclei are presented,together with the primary deformationsβ2 andβ4.Our calculations indicate the shape coexistence in the ground state of all these mirror partner nuclei.The moments of inertia of these mirror partner nuclei are not always the same in the yrast band.The rotational frequencies at which upbending occurs in^(74)Kr and^(74)Sr are nearly identical.However,in^(78)Sr and^(82)Zr,the upbending occurs earlier than in their mirror partners 78Zr and^(82)Mo.Theupbending phenomenon in^(74)Kr and^(74)Sr is attributed to the simultaneous alignment of protons and neutrons.Taking the nuclei^(78)Sr-78Zr as examples,we suggest that the first upbending is attributed to the alignment of protons and neutrons within the 1_(g9/2) orbitals,as evidenced by the calculated single-particle energy levels.These specific band crossings are further elucidated through quasiparticle Routhian diagrams,which characterize the alignment of high-j,low-Ωpairs,and reveal the underlying microscopic mechanism.Our results show that^(74)Kr and^(74)Sr maintain strong mirror symmetry in their rotational behavior.^(78)Sr and^(82)Zr exhibit earlier upbending than their mirrors,indicating possible mirror symmetry breaking.This study may provide new insights for future research into the mirror symmetry violation in nuclear excited states.展开更多
Using the total-Routhian-surface （TRS） method, the rotational behaviors of fission isomers in the second well of actinide nuclei 234-242U, 236-244pu and 238-246Cm were investigated. The pairing-deformation-frequency...Using the total-Routhian-surface （TRS） method, the rotational behaviors of fission isomers in the second well of actinide nuclei 234-242U, 236-244pu and 238-246Cm were investigated. The pairing-deformation-frequency self-consistent TRS calculations repro- duced reasonably the experimental moments of inertia extracted from spectroscopic data. It is calculated that, in these largely elongated （β2 ≈0.65 and β4≈ 0.03） fission isomers, the ν1/2-[981] neutron and π1/2＋[651] proton align simultaneously at rotational frequency hω≈0.4 - 0.6 MeV （corresponding to spin I≈80h）, which leads to clear upbending in moments of inertia （MoI＇s）. Our calculations have indicated that the hexadecapole deformation f14 influenced significantly the frequency of the rotational alignment of the proton 1/2＋[651] orbit.展开更多
基金Supported by the Natural Science Foundation of China under Grant Nos. 10975051, 10979024, 10905021the Natural Science Foundation of Zhejiang province, China under Grant No. Y6090210the Natural Science Foundation of Huzhou under Grant No. 2010YZll
文摘The properties of the high spin states of the neutron-rich 98-102Sr and 100-104Zr isotopes have been st udied using the projected shell model. In particular, the upbending phenomenon is investigated for these isotopes along the yrast line. The results show that the occurrence of upbending phenomenon is attributed to the band crossing between ground state band and 2-qp neutron band having configuration 2vh11/2[-3/2, 5/2], K = 1. Furthermore, the neutron two-quasi-particle structure of side bands in 98SR-102Zr is discussed in this paper.
基金Supported by the National Natural Science Foundation of China(12205076,12047504)the China Postdoctoral Science Foundation(2020M670012)+1 种基金the Launching Fund of Henan University of Technology(2021BS047)the Cultivation Programme for Young Backbone Teachers in Henan University of Technology(21421304)。
文摘Within the framework of the microscopic-macroscopic model,using total Routhian surface calculations in the three-dimensional space(β2,γ,andβ4),a systematic investigation of mirror-pair nuclei^(74)Kr-^(74)Sr,^(78)Sr-78Zr,and^(82)Zr-^(82)Mo is conducted to predict the mirror symmetry violation in their rotational properties.The empirical Pfactor,energy ratio R4/2,energies of the first excited state E_(2_(1)^(+)),and binding energies Ebind of these mirror partner nuclei are presented,together with the primary deformationsβ2 andβ4.Our calculations indicate the shape coexistence in the ground state of all these mirror partner nuclei.The moments of inertia of these mirror partner nuclei are not always the same in the yrast band.The rotational frequencies at which upbending occurs in^(74)Kr and^(74)Sr are nearly identical.However,in^(78)Sr and^(82)Zr,the upbending occurs earlier than in their mirror partners 78Zr and^(82)Mo.Theupbending phenomenon in^(74)Kr and^(74)Sr is attributed to the simultaneous alignment of protons and neutrons.Taking the nuclei^(78)Sr-78Zr as examples,we suggest that the first upbending is attributed to the alignment of protons and neutrons within the 1_(g9/2) orbitals,as evidenced by the calculated single-particle energy levels.These specific band crossings are further elucidated through quasiparticle Routhian diagrams,which characterize the alignment of high-j,low-Ωpairs,and reveal the underlying microscopic mechanism.Our results show that^(74)Kr and^(74)Sr maintain strong mirror symmetry in their rotational behavior.^(78)Sr and^(82)Zr exhibit earlier upbending than their mirrors,indicating possible mirror symmetry breaking.This study may provide new insights for future research into the mirror symmetry violation in nuclear excited states.
基金supported by Zhong Xia Interscholastic Scientific Research Fundthe National Key Basic Research Program of China(Grant No.2013CB34400)the National Natural Science Foundation of China(Grant Nos.11235001,11375016,11320101004 and J1103206)
文摘Using the total-Routhian-surface （TRS） method, the rotational behaviors of fission isomers in the second well of actinide nuclei 234-242U, 236-244pu and 238-246Cm were investigated. The pairing-deformation-frequency self-consistent TRS calculations repro- duced reasonably the experimental moments of inertia extracted from spectroscopic data. It is calculated that, in these largely elongated （β2 ≈0.65 and β4≈ 0.03） fission isomers, the ν1/2-[981] neutron and π1/2＋[651] proton align simultaneously at rotational frequency hω≈0.4 - 0.6 MeV （corresponding to spin I≈80h）, which leads to clear upbending in moments of inertia （MoI＇s）. Our calculations have indicated that the hexadecapole deformation f14 influenced significantly the frequency of the rotational alignment of the proton 1/2＋[651] orbit.
