The differential cross sections of proton-pickup reactions on ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ initiated by various heavy-ion projectiles have been uniformly analyzed in a distorted-wave Born-approximation model. There appears to be a spectroscopic-factor inconsistency depending on whether an odd-odd or an even-even nucleus (projectile or ejectile) participated in the reaction.

Long-lived metastable ${\mathrm{He}}_2^{-}$ negative ions have been observed for the first time. They were produced from ${\mathrm{He}}_2^{+}$ by two-step electron capture in a Cs vapor target. The apparent autodetachment decay rates have been measured at several delay times after formation, and indicate the presence of more than one state, with the lifetime of the major component exceeding 100 μs. The most likely configurations are ${{}_{}{}^4{}_{}{}^{}\Sigma _g^{}{}_{}{}^{}}^{+}$ and/or ${}_{}{}^4{}_{}{}^{}\Pi _g^{}{}_{}{}^{}$ states bound below ${\mathrm{He}}_2\left({{}_{}{}^3{}_{}{}^{}\Sigma _g^{}{}_{}{}^{}}^{+}\right)$.

By concentrating on the total electric polarization at the frequency of a wave generated by a coherent nonlinear optical process, the author extends the treatment of Bloembergen and Pershan to show that anomalously small multiphoton excitation is a consequence solely of Maxwell's equations, with no recourse to a quantum mechanical treatment of the nonlinear medium's polarization response to applied electric fields.

The theory of three-body bound states for particles moving on a lattice and interacting with attractive two-body pointlike potentials is presented. The applications are to bosons, fermions (no three-body bound states are found), and magnons. When a three-body bound state forms in three dimensions, it does so discontinuously. Thus there is a maximum size for the three-body bound state, of approximately two lattice constants. Some of the various analyses are relevant to magnetism and superconductivity.

X-ray reflectivity from the surface of a nematic liquid crystal is interpreted as the coherent superposition of Fresnel reflection from the surface and Bragg reflection from smectic order induced by the surface. Angular dependence of the Fresnel effect yields information on surface structure. Measurement of the intensity of diffuse critical scattering relative to the Fresnel reflection yields the absolute value of the critical part of the density-density correlation function.

Accurate interferometric line-shape data have been obtained for the pure vibrational ($Q$ branch) component in the Raman spectrum of supercritical ${\mathrm{N}}_2$. The data were obtained as a function of reduced temperature [$\epsilon =\frac{(T-T_c)}{T_c}$] under isochoric conditions, and analysis of the data clearly shows for the first time that inhomogeneous broadening is dominant when $\epsilon <0.001\mathrm{}$ at the critical density. It is proposed that in this static dephasing limit it should be possible to extract information pertaining to the statistical distribution of "local" densities within the fluid.

Linear arrays of damped multistable systems in a constant driving field $F$ are considered in the continuum limit. The existence of a universal localized relaxation mode ("inertia mode") of the driven kinks is explicitly proven. This mode, of frequency $\omega =\frac{-i\eta }{m}$, collapses in the undamped ($\eta \to 0$) free ($F\to 0$) chain into the Goldstone mode of the corresponding "free kink," and in a chain without inertia ($m\to 0$) it relaxes instantaneously.

The magnetic moment of oligatomic Ni(111) films on Re(0001) was measured in ultrahigh vacuum at 320 K, where they became ferromagnetic above 2.5 atomic layers. The magnetic moment increased when Ni(111) was coated by Pd(111) or prepared on a Pd(111) interlayer. Apparently, the Pd film is magnetized, by contact with Ni(111), with roughly $0.1{\mu }_{\mathrm{B}}$ per atom in the first five monolayers of the Pd coating or $0.2{\mu }_{\mathrm{B}}$ per atom in the last seven monolayers of the Pd interlayer. The measurements give some indication of ferromagnetic live layers, which might appear for $T<\mathrm{}180\mathrm{}$ K on top of pure Pd(111) films prepared on Re(0001).

The predictions of dynamic scaling theory are shown to be in disagreement with the observed wave-vector and temperature dependence of the inelastic neutron scattering from iron and nickel above $T_c$, outside the region of small wave vectors. This breakdown becomes particularly severe when the characteristic energy of the fluctuations becomes comparable to $\mathrm{kT}$, which occurs at considerably smaller reduced wave vectors for metallic ferromagnets such as Fe, Co, and Ni than for Heisenberg insulators such as EuO.

The dynamics of exciton screening in CuCl, following optical injection of a high-density hot plasma, is studied with subpicosecond resolution. A delayed response for exciton bleaching of ∼1 ps is attributed to thermal relaxation of the plasma. The results are compared to a theoretical treatment of the particle density- and temperature-dependent dielectric function.

The authors compute the temperature $T$ dependence of the upper critical field $H_{c^2}$ arising from incipient localization effects in highly disordered three-dimensional superconductors. In agreement with experiments, $H_{c^2}\mathrm{}\left(T\right)\mathrm{}$ is enhanced over the standard result for dirty superconductors. This enhancement is due to the field-induced suppression of localization. It is demonstrated that properties of $H_{c^2}\mathrm{}\left(T\right)\mathrm{}$ are intimately connected to those of the magnetoresistance. This connection and other predictions of the authors' theory can be tested experimentally.

The quantum mechanical expression for the current density is a function of the external vector potential. As a result, the sources of $\overrightarrow{\mathrm{A}}\left(\overrightarrow{\mathrm{r}}\right)$ can induce spurious sources of $\overrightarrow{\mathrm{j}}\left(\overrightarrow{\mathrm{r}}\right)$, if the wave functions are not carefully chosen. The ideal infinite solenoid is given as an example, and boundary conditions which enforce momentum conservation across the solenoid wall are introduced. As a consequence of these boundary conditions, the wave function in the exterior region is not, in general, single valued; it is a single-valued function multiplied by the well known Dirac phase factor.

The inclusive production cross sections and mean multiplicities of ${\pi }^{\pm }$, $K^{\pm }$, $p$, and $\overline{p}$ in $e^{+}{e}^{-}$ annihilation at a c.m. energy of 29 GeV have been measured with the time-projection chamber at PEP, using ionization energy loss to separate particle types. On average, 10.7±0.6 ${\pi }^{\pm }$, 1.35±0.13 $K^{\pm }$, and 0.60±0.08 $p$,$\overline{p}$ are contained in an annihilation event. The fraction of pions among final-state particles decreases from over 95% at 0.3 GeV/c momentum to about 60% at high momentum; the kaon and proton fractions rise correspondingly.

The magnetic moment of the ${\Xi }^{-}$ hyperon has been measured to be $\mu \left({\Xi }^{-}\right)=-0.69\mathrm{}\pm 0.04\pm 0.02$ nuclear magnetons, where the uncertainties are statistical and systematic, respectively.

The question whether the $\xi \mathrm{}\left(2.2\right)\mathrm{}$ recently discovered in $\frac{J}{\psi }\to \gamma +\xi$ can be a Higgs boson in a nonminimal Higgs scheme is discussed. It is pointed out that a search for $\xi$ in $B$ decays provides a critical test.

Measured fragment angular distributions for ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$- and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$-induced fission are compared to calculations assuming $K$ to be determined at the saddle point and using moments of inertia from calculated saddle-point shapes with diffuse surfaces. These calculations are consistent with experimental angular distributions in those cases where the fission barrier is comparable to or greater than the temperature at the saddle point. When the temperature exceeds the barrier height, the overall agreemtn with experiment is poor.

The authors calculate effects of direct meson-${\Delta }_{33}$ interactions on pion double charge exchange to isobaric analog states in ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$. Virtual ${\Delta }_{33}$'s in the ground, state are shown to contribute negligibly, contrary to recent expectations. On-shell ${\Delta }_{33}$ interactions can have a large effect through $\pi +\rho$ exchange, and inclusion of these terms improves agreement with experiment below resonance. Data at the higher energies cannot be explained by a simple combination of sequential pion-nucleon scattering plus direct meson-${\Delta }_{33}$ terms.

This paper reports the first measurement of the tensor polarization $t_{20}$ in $e-d$ elastic scattering. The polarization of the recoil deuterons was measured for two values of momentum transfer, $q=1.74\mathrm{} \mathrm{and} 2.03$ ${\mathrm{fm}}^{-1\mathrm{}}$, with a high-efficiency polarimeter. The results are in good agreement with reasonable models for the deuteron.

The thermal impulse produced along the path of an ultraheavy nucleus (e.g., uranium) moving in a pyroelectric material is shown to generate a fast electronic current pulse. Detectors have been made utilizing the pyroelectric response of polyvinylidene fluoride and lithium tantalate. The theory behind this new class of charged particle detectors and experimental results are presented. Polyvinylidene fluoride detectors may become useful in large-area space experiments for detection and trajectory determination of ultraheavy nuclei.

In the resonant formation of $\mathrm{dt}\mu$ mesonic molecules, the incoming orbital and molecular angular momenta contribute in an essential way. The earlier calculation of Vinitsky et al. for the resonant molecular formation rate is generalized to incorporate these effects, and the resultant contributions of hundreds of resonances are included. The muon cycling rate is calculated and compared with recent experimental results.