We study the effect of the temperature on the spatial correlations between two nucleons, induced by the pairing interaction. Both the Cooper pairs of superfluid nuclei as well as the low-lying pairing vibrations of the normal systems are strongly affected by temperatures of the order of the pairing gap, in keeping with the close origin existing between the two modes of excitation. Giant pairing vibrations, namely the zero sound of nuclei associated with the change of particle number in two, predicted to exist in both normal and superfluid systems, are not affected by temperature.

A general self-consistent approximation for statistical operators is introduced. The scheme reduces to a statistical mean-field description when applied to the case of single-particle observables. The present, quite general context allows, however, the examination of the approach from a different perspective, and enables the straightforward construction of higher order self-consistent approximations.

It is shown that a recently proposed method that reproduces the saturation in B(E${2;0}_1^{+}$→$2_1^{+}$) values in deformed nuclei also improves interacting boson model predictions for γ-band energy systematics near midshell. The method is based on an explicit recognition of the (Nilsson) orbit dependence of the valence p-n interaction and is, in effect, a refinement to the $N_p$$N_n$ scheme which linearizes the behavior of certain observables.

Neutral-pion photoproduction on the proton near threshold is treated in a Lippmann-Schwinger–type formalism. Rescattering effects are found to be important and depend strongly on the final-state πN $S_{11}$ interaction.

Spectra of energetic protons emitted in nucleus-nucleus collisions are calculated in the promptly-emitted-particle model and are confronted with the experimental data in the range of 10–20 MeV/nucleon. Theoretical calculations are found to be in good agreement with the experimental data. Emission from two-body collisions is found to play an important role in the quantitative understanding of the experimental results.

The effects of the nuclear binding on a previously derived single-particle parity-violating nuclear potential are investigated.

The implications of η and ω production in antiproton-nucleus annihilation are examined by means of a simplified cascade scheme. The intranuclear absorption of the pions ‘‘hidden’’ in the resonances is predicted smaller than the average pion absorption measured by experiment. It is also pointed out that the reaction ωN→ΛK might be a significant source of Λ production in antiproton-nucleus interactions. The possibility of studying η-nucleus interactions is examined.

The spectral distribution method is applied to evaluate the strength sums for Gamow-Teller and isovector M1 excitations and compared with shell-model predictions for (sd) shell nuclei.

We present a simple argument to show why a high entropy phase must exhibit an extended pion source lifetime. The plasmas that would be formed under the conditions of the recent heavy ion experiments would emit pions over a time of the order of 10 fm/c or longer, if the plasma has an entropy density larger than that of a pion gas by an order of magnitude.

The average binding energy per nucleon in nuclear matter had recently been calculated in the framework of a model space approach, including the sum of the particle-particle and hole-hole ring diagrams to all orders. It is pointed out that, in the case of the $V_{14}$ interaction, the calculated saturation properties are at variance with an upper bound evaluated from a variational method; they are also quite different from those derived from the standard hole-line expansion. It is suggested that these differences might be due to bubble contributions that have, in part, been omitted in the model space approach. It is also proposed to use the summation of particle-particle and hole-hole ring diagrams to test the convergence of the standard hole-line expansion.

Ring-diagram nuclear matter calculations using different choices for the single-particle spectrum are performed and discussed.

The observation of a peak structure in the electron spectra resulting from $e^{+}$+Th,U collisions with a measured FWHM of (3.7±0.5) keV cannot be attributed to a new phenomenon, i.e., the $e^{+}$$e^{\mathrm{-}}$ decay of a neutral particle as recently claimed, because in this case the expected resonance width is broadened to at least 60 keV (FWHM) in the laboratory frame because of the motion of the bound electrons.

The point raised by the preceding Comment depends essentially on the scenario of the generation mechanism of the relevant neutral object. The experiments repeated recently with a better instrumental resolution yielded a measured FWHM of (2.2±0.4) keV for the (330.8±0.5) keV peak reported in the previous paper and a measured FWHM of (2.4±0.4) keV for the newly discovered (409.2±0.5) keV peak.

It is shown that recently reported results on the charge densities of some Te isotopes are consistent with a quadratic relation between effective skin thickness and deformation and a constant value for the ‘‘real’’ skin thickness that is smaller than that used in the usual droplet model.

The rate of nuclear fusion from tunneling in very dense metallic hydrogen in the core of Jupiter is calculated to be ${10}^{\mathrm{-}50}$ per hydrogen-deuterium pair per second. It is estimated that the width of the fusion barrier for deuterium in palladium or a similar metal must be reduced to, of order, 0.1 Å for the fusion rate to be ${10}^{\mathrm{-}25}$ per deuterium per second. If this scale is achieved, the ratios of various nuclear reaction rates will be very different for cold versus thermonuclear fusion.

We report on a search for neutrons from dd fusion in Pd rods loaded electrochemically with deuterium. In a four-week measurement we observe <0.007 n/(sec g) Pd, compared to 2.6×${10}^3$ n/(sec g) Pd, claimed recently by Pons, Fleischmann, and Hawkins. Our result implies <2.2×${10}^{\mathrm{-}24}$ (ddn) fusions/[(dd pair) sec], as compared to ∼${10}^{\mathrm{-}23}$ (ddn) fusions/[(dd pair) sec] observed by Jones et al. in a Ti electrode.

The first cross-section measurements for the reaction ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$(p,n${)}^{22}$Na were performed at several proton energies from threshold to 18 MeV. A gas cell target containing natural Ne gas was irradiated on the beam line of a cyclotron. The yield of ${}_{}{}^{22}{}_{}{}^{}\mathrm{Na}$($T_{1/2}$=2.6 yr) was subsequently determined by counting gamma rays with a Ge detector. Several systematic corrections associated with the counting geometry and beam heating of the gas during bombardment were applied.

Two-particle rapidity correlations are studied in dC, αC and CC interactions at 4.2 GeV/c per nucleon using 2 m propane bubble chamber. The influence of collision centrality on the short-range correlation strength is also analyzed. Comparison with the Dubna intranuclear cascade model indicates that the independent nucleon-nucleon collisions may account for the observed correlations.

Continuum γ-ray spectra from the decay of ${}_{}{}^{59}{}_{}{}^{}\mathrm{Cu}$ formed at excitation energies of 54 and 74 MeV and angular momenta up to 40ħ have been measured and analyzed. The parameters of the giant dipole resonance have been extracted using the statistical model. The giant dipole resonance parameters for the lower excitation energy agree well with published data for spherical ${}_{}{}^{63}{}_{}{}^{}\mathrm{Cu}$ nuclei. At the higher excitation, the giant dipole resonance strength distribution is not described by a single Lorentzian fit in disagreement with the findings for ${}_{}{}^{63}{}_{}{}^{}\mathrm{Cu}$ at the same excitation energy. This seems to be correlated with the onset of spin driven deformations as recently evidenced from the shapes of evaporative particle spectra.