It is of great importance to relate the results of nuclear gamma-ray distribution measurements to the fundamental parity (P) and time (PT) violating meson-nucleon coupling constants. To facilitate this program we derive a one-body mean-field potential from the two-body PT violating pion-exchange potentials. This potential includes a suppression due to the finite meson range of about 0.7 in the rare-earth nuclei and 0.4 in the s-d shell nuclei. We compare exact numerical results to an approximate analytic formula and find good agreement. We discuss the energy distribution of the nuclear PT violating impurity. This is overwhelmingly concentrated at relatively large excitation energies, around 1ħω. Nevertheless, in heavier deformed nuclei there is a small PT violating strength at low energies due to the interaction of natural parity states with the unnatural parity intruder subshell. This impurity can be significantly enhanced due to the small energy denominators.

The ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$(α,n${)}^{25}$Mg reaction has been investigated in the energy range ${\mathit{E}}_{\mathrm{\alpha }}^{\mathrm{lab}}$=0.73–2.10 MeV using high-resolution ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ ionization chambers. Sixteen resonances have been observed in the three neutron channels to the ground state and the first two excited levels of ${}_{}{}^{25}{}_{}{}^{}\mathrm{Mg}$. From the analysis of neutron angular distributions, spin and parity assignments could be made for eight resonances. Furthermore, partial widths as well as absolute cross sections have been obtained yielding resonance strengths for the observed levels. The role of the ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$(α,n) reaction as a neutron source for the s process is briefly discussed.

The Cu(p,X${)}^{24}$Na cross section was measured at energies of 30, 150, 400, and 800 GeV. Proton fluences were determined with beam current transformer systems which were calibrated electrically in situ. The ${}_{}{}^{24}{}_{}{}^{}\mathrm{Na}$ produced in Cu targets was assayed by comparing the intensity of its 1368-keV γ ray with that of the 1332-keV γ ray from ${}_{}{}^{60}{}_{}{}^{}\mathrm{Co}$ standard sources. Results are consistent with an energy-independent cross section of 3.59±0.14 mb.

A kinematically complete study of the ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$(p,γ${)}^8$${\mathrm{Be}}^{\mathrm{*}}$→2α reaction at ${\mathit{E}}_{\mathit{p}}$=25 MeV is described. An upper limit of dσ/dΩ<0.04 μb ${\mathrm{sr}}^{\mathrm{-}1}$ is reported for the ${\mathrm{\theta }}_{\gamma }$=90° capture cross section to the $2^{+}$ states at 16.62 and 16.93 MeV, which is five times smaller than published results. This new datum is shown to be more consistent with a semidirect reaction mechanism involving the giant dipole resonance built on the ${}_{}{}^8{}_{}{}^{}\mathrm{Be}_{}^{\mathrm{*}}{}_{}{}^{}$ 2.94-MeV state than the previously proposed direct reaction mechanism.

Many resonances in the reaction ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$+p for ${\mathit{E}}_{\mathit{p}}$=3.58–4.06 MeV were observed corresponding to excitation energies ${\mathit{E}}_{\mathit{x}}$=15.03–15.50 MeV of the compound system ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$. We measured the excitation functions for the decay mode with exit channels (${\mathit{p}}_{0–}$${\mathit{p}}_4$,${\mathrm{\alpha }}_0$,${\mathrm{\alpha }}_1$,γ) in the above proton energy range with energy steps of 2 keV at 135° and 145° for proton and α particles and at 60° for gamma rays. Two solid-state detectors and a 5.1 cm×5.1 cm NaI(Tl) scintillator were employed. High experimental resolution of ∼1 keV enables us to deduce the average ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ level spacing in the region of 15 MeV excitation. The structure of resonances is discussed and energies, together with widths of resonances, are presented. The ${\mathit{J}}^{\mathrm{\pi }}$ assignment for several resonances was proposed as well.

Radioactive ${}_{}{}^{32}{}_{}{}^{}\mathrm{Si}$ was produced by double neutron capture in natural silicon. From a measurement of the isotopic ratio ${}_{}{}^{32}{}_{}{}^{}\mathrm{Si}$${/}^{30}$Si by means of accelerator mass spectrometry the neutron-capture cross section for radioactive ${}_{}{}^{31}{}_{}{}^{}\mathrm{Si}$ (${\mathit{T}}_{1/2}$=2.622 h) was deduced to be 73±6 mb.

We discuss the transformation from a scalar and vector Dirac equation to either a scalar and tensor or a vector and tensor equation in both the single-channel (static potential) and coupled-channel (nonstatic potential) cases. The relationship to the σ-ω Lagrangian in the mean-field theory is pointed out. The failure to obtain such a transformation in the coupled-channel case, except when the states are degenerate, is explained simply and analyzed in some detail.

Nonpairing like-nucleon residual interactions, δ${\mathit{V}}_{\mathit{n}\mathit{n}}$ and δ${\mathit{V}}_{\mathit{p}\mathit{p}}$, of the last two neutrons or protons are extracted from double differences of nuclear binding energies for all even-even nuclei. They are found to be weakly repulsive and, combined with analogous information on p-n interactions, provide an alternate way of demonstrating that the T=0 interaction is strongly attractive. Anomalies in δ${\mathit{V}}_{\mathit{n}\mathit{n}}$ and δ${\mathit{V}}_{\mathit{p}\mathit{p}}$ are shown to correlate with changes in core structure, and repulsive spikes for N=Z nuclei are interpreted in terms of shell-model calculations with realistic interactions.

The effect of model-space size on the model-space Brueckner-Hartree-Fock (MBHF) results of the nuclear matter saturation property is discussed with the Reid soft-core and Paris nucleon-nucleon interactions. A prescription for optimal choice of the model-space size in the nuclear matter MBHF calculation is suggested.

The unitary pole approximation is used to construct a separable representation for a potential U which consists of a Coulomb repulsion plus an attractive potential of the Yamaguchi type. The exact bound-state wave function is employed. U is chosen as the potential which binds the proton in the 1${\mathit{d}}_{5/2}$ single-particle orbit in ${}_{}{}^{17}{}_{}{}^{}\mathrm{F}$. Using the separable representation derived for U, and assuming a separable Yamaguchi potential to describe the 1${\mathit{d}}_{5/2}$ neutron in ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$, the energies and wave functions of the ground state ($1^{+}$) and the lowest $0^{+}$ state of ${}_{}{}^{18}{}_{}{}^{}\mathrm{F}$ are calculated in the core-plus-two-nucleons model solving the Faddeev equations.

When the Elliott U(3) symmetry is spontaneously broken in a nonrelativistic nuclear system, a type of superconductivity order parameter leads to six Nambu-Goldstone bosons with spin zero and two. The rotational symmetry is not broken.

We report that a recent conclusion by Gibson, Pearce, and Payne indicating a violation of the conjectured variational principle underlying the calculation of three-body binding energies within the W-matrix approach is in error.

We reply to the preceding comment.

A weakly populated rotational band with energy spacings characteristic of superdeformation has been found in the reaction ${}_{}{}^{154}{}_{}{}^{}\mathrm{Sm}$${(}^{48}$Ca,xn) at E${(}^{48}$Ca)=205 MeV. This band has seven transitions with an average γ-ray energy spacing of approximately 42 keV. It is assigned to ${}_{}{}^{198}{}_{}{}^{}\mathrm{Pb}$ on the basis of the excitation-function results. We also confirm the isotopic assignment of a previously reported superdeformed (SD) band in ${}_{}{}^{196}{}_{}{}^{}\mathrm{Pb}$ via the cross bombardments ${}_{}{}^{176}{}_{}{}^{}\mathrm{Yb}$${(}^{26}$Mg,xn) and ${}_{}{}^{176}{}_{}{}^{}\mathrm{Yb}$${(}^{24}$Mg,xn). Three SD bands have now been identified in the Pb isotopes with neutron numbers 112, 114, and 116.

The neutron decay of the giant electric dipole resonance of ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ has been determined by a measurement of the differential cross section, dσ(${\mathit{E}}_{\gamma }$,${\mathit{E}}_{\mathit{n}}$)/${\mathit{dE}}_{\mathit{n}}$ of the ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$(γ,n) reaction for 20 contiguous photon energy bands between 11.2 and 15.7 MeV. The statistical component of the decay was calculated in the Hauser-Feshbach formalism. A nonstatistical component of the decay to low-lying hole states is unambiguously identified. The magnitude of this component is strongly energy dependent.

Particle-particle coincidence measurements have been made for the reactions 312 and 680 MeV ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$${+}^{\mathrm{nat}}$Ag. The large-angle correlation data indicate essentially complete energy thermalization even for 680 Mev ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$${+}^{\mathrm{nat}}$Ag. They also allow for an assignment of ≊64ħ for the rms spin and ≊4.3 MeV for the average initial temperature of the composite nuclei formed by incomplete fusion. The small-angle correlation data for ${}_{}{}^1{}_{}{}^{}\mathrm{-}_{}^1{}_{}{}^{}$H and ${}_{}{}^2{}_{}{}^{}\mathrm{-}_{}^2{}_{}{}^{}$H are consistent with phase-space, statistical-model predictions of the evaporation lifetimes. This result implies that energy mixing and evaporation particle emission steps occur with intervals of ≊${10}^{\mathrm{-}22}$ s, a time period comparable to the traversal time for a projectile velocity of 17 MeV/nucleon.