Critical scattering predictions of the Percus-Yevick, hypernetted-chain, and Yvon-Born-Green integral equations for fluids are described for general dimensions $d$. The first two equations are unsatisfactory. The Yvon-Born-Green equation predicts critical scattering of Ornstein-Zernike form for $d>\mathrm{}4\mathrm{}$, but for $d<~4$ the compressibility, $K_T$, remains bounded unless the net correlation function, $g\left(r\right)-1\mathrm{}$, becomes negative near criticality for intermediate and large $r$: In that case scaling behavior occurs with $\eta =4-d$ and $K_T\to +\infty$ for $d>\mathrm{}{d}_0\simeq 2.2$.

Measurements of the dynamic structure factor at $Q_0$, the momentum transfer of the first maximum of $S(Q,0\mathrm{})\mathrm{}$, have been made for droplet samples of Sn and Sn + Pb liquid alloys into the supercooled region. It is shown that half-width variations with temperature are inconsistent with expectations from instability theories for the liquid-solid phase transition, but correlate well with changes in atomic diffusivities with alloy composition.

The difference in chemical potential $\delta \mu$ between the $A$ and $B$ phases of superfluid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ has been obtained from measurements of the nuclear susceptibility and of the $A-B$ transition temperature in fields up to 4.4 kG. The effect of strong coupling is found to increase rapidly with pressure.

Internal friction, ultrasonic attenuation, and electric modulus measurements on $\beta$- alumina, which are inconsistent with simple Debye theory, are found to be in good agreement with each other when analyzed with use of the "universal" dielectric response theory. It is suggested that this theory may be used to analyze mechanical relaxation data from other ionic conductors.

A description is given of a novel technique for measuring the thermal resistance ($R_{\mathrm{p}\mathrm{h}-\mathrm{q}\mathrm{u}}$) between phonons and quasiparticles in a bulk sample of dilute mixture of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ in liquid ${}_{}{}^4{}_{}{}^{}\mathrm{He}$. For 0.1% ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ we find $V{R}_{\mathrm{p}\mathrm{h}-\mathrm{q}\mathrm{u}}{T}^{6.5}=3.7\mathrm{}\times {10}^{-11\mathrm{}}$ ${\mathrm{m}}^3$${\mathrm{K}}^{7.5}$ ${\mathrm{W}}^{-1\mathrm{}}$ for $35<T<\mathrm{}60\mathrm{}$ mK, in fair agreement with known interactions between phonons and quasiparticles. The discrepancy, however, suggests an additional, unidentified, inelastic scattering process.

Near a tricritical point of an $n$-component spin system, fluctuations turn the first-order transition (predicted by the Landau theory) into second order. We show that when this happens, quadratic anisotropies turn the transition first order again. In systems which exhibit fluctuation-driven first-order transitions, increasing anisotropies yield two consecutive tricritical points. These effects are predicted to result from the application of magnetic fields or uniaxial stresses to MnO, BaTi${\mathrm{O}}_3$, $\mathrm{K}{\mathrm{Ta}}_x{\mathrm{Nb}}_{1-x}{\mathrm{O}}_3$ (KTN), TbP, etc.

The dispersion and symmetry of the surface states along the $\overline{\Gamma }-\overline{M}$ symmetry line of the W(100) surface Brillouin zone have been determined with use of high-resolution angle-resolved photoemission. Comparison with available calculations shows poor agreement, throwing serious doubts on the role played by the surface states in the W(100) reconstruction.

An exchange-correlation functional for nonuniform electronic systems is developed which provides an easily implementable correction to the local density approximation. It is applied to metallic surface energies, as well as to self-consistent atomic calculations which include the ground-state energies of a number of atoms, plus the removal energies for $1s$, $2s$, $3s$, $4s$, $2p$, $3p$, and $3d$ electrons. In all cases tried a substantial improvement was found.

It is shown that the center of localized orbitals and their symmetry can be deduced from experimental or computational information about the symmetry of Bloch functions at different points in the Brillouin zone.

It is shown that a proper analytic continuation of eigenvalues of a special inhomogeneous eight-vertex system determines the "phases" and the spectrum of a one-dimensional fermion gas model, and thus provides a particular example of the long suspected connection between factorized $S$ matrices and lattice statistical systems.

If electrically or magnetically charged particles of the Planck mass or the grand unification mass exist, a measurable flux of them could be reaching Earth but would probably have remained undetected. However, they should make a signature in a properly instrumented detector array. With a small proportional counter array, upper limits between 0.03 and 0.06 ${\mathrm{m}}^{-2\mathrm{}}$ ${\mathrm{sr}}^{-1\mathrm{}}$ ${\mathrm{d}}^{-1\mathrm{}}$ are set on their flux at velocities between 100 and 350 km/sec.

We have measured the total hadronic cross section of virtual photons incident on carbon, copper, and lead in the region $Q^2=0.01-30\mathrm{}$ Ge${\mathrm{V}}^2$ and $\nu =40-200\mathrm{}$ GeV. A 209-GeV/c muon beam was used as a source of virtual photons. The results indicate shadowing of the virtual photons below $Q^2=1\mathrm{}$ Ge${\mathrm{V}}^2$ and a decrease of shadowing for $Q^2>3\mathrm{}$ Ge${\mathrm{V}}^2$. The shadowing persists to larger $Q^2$ than indicated by experiments at lower $\nu$.

Hadronic collision models based on quantum chromodynamics predict remarkably large cross sections for diffractive scattering of hadrons on a nuclear target. The diffraction arises from the transparency of a nucleus to the portion of the projectile wave function having small transverse separation between its constituents. Correspondingly, the typical transverse momentum within the diffracted system is significantly enhanced. This quantum-chromodynamics-based picture leads to large cross sections for diffractive charm production.

The reaction ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}$($p$,$n$)${}_{}{}^{54}{}_{}{}^{}\mathrm{Co}$ has been studied at $E_p=32, 35, \mathrm{and} 40$ MeV. Two prominent peaks observed at $E_x=5.32\mathrm{} \mathrm{and} 10.23$ MeV are assigned as $1^{+}$ from the energy dependence of cross sections and the angular distribution measurements, and interpreted as the $T=0\mathrm{}$ and $T=1\mathrm{}$ components of the Gamow-Teller giant resonance. They carry 40-50% of the expected strengths. The energies and strengths of these peaks agree with a recent shell-model calculation.

The neutron-proton capture differential cross section has been measured at extreme forward and backward angles for 72-MeV neutron energy corresponding to a $\gamma$-ray energy of 38.2 MeV in the inverse reaction. The results agree well with recent photodisintegration data at forward angles, but only partially with potential model calculations.

We calculate gyrogmagnetic factors of high-spin collective states in three ytterbium isotopes using the Hartree-Fock-Bogolyubov cranking model. Theoretical results for ${}_{}{}^{170}{}_{}{}^{}\mathrm{Yb}$ and ${}_{}{}^{174}{}_{}{}^{}\mathrm{Yb}$ are in good agreement with the recent measurements. In ${}_{}{}^{172}{}_{}{}^{}\mathrm{Yb}$ a greater precision in the measurements is needed to test the calculated decrease of $g$ factors with spin.

The ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$+${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$+${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$ total fusion cross sections have been measured over a laboratory energy range from 10 to 54 MeV. It has been found that the limitation in the fusion cross sections for these systems cannot presently be explained by the properties of the compound nucleus.

Cross-section and analyzing-power angular distributions for elastic scattering of 400-MeV protons by ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ have been measured between 3° and 51°. Results have been compared to second-order Kerman-McManus-Thaler calculations of the optical potential. There is evidence that free nucleon-nucleon scattering amplitudes do not adequately describe nucleon propagation in nuclear matter at this energy.

The controversial results for the fission decay of the isoscalar giant quadrupole resonance in ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ have been investigated by electron- and positron-induced fission experiments ($E_e=10-35\mathrm{}$ MeV). The measured cross-section ratio $\frac{{\sigma }^{-}}{{\sigma }^{+}}$ and absolute cross sections were analyzed with use of available distorted-wave Born-approzimation virtual-photon spectra. Within this analysis no fission decay of the giant quadropole resonance could be detected, in contrast to a recent inclusive electrofission work.

We report the experimental observation of free negatively charged water clusters, i.e., ${{\left({\mathrm{H}}_2\mathrm{O}\right)}_n}^{-}$ with $n>~8$. These species have been postulated to occur in irradiated liquids or high-density vapors—the so-called hydrated electrons—but have never been observed so far in the gas phase.