For hot nuclei with A≃120, a comparison is made between nuclear temperatures derived from spectral slope parameters for well-characterized equilibrated systems and those derived from state population ratios. When suitable account is taken of the deexcitation cascade, the two techniques lead to similar results, confirming the utility of the state ratio method. The general relationship between the measured quantities and the initial temperature for medium to heavy mass hot nuclei is discussed and a calibration of these is presented for measurements based on ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ and ${}_{}{}^5{}_{}{}^{}\mathrm{Li}$ detection.

We have applied gamma-ray spectroscopy and selection techniques to study for the first time high spin states in ${}_{}{}^{114}{}_{}{}^{}\mathrm{Xe}$. This provides evidence for broken reflection symmetry near the N=Z line in medium-mass nuclei. We discuss simple scaling for enhanced E1’s in nuclei exhibiting broken reflection symmetry.

Directional correlations of γ rays observed in the decay of the ${16}^{+}$ isomeric state in ${}_{}{}^{178}{}_{}{}^{}\mathrm{Hf}$ were measured with a multidetector system. Multipole mixing ratios for four γ transitions in the rotational band based on the $8^{\mathrm{-}}$ two-quasiparticle isomeric state in ${}_{}{}^{178}{}_{}{}^{}\mathrm{Hf}$ are derived, and the structure of this band is discussed.

Deuteron elastic scattering cross sections ahve been measured at 110 and 120 MeV on C, ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$, and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$. Optical model potentials have been extracted and compared to deuteron global optical model potentials.

The radioactivity of neutron-deficient platinum isotopes ${}_{}{}^{177\mathrm{-}181}{}_{}{}^{}\mathrm{Pt}$ was studied after the production in ${}_{}{}^{146}{}_{}{}^{}\mathrm{Nd}$${(}^{36}$Ar,xn) and ${}_{}{}^{148}{}_{}{}^{}\mathrm{Nd}$${(}^{36}$Ar,xn) reactions. The β-decay branches were identified by the detection of γ transitions in the iridium daughter nuclei. We report γ rays, γγ coincidences, and half-lives. Ground and excited states are discussed in terms of the single-particle structure in deformed nuclei and new results are presented for the systematics of the intruder ${\mathit{h}}_{9/2}$ band and ${\mathit{d}}_{3/2}$ states in iridium.

The deformation energy along the fission path is calculated for heavy nuclei at different temperatures by relaxing the constraint of volume conservation. The density at the saddle point is then found to increase by a few percent whereas the fission barrier decreases approximately by 10% for the systems studied. The effect of the nuclear equation of state on the fission path is also studied.

A method for solving the resonating group method equation in momentum space is presented. To examine the numerical accuracy of this method, the phase shifts of α-α and ${}_{}{}^{16}{}_{}{}^{}\mathrm{-}_{}^{16}{}_{}{}^{}$O scattering are calculated and are compared with those by the conventional coordinate-space calculation. It is shown that the momentum-space method provides us with an efficient and useful mean to treat the nucleus-nucleus scattering problem, especially for heavy systems.

Calculations of energy levels, wave functions, and electromagnetic properties in the even Te isotopes have been made assuming a quadrupole vibrator coupled to two particles. The value of δ($2_2^{+}$2-${>}_1^{+}$) shows a strong dependence on the coupling parameter η. A correlation exists between the signs of δ($2_2^{+}$→$2_1^{+}$) and ΔE=E($4_1^{+}$)-E($2_2^{+}$).

We derive a set of relativistic three-particle scattering equations in the three-particle c.m. frame employing a relativistic three-particle propagator suggested long ago by Ahmadzadeh and Tjon in the c.m. frame of a two-particle subsystem. We make the coordinate transformation of this propagator from the c.m. frame of the two-particle subsystem to the three-particle c.m. frame. We also point out that some numerical applications of the Ahmadzadeh and Tjon propagator to the three-nucleon problem use unnecessary nonrelativistic approximations which do not simplify the computational task, but violate constraints of relativistic unitarity and/or covariance.

In discussing the disappearance of nuclear shell effects at high temperatures, it is important to distinguish between the ‘‘smearing out’’ of the single-particle spectrum with increasing temperature and the vanishing of shell related structures in many-body quantities such as the excitation energy per nucleon. We propose a semiempirical method to obtain an upper bound on the temperature required to smooth the single-particle spectrum, and point out that shell effects in many-body parameters may persist above this temperature. We find that the temperature required to smear out the single-particle spectrum is approximately 1 MeV for heavy nuclei (A≳150) and about 3–4 MeV for light nuclei (A≲50), in reasonable agreement with the estimate of 41/π${\mathit{A}}^{1/3}$ obtained from calculations with harmonic oscillator potentials. These temperatures correspond to many-body excitation energies of approximately 20 and 60 MeV, respectively.

We show that by a slight redefinition, the (real) Kowalski-Noyes f ratios can be defined for coupled as well as uncoupled channels, and, with this, we find a separable representation of t matrices whose complex nature is dependent only on on-shell observables.

New data on the spectrum of α particles following the ${}_{}{}^{16}{}_{}{}^{}\mathrm{N}$ β decay are used to revise and extend a previous evaluation of the E1 part of the astrophysical S factor for the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(α,γ${)}^{16}$O reaction.

A recent study of the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$${(}^{16}$O${,}^8$Be${)}^{20}$Ne and ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$${(}^{16}$O,α${)}^{24}$Mg reactions has led, through cross channel correlation analysis, to the identification of two superdeformed shape isomeric states in ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ at excitation energies of 43.7 and 46.2 MeV. We suggest that both these states may have α-α${\mathrm{-}}^{16}$O-α nuclear molecule structure. Our suggestion is supported theoretically by cranked cluster model calculations and experimentally by previous studies of the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$${(}^{12}$C,αα${)}^{16}$O reaction, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$${+}^{12}$C scattering, and the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$${(}^{20}$Ne${,}^{12}$${\mathrm{C}}^{12}$C${)}^8$Be transfer reaction.

Our recent study of the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$${(}^{16}$O${,}^8$Be${)}^{20}$Ne and ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$${(}^{16}$O,α${)}^{24}$Mg reactions has led to the identification of two superdeformed shape isomeric states in ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ at excitation energies of 43.7 and 46.2 MeV. We conjectured from this study that these resonances have structures which correspond to the secondary minimum with deformation parameters ε=1.35 and γ=60° according to Nilsson-Strutinsky calculations. We give arguments to show that this conjecture is more appropriate and consistent with the presently available evidence.

A new resonance at ${\mathit{E}}_{\mathit{R}}$=1422 keV has been found in the reaction ${}_{}{}^{36}{}_{}{}^{}\mathrm{Ar}$(p,γ${)}^{37}$K. From its measured resonance strength of ωγ=(6.0±1.5)×${10}^{\mathrm{-}4}$ eV the proton partial width ${\mathrm{\Gamma }}_{\mathit{p}}$ can be calculated. Our data suggest a value of ${\mathrm{\Gamma }}_{\gamma }$/${\mathrm{\Gamma }}_{\mathit{p}}$≊40 for the ratio of γ to proton partial width for the corresponding state at ${\mathit{E}}_{\mathit{x}}$=3241 keV in ${}_{}{}^{37}{}_{}{}^{}\mathrm{K}$. We find that the corrected distribution of Gamow-Teller strength below the isobaric analog state as obtained from the β-delayed proton decay of ${}_{}{}^{37}{}_{}{}^{}\mathrm{Ca}$ is in agreement with the results inferred from the ${}_{}{}^{37}{}_{}{}^{}\mathrm{Cl}$(p,n${)}^{37}$Ar reaction.

Data on the fragmentation of ${}_{}{}^{12,14}{}_{}{}^{}\mathrm{Be}$ on ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ at 56 and 65 MeV per nucleon have been obtained. The ${}_{}{}^{12}{}_{}{}^{}\mathrm{Be}$ fragments from the breakup of ${}_{}{}^{14}{}_{}{}^{}\mathrm{Be}$ display both a narrow longitudinal momentum distribution and a distinctive angular distribution that is consistent with an extended neutron ‘‘halo’’ in this nucleus. This is the first experiment in which both longitudinal and transverse fragment momentum distributions of exotic nuclei have been simultaneously measured.

It is shown that a very accurate fermion SO(6) dynamical symmetry exists for ${}_{}{}^{196}{}_{}{}^{}\mathrm{Pt}$, even though the coupled system has no such formal dynamical symmetry in the fermion dynamical symmetry model. Implications of this effective dynamical symmetry are discussed.

The rotational behavior together with in-plane collective flow for the intermediate energy ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$${+}^{27}$Al reaction is investigated by analyzing the rapidity-dependent azimuthal distributions with the Boltzmann-Uehling-Uhlenbeck (BUU) model. The azimuthal distributions are fitted by a Legendre polynomial expansion up to the second order. By incorporating the uncertainties in the experimental reaction plane determination into our calculations, quantitative agreement between the calculations and data is obtained. It is found that the rotational behavior at midrapidity depends strongly on the impact parameter. Information about the in-plane collective flow is also extracted from the azimuthal distributions. Both the rotational behavior and the in-plane collective flow depend strongly on the in-medium nucleon-nucleon cross section and nuclear equation of state.

The alpha decay hindrance factors from the ${}_{}{}^{229}{}_{}{}^{}\mathrm{Pa}$ 5/$2^{+}$ ground state to the 5/$2^{\pm }$ parity doublet bands in ${}_{}{}^{225}{}_{}{}^{}\mathrm{Ac}$ suggest strong reflection asymmetry in ${}_{}{}^{229}{}_{}{}^{}\mathrm{Pa}$ and the expectation that a 5/$2^{\pm }$ parity doublet will be found in this nucleus.