Long cascades of stretched E2 transitions have been observed in ${}_{}{}^{143}{}_{}{}^{}\mathrm{Eu}$ and ${}_{}{}^{144}{}_{}{}^{}\mathrm{Eu}$ nuclei which at low excitation exhibit spherical shape. Lifetime experiments demonstrate high collectivity values up to B(E2)≊100 W.u. among these E2 cascades. The total Routhian surface calculations indicate many crossing rotational bands of the nucleus with triaxial shape at ${\mathrm{\beta }}_2$≊0.25 and γ≊30°. The E2 cascades in ${}_{}{}^{143}{}_{}{}^{}\mathrm{Eu}$ are proposed to represent the ν${\mathit{h}}_{11/2}^2$π${\mathit{h}}_{11/2}^{\mathit{n}}$ configurations with an additional ν${\mathit{d}}_{3/2}^{\mathrm{-}1}$${\mathit{i}}_{13/2}$ excitation at the highest states.

The parity nonconserving (PNC) resonant scattering of neutrons at epithermal energies is discussed within the optical model. We show that the empirical optical-model potential with real PNC interaction does not account for the appreciable resonance-averaged difference between positive and negative helicity total p-neutron cross sections 〈Δσ〉 for ${}_{}{}^{232}{}_{}{}^{}\mathrm{Th}$, but reproduces the very small 〈Δσ〉 for ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$. It is suggested that the 2p-1h local doorway, previously proposed to account for the sign correlation in ${}_{}{}^{232}{}_{}{}^{}\mathrm{Th}$, is the main source for the large 〈Δσ〉 seen in this system. It is further proposed that if an optical potential is used to account for 〈Δσ〉, a complex PNC interaction is required in cases involving strong sign correlation.

Differential cross section, polarization observables, and phase-shift and mixing parameters up to L=4 and J≤11/2 are calculated for p-d and n-d elastic scattering below the breakup threshold. The method consists in an expansion of the wave function in terms of the pair correlated hyperspherical harmonic basis. The reactance matrix of the system is found by means of the Kohn variational principle. As a difference with the Faddeev technique, the inclusion of the Coulomb interaction does not give any additional difficulty. The accuracy of the method allows for a detailed comparison with experimental results and for the evaluation of Coulomb effects.

The ground state properties of O isotopes have been studied in the nonlinear relativistic mean-field theory with NL-SH parameters. Neutron halos in ${}_{}{}^{24}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{26}{}_{}{}^{}\mathrm{O}$, and ${}_{}{}^{28}{}_{}{}^{}\mathrm{O}$ are predicted. The variation of the spin-orbit splitting with the neutron excess for O isotopes is also investigated with both NL-SH and NL1 parameters. Detailed comparison and analysis on the results are given.

By assuming the existence of a pseudopotential smooth enough to do Hartree-Fock variations and good enough to describe nuclear structure, we construct mass formulas that rely on general scaling arguments and on a schematic reading of shell model calculations. Fits to 1751 known binding energies for N,Z≥8 lead to rms errors of 375 keV with 28 parameters. Tests of the extrapolation properties are passed successfully. The Bethe-Weizsäcker formula is shown to be the asymptotic limit of the present one(s). The surface energy of nuclear matter turns out to be probably smaller than currently accepted.

Using hadron dynamics we calculate nuclear transparencies for protons, knocked-out in high-${\mathit{Q}}^2$, semi-inclusive reactions. Predicted transparencies are roughly half a standard deviation above the NE18 data. The latter contain the effects of binned proton missing momenta and mass, and of finite detector acceptances. In order to test sensitivity we compare computed transparencies without restrictions and the same with maximal cuts for missing momenta and the electron energy loss. We find hardly any variation, enabling a meaningful comparison with data and predictions based on hadron dynamics. Should discrepancies persist in high-statistics data, the above may with greater confidence be attributed to exotic components in the description of the outgoing proton.

The decay of the highly deformed (HD) band in the nucleus ${}_{}{}^{137}{}_{}{}^{}\mathrm{Nd}$ has been studied with the GASP array using the reactions ${}_{}{}^{110}{}_{}{}^{}\mathrm{Pd}$${+}^{30}$Si and ${}_{}{}^{123}{}_{}{}^{}\mathrm{Sb}$${+}^{19}$F. Four decay paths linking the HD band to the normal-deformed states have been established, which fix ${\mathit{I}}^{\mathrm{\pi }}$=29/$2^{+}$ for the lowest state of the HD band lying at ${\mathit{E}}_{\mathit{x}}$=4885 keV. The sudden disappearance, at the low spin side, of the HD bands in the ${}_{}{}^{133,135,137}{}_{}{}^{}\mathrm{Nd}$ isotopes can be explained by total Routhian surface calculations through a change of the nuclear shape which is microscopically related to the transfer of the valence neutron from a N=6 to a N=4 Nilsson orbital.

The Faddeev equations are solved in momentum space for the trinucleon bound state with the new Tucson-Melbourne π and ρ exchange three-nucleon potentials. The three-nucleon potentials are combined with a variety of realistic two-nucleon potentials. The dependence of the triton binding energy on the πNN cut-off parameter in the three-nucleon potentials is studied and found to be reduced compared to the case with pure π exchange. The ρ exchange parts of the three-nucleon potential yield an overall repulsive effect. When the recommended parameters are employed, the calculated triton binding energy turns out to be very close to its experimental value. Expectation values of various components of the three-nucleon potential are given to illustrate their significance for binding.

The Faddeev equations for the hypertriton are solved precisely using the Nijmegen hyperon-nucleon and realistic NN interactions. The hypertriton turns out to be bound at the experimental value. Thereby the Λ-Σ conversion is crucial. States of the Λ(Σ)NN system with quantum numbers (T,J) different from (0,1/2) are not bound. We visualized properties of the hypertriton wave function in various ways.

Manifestations of T- and P-odd weak interaction between nucleons in a nucleus are considered. Renormalization of this interaction due to residual strong interaction is studied both analytically and numerically. Expression for the effective two-body T- and P-violating interaction between nucleons in a nucleus, which incorporates the effects of the renormalization due to the residual strong interaction, is derived. Mean square matrix elements of the T- and P-odd weak interaction between nuclear compound states are calculated. Correlators between the T- and P-odd and the T-even and P-odd weak interaction matrix elements in the compound states are considered and estimates for these quantities are obtained.

The Coleman-Glashow scheme for Δ${\mathit{I}}_{\mathit{z}}$=1 charge symmetry breaking (CSB) applied to meson and baryon SU(2) mass splittings suggests a universal scale. This scale can be extended to ΔI=1 nonstrange CSB transitions 〈${\mathrm{\rho }}^0$‖${\mathit{H}}_{\mathrm{em}}$‖ω〉 and 〈${\mathrm{\pi }}^0$‖${\mathit{H}}_{\mathrm{em}}$‖${\mathrm{\eta }}_{\mathit{N}\mathit{S}}$〉 of size -0.005 ${\mathrm{GeV}}^2$ in the energy region 760–780 MeV. The resulting nucleon-nucleon vector meson exchange CSB potential then predicts ΔI=1 effects which are in approximate agreement with recent data characterizing nuclear charge asymmetry.

High spin states in ${}_{}{}^{76}{}_{}{}^{}\mathrm{Rb}$ were investigated via the reaction ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$${(}^{40}$Ca,3pn${)}^{76}$Rb at 128 MeV. The level scheme was established from γγ, γγγ and recoil-γ coincidences measured in the EUROGAM I array in combination with the Daresbury recoil separator. The known rotational bands were extended up to the excitation energy ${\mathit{E}}_{\mathit{x}}$≊9.2 MeV and spins ${\mathit{I}}^{\mathrm{\pi }}$=(${21}^{+}$) and (${19}^{\mathrm{-}}$). The band head energies could be fixed by many interband transitions. Two new bands were identified. The level scheme is discussed in terms of the cranked shell model. In the negative parity bands ${}_{}{}^{76}{}_{}{}^{}\mathrm{Rb}$ behaves like a rigid rotor until the first band crossings.

Proton yields in the energy range of ∼10–30 MeV have been measured in the reactions ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$${+}^{93}$Nb at E${(}^{12}$C)=40, 45, 50, and 56 MeV and ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$${+}^{103}$Rh at E${(}^{12}$C)=53 MeV at ${\mathrm{\theta }}_{\mathrm{lab}}$=125° and 155°. From these measurements the energy variation of the total nuclear level density has been extracted for ${}_{}{}^{104}{}_{}{}^{}\mathrm{Pd}$ and ${}_{}{}^{114}{}_{}{}^{}\mathrm{Sn}$ in the excitation-energy range of ∼7–24 MeV and ∼12–24 MeV, respectively. No sizable effect of the proton shell closure at Z=50 is seen at excitation energies beyond ∼15 MeV though there is an indication of this effect becoming important at lower energies.

Excited states in ${}_{}{}^{164}{}_{}{}^{}\mathrm{Dy}$ were produced using Coulomb excitation. Rotational properties of the ground-state and gamma-vibrational band were studied. Angular distribution and band-mixing parameters were extracted from the data. No evidence was found for a two-phonon gamma vibration with anharmonicity in the range 1.7≤E($4_{\gamma \gamma }^{+}$)/E($2_{\gamma }^{+}$)≤2.7.

The high-spin states of ${}_{}{}^{82}{}_{}{}^{}\mathrm{Y}$ have been studied up to an excitation energy ∼10 MeV and a spin of 23ħ through the ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$${(}^{27}$Al,2pn${)}^{82}$Y reaction using 92 MeV ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$ beam and in-beam γ-ray spectroscopic techniques. The electromagnetic properties and the structure of high-spin states in the positive parity band and the negative parity band have been investigated through a measurement of several new lifetimes. The experimentally obtained transition quadrupole moments exhibit a transition from a near spherical shape with ${\mathit{Q}}_{\mathit{t}}$∼0.6 eb to a deformed shape with ${\mathit{Q}}_{\mathit{t}}$∼2.1 eb around a spin I∼9ħ for the positive and negative parity bands and are in reasonable agreement with those calculated using deformation parameters (β,γ) as predicted by the total Routhian surface calculations. The observed signature splitting, quasiparticle alignments, the kinematic, and dynamic moment of inertias as a function of rotational frequency ħω or spin I have been discussed within the framework of the cranked shell model and the projected Hartree-Fock calculations. The experimental and theoretical results indicate the two neutron alignment at ħω∼0.66 MeV in the positive parity band. The observed band-crossing frequency ħω∼0.67 MeV in the negative parity band also indicates two neutron alignment.

The schematic model proposed by Moszkowski to study the interplay between single particle and collective degrees of freedom is extended to a heterogeneous system of protons and neutrons. The pairing correlations are also introduced. The magnetic states are defined with respect to an ${\mathit{gerR}}_3$ group acting in a fictitious three-dimensional space. Their properties are successively considered within three different approaches. The numerical analysis shows that most of the scissors mode properties, which are pointed out in realistic calculations, are qualitatively described by this very simple model.

The nuclear magnetization distribution and the magnetic moment of the ground state of ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}$ are calculated within a dynamic-correlation model. The obtained ground-state magnetization reproduces successfully the hyperfine structure splitting (HFS) of mesonic and electronic ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}$. The evaluated nuclear radius and the electric charge distribution are also in very good agreement with experimental data. The dynamic model is based on the introduction of configuration mixing wave functions (CMWF), generated by breaking the particle-hole symmetry of the ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ closed-shell core via the two-body interaction. The 2-particle–1-hole states in this calculation are restricted to a 2ħω configuration space in the protons and in the neutrons. The particle-hole excitations, introduced by this nonperturbative approximation are of collective character and therefore can also be associated with the creation of virtual bosons in the dynamic nuclear structure calculation. In the framework of this dynamic nuclear model it is possible to set a realistic limit for the nuclear contributions for calculations of the ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}_{}^{82+}{}_{}{}^{}$ hyperfine structure splitting, and therefore to allow, for the first time, a test of QED corrections in the strong magnetic field of high-Z atoms.

In this paper, we first demonstrate the applicability of a phenomenological two-parameter formula, as introduced by Holmberg and Lipas from the Bohr Hamiltonian in a way that is different from Wu and Zeng. Second, for the first time, we show microscopically that Holmberg’s two-parameter formula can be applied to diatomic molecules and that it can fit the experimental data of rotational spectra of HCl, HBr, and HF very well when the parameters are determined by two arbitrary experimental levels. Third, we derive a two-parameter formula describing γ-soft rotational spectra which is similar to the Holmberg formula, called Holmberg-like formula in this paper. The experimental yrast lines of nine nuclei in the light rare-earth region are fitted by this formula. For the nuclear γ stiffness, γ softness, and for molecular rotational spectra, all the two-parameter formulas are obtained by making use of a single potential function. It is demonstrated that the reason why one can give a unified description for those three systems is the common rotational features like the widely used harmonic oscillator approximation. More importantly, from the more microscopic nuclear fermion dynamical symmetry model (FDSM), we may derive the variable moment of inertia (VMI) model, and further obtain the Holmberg formula and Holmberg-like formula under a certain approximation, as from the nuclear geometric description within the Bohr-Mottelson model (BM). It is shown that the bridge between the descriptions of the FDSM and of the BM is the effect of stretched alignment (stretching effect). According to another interpretation of the FDSM for the nuclear stretching effect, we also give a simple formula to explain the γ-soft rotational spectra and compare the formula with the above one. Finally, we give a phenomenological generalization to the combination of the Holmberg and Holmberg-like formulas, which may describe a transition from γ-stiff rotations to γ-soft rotations.

A model Hamiltonian describing a system of (N,Z) nucleons moving in a mean field of the Moszkowski model and interacting by T=1 pairing and Gamow-Teller forces is used to study the 2νββ Gamow-Teller transition. Resemblances and differences with realistic calculations are pointed out. The cancellation of the transition amplitude ${\mathit{M}}_{\mathrm{GT}}$ for a certain value of the particle-particle interaction strength can be studied in detail in this model. This cancellation is determined by a quasidegenerate structure of the Gamow-Teller giant resonance.

Nuclear ground-state moments of inertia for heavy deformed nuclei are calculated using a rotating intrinsic wave function in the laboratory system. Numerical calculations are reported for rare-earth nuclei. The results show that the agreement between the theoretical values and the experimental observations have been improved.