Results are reported from a study of the impact parameters of electrons in hadronic events produced at the PEP $e^{+}{e}^{-}$ storage ring. Electrons in hadronic events are produced by bottom and charm decay and their impact parameters show hadrons containing bottom quarks to have a lifetime of ${1.16}_{-0.34\mathrm{}}^{+0.37\mathrm{}}$(stat.) ±0.23 (syst.) psec. This result is used to constrain elements of the Kobayashi-Maskawa mixing matrix.

Faddeev calculations for the triton are performed with three two-body potentials (RSC, URG, and Paris) taking eighteen channels, $J<~2$, for an interacting pair. Using these wave functions, we calculate the first-order perturbation energy for the Tucson-Melbourne three-body interaction. For the usual dipole pionic form factor with the cutoff parameter of $\Lambda =800\mathrm{}$ MeV, we get 0.89 MeV (RSC), 0.50 MeV (URG), and 0.67 MeV (Paris). Thus, the calculated triton binding energies amount to 8.13 MeV (RSC), 8.00 MeV (URG), and 8.23 MeV (Paris). These values are very close to the experimental value of 8.482 MeV.

It is demonstrated that in polarized heavy-ion scattering the effects of a second-rank spin-dependent interaction depending quadratically on momentum ($T_P$-type) can be clearly distinguished from the more usual $T_R$-type tensor interaction which depends quadratically on position. A simple criterion involving the ratio of two components of the tensor analyzing power for elastic scattering is proposed, and it is shown that the existing data for ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ scattering from ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$ offer the first evidence for a $T_P$-type interaction in nuclear physics.

It is shown that in any reaction involving, partially or entirely, spin-1 particles, the reaction amplitudes can be completely determined from a set of experiments that does not include measurements of vector polarization for any of the spin-1 particles in the reaction. In this sense, measurements of the vector polarization of the spin-1 particles in the reaction are dispensable. The result is applicable to any nuclear or particle reaction, for example, those containing deuterons, rho mesons, etc.

Precise intrinsic quadrupole and hexadecapole moments of ${}_{}{}^{233,234,235,238}{}_{}{}^{}\mathrm{U}$ have been determined from muonic $K$, $L$, $M$, and $N$ x rays. For ${}_{}{}^{233,235}{}_{}{}^{}\mathrm{U}$ seven $E2$ matrix elements were independently determined. These $E2$ matrix elements are in good agreement with the adiabatic rotational model; this agreement is further improved if a correction for $\Delta K=1\mathrm{}$ band mixing is included. The measured hexadecapole moments are in good agreement with shellcorrection calculations and Hartree-Fock calculations.

The pronounced selectivity of near-threshold ($p$, ${\pi }^{-}$) reactions for high-spin two-particle, one-hole states is exploited, in the first spectroscopic application of a ($p$, $\pi$) reaction, to identify previously unknown $\frac{25}{2^{+}}$ and $\frac{21}{2^{+}}$ ${\left(g_{\frac{9}{2}}\right)}^3$ states in ${}_{}{}^{89}{}_{}{}^{}\mathrm{Zr}$. Relative cross sections for the two transitions are well reproduced by simple model calculations. The analyzing power for the $\frac{25}{2^{+}}$ state is markedly similar to previous ($p_{\mathrm{pol}}$, ${\pi }^{-}$) results for two-particle, one-hole stretched states in lighter nuclei.

The rare double gamma decay of the first excited $0^{+}$ state in ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ and ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ has been measured with a segmented $4\pi$ NaI detector system, which allows suppression of the perturbing background due to positron annihilation in flight. In both cases the directional correlation of the two photons is found to be asymmetric around 90°, which is explained by an interference of $2E1$ and $2M1$ transitions. The deduced $M1\mathrm{}$ quenching factors agree with those from ($e$,$e^{\prime }$) and ($p$,$p^{\prime }$) measurements.

To connect the field and photon points of view we have observed the spectra of Na atoms in the presence of weak to strong microwave fields. Using these spectra and a model based on atomic hydrogen, we connect the previous Landau-Zener description of transitions in strong, temporally varying electric fields to a description based on a photon point of view. In this regime, both descriptions predict similar microwave ionization thresholds.

The presence of fishbone events in the PDX tokamak is correlated with a reduction in the burnup of 0.8-MeV ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ ions. This reduction is probably caused by distortion of the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ drift orbits in the helical magnetic fields associated with the instability, resulting in the loss of about 70% of the confined ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ ions in a moderately strong fishbone. Such a nonresonant loss of particles with large orbits indicates that fishbone events may influence 3.5-MeV alphas in ignition experiments.

Magnetic fluctuations in a dense discharge plasma ($n_e\gtrsim {10}^{11}$ ${\mathrm{cm}}^{-3\mathrm{}}$, $k{T}_e\simeq 7$ eV, $B_0\simeq 10$ G) have been analyzed in frequency ($0<\mathrm{}\omega <3.5\mathrm{}{\omega }_{\mathrm{ce}}$) and wave number by cross-spectral techniques. The fluctuations are found to consist of circularly polarized waves propagating along ${\overrightarrow{\mathrm{B}}}_0$ with dispersion $\omega \simeq \mathrm{kv}$, i.e., they are not whistlers or cyclotron harmonic waves. Measurements of the electron distribution function reveal that magnetic electrons drifting with $v\simeq \frac{\omega }{k}$ along ${\overrightarrow{\mathrm{B}}}_0$ support the modes.

Observations of Raman scattering in laser-produced plasma can be explained by incoherent Thomson scattering, with a greatly enhanced "plasma line." Reversed-slope velocity distributions in the underdense region are produced by hot-electron pulses originating near the quarter-critical surface ($\frac{n_c}{4}$). The model explains the two gaps in the Raman spectrum, the correlation of scattering "onset" with that of instability at $\frac{n_c}{4}$, the "scintillation" in frequency and time, and the weak angular variation. An "upscattered" frequency band is predicted and has been verified by experiment.

The simultaneous excitation of nonlinear ion-acoustic and slow beam-mode waves has been experimentally found to occur in an ion-beam-plasma system. Further, the collision between the two different nonlinear modes is observed to result in the formation of a new mode, probably corresponding to a nonlinear explosive mode theoretically predicted by Yajima, Kono, and Ueda.

We calculate the surface dipolar recombination rate $L_s$ for spin-polarized hydrogen adsorbed on ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ surfaces at temperatures in the 0.2- to 0.6-K regime and for magnetic fields up to 30 T. For a magnetic field of 7.6 T normal to the surface and 0.4 K we find $L_s=1.3\mathrm{}\left(3\right)\mathrm{}\times {10}^{-25\mathrm{}}$ ${\mathrm{cm}}^4$ ${\mathrm{s}}^{-1\mathrm{}}$ increasing by 10%/T in the range of experimental interest. The anisotropy with the direction of the magnetic field is considerably smaller than in the case of the surface dipolar relaxation.

We have measured by light scattering the divergence of the elastic constants $K_2$ and $K_3$ at the nematic-smectic-$A$ transition in the liquid crystals 8OCB, $\bar{8}\mathrm{S}5$, and 8CB over a reduced temperature range ${10}^{-5\mathrm{}}<t<\mathrm{}{10}^{-2\mathrm{}}$. We find critical exponents ${\nu }_{\parallel }$ and ${\nu }_{\perp }$ and power-law coefficients ${\xi }_{\parallel }^0$ and ${\xi }_{\perp }^0$ which agree with values obtained from x-ray scattering within experimental error.

We report the first measurements of the Raman spectra of an alkali ternary-solid-solution graphite-intercalation compound ${\mathrm{K}}_{1-x}{\mathrm{Rb}}_x{\mathrm{C}}_8$, $0<~x<~1$. A broad asymmetric softening of the graphite $M$-point phonon modes is observed at $x\approx 0.67$. This anomaly is attributed to electronic band-structure modifications which alter the electron-phonon contribution to the phonon self-energies and which result from the formation of K${\mathrm{Rb}}_2$-like clusters.

The melting of incommensurate solid ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ monolayers on graphite is studied with a strain gauge sensitive to two-dimensional pressure. The observations are characteristic of first-order transitions broadened by substrate heterogeneity and inconsistent with the calculated behavior of dislocation-mediated melting. These results and other recent experiments raise serious questions as to the completeness of the theory.

Two-dimensional criticality is studied in the Klauder and double-Gaussian $O\mathrm{}\left(1\right)\mathrm{}$ models which interpolate from a Gaussian model at $y=0\mathrm{}$ to the $S=\frac{1}{2}$ Ising model at $y=1\mathrm{}$. Despite strong crossover effects for $0<y\lesssim 0.6$, partial differential approximants for the two-variable susceptibility series indicate criticality of Ising type for all $y>\mathrm{}0\mathrm{}$ and yield a correction exponent $\theta =1.35\mathrm{}\pm 0.25$. The conjecture $\theta =\frac{4}{3}$ in the absence of a related critical operator, and the observation ${\gamma }_{\mathrm{eff}}\simeq 2.0$ in the Klauder, double-Gaussian, and $\lambda {\varphi }^4$ models, are discussed.

Measurements of the pressure and magnetic field dependence of the $A_1$ and $A_2$ transitions in superfluid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ are reported. The $A_1-A_2$ splitting, $T_{A_1}-T_{A_2}$, is nearly a linear function of field over the range 0-9.4 T. For a given field, the observed increase of $T_{A_1}-T_c$ with increasing pressure is in accordance with a recent theory by Bedell and Quader.

The $A_1$ and $A_2$ transitions, which delineate the $A_1$ phase of superfluid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$, are measured in magnetic fields up to 3 T over a wide range of pressures. At zero pressure the $A_1-A_2$ splitting is found to be smaller than at melting pressure by a factor of 5. Strong-coupling effects are similarly smaller by an order of magnitude.

A recently developed Landau description of short-range icosahedral order in supercooled liquids and metallic glasses is used to calculate density correlation functions in these systems. The theory predicts frustration-broadened peaks in the structure factor, at positions determined by the symmetries of an ideal, curved-space icosahedral crystal. The results provide a good fit to experiments on vapor-deposited metal films.