New information is presented on the decay of 40-s ${}_{}{}^{132}{}_{}{}^{}\mathrm{Sn}$ to levels of odd-odd ${}_{}{}^{132}{}_{}{}^{}\mathrm{Sb}$. A second ${\beta }^{\mathrm{-}}$-fed $1^{+}$ level was identified in ${}_{}{}^{132}{}_{}{}^{}\mathrm{Sb}$; it lies at an energy of 2268 keV and is fed by a relatively strong 0.83% ${\beta }^{\mathrm{-}}$-decay branch. Four γ rays were identified that form a weakly populated cascade from a level at 483 keV. Coincidence data demonstrate that the 254-keV level in this cascade is the 102-ns isomer identified previously by Clark et al. A 96-keV, isomeric γ ray has been assigned to the decay of the 4.1-min, $8^{\mathrm{-}}$ isomer in ${}_{}{}^{132}{}_{}{}^{}\mathrm{Sb}$. It may also be the 96-keV transition that is associated with the 1.8-μs isomer identified in the A=132 chain by Clark et al. The splitting of the levels in the proton-neutron multiplets is discussed and compared with the results of several recent shell-model calculations.

On-line mass separation and K x-ray coincidences were used to identify the β decays of ${}_{}{}^{145}{}_{}{}^{}\mathrm{Er}$ and ${}_{}{}^{145}{}_{}{}^{}\mathrm{Ho}$. Only β-delayed proton emission was observed for ${}_{}{}^{145}{}_{}{}^{}\mathrm{Er}$ ($T_{1/2}$=0.9±0.3 s), and a total of 16 γ-ray transitions were assigned to the β decay of ${}_{}{}^{145}{}_{}{}^{}\mathrm{Ho}$ ($T_{1/2}$=2.4±0.1 s). A ${}_{}{}^{145}{}_{}{}^{}\mathrm{Ho}$ decay scheme was constructed which incorporates 13 γ-ray transitions and 10 excited levels in ${}_{}{}^{145}{}_{}{}^{}\mathrm{Dy}$ and establishes the ν$h_{11/2}$ isomeric level at $E_x$=118.2 keV. The low-lying neutron-hole structure in ${}_{}{}^{145}{}_{}{}^{}\mathrm{Dy}$ is compared to level systematics in even-Z nuclei with N=77, 79, and 81.

The first information on excited states in neutron-rich ${}_{}{}^{74}{}_{}{}^{}\mathrm{Zn}$ populated in the β decay of ${}_{}{}^{74}{}_{}{}^{}\mathrm{Cu}$ is presented. The ${}_{}{}^{74}{}_{}{}^{}\mathrm{Cu}$ half-life was measured to be 1.59±0.05 s. On the basis of γ singles and coincidence measurements, a total of 19 γ rays were placed in a level scheme for ${}_{}{}^{74}{}_{}{}^{}\mathrm{Zn}$ with 10 excited states up to about 3 MeV. The low-lying level structure is satisfactorily reproduced by a shell-model calculation involving active protons in orbitals between the magic numbers 28 and 50 and neutrons filling the subshell between 38 and 50.

The beta-delayed alpha-particle emission from ${}_{}{}^{18}{}_{}{}^{}\mathrm{N}$ has been studied and the absolute beta decay branching ratios of ${}_{}{}^{18}{}_{}{}^{}\mathrm{N}$ to the $1_3^{\mathrm{-}}$ and $1_4^{\mathrm{-}}$ states in ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$ measured. The ${}_{}{}^{18}{}_{}{}^{}\mathrm{N}$ nuclei were produced using a 35-MeV/nucleon ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$ beam and a thick Ta target. Reaction products were separated (from the beam) using a reaction products mass separator. A silicon telescope including five detectors and a two-dimensional, position-sensitive, gas counter was used in the focal plane of the mass separator. We obtain beta decay branching ratios of 6.8±0.5% and 1.8±0.2 % to the $1_3^{\mathrm{-}}$ and $1_4^{\mathrm{-}}$ states, respectively, assuming 100% alpha-particle decay branching ratios for these states. Shell-model predictions are compared with these experimental results. The relevance of these data to a new proposed search for parity violation in ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$ is discussed.

A new model is proposed for the mechanism of cluster formation and then penetration of the confining nuclear interaction barrier in radioactive nuclei. The cluster formation is treated as a quantum-mechanical fragmentation process and the WKB penetrability is found analytically. Applications of the model are made to ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$ decay of ${}_{}{}^{222\mathrm{-}224}{}_{}{}^{}\mathrm{Ra}$ and ${}_{}{}^{24}{}_{}{}^{}\mathrm{Ne}$ decay of ${}_{}{}^{232}{}_{}{}^{}\mathrm{U}$. The branching ratio for ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$ decay of ${}_{}{}^{232}{}_{}{}^{}\mathrm{U}$ is also calculated and is found to be incredibly small as compared to that for its ${}_{}{}^{24}{}_{}{}^{}\mathrm{Ne}$ decay.

A new approach to many-body dynamics that combines successive boson expansion and mean-field techniques, and which was recently developed for boson systems, is extended to fermion systems. The procedure is developed for both the ground state and for low-lying excited states and is tested in the context of the two-level pairing model. Special attention is focused on the problem of unphysical states.

The finite-temperature Hartree-Fock-Bogoliubov cranking equation is solved for the transitional nucleus ${}_{}{}^{158}{}_{}{}^{}\mathrm{Yb}$. The deformation and pair gaps are calculated as functions of temperature and angular momentum. There is a transition from prolate collective rotation to oblate noncollective rotation for spins above 39ħ or temperatures above a spin-dependent critical temperature. When statis- tical shape fluctuations are included for spins above 39ħ, collective structures are populated at moderate temperatures. Although the yrast line is noncollective for I>39ħ, the shape fluctuations produce a collective B(E2) value at moderate temperatures.

The high-spin yrast spectra with $J_{\max {}^{\pi }{=(16\mathrm{}}^{+}}$) and the observed gradual shape transition at ${}_{}{}^{108}{}_{}{}^{}\mathrm{Pd}$ in the nuclei ${}_{}{}^{100\mathrm{-}114}{}_{}{}^{}\mathrm{Pd}$ are examined by carrying out Hartree-Fock-Bogoliubov calculations employing a pairing-plus-quadrupole-quadrupole effective interaction operating in a reasonably large valence space outside an inert ${}_{}{}^{80}{}_{}{}^{}\mathrm{Zr}$ core. Our calculations reveal that the gradual shape transition at ${}_{}{}^{108}{}_{}{}^{}\mathrm{Pd}$ is intricately linked with the simultaneous change of relative occupation probabilities of ($g_{7/2}$)-neutron and ($g_{9/2}$)-proton orbits.

Isoscalar giant resonances in finite nuclei are studied in a relativistic random-phase approximation approach. The model is self-consistent in the sense that one set of coupling constants generates the Dirac-Hartree single-particle spectrum and the residual particle-hole interaction. The relativistic random-phase approximation is used to calculate response functions of multipolarity L=0, 2, 3, and 4 in light and medium nuclei. It is found that monopole and quadrupole modes exhibit a collective character. The peak energies are overestimated, but not as much as one might think if the bulk properties (compression modulus, effective mass) were the only relevant quantities.

We derive a unitary transformation relating color singlet six-quark states constructed in the color-spin (CS) and isospin-spin (TS) schemes. The chosen orbital symmetries are [42] in the TS=(01) sector and [33] in the TS=(00) sector. They are important in the description of the NN system.

We discuss the restoration of the chiral symmetry in the case of the N-N interaction on the basis of the cloudy bag model. A quantum-chromodynamics-based many-body theory of confined quarks, confined gluons, and pions is developed. In terms of the Green’s functions and vertex functions of these fields, the energy shift due to gluon and pion exchange between quarks is calculated systematically and the short-range and long-range parts of the effective nuclear potential are obtained. For the short-range part, a soft repulsive core is obtained using the cloudy bag model parameters and the main contribution comes from the gluon exchange, as expected. The height of the core, however, is sensitive to the (poorly determined) subtraction required to remove the kinetic energy of the relative N-N motion. For the long-range part, an explicit formula, which is the same as one-pion-exchange potential, is obtained, but the strength of this part is 30% lower than that of one-pion-exchange potential when $f_{\pi }$ is chosen as 93.0 MeV.

Excited states in ${}_{}{}^{119}{}_{}{}^{}\mathrm{Xe}$ have been populated via the ${}_{}{}^{95}{}_{}{}^{}\mathrm{Mo}$${(}^{27}$Al,p2n) reaction at a beam energy of 105 MeV. The high-spin level structure is interpreted as consisting of rotational bands built on quasineutron $h_{11/2}$, $d_{5/2}$, and $g_{7/2}$ states. Although these positive-parity configurations differ from previous interpretations, most notably an earlier $g_{9/2}$ assignment, they are supported by experimental B(M1;I→I-1)/B(E2;I→I-2) ratios plus additional levels presented here. A backbend in the $g_{7/2}$ band is attributed to the rotation alignment of a pair of ν$h_{11/2}$ quasiparticles.

We investigate the pseudoscalar pion-nucleon constants in the framework of various chiral models of the nucleon. We demonstrate that strong isospin violation ($m_u$≠$m_d$) does not lead to a charge dependence of the pion-nucleon vertex as recently reported on the basis of NN scattering data. Using the equivalence theorem, we show that the pion mass difference leads to a 3% effect in the pseudovector πN coupling constants.

In the interacting boson model including g bosons for the nuclei ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ and ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$ and employing an interaction that interpolates the various dynamical symmetries in the model, spectra and E2 and E4 matrix elements are calculated. The results are in good agreement with data.

We have studied the heavy-ion fusion reactions by a macroscopic model which was proposed by Bertsch several years ago. It employed the Newtonian dynamics and was constructed in such a way that the essential features of time-dependent Hartree-Fock results could be reproduced. We have applied the model to fusion of light heavy-ion systems leading to the same compound nucleus ${}_{}{}^{56}{}_{}{}^{}\mathrm{Ni}$. It is shown that the model, being incorporated with the angular-momentum-dependent extra-push energy of Swiatecki, can account well for the fusion cross sections up to very high energies where cross section decreases as energy increases, and that the main reason for the decrease is the opening of the low angular momentum window.

A method for choosing and deriving a suitable single-particle potential for many-body calculations at finite temperature is suggested. With this potential one can readily determine the self-consistent correlated chemical potential and consequently the resulting equations of state rigorously satisfy a number of basic thermodynamic relations. Application of our method to a Brueckner-Hartree-Fock nuclear matter calculation yields results in remarkably good agreement with the Hugenholtz–Van Hove theorem.

A systematic study of the contribution of λ=4 deformations to the enhancement of subbarrier fusion cross sections is carried out. The analysis is based on calculations that cover the full range of values of hexadecapole deformations found in actual nuclear systems. The interplay of this shape degree of freedom with the presence of prolate quadrupole deformations is also comtemplated.

The origin of a rather large deep inelastic component in the total cross section for heavy-ion collisions at energies below or slightly above the Coulomb barrier is discussed. Calculations for the reactions ${}_{}{}^{58}{}_{}{}^{}$Ni${+}^{122}$,124Sn show a quantitative agreement with recently obtained experimental data.

We comment on a recent paper from Adelseck and Wright in which kaon photoproduction and electroproduction data have been fit within a diagrammatic model. The importance of the resonance $K_1$(1280) in recovering the canonical Born coupling constants is questioned.

We reply to the preceding Comment.