We report the experimental observation of the inelastic scattering of slow neutrons by two-magnon processes and present theoretical calculations which account for the shape and wave-vector dependence of the spectrum.

We demonstrate an exact equivalence between a Kondo problem and the thermodynamics of a classical one-dimensional gas with alternating charges and a logarithmic potential. This classical gas has a critical point.

By using a functional integral formulation of the theory of itinerant ferromagnets above the Curie point, we show that for strong Coulomb interaction $U$, there are localized moments exhibiting a characteristic Curie-law susceptibility with the correct free spin-½ limiting value of the Curie constant. For weak $U$ the same formulation gives a Pauli-like susceptibility, again with the proper limit, while for intermediate values the theory gives a smooth interpolation between the extreme cases.

A simple explanation of the Kondo effect is shown to follow from a functional integral form of Anderson's dilute-alloy model.

The magnetic-phase diagram, in the $H-T$ plane, of Mn${\mathrm{F}}_2$ was measured using ultrasonic and differential magnetization techniques. The paramagnetic-antiferromagnetic boundary, for $\overrightarrow{\mathrm{H}}$ along the $c$ axis, is well represented by $T_{\mathrm{N}}-T=(1.65\mathrm{}\pm 0.15)\times {10}^{-10\mathrm{}}{H}^2$ °K/${\mathrm{G}}^2$. The triple point is at $T_3=65.1\mathrm{}\pm 0.2°$K and $H_3=120\mathrm{}\pm 4$ kG. The phase boundaries are discussed in light of existing theories.

It is pointed out that the (zero-field) oscillations seen in the decay curves for atoms excited by beam-foil collisions may be due to interference of light from different fine-structure levels; the interference can only be seen, however, if light of different polarizations is detected with different sensitivity.

The specific heat of metallic bismuth has been measured from 0.05 to 0.8 K. The nuclear-quadrupole heat capacity expected from NMR measurements is not observed, allowing a more accurate determination of the electronic specific heat than has been possible previously. A lower limit for the nuclear spin-lattice relaxation time is estimated.

Quantum effects of cyclotron resonance of holes have been observed in tellurium by using high-resolution HCN and ${\mathrm{D}}_2$O submillimeter laser spectrometers. The multiplicity of resonance absorption lines in both parallel and perpendicular directions with respect to the principal axis suggests complex energy surfaces with highly warped bands. In addition, cyclotron resonance of electrons thermally excited across the gap was obtained.

It is shown that in a class of randomly diluted Ising ferromagnets the magnetization fails to be an analytic function of the field $H$ at $H=0\mathrm{}$ for a range of temperatures above that at which spontaneous magnetization first appears.

Proton strength functions were determined from the ($p, n$) reactions for 3- to 5.5-MeV protons on ${}_{}{}^{117,119,120,122,124}{}_{}{}^{}\mathrm{Sn}$. The $3p$ size resonance was found. Optical-model analyses show that the energy dependence in the real well is 3 times greater for 5- to 10- MeV protons than for 10- to 16-MeV protons. The best fit potential for 3- to-5.5 MeV protons has a surface absorptive layer about half as thick as at 10 MeV.

The elastic and inelastic scattering of protons by ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ were studied at bombarding energies from 4.8 to 6.2 MeV. 60 resonances were identified. The spins of most of them and their partial widths for decay to the ground state and to the first four excited states in ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ were determined. Levels in ${}_{}{}^{41}{}_{}{}^{}\mathrm{Sc}$ having configurations with a large two-particle, one-hole component were identified and compared with similar levels in ${}_{}{}^{41}{}_{}{}^{}\mathrm{Ca}$.

The theory of the parity-nonconserving alpha decays from the $2^{-}$ (8.88 MeV), $0^{-}$ (10.937 MeV), and $3^{+}$ (11.05 MeV) ${\mathrm{O}}^{16}$ levels is developed. Using the weak nucleon-nucleon interaction of Blin-Stoyle and Herczeg and known ${\mathrm{O}}^{16}$ wave functions modified by short-range correlations via the Bethe-Goldstone equation, the irregular alpha widths have been related to known regular widths. The influence by the hard core of the strong interaction has been studied.

We present preliminary results of an analysis of the experimental data pertaining to $K^{-}$ capture on complex nuclei. The theory takes explicit account of the ${Y_0}^{*}$ resonance as well as the change in the neutron-to-proton density ratio in going from the nuclear core to the region outside the normal nuclear radius. We obtain results which are in rough accord with experiment, and we conclude that the role of the ${Y_0}^{*}$ cannot be ignored in deducing properties of the nuclear surface.

Electron inertia is predicted to have a dominant influence on ion cyclotron-wave propagation as the wave frequency approaches the ion cyclotron frequency. This influence should effect a reduction in the Stix coil coupling to a plasma column as the plasma density is lowered. Experimental coupling measurements, taken over an appropriate range of plasma density (2×${10}^{10}$ to 2.8×${10}^{12}$ ${\mathrm{cm}}^{-3\mathrm{}}$) on the Model-C stellarator, demonstrate the validity of the theoretical conclusion.

Second order energies and the probabilities of two-particle, two-hole components in the ground states of ${\mathrm{He}}^4$ and ${\mathrm{O}}^{16}$, calculated using perturbation theory in Hartree-Fock bases, show that excitations to high lying levels are more important than the shell model predicts. The importance of these excitations stems from the relative phases of the Hartree-Fock wave functions for unoccupied states and this phase relation can be explained quite simply.

The nuclear magnetic structure of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ has been investigated by 180° scattering of 56.6-MeV electrons. The first observation of the $M1\mathrm{}$ continuum in ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ from 6 to 20 MeV is reported. The $M1\mathrm{}$ component of the breakup from ${}_{}{}^3{}_{}{}^{}\mathrm{He}(e, e^{\prime })d, p$ together with ${}_{}{}^3{}_{}{}^{}\mathrm{He}(e, e^{\prime })p, p, n$ has been measured and is discussed in light of possible isovector and isoscalar meson-exchange currents in the trinucleon system. The elastic magnetic form factor of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ at $q=0.561\mathrm{}$ ${\mathrm{fm}}^{-1\mathrm{}}$ is 0.80, giving a rms magnetic radius $a=1.94\mathrm{}\pm 0.19$ fm.

It is suggested, on the basis of a simplified model of nucleon-antinucleon interaction, that a spatial separation of baryons and antibaryons might occur in the blackbody radiation at very high temperatures, typically larger than $kT=350\mathrm{}$ MeV. Some applications to astrophysical data, like the matter density of the universe and a mechanism for quasistellar objects, are sketched.

Recently evidence has been presented for the production of an $I=\frac{5}{2}$ nonstrange baryon resonance of mass ≅1640 MeV/${\mathit{c}}^2$ in the reaction ${\pi }^{-}d\to \mathrm{}\left(p\right)n{\pi }^{-}{\pi }^{-}{\pi }^{+}$. With much greater statistics, our data for the charge-symmetric reaction fail to show any evidence for such a resonance.

We observed statistically significant peaks in the charged and neutral three-pion mass spectra at the position of the $A_1$ in the reactions $K^{+}p\to K^{0,+}p{\pi }^{+}{\pi }^{-}{\pi }^{+,0\mathrm{}}$ at 12.7 GeV/c. We discuss the possible interpretation of these peaks.

The isoscalar part of the ${\eta }^0$ photoproduction amplitude near threshold has been determined by differential cross-section measurements of the coherent process $\gamma +d\to {\eta }^0+d$ from near threshold to 150 MeV above threshold. By comparison of the results with earlier measurements of $\gamma +p\to {\eta }^0+p$ and a recent measurement of $\gamma +d\to {\eta }^0+(p, n)$ it is possible to argue that the isovector part of the ${\eta }^0$ photoproduction amplitude near threshold is much smaller than the isoscalar part and is consistent with zero.