A model for magnetic impurities in metals is introduced and solved exactly. It treats longitudinal impurity-electron coupling in the long-time approximation of the x-ray threshold problem and treats transverse spin-density operators in a fermion representation. For antiferromagnetic coupling, the magnetization in field $H$ vanishes as $H^{2J_{\parallel }}$ and saturates when $H$ is of order ${\left(\frac{J_{\perp }^{}{}_{}{}^2}{J_{\parallel }}\right)}^{\frac{1}{2}{J}_{\parallel }}$ $J_{\parallel }$ and $J_{\perp }$ are longitudinal and transverse exchange constants). For ferromagnetic coupling, the free moment is only slightly renormalized.

The wavelength-modulated absorption and reflection spectra of SrTi${\mathrm{O}}_3$ have been measured as functions of temperature. Over a 60-K temperature range around the structural phase transition the band gaps of both high- and low-temperature phases are observed simultaneously. This effect and an associated band-gap shift are attributed to the fluctuations at the second-order phase transition.

A 20% peak in the thermal resistivity $w$ is observed in the temperature interval 7 to 12°K for CeAl, an antiferromagnet with a Néel temperature of 9.5°K. The maximum value of $w$ occurs above $T_{\mathrm{N}}$ at about 9.8°K, while the slope $\frac{\mathrm{dw}}{\mathrm{dT}}$ has a positive peak at $T_{\mathrm{N}}$. This is the first experimental evidence for a divergent $\frac{\mathrm{dw}}{\mathrm{dT}}$ in a metallic magnet. The Lorentz number has a monotonic temperature dependence with $\frac{\mathrm{dL}}{\mathrm{dT}}$ maximum at $T_{\mathrm{N}}$.

We propose a new phonon relaxation mechanism, in which the phonon couples to two electronic excitations, nearly resonant in energy. As a striking illustration of this effect we explain the anomalous temperature dependence of the linewidth of the $\overrightarrow{\mathrm{k}}$, $E_g$ phonon in Co${\mathrm{F}}_2$ by its coupling to physically renormalized exciton-magnon states which detune with increasing temperature.

The lifetime and the $g$ factor of the ${19/2}^{-}$ three-quasiparticle isomeric state ${|{\left(\nu f_{\frac{7}{2}}\right)}_{6^{+}}^2-(\pi f_{\frac{7}{2}}\left)\right|}_{{\frac{19}{2}}^{-}}$ in ${}_{}{}^{43}{}_{}{}^{}\mathrm{Sc}$ have been measured. Both the time-differential perturbed-angular-distribution and the stroboscopic-resonance methods were used in the $g$-factor determination. The results obtained are $\tau =0.65\mathrm{}\pm 0.02$ μsec and $g({\frac{19}{2}}^{-},{}_{}{}^{43}{}_{}{}^{}\mathrm{Sc})=+0.331\mathrm{}\pm 0.002$. The $g$ factor of the $f_{\frac{7}{2}}$ proton, deduced from present results combined with the $g$ factor of the $6^{+}$ state in ${}_{}{}^{42}{}_{}{}^{}\mathrm{Ca}$, is discussed.

The possible excitation of nuclear deformation (beta) vibrations in muonic tungsten is described as being due to a near degeneracy between muonic and nuclear states. The model calculations indicate that this effect may be verified by observing the $E2\mathrm{}$ nuclear de-excitation $\gamma$ rays.

The zenith-angle distribution of high-energy cosmic-ray muons has been further investigated using a sample of 2 × ${10}^5$ muons observed in the Utah underground detector. The data have been analyzed in such a way that the angular dependence can be extracted without substantial sensitivity to the parameters of cosmic-ray phenomenology. The zenithangle distribution is flatter than expected on the basis of muon production via pion and kaon decay. An isotropic component (of unspecified origin) is required which rises to a maximum contribution of about 0.5 of the vertical intensity in the muon energy range 1-3 TeV and threafter decreases.

In order to test the possibility of explaining Utah's observed underground muon deficit at large zenith angles on the basis of rock density anomalies, a portable cosmic ray telescope was set up at five different locations under the beam line of the large Utah neutrino detector. The main rock density above each station could be accurately inferred from the observed vertical intensity. If the resulting values are incorporated into the Utah data, the existence of an isotropic muon component, as inferred from the Utah extrapolations, seems to be substantiated.

The total cross section is computed for the resonant process ${\mu }^{\pm }+Z\to {\mu }^{\pm }+Z+B^0\to {\mu }^{\pm }+Z+(\mathrm{hadrons} or \mathrm{leptons})$, where $B^0$ is the hypothetical massive spin-1 boson of electromagnetic interactions, proposed by Lee and Wick, and where $Z$ is either a proton or Fe. Only those diagrams in which the $B^0$ is emitted by the muon are calculated.

We report measurements of the cyclotron effective mass of AgBr as a function of the temperature, which show a temperature dependence given by $m^{*}\mathrm{}\left(T\right)=m^{*}\mathrm{}\left(0\right)+\mu \exp (-\frac{\theta }{T})$. The quantities $\mu$ and $m^{*}\mathrm{}\left(0\right)\mathrm{}$ are expressed in units of the free electron mass; $\mu$ is sample dependent and on the order of 1, $m^{*}\mathrm{}\left(0\right)\mathrm{}$ is between 0.286 and 0.289, and the activation temperature $\theta$ is ≅80°K. This result can be interpreted as arising from a resonant electronphonon interaction between an electron in the conduction band of the crystal and a bound impurity state mediated by a LA phonon.

The ferroelectric phase of K${\mathrm{H}}_2$P${\mathrm{O}}_4$ and the antiferroelectric phase of N${\mathrm{H}}_4$${\mathrm{H}}_2$P${\mathrm{O}}_4$ vanish at hydrostatic pressures >17 and 33 kbar, respectively. The results are qualitatively discussed in terms of the coupled proton-lattice model developed by Kobayashi and others, and they reemphasize the important role of the hydrogen bond in these crystals. We discuss possible important changes with increasing pressure in the character of the ferroelectric mode in K${\mathrm{H}}_2$P${\mathrm{O}}_4$.

The isospin-forbidden reaction ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}(d,{\alpha }_2){}_{}{}^{10}{}_{}{}^{}\mathrm{B}\mathrm{}(1.74,T=1)\mathrm{}$ was investigated for $E_d=14.0\mathrm{} \mathrm{to} 17.0$ MeV. Several full angular distributions were obtained and the excitation function from $E_d=16.0\mathrm{} \mathrm{to} 17.0$ MeV was measured at ${\theta }_{\mathrm{lab}}=152\mathrm{}°$. In the light of these new data, it is clearly not sufficient to interpret the reaction in terms of simple compound-nucleus formation, as seemed to be indicated in previous investigations.

In contrast to earlier measurements reporting a large negative quadrupole moment for the $2^{+}$ state in ${\mathrm{Cd}}^{114}$ near the rotational model value of -0.65e b, new detailed investigations of the reorientation effect in ${\mathrm{Cd}}^{114}$ yield $Q_{2^{+}}=(-0.28\mathrm{}\pm 0.09)$e b with $B(E2;0\mathrm{}\to 2)=(0.513\pm 0.005)$${\mathit{e}}^2$ ${\mathrm{b}}^2$, or $Q_{2^{+}}=(-0.03\mathrm{}\pm 0.09)$e b with $B(E2;0\mathrm{}\to 2)=(0.512\pm 0.005)$${\mathit{e}}^2$ ${\mathrm{b}}^2$. For ${\mathrm{Cd}}^{110}$, $Q_{2^{+}}=[-(0.42\mathrm{} or 0.21)\pm 0.10]$e b with $B(E2;0\mathrm{}\to 2)=(0.432\pm 0.006)$${\mathit{e}}^2$ ${\mathrm{b}}^2$.

Experimental results are reported for the neutron polarization from the reaction $\mathrm{D}\mathrm{}(d,n)\mathrm{}{}_{}{}^3{}_{}{}^{}\mathrm{He}$ at 0° with the incoming beam polarized to the extent $p_3=p_{33}\approx 0.82$ perpendicular to the direction of motion, where $p_3$ and $p_{33}$ are components of vector and tensor polarizations, respectively. The measured neutron polarization varies in the range 0.65 to 0.72 for $E_d$ in the range 4.1 to 15.1 MeV. The measurements are consistent with a process in which the neutron spin suffers little interaction. The influence of the deuteron $D$ state is noted. Comparison is made to several other sources of polarized neutrons, with the conclusion that near $E_n=10\mathrm{}$ MeV this process is outstanding.

The ${}_{}{}^{232}{}_{}{}^{}\mathrm{Th}$ neutron-capture cross section has been measured from 20 to 30 keV on the Physics-8 underground explosion. Resonance parameters and systematics for $s$-wave and $p$-wave levels that were obtained in the resolvable region, to 2000 eV, were used directly to calculate the average cross sections in the unresolved region. These calculations were in good agreement with the measured cross section. Our results do not support the Porter-Thomas postulate for single-channel reactions.

The process $\gamma +p\to {\pi }^{+}+n$ has been studied with 12-GeV linearly polarized photons for momentum transfer $t$ from - 0.04 to - 1.0 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$. The experiment used a coherent bremsstrahlung beam produced by a diamond crystal. The measured asymmetry, $\frac{(d{\sigma }_{\perp }-d{\sigma }_{\parallel })}{(d{\sigma }_{\perp }+d{\sigma }_{\parallel })}$, is positive throughout this $t$ range and is similar to measurements at lower energies.

Positive pion electroproduction data are compared to predictions of the vector-meson-dominance model. Reasonable agreement is found for all parts of the cross section, except for the longitudinal-transverse interference term.

In a recent Letter on the hyperfine shifts in HeH the conclusion was reached that the hyperfine shift is never negative, even at the largest separations. This conclusion, which is in disagreement with fundamental ideas regarding the role of the van der Waals interaction in hyperfine pressure shifts, is traced to an uncritical use of Brillouin's theorem. Upon making the necessary corrections, we obtain a long-range negative shift of proper magnitude.

The radial localization of trapped-particle instabilities is studied for a peaked diamagnetic-frequency profile and for a realistic profile. In the later case it is shown that modes can be excited only with a high radial wave number. The correspondingly reduced coefficient of turbulent diffusion is computed for the collisionless instability.

We exhibit the exact ground state and the corresponding binding energy of the system composed of $N$ (nonidentical) quantum-mechanical particles interacting in one dimension via the potential $V_{\mathrm{ij}}(x_i-x_j)=g{(x_i-x_j)}^{-2\mathrm{}}+(f_i-f_j){(x_i-x_j)}^{-1\mathrm{}}$. We discuss some special choices of the constants $f_i$ and $g$ that yield examples of possible physical interest.