Results of the first heat-capacity measurements of free-standing liquid-crystal films are presented. The nature of the $\mathrm{smectic}-A-\mathrm{hexatic}-B$ transition of $n-\mathrm{butyl}-4^{\prime }-n-\mathrm{hexyloxybiphenyl}-4-\mathrm{carboxylate}$ (46OBC) has been studied for films from about ten to thousands of smectic layers thick. Convolution fitting of thick-film results has given values of the critical exponent and amplitude ratio consistent with bulk-sample fitting results. Thin-film heat-capacity anomalies are asymmetric in shape, in contrast to results for thick films.

We have studied spin-polarized deuterium, ${\mathrm{D}}_{\downarrow }$, in the temperature range 0.3 to 0.7 K in a field of 40 kG using electron-spin resonance at 114 GHz. The intrinsic rates for recombination of two D atoms to form ${\mathrm{D}}_2$ on the surface of $l-{}_{}{}^4{}_{}{}^{}\mathrm{He}$ have been measured for both the ortho and para channels. The two rates are approximately equal and when extrapolated to zero field are 1600 times greater than the rates for ${\mathrm{H}}_2$ formation. Doubly spin-polarized deuterium, ${\mathrm{D}}_{\downarrow ,↡}$, has been observed for the first time, with nuclear-spin purities > 0.98 and sample lifetimes as long as 1 h.

A new ultraviolet-irradiation-induced ordered structure is observed for Ca${\mathrm{F}}_2$/Si(111) by angle-resolved photoelectron spectroscopy. The new structure can be viewed as an ordered array of surface $F$ centers and is characterized by a half-filled band extending 0.5 eV below the Fermi level.

Phase transition in $d=3\mathrm{}$ ferromagnetic Ising models with random fields is analyzed directly at the zero-temperature critical point. Critical behavior is extracted from correlation functions averaged over an ensemble of exact ground states obtained with a new integer optimization algorithm. For Gaussian distribution of random fields finite-size scaling demonstrates a continuous phase transition with effective disconnected susceptibility exponent $\tilde{\eta }\approx -0.9\mathrm{}$, correlation-length exponent $\nu \approx 1.0$, and magnetization exponent $\beta \approx 0.05$.

We report the first Knight-shift studies of the heavy-fermion superconducting state. In 5 kOe the Knight shift of muons in superconducting ${\mathrm{U}}_{1-x}{\mathrm{Th}}_x{\mathrm{Be}}_{13}$ remains near the normal-state value for $x=0.033\mathrm{}$, but shows an unexpected strong decrease for $x=0\mathrm{}$. If the pairing is of odd parity, this decrease suggests that the anisotropic order parameter is pinned to the lattice. The qualitatively different behavior for $x=0.033\mathrm{}$ reflects either spin-orbit scattering by Th doping or a change of pairing symmetry.

The report measurements of the upper critical field, $H_{c2\mathrm{}}$, inclined at various angles with respect to the $c$ axis in the heavy-fermion superconductor U${\mathrm{Pt}}_3$. The angular anisotropy observed near $T_c=0.53\mathrm{}$ K cannot be explained quantitatively by presently available theoretical expressions which consider either isotropic or anisotropic pairing. In addition, we find that the anisotropy apparently disappears at $T\sim 200$ mK, only to reemerge at lower temperatures with an opposite sense. We have also studied $H_{c2\mathrm{}}$ in the basal plane of this hexagonal crystal and find no angular dependence within the limits of our measurements.

The electronic spectral density in heavy-fermion metals is determined by use of the periodic Anderson Hamiltonian with interatomic hybridization. The electronic density of states $N\left(\epsilon \right)$ exhibits pronounced structure consisting of a narrow peak centered at the Fermi level and two broad side peaks. These results are used to interpret x-ray photoemission spectroscopy and bremsstrahlung isochromat spectroscopy data. The electronic mass enhancement $\frac{m^{*}}{m}$ is calculated as a function of the intra-atomic Coulomb interaction.

We have studied the optical line shapes of deoxy myoglobin (Mb) and its ligand-bound form (MbCO). Simulations of the observed line shapes using "transform" and time-correlator techniques show the presence of strong coupling to low-frequency modes in MbCO and substantial non-Gaussian inhomogeneous broadening in Mb. The iron-porphyrin disorder parameter in Mb is found to be $\sigma =0.25\mathrm{}$ Å, and the quadratic dependence of the $\pi -{\pi }^{*}$ electronic excitation energy on the iron coordinates is also determined.

The adiabatic conversion of solar electron neutrinos to muon neutrinos via the Mikheyev-Smirnov-Wolfenstein mechanism is discussed as a level-crossing problem. Solutions to the ${}_{}{}^{37}{}_{}{}^{}\mathrm{Cl}$ puzzle obtained numerically by Mikheyev and Smirnov, Rosen and Gelb, and others are shown to form the boundary of the region in the $\delta m^2-{sin}^{2}2\theta$ plane where adiabatic conversion occurs. Most of the region within this boundary is ruled out by the nonzero signal in Davis's experiment. The Landau-Zener description of the adiabatic boundary is employed.

Analytic results are presented for the probability of detecting an electron neutrino after passage through a resonant oscillation region. If the electron neutrino is produced far above the resonance density, this probability is simply given by $〈P_{{\nu }_e}〉\approx {sin}^2{\theta }_0+P_{x}cos2{\theta }_0$, where ${\theta }_0$ is the vacuum mixing angle. The probability is averaged over the production as well as the detection positions of the neutrino and $P_x$ is the Landau-Zener transition probability between adiabatic states. Finally, this result is applied to resonance oscillations within the solar interior.

The problem of calculating the eigenvalues of the Dirac equation by the finite-basis expansion method is studied. Bounds for the eigenvalues are obtained explaining the numerical results on the spectrum that have been observed previously. It is argued that the problem of variational collapse can be avoided by finding the minimum over the wave-function large component of the maximum over the wave-function small component of the energy functional. A numerical example is discussed.

It is proved that charge transport induced by adiabatic variations of an incommensurate potential acting on noninteracting electrons is quantized. The corresponding integers are topological invariants (Chern numbers of various kinds) which label the gaps. Similar results are obtained for electrons in a periodic potential, under the influence of an irrational magnetic field.

A mapping of the unit interval of all realizations of the disorder for a random multiplicative process allows us to show that (a) the flucatuations due to different realizations of the disorder are characterized by a multifractal spectrum and (b) the fluctuations in space for a given realization of the disorder do not possess properties of self-similarity. These results have relevant implications for various physical problems with a multiplicative structure.

In (3 + 1)-dimensional finite-temperature and -density SU(2) gauge theories with left-handed fermions, the three-dimensional Chern-Simons term (topological mass) can be induced by radiative corrections. This result is derived by use of a family's index theorem which also implies that in many other quantum field theories various additional lower-dimensional topological terms can be induced. In the high-temperature limit these terms dominate the partition function, which suggests applications to early-Universe cosmology.

We calculate the rate and the $\mathrm{CP}$-nonconservation asymmetry for the rare decay $B\to K{l}^{+}{l}^{-}$ ($l=e or \mu$). In the standard model with three generations we find the branching ratio to be of the order of ${10}^{-6\mathrm{}}$, and the $\mathrm{CP}$-nonconservation asymmetry at most about 1%. The decay proceeds via the flavor-changing loop structure of the standard model, and unlike $K\to \pi e^{+}{e}^{-}$ suffers few uncertainties and can therefore be used as a probe of new physics. We also comment on other rare decay modes of the $B$ meson.

We calculate the invariant-mass distribution for $\mathrm{pp}\to W^{+}{W}^{-}X$ without using the effective-$W$ approximation.

We construct an impulse operator for pion photoproduction from threshold through the $\Delta$ region, suitable for nuclear use, with improved Born dynamics and unitarity. Taking the example of the reaction ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}(\gamma ,{\pi }^{+}){}_{}{}^{14}{}_{}{}^{}\mathrm{C}(\mathrm{g}.\mathrm{s}.\mathrm{})$, we demonstrate superior features of the amplitude at different energies. At or near the $\Delta$ resonance, very sizable effects arise both from the unitarity and from the refined treatment of the pionic final-state interaction in the $\Delta$-hole approach.

The results of comprehensive distorted-wave impulse-approximation calculations are presented for the reaction ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}({\pi }^{+},K^{+}){}_{\Lambda }{}^{12}{}_{}{}^{}\mathrm{C}$ and compared to recent experimental data. The calculation includes scattering from bound states and resonances plus quasifree scattering in one consistent formalism. The features of the data are reproduced by the calculation, and these features are identified with underlying shell-model configurations.

The observed masses of neutron stars are used to shed some light on the current controversy concerning the value of the nuclear compression modulus. We find that values less than about 200 MeV are incompatible with the observed masses.

It is argued that any estimate of the shape parameter $\gamma$ determined from interacting-boson-model (IBM) wave functions depends on the choice of $\chi$ in the definition of the IBM quadrupole operator $d_{\mu }^{†}s+s^{†}{\tilde{d}}_{\mu }+\chi {\left(d^{†}d\right)}_{2\mu }$. The consequences of different choices are discussed.