In lattice quantum chromodynamics, the hadronic mass spectrum is evaluated by computer simulations in the approximation where closed quark loops are neglected. Chiral symmetry is shown to be spontaneously broken and an estimate of the pion decay constant is given.

It is shown that in an SU(2) lattice gauge theory, in the approximation where internal quark closed loops are neglected, chiral symmetry is broken. With use of partially conserved axial-vector current $f_{\pi }$, the bare masses of the $u$ and $d$ quarks, and the $\rho$ and $\delta$ masses are estimated.

It is shown that initial-state interactions violate the usual QCD factorization predictions for massive lepton-pair production in leading twist. The initial-state collisions correct $\frac{d\sigma }{d{Q}^2}d{x}_{\mathrm{F}}$ and also smear the lepton-pair transverse momentum distribution.

Measurements of the proton polarization in the reactions ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$(${}_{}{}^3{}_{}{}^{}\mathrm{He}$,$p_{\mathrm{pol}}$)${}_{}{}^9{}_{}{}^{}\mathrm{Be}$ and ${}_{}{}^9{}_{}{}^{}\mathrm{Be}$(${}_{}{}^3{}_{}{}^{}\mathrm{He}$,$p_{\mathrm{pol}}$)${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ and of the analyzing powers of the inverse reactions, initiated by polarized protons at the same c.m. energies, show significant differences which imply the failure of the polarization-analyzing-power theorem and, prima facie, of time-reversal invariance in these reactions.

The predictions of a variety of current theoretical models of high-energy nuclear collisions are compared with recent experimental data for central collisions of ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ on ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ at $E_{\mathrm{lab}}=393\mathrm{}$ MeV/u. The experimental observation of broad sideward maxima in the angular distributions of low- and medium-energy protons is reproduced by a nuclear fluid-dynamical calculation with final freezeout of the protons. In contrast, the current intranuclear-cascade and simplified collision models predict forward-peaked angular distributions.

The spin rotation parameter $Q$ has been measured for $p$-${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ elastic scattering at 497 MeV for $0.01<~-t<~0.15$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ with use of the new high-resolution spectrometer focalplane polarimeter. In conjunction with analyzing power and differential cross section, this measurement uniquely determines the elastic scattering amplitudes up to an arbitrary phase. A parameter-free analysis within the Glauber diffractive approximation with use of $N-N$ phase-shift solutions is presented.

Deuteron electromagnetic form factors are calculated in the relativistic impulse approximation for $q^2<~6$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$. Shift in the proton-neutron relative momentum due to Lorentz transformation to the deuteron rest frame is shown to be the most important relativistic kinematical effect. A new treatment of this effect results in a remarkable agreement with the available data. Predictions are made for the tensor polarization in ed elastic scattering. These differ markedly from the standard results.

Empirical values of $\frac{E2}{M1}$ mixing ratios in even-even deformed nuclei are compared with the predictions of the interacting-boson-approximation (IBA) model. It is shown that the IBA results are equivalent to those obtained from a geometrical approach, and also lead to certain unique predictions concerning the relative magnitudes and signs of the $\delta \left(\frac{E2}{M1}\right)$ values. The application of the IBA $M1$ operator in other regions is also discussed.

Recently derived data-to-data (DTD) relations have been applied to elastic and inelastic scattering of 800-MeV protons from ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ and ${}_{}{}^{92}{}_{}{}^{}\mathrm{Zr}$. Significant differences between the cross sections for the $2_1^{+}$ and $4_1^{+}$ states in the two nuclei suggest that DTD relations between elastic and inelastic cross sections are inadequate. Nevertheless, the DTD relation which predicts the analyzing power ($A_y$) from the cross section for inelastic transitions yields excellent agreement with the data. The physical significance of the fitting parameters is discussed.

An experiment is reported in which an intense laser is used to cause the intercombination transfer of metastable $1s2s2p{}_{}{}^4{}_{}{}^{}P_{\frac{5}{2}}^{}{}_{}{}^{}$ atoms to the $1s2p^2{}_{}{}^2{}_{}{}^{}P_{\frac{3}{2}}^{}{}_{}{}^{}$ level with subsequent radiation in the extreme ultraviolet, thereby providing the first direct tie between the quartet and doublet manifolds in neutral Li. Intercombination transfer between the triplet and singlet manifolds of ${\mathrm{Li}}^{+}$ and tunable anti-Stokes radiation centered near 199 Å are also described.

Rotational-state distributions have been measured for the first time in molecules thermally desorbed from a metal single crystal. Laser-excited fluorescence has been used to monitor, under ultrahigh-vacuum conditions, the desorption of NO from Ru(001). The population distribution for those states with less than 400 ${\mathrm{cm}}^{-1\mathrm{}}$ of rotational energy (including spin) can be represented by a single Boltzmann factor, $T_{\mathrm{rot}}=235\mathrm{}\pm 35$ K, significantly lower than the surface temperature at the desorption maximum, $T_S=455\mathrm{}\pm 20$ K.

A tandem-mirror plasma has been sustained and heated by rf alone without the need for neutral beams. End plug density and energy are maintained by ion cyclotron-resonance heating which traps and heats a fraction of the central-cell loss stream. The central-cell plasma is maintained by gas fueling and rf heating. Magnetohydrodynamic stability limits the ratio of the central-cell to plug plasma pressure, and the central-cell electron temperature must be kept high enough for ionization. A quasi steady state is achieved that lasts much longer than the decay times of the plugs and central cell.

A model describing the relaxation dynamics of an interface of Ising-like systems is introduced. By means of renormalized field theory in $d=1+\epsilon$ dimensions the dynamic critical exponent is found as $z=2+\epsilon -\frac{1}{2}{\epsilon }^2+O\left({\epsilon }^3\right)$. Interpolation with the known result near four dimensions yields good agreement with a high-temperature expansion and with recent real-space and Monte Carlo renormalization-group calculations in two dimensions.

A universal description of the low-energy properties of one-dimensional quantum fluids, based on a harmonic theory of long-wavelength density fluctuations with use of renormalized parameters, is outlined. The structure of long-distance correlations of a spinless fluid is obtained, showing the essential similarity of one-dimensional Bose and Fermi fluids. The results are illustrated by application to the one-dimensional Bose fluid with $\delta$-function interaction.

This paper presents the results of Monte Carlo simulations of a pseudoatom model of the liquid-metal-vapor interface. The surface density profile is found to have stable density oscillations, with spacing about one atomic diameter, extending several layers into the bulk liquid. This effect is ascribed to the presence of the "structure-independent" electronic energy, which is characteristic of simple metals, in the effective Hamiltonian for the classical pseudoatoms.

The temperature dependence of the structure factor of glassy ${\mathrm{As}}_2$${\mathrm{Se}}_3$ has been measured. Surprising results were found for the first peak, which shows a large increase in intensity from 40 K to the glass transition temperature, $T_g$; in contrast the second peak decreases in this range. The first peak corresponds to interlayer correlation in the glass. Its increase indicates a smoothing of the layers which may lead to layers slipping past one another, thus decreasing the viscosity above $T_g$.

SQUID measurements of susceptibility $\chi$ versus field $H$ are fitted by $\chi ={\chi }_0-{\chi }_1{H}^{a-1\mathrm{}}$ at a given temperature $T$, for two classic spin-glasses: 4.6% Mn in Cu (polycrystalline) and 37% Gd in Al (amorphous). ${\chi }_1\mathrm{}\left(T\right)\mathrm{}$ shows a much stronger anomaly than ${\chi }_0\mathrm{}\left(T\right)\mathrm{}$, while $a\mathrm{}\left(T\right)\mathrm{}$ has a minimum at the freezing temperature $T_f$. The data can also be scaled according to ${\chi }_0-\chi =H^{\frac{2}{\delta }}f\left(\frac{(T-T_f)}{H^{\frac{2}{\varphi }}}\right)$ with $\delta =5\mathrm{}\pm 1$ and $\varphi =4.5\mathrm{}\pm 0.5$.

The spatial distributions of temperature and density in electron-hole plasmas in surface-excited semiconductors are investigated with use of linear irreversible thermodynamics and a microscopic plasma theory. Above a certain threshold the density distribution is dominated by a characteristic density, which increases with temperature. Experimental results for Ge, unstressed Si, and Si under high uniaxial stress are in agreement with the theory.

The first observation of EPR of electrons at dislocations in Ge is reported. Under optical excitation two sets of lines are detected: four lines about the $〈111〉$ axes with $g_{\parallel }=0.34\mathrm{}$ and $g_{\perp }=1.94, \mathrm{and} 24$ lines with $g_{\parallel }=0.73\mathrm{}$ and $g_{\perp }=1.89\mathrm{}$ about $〈111〉$ axes with a sixfold 1.2° distortion. The lines persist for hours after excitation and are inverted in sign.

A new double Penning trap structure has been built which permits one to trap a positron in a well-compensated experiment trap where measurements have yielded the geonium positron $g$-factor anomaly, $\frac{g\left(e^{+}\right)}{2}-1\mathrm{}\equiv a\left(e^{+}\right)=(1\mathrm{}159652222\pm 50)\times {10}^{-12\mathrm{}}$. The uncertainty is based on the resonance linewidths and an estimate of the remaining systematic error associated with extrapolating to zero spin-flip power. By comparison to the electron-spin anomaly, a positron/electron $g$-factor ratio of 1 + (22±64)×${10}^{-12\mathrm{}}$ is obtained.