Excited states in the odd-proton nucleus 125Cs were investigated by means of in-beam β-ray spectroscopy. The πg7/2 band is observed to fork into a △I = 1 coupled band and a △I = 2 decoupled band at high spins. To ...Excited states in the odd-proton nucleus 125Cs were investigated by means of in-beam β-ray spectroscopy. The πg7/2 band is observed to fork into a △I = 1 coupled band and a △I = 2 decoupled band at high spins. To assign the possible configurations of these two bands, experimental B（M1）/B（E2） ratios and signature splittings have been evaluated for the △I = 1 band, and calculations based on the geometrical model, cranked shell model and total Routhian surfaces model have been performed. They are suggested to be a near-oblate band built on the （πg7/2/d5/2） （vh11/2）2 configuration and a prolate band built on the πg7/2 （πh11/2）2 configuration, respectively.展开更多
The multi-particle states and rotational properties of the two-particle bands in 254No are investigated by the cranked shell model with pairing correlations treated by the particle number conserving method. The rotati...The multi-particle states and rotational properties of the two-particle bands in 254No are investigated by the cranked shell model with pairing correlations treated by the particle number conserving method. The rotational bands on top of the two-particle Kπ= 3+, 8- and 10+ states and the pairing reduction are studied theoretically in 254No for the first time. The experimental excitation energies and moments of inertia of the multi-particle states are reproduced well by the calculations. Better agreement with the data is achieved by including the high-order deformation ε6,J（1） in these two-particle bands compared with the ground state band is attributed to the pairing reduction due to the Pauli blocking effect.展开更多
The microscopic mechanism of four experimentally observed bands in 172Tm is investigated using the particle-number conserving method of the cranked shell model with monopole and quadrupole paring interactions.The expe...The microscopic mechanism of four experimentally observed bands in 172Tm is investigated using the particle-number conserving method of the cranked shell model with monopole and quadrupole paring interactions.The experimental results,including the moments of inertia and angular momentum alignments of four bands in 172Tm are reproduced well by the particle-number conserving calculations.The ω variation of the occupation probability of each cranked orbital and the contribution to moment of inertia from each cranked orbital are analyzed.Other unobserved low-lying bands of 2-quansiparticles in 172Tm are predicted.展开更多
High-spin states in 187Pt were studied via the 173Yb(18O,4n) reaction. Rotational bands based on the νi13/2,ν7/2-[503],νi213/2νj,ν3/2-[512] and ν1/2-[521] configurations were observed,and interpreted within the ...High-spin states in 187Pt were studied via the 173Yb(18O,4n) reaction. Rotational bands based on the νi13/2,ν7/2-[503],νi213/2νj,ν3/2-[512] and ν1/2-[521] configurations were observed,and interpreted within the framework of the cranked shell model. The TRS calculations show that the νi13/2 band has an appreciable negative γ deformation,and the negative-parity bands tend to have a near prolate shape with small positive γ values. Experimental values of B(M1) /B(E2) ratios have been extracted and compared with theoretical values from the semi-classical D-nau and Frauendof approach,strongly suggesting a low frequency πh9/2 alignment in the ν7/2-[503] band.展开更多
High spin states in the odd-odd nucleus 124Cs have been investigated through the fusion-evaporation reaction 116Sn（11B, 3n）l24 Cs with a beam energy of 45 MeV. A new rotational band is established and assigned as th...High spin states in the odd-odd nucleus 124Cs have been investigated through the fusion-evaporation reaction 116Sn（11B, 3n）l24 Cs with a beam energy of 45 MeV. A new rotational band is established and assigned as the high-k configuration of πg9/2140419/2＋ ⊙vh 11/2[523]7/2-. Some structures linking to this band have also been observed. According to the results of the excitation energy systematics, the lowest level of this band is assigned as 9-, and the 8- isomer bandhead has not been observed. Another isomer with a half life of 6.3 s has also been observed with its new decay paths established, Its excitation energy is raised by 79 keV, but its Iπ is not changed.展开更多
The collective rotations of the K^π=5^- configuration in neutron-rich Mo, Ru and Pd isotopes were systematically investigated by the configuration-constrained cranking shell model based on the Skyrme Hartree-Fock met...The collective rotations of the K^π=5^- configuration in neutron-rich Mo, Ru and Pd isotopes were systematically investigated by the configuration-constrained cranking shell model based on the Skyrme Hartree-Fock method with pairing treated by shell-model diagonalization. The calculations efficiently reproduce the experimental moments of inertia of both the ground-state and side bands. Rotational bands built on two-particle K^π=5^- configurations have been the subject of intense study. Possible configurations were assigned to the observed 5^- bands in ^102-106Mo,^108-112Ru and ^112-114Pd. We predict the existence of the 5^- bands in ^108,110Mo. These results provide deep insights into the structure of neutron-rich nuclei, and provide useful information for future experiments.展开更多
High-spin yrast structures of even-even superheavy nuclei 254-25SRf are investigated by means of total- Routhian-surface approach in three-dimensional （f12, 7, f14） space. The behavior in the moments of inertia of 2...High-spin yrast structures of even-even superheavy nuclei 254-25SRf are investigated by means of total- Routhian-surface approach in three-dimensional （f12, 7, f14） space. The behavior in the moments of inertia of 256Rf is well reproduced by our calculations, which is attributed to the J15/2 neutron rotation-alignment. The competition between the rotationally aligned ila/2 proton and j15/2 neutron may occur to a large extent in 256Rf. High-spin predictions are also made for its neighboring isotopes 254＇2ssRf, showing that the alignment of the j15/2 neutron pair is more favored than that of the i13/2 proton pair.展开更多
Proton radioactivity is an important decay mode for nuclei near the proton drip-line. Studies of this decay mode can reveal valuable information on exotic nuclear structure and provide important information on the stu...Proton radioactivity is an important decay mode for nuclei near the proton drip-line. Studies of this decay mode can reveal valuable information on exotic nuclear structure and provide important information on the stucture of nuclei in extreme conditions. The new experimental data can let us understand the interactions in exotic systems, which motivate further theoretical development. The most recent application of the projected shell model(PSM) for proton emitters is represented. We study the rotational bands of the deformed proton emitter141 Ho by using the PSM. The experimental data are well reproduced. Strongly suppressed γ transition from the low-lying I~π= 3/2+state makes this state isomeric. Variations in the dynamical moment of inertia are discussed due to band crossings using the band diagram. The calculated results for proton emitter ^(151)Lu shows it is oblately deformed.展开更多
The configuration-dependent cranked Nilsson-Strutinsky approach was used to investigate the rotational structures in 128Pr and signature splittings of some observed bands could be well described quantitatively at high...The configuration-dependent cranked Nilsson-Strutinsky approach was used to investigate the rotational structures in 128Pr and signature splittings of some observed bands could be well described quantitatively at high spin. Its modified model was used to calculate special configurations in order to distinguish the N=4 d3/2s1/2 and g7/2d5/2 orbitals. All observed bands were compared with the calculated configuration assigned to the band and the agreement between experiment and theory is remarkable.展开更多
The experimental rotational spectra of the deformed nuclei available in even-even and odd-A nuclei in the rare-earth and actinide regions are systematically analyzed with several rotational spectra formulas, including...The experimental rotational spectra of the deformed nuclei available in even-even and odd-A nuclei in the rare-earth and actinide regions are systematically analyzed with several rotational spectra formulas, including Bohr-Mottelson＇s I（I＋ 1）-expansion, Harris＇ ω^2-expansion, ab and abc formulas. It is shown that the simple 2-parameter ab formula is much better than the widely used 2-parameter Bohr-Mottelson＇s AB formula and Harris＇ αβ formula. The available data of the rotational spectra of both ground-state band in even-even nuclei and one-quasiparticle band in odd-A nuclei can be conveniently and rather accurately reproduced by ab formula and abc formula. The moment of inertia and the variation with rotational frequency of angular momentum can be satisfactorily reproduced by ab and abc formulas.展开更多
In the framework of the projected shell model, we investigate the competition between the two-quasineutron and two-quasiproton K~π=6~＋ states in the ytterbium isotopes and N =104 isotones adjacent to ^（174）Yb. Th...In the framework of the projected shell model, we investigate the competition between the two-quasineutron and two-quasiproton K~π=6~＋ states in the ytterbium isotopes and N =104 isotones adjacent to ^（174）Yb. The ^（174）Yb results are compared with the experimental data.The K~π =6~＋ isomer observed in ^（174） Yb is assigned as an admixture of the ν7/2^-[514] ν5/2^-[512] and π7/2~＋ [404]π5/2~＋ [402] intrinsic structure, which explains the experimental ｜g K-g R ｜ value. Similar mixing would appear in ^（174） Yb, ^（176） Hf,and ^（178） W. The low-lying K~π=6~＋ states are also predicted in ^（170-178） Yb.展开更多
基金Supported in part by National Natural Science Foundation of China(11475072)
文摘Excited states in the odd-proton nucleus 125Cs were investigated by means of in-beam β-ray spectroscopy. The πg7/2 band is observed to fork into a △I = 1 coupled band and a △I = 2 decoupled band at high spins. To assign the possible configurations of these two bands, experimental B（M1）/B（E2） ratios and signature splittings have been evaluated for the △I = 1 band, and calculations based on the geometrical model, cranked shell model and total Routhian surfaces model have been performed. They are suggested to be a near-oblate band built on the （πg7/2/d5/2） （vh11/2）2 configuration and a prolate band built on the πg7/2 （πh11/2）2 configuration, respectively.
基金Supported by the National Natural Science Foundation of China(11775112,11535004,11875027,11761161001)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘The multi-particle states and rotational properties of the two-particle bands in 254No are investigated by the cranked shell model with pairing correlations treated by the particle number conserving method. The rotational bands on top of the two-particle Kπ= 3+, 8- and 10+ states and the pairing reduction are studied theoretically in 254No for the first time. The experimental excitation energies and moments of inertia of the multi-particle states are reproduced well by the calculations. Better agreement with the data is achieved by including the high-order deformation ε6,J（1） in these two-particle bands compared with the ground state band is attributed to the pairing reduction due to the Pauli blocking effect.
基金Supported by the National Natural Science Foundation of China (Grant No.10675006)
文摘The microscopic mechanism of four experimentally observed bands in 172Tm is investigated using the particle-number conserving method of the cranked shell model with monopole and quadrupole paring interactions.The experimental results,including the moments of inertia and angular momentum alignments of four bands in 172Tm are reproduced well by the particle-number conserving calculations.The ω variation of the occupation probability of each cranked orbital and the contribution to moment of inertia from each cranked orbital are analyzed.Other unobserved low-lying bands of 2-quansiparticles in 172Tm are predicted.
基金the National Natural Science Foundation of China (Grant Nos. 10475097 and 10505025)
文摘High-spin states in 187Pt were studied via the 173Yb(18O,4n) reaction. Rotational bands based on the νi13/2,ν7/2-[503],νi213/2νj,ν3/2-[512] and ν1/2-[521] configurations were observed,and interpreted within the framework of the cranked shell model. The TRS calculations show that the νi13/2 band has an appreciable negative γ deformation,and the negative-parity bands tend to have a near prolate shape with small positive γ values. Experimental values of B(M1) /B(E2) ratios have been extracted and compared with theoretical values from the semi-classical D-nau and Frauendof approach,strongly suggesting a low frequency πh9/2 alignment in the ν7/2-[503] band.
基金supported by National Natural Science Foundation of China(Nos.10105003,11075064,11075214 and 10927507)the Specialized Research Fund for the Doctoral Programme of Higher Education of China(No.20050183008)the National Basic Research Programme of China(No.2007CB815005)
文摘High spin states in the odd-odd nucleus 124Cs have been investigated through the fusion-evaporation reaction 116Sn（11B, 3n）l24 Cs with a beam energy of 45 MeV. A new rotational band is established and assigned as the high-k configuration of πg9/2140419/2＋ ⊙vh 11/2[523]7/2-. Some structures linking to this band have also been observed. According to the results of the excitation energy systematics, the lowest level of this band is assigned as 9-, and the 8- isomer bandhead has not been observed. Another isomer with a half life of 6.3 s has also been observed with its new decay paths established, Its excitation energy is raised by 79 keV, but its Iπ is not changed.
基金Supported by the National Key R&D Program of China(2018YFA0404401)the National Natural Science Foundation of China(11835001,11575007,11847203)the China Postdoctoral Science Foundation(2018M630018)
文摘The collective rotations of the K^π=5^- configuration in neutron-rich Mo, Ru and Pd isotopes were systematically investigated by the configuration-constrained cranking shell model based on the Skyrme Hartree-Fock method with pairing treated by shell-model diagonalization. The calculations efficiently reproduce the experimental moments of inertia of both the ground-state and side bands. Rotational bands built on two-particle K^π=5^- configurations have been the subject of intense study. Possible configurations were assigned to the observed 5^- bands in ^102-106Mo,^108-112Ru and ^112-114Pd. We predict the existence of the 5^- bands in ^108,110Mo. These results provide deep insights into the structure of neutron-rich nuclei, and provide useful information for future experiments.
基金Supported by National Natural Science Foundation of China(10805040,11175217)Foundation and Advanced Technology Research Program of Henan Province(132300410125)S&T Research Key Program of Henan Province Education Department(13A140667)
文摘High-spin yrast structures of even-even superheavy nuclei 254-25SRf are investigated by means of total- Routhian-surface approach in three-dimensional （f12, 7, f14） space. The behavior in the moments of inertia of 256Rf is well reproduced by our calculations, which is attributed to the J15/2 neutron rotation-alignment. The competition between the rotationally aligned ila/2 proton and j15/2 neutron may occur to a large extent in 256Rf. High-spin predictions are also made for its neighboring isotopes 254＇2ssRf, showing that the alignment of the j15/2 neutron pair is more favored than that of the i13/2 proton pair.
基金National Natural Science Foundation of China(11005050)
文摘Proton radioactivity is an important decay mode for nuclei near the proton drip-line. Studies of this decay mode can reveal valuable information on exotic nuclear structure and provide important information on the stucture of nuclei in extreme conditions. The new experimental data can let us understand the interactions in exotic systems, which motivate further theoretical development. The most recent application of the projected shell model(PSM) for proton emitters is represented. We study the rotational bands of the deformed proton emitter141 Ho by using the PSM. The experimental data are well reproduced. Strongly suppressed γ transition from the low-lying I~π= 3/2+state makes this state isomeric. Variations in the dynamical moment of inertia are discussed due to band crossings using the band diagram. The calculated results for proton emitter ^(151)Lu shows it is oblately deformed.
文摘The configuration-dependent cranked Nilsson-Strutinsky approach was used to investigate the rotational structures in 128Pr and signature splittings of some observed bands could be well described quantitatively at high spin. Its modified model was used to calculate special configurations in order to distinguish the N=4 d3/2s1/2 and g7/2d5/2 orbitals. All observed bands were compared with the calculated configuration assigned to the band and the agreement between experiment and theory is remarkable.
基金Supported by National Natural Science Foundation of China (10575004,10675007)
文摘The experimental rotational spectra of the deformed nuclei available in even-even and odd-A nuclei in the rare-earth and actinide regions are systematically analyzed with several rotational spectra formulas, including Bohr-Mottelson＇s I（I＋ 1）-expansion, Harris＇ ω^2-expansion, ab and abc formulas. It is shown that the simple 2-parameter ab formula is much better than the widely used 2-parameter Bohr-Mottelson＇s AB formula and Harris＇ αβ formula. The available data of the rotational spectra of both ground-state band in even-even nuclei and one-quasiparticle band in odd-A nuclei can be conveniently and rather accurately reproduced by ab formula and abc formula. The moment of inertia and the variation with rotational frequency of angular momentum can be satisfactorily reproduced by ab and abc formulas.
基金Supported by National Natural Science Foundation of China (10975006)
文摘In the framework of the projected shell model, we investigate the competition between the two-quasineutron and two-quasiproton K~π=6~＋ states in the ytterbium isotopes and N =104 isotones adjacent to ^（174）Yb. The ^（174）Yb results are compared with the experimental data.The K~π =6~＋ isomer observed in ^（174） Yb is assigned as an admixture of the ν7/2^-[514] ν5/2^-[512] and π7/2~＋ [404]π5/2~＋ [402] intrinsic structure, which explains the experimental ｜g K-g R ｜ value. Similar mixing would appear in ^（174） Yb, ^（176） Hf,and ^（178） W. The low-lying K~π=6~＋ states are also predicted in ^（170-178） Yb.
