https://digital.library.unt.edu/ark:/67531/metadc888955/m2/1/high_res_d/900147.pdf

ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology

EMPIRE: Nuclear Reaction Model Code System for Data Evaluation

Energy levels of A = 21−44 nuclei (V)

https://www.cns.s.u-tokyo.ac.jp/~shimoura/research/nuc_data/pdf/11.pdf

Energy levels of light nuclei A = 11-12

Shape coexistence in nuclei appears to be unique in the realm of finite many-body quantum systems It differs from the various geometrical arrangements that sometimes occur in a molecule in that in a molecule the various arrangements are of the widely separated atomic nuclei In nuclei the various ''arrangements'' of nucleons involve (sets of) energy eigenstates with different electric quadrupole properties such as moments and transition rates, and different distributions of proton pairs and neutron pairs with respect to their Fermi energies Sometimes two such structures will ''invert'' as a function of the nucleon number, resulting in a sudden and dramatic change in ground-state properties in neighboring isotopes and isotones In the first part of this review the theoretical status of coexistence in nuclei is summarized Two approaches, namely, microscopic shell-model descriptions and mean-field descriptions, are emphasized The second part of this review presents systematic data, for both even- and odd-mass nuclei, selected to illustrate the various ways in which coexistence is observed in nuclei The last part of this review looks to future developments and the issue of the universality of coexistence in nuclei Surprises continue to be discovered With the major advances in reaching to extremes of proton-neutronmore » number, and the anticipated new ''rare isotope beam'' facilities, guidelines for search and discovery are discussed« less

Shape coexistence in atomic nuclei

Analyses of continuum spectra of light-ion reactions, in terms of multistep direct reaction methods are discussed. The formulation used in the calculations is presented first, and is followed by several examples which show that this method works rather well in a variety of cases. Comparison with related theories is also made.NUCLEAR REACTIONS Multistep direct reaction method, calculations of cross sections, and polarizations of continuum spectra of reactions induced by light ions.

Multistep direct reaction analysis of continuum spectra in reactions induced by light ions

It is shown that massive transfer reactions emitting energetic light particles can be described in terms of two-step processes, in which breakup of the projectile takes place first, followed by an absorption of the massive partner of the broken-up pair by the target.

Breakup-fusion description of massive transfer reactions with emission of fast light particles

Deep inelastic reactions treated as multi-step direct reaction processes Application to (p, p') reaction

Compact reformulation of distorted-wave and coupled-channel Born approximations for transfer reactions between nuclei

A new approach to calculation of the fusion cross section ${\ensuremath{\sigma}}_{F}$, based on the direct reaction concept, is presented. The method is to define a fusion potential ${W}_{F}$ [with r\ensuremath{\le}${R}_{F}$=${r}_{F}$(${A}_{1}^{1/3}$+${A}_{2}^{1/}$ 3)] as a part of the imaginary potential of the usual optical model. The ${\ensuremath{\sigma}}_{F}$ is then obtained as that part, due to only ${W}_{F}$, of the total absorption cross section. It is seen that, if ${r}_{F}$ is chosen as 1.40--1.50 fm, the value of ${\ensuremath{\sigma}}_{F}$ computed as described fits the experimental ${\ensuremath{\sigma}}_{F}$ very well, in both sub- and above-barrier regions, and for a variety of fusing nuclear pairs ${A}_{1}$ and ${A}_{2}$. In most cases, it is sufficient to consider only the incident (elastic scattering) channel. In a few cases, in which some specific nuclear structure effects are involved, it is found necessary to perform coupled-channel calculations. Then absorption due to other channels is also taken into account explicitly. It is shown that adding these contributions is the key to getting good fits to data, under the above-mentioned special circumstances. A possible relation of what the present approach describes, particularly when it is used in the sub-barrier region, to (spontaneous) fission is also discussed.

Taro Tamura

Papers

Multistep direct reaction analysis of continuum spectra in reactions induced by light ions

Breakup-fusion description of massive transfer reactions with emission of fast light particles

Deep inelastic reactions treated as multi-step direct reaction processes Application to (p, p') reaction

Compact reformulation of distorted-wave and coupled-channel Born approximations for transfer reactions between nuclei

Direct reaction description of sub- and above-barrier fusion of heavy ions.