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
Generally, rotation-vibration molecular spectra are described by the Dunham expression in the form E（v, I）=sum from n=i,j Y<sub>i,j</sub>（v+1/2）<sup>i</sup>[I（I+1）]<sup>j</sup>...Generally, rotation-vibration molecular spectra are described by the Dunham expression in the form E（v, I）=sum from n=i,j Y<sub>i,j</sub>（v+1/2）<sup>i</sup>[I（I+1）]<sup>j</sup> , （1）where I is the angular momentum and v is the vibrational quantum number. The numerical coefficients Y<sub>i,j</sub> of the first few terms of the Dunham expression are obtained by the solution of the Schrdinger equation for the Morse potential, while the rest is fixed by experimental data. For rotational spectra, the Dunham expansion can be written展开更多
Two parameter expressions for rotational spectra viz. variable moment of inertia （VMI）, ab formula and three parameter Harris w2 expansion are used to assign the band head spins （I0） of four rotational superdeform...Two parameter expressions for rotational spectra viz. variable moment of inertia （VMI）, ab formula and three parameter Harris w2 expansion are used to assign the band head spins （I0） of four rotational superdeformed bands in 86Zr. The least-squares fitting method is employed to obtain the band head spins of these four bands in the A - 80 mass region. Model parameters are extracted by fitting of intraband y-ray energies, so as to obtain a minimum root-mean-square （rms） deviation between the calculated and the observed transition energies. The calculated transition energies are found to depend sensitively on the assigned spins. Whenever an accurate band head spin is assigned, the calculated transition energies axe in agreement with the experimental transition energies. The dynamic moment of inertia is also extracted and its variation with rotational frequency is investigated. Since a better agreement of band head spin with experimental results is found using the VMI model, it is a more powerful tool than the ab formula and Harris w2 expansion.展开更多
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Project partly supported by the National Natural Science Foundation of ChinaProject partly supported by the Grant LWTZ-1298 of Chinese Academy of Sciences.
文摘Generally, rotation-vibration molecular spectra are described by the Dunham expression in the form E（v, I）=sum from n=i,j Y<sub>i,j</sub>（v+1/2）<sup>i</sup>[I（I+1）]<sup>j</sup> , （1）where I is the angular momentum and v is the vibrational quantum number. The numerical coefficients Y<sub>i,j</sub> of the first few terms of the Dunham expression are obtained by the solution of the Schrdinger equation for the Morse potential, while the rest is fixed by experimental data. For rotational spectra, the Dunham expansion can be written
基金Financial support from the Department of Science and Technology,Government of India is gratefully ac-knowledged
文摘Two parameter expressions for rotational spectra viz. variable moment of inertia （VMI）, ab formula and three parameter Harris w2 expansion are used to assign the band head spins （I0） of four rotational superdeformed bands in 86Zr. The least-squares fitting method is employed to obtain the band head spins of these four bands in the A - 80 mass region. Model parameters are extracted by fitting of intraband y-ray energies, so as to obtain a minimum root-mean-square （rms） deviation between the calculated and the observed transition energies. The calculated transition energies are found to depend sensitively on the assigned spins. Whenever an accurate band head spin is assigned, the calculated transition energies axe in agreement with the experimental transition energies. The dynamic moment of inertia is also extracted and its variation with rotational frequency is investigated. Since a better agreement of band head spin with experimental results is found using the VMI model, it is a more powerful tool than the ab formula and Harris w2 expansion.
