The cross sections for the ν-d and ν¯-d reactions are calculated for neutrino energies of astrophysical interest. We make a detailed assessment of the possible effects of the approximations involved in the existing works and present improved estimates of the cross sections.

The reaction ${}_{}{}^8{}_{}{}^{}\mathrm{Li}$(α,n${)}^{11}$B is of interest in inhomogeneous big bang nucleosynthesis. A distorted wave Born approximation calculation employing folding potentials is presented for energies below the Coulomb barrier. The recently observed resonance at about 540 keV center-of-mass energy can be reproduced. The astrophysical S factor is calculated for the ground-state transition as well as for the transitions to the first four excited states of ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$. The reaction rate is derived and compared to literature data. The inclusion of the excited states increases the rate by a factor of 1.5 compared to the ground-state transition.

The differential cross section for pp→ppγ has been measured at an average bombarding energy of 294 MeV and for proton laboratory angles between 5° and 12°. The absolute normalization of the data is based on the concurrent measurement of pp elastic scattering. The experiment has been carried out with the Indiana University Cyclotron Facility Cooler Ring using an internal gas jet target in an electron-cooled beam. The data cover a region of the kinematic space where off-shell contributions of the NN interaction are expected to be enhanced. The shape of the measured cross sections as a function of the photon angle agrees fairly well with the expectation from phase space alone.

The analyzing powers of the ${}_{}{}^1{}_{}{}^{}\mathrm{H}$(d→,pp)X reaction have been measured using polarized deuteron beams at ${\mathit{T}}_{\mathit{d}}$=2.1 GeV, θ=17° and ${\mathit{T}}_{\mathit{d}}$=1.722 GeV, θ=0°. In both cases a small oscillatory pattern has been observed in the tensor analyzing power at the same two-proton invariant mass and width ${\mathit{M}}_{\mathit{p}\mathit{p}}$=1.945 GeV, ${\mathrm{\Gamma }}_{1/2}$≊8 MeV. The number of standard deviations are equal to 2.5 and 3.9, respectively.

This paper is an extension of a previous study of the pairing effects in the N=82 isotones. It is concerned with high-spin states in the nuclei from ${}_{}{}^{146}{}_{}{}^{}\mathrm{Gd}$ through the recently explored ${}_{}{}^{153}{}_{}{}^{}\mathrm{Lu}$ and ${}_{}{}^{154}{}_{}{}^{}\mathrm{Hf}$. The results obtained confirm the importance of proton pairing correlations in the N=50–82 shell.

The three processes γ+d→${\mathrm{\Lambda }}^0$(${\mathrm{\Sigma }}^0$)+${\mathit{K}}^0$+p and γ+d→${\mathrm{\Sigma }}^{\mathrm{-}}$+${\mathit{K}}^{+}$+p are investigated in the framework of the impulse approximation. The exclusive reactions d(γ,Kp)Y where the proton is detected in coincidence with the ${\mathit{K}}^0$ or ${\mathit{K}}^{+}$ should provide unique signatures for each of the processes. In most kinematic situations the final-state Yp interaction is insignificant and the elementary process cross section for γ+n→Y+K can be reliably extracted. Cross-section estimates are given for several models of the basic production operator.

Recent work of Cohen, Furnstahl, and Griegel has advanced our understanding of the behavior of quark and gluon condensates in nuclear matter. We make use of their analysis to discuss the role of chiral condensates as they appear in relativistic Brueckner-Hartree-Fock theory. We find some support for assumptions we used to discuss the properties of nuclear matter in our earlier work. We also find that a rather consistent picture emerges from these studies, when we relate the parameters of the boson-exchange model of nuclear forces to an underlying field-theoretic description of nuclear matter.

The ${\mathit{K}}^{+}$-nucleus interaction is investigated in the context of a covariant, momentum-space optical potential that incorporates covariant kinematics, relativistic normalizations, and phase-space factors, a covariant treatment of the recoil of the target nucleus, utilizes invariant amplitudes which are free of kinematic singularities, and allows an exact performance of the Fermi integration over the momentum of the struck nucleon. Elastic differential cross sections for ${\mathit{K}}^{+}$ scattering from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ and total cross sections for ${\mathit{K}}^{+}$ scattering from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ are calculated. An enhanced, in-medium, two-body interaction is indicated as the data is consistent with an approximate 30% enhancement of the theoretical calculations.

We analyze a recent experiment in which the spin-correlation parameter ${\mathit{A}}_{\mathit{z}\mathit{z}}$ in np scattering at ${\mathit{T}}_{\mathrm{lab}}$=67.5 MeV was measured. The I=0 phase parameters can now be determined much more accurately in a single-energy analysis at 50 MeV. The value found for the ${}_{}{}^3{}_{}{}^{}$${\mathit{S}}_{1\mathrm{-}}^3$${\mathit{D}}_1$ mixing parameter ${\mathrm{\varepsilon }}_1$ is in excellent agreement with modern potential-model predictions.

We comment on a recent paper from Zhang Yu-shun in which it is claimed that virtual excitation of low vibrational states has strong effects on the elastic scattering of pions. We find a substantially weaker influence of these excitations, using fully coupled-channels calculations with both phenomenological and microscopic models for the interaction. Further, higher-order effects on the inelastic cross sections are also weak for typical vibrational nuclei.

Replying to a recent Comment by R. L. Workman, it is shown that our analysis [Phys. Rev. C 42, 108 (1990)] of the elementary kaon photoproduction reaction allows a meaningful determination of the relevant coupling constants.

Low spin identical bands are found in sets of widely dispersed nuclei, spanning as much as 24 mass units. Moreover, they occur in regions of rapid structural and shape changes. A correlation ansatz to identify such nuclei, based on the concepts of ${\mathit{N}}_{\mathit{p}}$${\mathit{N}}_{\mathit{n}}$ and F spin, is discussed.

A recent publication claimed incomplete mixing of states with different K quantum numbers in the neutron resonance region. We discuss the theoretical implications of such a claim and show that it leads to serious discrepancies with the statistical model. We, therefore, reexamine the experimental data on which such a claim is based. The totality of the evidence invalidates the claim that K mixing in the resonance region is incomplete.

Three superdeformed (SD) bands including states with spins ${\mathit{I}}^{\mathrm{\pi }}$≤${22}^{+}$ are predicted for ${}_{}{}^{192}{}_{}{}^{}\mathrm{Hg}$. The SD and normally deformed levels are calculated as eigenstates of the Griffin-Hill-Wheeler equation treated in the Gaussian overlap approximation. Potential and tensor of inertia are deduced from constrained Hartree-Fock-Bogoliubov calculations based on Gogny’s force. Rates for E2 in-band transitions are deduced and compared with recent measurements. The decay out of SD bands is discussed.

Threshold behavior of S-wave phase shifts is studied for NΔ scattering with a nearby S-matrix pole. The phase ${\mathrm{\delta }}_{\mathit{N}\mathrm{\Delta }}$ for pp${(}^1$${\mathit{D}}_2$)→DΔ${(}^5$${\mathit{S}}_2$) obtained by experiments for pp→np${\mathrm{\pi }}^{+}$ are explained on the basis of the pole of unstable bound state type or broad dibaryon, (M=2144 MeV, I=1, ${\mathit{J}}^{\mathit{P}}$=$2^{+}$), by taking into account instability of the Δ, NN final-state interaction for NΔ→np${\mathrm{\pi }}^{+}$ and a factor i due to p-wave pion emission. This pole explains also the ${}_{}{}^1{}_{}{}^{}$${\mathit{D}}_2$ phase parameters for pp→pp around 2144 MeV in √s .

We study the proton-deuteron radiative capture reaction at low energies (${\mathit{E}}_{\gamma }$≃10 MeV) with the three-nucleon Faddeev wave functions for various combinations of available realistic nucleon-nucleon potentials and the two-pion exchange three-nucleon potential. The calculated values of tensor analyzing power ${\mathit{A}}_{\mathit{y}\mathit{y}}$(θ) are found to be sensitive to a different choice of realistic potentials and introduction of the three-nucleon potential. The comparison with available data shows the necessity of the three-nucleon potential.

Isovector stretched-state excitations were studied in the (p,n) reaction at 136 MeV on the self-conjugate s-d shell nuclei ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$, ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$, ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$, and ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$. The measurements were performed in three separate experiments using the beam-swinger neutron time-of-flight facility at the Indiana University Cyclotron Facility. Neutrons were detected in large-volume plastic scintillation detectors located in three detector stations at 0°, 24°, and 45° with respect to the undeflected beam line; the flight paths varied from 75 to 134 m. Overall time resolutions of about 825 ps provided energy resolutions of about 320 keV in the first two stations and about 425 keV in the third station. Both (${\mathit{d}}_{5/2}$,${\mathit{d}}_{5/2}^{\mathrm{-}1}$)$5^{+}$ 0ħω and (${\mathit{f}}_{7/2}$,${\mathit{d}}_{5/2}^{\mathrm{-}1}$)$6^{\mathrm{-}}$ 1ħω stretched-state excitations are observed in the (p,n) reaction on ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$, ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$, and ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$.

For the (p,n) reaction on ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$, only the $6^{\mathrm{-}}$ strength is observed. The states are identified by comparison of the extracted angular distributions with distorted-wave impulse-approximation calculations and by comparison with known analog states observed in inelastic scattering. In the ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ and ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$(p,n) reactions, the majority of the $5^{+}$ strength is observed in single states at low excitation energy; the strengths are described well by full s-d shell-model calculations. A weak $5^{+}$ state is observed in the ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$(p,n${)}^{28}$P reaction that corresponds to the strength expected if there is ∼1/3 of a hole in the ${\mathit{d}}_{5/2}$ proton orbital. The $6^{\mathrm{-}}$ 1ħω strength is fragmented in all four reactions. Less than 60% of the strength expected in the extreme single-particle-hole model is observed in each case. The observed $6^{\mathrm{-}}$ strengths and distributions in the ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ and ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$(p,n) reactions are described well by large-basis shell-model calculations.

The low-lying excited states of two rotational nuclei, ${}_{}{}^{176}{}_{}{}^{}\mathrm{Yb}$ and ${}_{}{}^{180}{}_{}{}^{}\mathrm{Hf}$, have been investigated up to an excitation energy of 3.5 MeV by means of high-resolution inelastic scattering of 98.4-MeV polarized protons. The spins and excitation strengths of the observed levels have been deduced by comparing the measured cross sections and asymmetries with coupled-channel calculations. The deduced quadrupole, hexadecapole, and octupole strengths have been compared with the predictions of the interacting boson model in the sdg- and sdf-boson schemes.

The decay of the $6^{\mathrm{-}}$ isomer of ${}_{}{}^{164}{}_{}{}^{}\mathrm{Tm}$ has been studied by gamma-ray spectroscopy with large-volume high-resolution germanium detectors. Levels in ${}_{}{}^{164}{}_{}{}^{}\mathrm{Er}$ belonging to six different bands with ${\mathit{K}}^{\mathrm{\pi }}$=$0^{+}$, $2^{+}$, $0^{\mathrm{-}}$, $2^{\mathrm{-}}$, $5^{\mathrm{-}}$, and $7^{\mathrm{-}}$ are observed in the 5.1 min ${}_{}{}^{164}{}_{}{}^{}\mathrm{Tm}$ decay. Two new levels at 1683.64 and 3302.8 keV and four levels at 1610.5, 1764.1, 1798.8, and 2163.65 keV known from reaction studies in ${}_{}{}^{164}{}_{}{}^{}\mathrm{Er}$ are observed to be populated in the decay. The revised decay scheme of the 5.1 min ${}_{}{}^{164}{}_{}{}^{}\mathrm{Tm}$ based on the present work shows 17 additional γ-ray transitions including eight new transitions with energies 73.0, 199.5, 486.0, 551.5, 624.6, 737.06, 1139.2, and 1317.6 keV, and nine other γ-ray transitions with energies 178.61, 251.0, 299.8, 347.2, 520.3, 1059.4, 1149.6, 1184.3, and 1499.3 keV, in agreement with the results of reaction studies. The results of the measurements are discussed in the light of the known band structure of ${}_{}{}^{164}{}_{}{}^{}\mathrm{Er}$.