The odd-odd nucleus ${}_{}{}^{196}{}_{}{}^{}\mathrm{Au}$ has been studied by the ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$ (p,d${)}^{196}$Au reaction at an incident proton energy of 25 MeV and with an energy resolution of 12 keV. From measurements at 12 angles, l=1, 3, and 6 transfers were clearly characterized. Level energies, l values, and absolute spectroscopic factors have been obtained, and for negative parity levels, comparisons of energies, spins, and strengths have been made with theoretical calculations performed within the framework of the extended supersymmetry scheme. Tentative spins are suggested for several levels, and a levels scheme for ${}_{}{}^{196}{}_{}{}^{}\mathrm{Au}$ is proposed.

Product recoils from the reaction ${}_{}{}^{96}{}_{}{}^{}\mathrm{Ru}$ +255 MeV ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$ → ${}_{}{}^{154}{}_{}{}^{}\mathrm{Hf}_{}^{\mathrm{*}}{}_{}{}^{}$ were analyzed using the Argonne Fragment Mass Analyzer and transported to a collector foil behind the focal plane, where decay of μs isomers could be studied under low background conditions. The recoils were dispersed in A/q as they traversed the position-sensitive focal-plane detector, and recoil–γ-ray coincidences could thus be used to assign masses for specific γ-ray cascades. By use of these methods, yrast isomers with half-lives of 2.6(7) μs and 20(1) μs have been firmly assigned to the exotic N=81 nucleus ${}_{}{}^{151}{}_{}{}^{}\mathrm{Yb}$, and the main features of the isomeric decays have been established. The yrast level structure of ${}_{}{}^{151}{}_{}{}^{}\mathrm{Yb}$ and lighter N=81 isotones are compared.

The Daresbury recoil separator has been used to measure proton radioactivity from the nuclei ${}_{}{}^{150}{}_{}{}^{}\mathrm{Lu}$, ${}_{}{}^{151}{}_{}{}^{}\mathrm{Lu}$, and ${}_{}{}^{147}{}_{}{}^{}\mathrm{Tm}$, produced using the reactions ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$${+}^{96}$Ru${\to }^{154}$${\mathrm{Hf}}^{\mathrm{*}}$ and ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$${+}^{92}$Mo${\to }^{150}$${\mathrm{Yb}}^{\mathrm{*}}$. The half-life of ${}_{}{}^{150}{}_{}{}^{}\mathrm{Lu}$ has been measured for the first time as 35±10 ms, which identifies the proton decay as an l=5 transition from the ${\mathit{h}}_{11/2}$ proton state. New half-life and energy measurements have been made for the known proton transitions from ${}_{}{}^{147}{}_{}{}^{}\mathrm{Tm}$ and ${}_{}{}^{151}{}_{}{}^{}\mathrm{Lu}$, which have been unambiguously assigned using the direct mass identification of the recoil separator. A new half-life measurement of the proton emitter ${}_{}{}^{109}{}_{}{}^{}\mathrm{I}$ is also reported.

The ${}_{}{}^{165}{}_{}{}^{}\mathrm{Ho}$ (α,t) and ${(}^3$He,d) reactions have been measured at beam energies of 40 and 25 MeV to look for the ${\mathit{K}}^{\mathrm{\pi }}$=$1^{+}${9/$2^{\mathrm{-}}$[514]-7/$2^{\mathrm{-}}$[523]} two-proton band structure in ${}_{}{}^{166}{}_{}{}^{}\mathrm{Er}$. Reaction products were analyzed using a quadrupole-three-dipole spectrometer. Distorted-wave Born approximation predictions were used to extract candidate states with angular momentum transfer l=5. The measured strengths of all the candidates for l=5 transitions were compared with the Nilsson fingerprint pattern of the ${\mathit{K}}^{\mathrm{\pi }}$=$1^{+}${9/$2^{\mathrm{-}}$[514]-7/$2^{\mathrm{-}}$[523]} band to identify the structure. No strong population of this configuration was found. At best two tentative candidates for the ${\mathit{I}}^{\mathrm{\pi }}$=$3^{+}$ and $4^{+}$ members of this band could be identified, which would represent at most 38% of the expected strength for this configuration. The bandhead for this tentative ${\mathit{K}}^{\mathrm{\pi }}$=$1^{+}$ excitation does not correspond to any ${\mathit{I}}^{\mathrm{\pi }}$=$1^{+}$ state observed in the ${}_{}{}^{166}{}_{}{}^{}\mathrm{Er}$(γ,γ’) reaction.

We have made precise final state interference measurements using very intense Mössbauer sources and an exact line-shape analysis. Two transitions in tungsten metal, as well as one in iridium metal and one in terbium oxide, have been studied. The interference parameters 100β found are -1.3(3) for the 99.1-keV transition in ${}_{}{}^{183}{}_{}{}^{}\mathrm{W}$, -1.2(1) for the 100.1-keV transition in ${}_{}{}^{182}{}_{}{}^{}\mathrm{W}$, -0.71(8) for the 129.4-keV transition in ${}_{}{}^{191}{}_{}{}^{}\mathrm{Ir}$, and -0.48(5) for the 58.0-keV transition in ${}_{}{}^{159}{}_{}{}^{}\mathrm{Tb}$. All values agreed with theory to within error. Our measurement of 1.16(2) cm/s for the ${}_{}{}^{191}{}_{}{}^{}\mathrm{Ir}$ linewidth agrees with other Mössbauer measurements and shows no indication of hyperfine broadening, but disagrees with some non-Mössbauer measurements reported in the literature. The tungsten and terbium transitions also show no signs of broadening or splitting.

Heavy hypernuclei are produced in the annihilation of antiprotons in ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$. The delayed fission of heavy hypernuclei and hypernuclei of fission fragments are observed by using the recoil-distance method in combination with measurement of secondary electron multiplicity. The lifetime of hypernuclei in the region of uranium is found to be (1.25±0.15)×${10}^{\mathrm{-}10}$ sec. It is observed that Λ hyperons predominantly stick to the heavier fission fragments. The yield of hypernuclei is found to be (7.4±1.7)×${10}^{\mathrm{-}3}$ per stopped antiproton. No coincidences with ${\mathit{K}}^{+}$ were found. Statistical and systematic errors on the number of events expected do not rule out this possibility.

We calculate the correlation diagrams for Λ-hyperonic levels in ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ along several fission paths with different asymmetry. Several mechanisms are discussed which control the occupation probability of the hyperonic states during fission: nonadiabatic effects, induced by the rate of change of the mean field, and collisions of the hyperon with thermally excited nucleons and with thermal surface phonons. Only if the Λ-nucleon residual interaction is strong enough to establish thermal equilibrium before fission does the attachment probability as a function of the mass split allow us to determine a fission velocity between saddle and scission and temperature. However, for that purpose the statistics of measured data has to be improved considerably.

The influence of finite temperature nuclear effects upon the adiabatic index, for a system of nuclei, nucleons, and leptons, is discussed. It is found that the inclusion of temperature-dependent nuclear binding energies affects the behavior of the adiabats and of the adiabatic index, particularly, at low entropies.

States made from the new S pairs which are used for dealing with the seniority mixing problem give energies and occupation numbers in close agreement with those made from the usual S pairs.

Using axially symmetric deformed configuration mixing and angular momentum projection techniques, we have studied the signature effects in the π${\mathit{h}}_{11/2}$ bands of ${}_{}{}^{147}{}_{}{}^{}\mathrm{La}$, ${}_{}{}^{149}{}_{}{}^{}\mathrm{Pr}$, and ${}_{}{}^{151}{}_{}{}^{}\mathrm{Pm}$ nuclei. Effects of rotation alignment on the signature splitting in energy and signature inversion in the B(E2,I→I-1) values are discussed. We find that transition from a strongly rotation-aligned limit to a weakly rotation-aligned (or more regular rotational behavior) regime or vice versa leads to signature inversion of the B(E2) values.

Mean-field theory of quantum hadrodynamics is used to study the Coulomb instability of asymmetric nuclear matter at finite temperature. The critical temperature for the liquid-gas phase transition in nuclear matter and its dependence on an asymmetry parameter are calculated. The limiting temperature ${\mathit{T}}_{\lim }$, which reflects the Coulomb instability of hot nuclei is studied.

It is found that B(E1) values calculated by using a model in which one quasiparticle is coupled to a rotor are more than an order of magnitude too small compared with measured B(E1) values in low-energy transitions observed in the yrast spectroscopy of odd-A rare-earth nuclei. Thus, the measured B(E1) values are analyzed by introducing the parameters which effectively take into account the octupole softness. The parameters thus determined for two sets of bands in ${}_{}{}^{169}{}_{}{}^{}\mathrm{Lu}$ are considerably different. Interpreting the difference in terms of a difference in blocking of the particular orbitals in octupole vibration amplitudes, an estimate of the difference is made using a microscopic model. A full agreement between the estimated values and the values necessary for reproducing data is not obtained.

The structure of high-spin states in the transitional nuclei ${}_{}{}^{190,192,194}{}_{}{}^{}\mathrm{Hg}$ is described in the framework of the interacting boson model with one and two broken pairs. The interacting boson model is extended to the physics of high-spin states by including selective noncollective fermion states through the successive breaking of (S,D) pairs. High-spin states are described in terms of broken pairs. In ${}_{}{}^{190,192,194}{}_{}{}^{}\mathrm{Hg}$, yrast states up to J=24ħ, including the positions of the first and second backbending, are reproduced by the calculation. Data on E2 transitions in the region of the first backbending are compared with model calculations.

A fully distorted partial-wave calculation is presented for the reaction ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$(e,e’p${)}^{39}$K which uses relativistic self-consistent Hartree wave functions for both the target nucleus and the residual nucleus. The final state interaction of the knocked-out nucleon is described by an optical potential and the Coulomb distortion of the electron wave functions is also included. We assume standard values for meson coupling constants and masses in the Hartree calculations and the optical potential used comes from global fits to elastic proton scattering; hence, this calculation is a description of (e,e’p) reactions with no free parameters. We examine the proton knocked-out from the ${\mathit{d}}_{3/2}$ state of ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ which leaves the residual nucleus ${}_{}{}^{39}{}_{}{}^{}\mathrm{K}$ in its ground state. Agreement with the experimental data of NIKHEF is good and the calculated spectroscopic factor agrees very well with the one extracted from experiment. There seems to be no need to make the assumption that the ${\mathit{d}}_{3/2}$ state is appreciably depleted. We also calculate the (e,e’p) cross section from the 2${\mathit{s}}_{1/2}$ and 1${\mathit{f}}_{7/2}$ orbitals. For the 2${\mathit{s}}_{1/2}$ orbital the shape does not agree so well with the experimental data. The ${\mathit{f}}_{7/2}$ orbital leads to approximately the correct shape and we extract a spectroscopic factor of 3.7%.

A new region of proton-rich parent nuclei decaying by spontaneous cluster emission with a measurable branching ratio relative to alpha decay is predicted within the analytical superasymmetric fission model. After a brief presentation of the model and of the seven mass tables used to calculate the released energy, the obtained results are discussed. Measurable half-lives and branching ratios are estimated for ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$, and other cluster radioactivities of some nuclides having proton and neutron numbers in the range Z=56–64 and N=58–72. Such nuclei far from stability could be produced in reactions induced by radioactive beams.

The ${\mathit{T}}_{\mathit{Z}}$=-3/2, A=4n+1 nuclide ${}_{}{}^{65}{}_{}{}^{}\mathrm{Se}$ produced in the ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$${(}^{28}$Si,3n) reaction has been observed via beta-delayed proton emission. A single proton group at 3.55±0.03 MeV has been observed, corresponding to the decay of the T=3/3 isobaric analog state in ${}_{}{}^{65}{}_{}{}^{}\mathrm{As}$ to the ground state of ${}_{}{}^{64}{}_{}{}^{}\mathrm{Ge}$. Combining this measurement with a Coulomb displacement energy calculation yields a mass excess for ${}_{}{}^{65}{}_{}{}^{}\mathrm{Se}$ of -33.41±0.26 MeV.

Fusion cross sections have been measured for the system ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$${+}^{144}$Nd at bombarding energies in the range 67 MeV≤${\mathit{E}}_{\mathrm{lab}}$≤90 MeV by detecting directly evaporation residues in Si detectors and in the range 60 MeV≤${\mathit{E}}_{\mathrm{lab}}$≤75 MeV by off-line detection of the K x rays emitted by the radioactive evaporation residues and daughters. In order to obtain the spin distributions in the compound system gamma-ray multiplicity distributions for the most important neutron evaporation channels were also measured using a 4π ${\mathrm{BaF}}_2$ array, in conjunction with Ge detectors. Results are compared with calculations based on models that consider fluctuations in barrier height due to ground-state zero-point vibrations as well as couplings to various inelastic and transfer channels.

Excitaion functions for the reactions ${}_{}{}^{128}{}_{}{}^{}\mathrm{Te}$(α,np${)}^{130}$I, ${}_{}{}^{130}{}_{}{}^{}\mathrm{Te}$(α,np${)}^{132}$I, and ${}_{}{}^{130}{}_{}{}^{}\mathrm{Te}$(α,np${)}^{132\mathit{m}}$I have been measured using the stacked foil technique and have also been calculated using a statistical model with and without the inclusion of preequilibrium emission. As expected, the inclusion of preequilibrium emission in compound nucleus calculations agrees well with the experimental excitation functions. The preequilibrum fraction has been found to be energy and target mass number dependent.

A high pressure polarized ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ gas target has been used to measure spin observables and absolute cross sections for (p→,2p) and (p→,pn) nucleon knockout in quasielastic kinematics at 220 MeV. The neutron knockout spin observables exhibit large deviations from plane wave impulse approximation (PWIA) calculations and show the importance of rescattering corrections. At this energy, the proton knockout spin observables differ slightly from PWIA calculations, especially at low energy transfers (ω), but this discrepancy may be resolved when final state interactions between nucleons of the two-body recoil scattering state are included. The large rescattering effects observed in the (p→,pn) results may have implications for experiments which consider polarized ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ as a polarized neutron.

Differential cross sections for the (p,n) reaction to the ground-state and excited-state analogs of ${}_{}{}^{105}{}_{}{}^{}\mathrm{Pd}$ have been measured at a proton bombarding energy of 26 MeV. Both the magnitude and the angular distribution of the cross sections for the analog states are found to follow the same general trend observed for the even-even palladium isotopes. Contributions to the analog transition on odd-A targets from spin-flip, higher multipoles, collective admixtures, and multistep processes are calculated and are found to be of order 1/(N-Z) or smaller, as compared to the (N-Z) scaling expected for the Fermi transition. This is in agreement with our experimental data which show that the analog cross section scales as (N-Z) relative to the neighboring nuclei. Among the excited analog states within the first MeV of excitation, the levels at 0.44 and 0.78 MeV were the most strongly populated. This is consistent with a two-step mechanism involving inelastic scattering and charge exchange, since these two states are also known to have the largest B(E2) values. Although the small predicted magnitude of the additional contributions for nonzero spin targets agrees nicely with the present measurements for ${}_{}{}^{105}{}_{}{}^{}\mathrm{Pd}$, it leaves the puzzle as to why cross sections for odd isotopes for titanium and molybdenum measured in previous work were found to be larger than corresponding cross sections for adjacent even isotopes.