The power of electromagnetic radiation from a current-carrying loop of superconducting string is much greater than that given by a naive estimate. Most of the radiation originates near the cusps where the string velocity reaches the speed of light, and is emitted in short and sharply directed pulses.

We present a manifestly covariant Parisi-Sourlas field theory of relativistic point particles with arbitrary Lorentz-invariant self-interactions.

We show that a ${\mathrm{Z}}_2$⊗${\mathrm{Z}}_3$ symmetry leads to the radiative generation of naturally small Dirac neutrino masses in a class of superstring theories. This model realizes in a simple and consistent way a recent suggestion by Masiero, Nanopoulos, and Sanda.

Angular correlations in the cascade reaction $e^{+}$$e^{\mathrm{-}}$→Υ(2S)→γ${\chi }_b$, ${\chi }_b$→γΥ, Υ→${\mu }^{+}$${\mu }^{\mathrm{-}}$ or Υ→$e^{+}$$e^{\mathrm{-}}$, have been used for the first time to investigate the spins of the ${\chi }_b$ states. The results support the ${\chi }_b$ spins predicted by the potential models of heavy quarkonia.

We compute longitudinal and scalar multipoles in the ${\gamma }_v$N→Δ transition in nonrelativistic quark shell models as a function of the virtual-photon mass squared. We show that the gauge relation between these multipoles for arbitrary virtual-photon mass squared is violated in the truncated quark–shell-model basis. The computed scalar multipole, insensitive to this truncation effect, should provide an accurate test of quark models. Existing experiments support the role of color-magnetic tensor force in hadronic structure.

A new manifestation of the Berry phase is presented in theory of fast-rotating superfluid nuclei: diabolic pair transfer, i.e., oscillation of the pair-transfer matrix elements as a function of the angular velocity, is shown to be the direct consequence of the Berry phase, giving a nontrivial contribution at the diabolical points of cranked Hartree-Fock-Bogoliubov spectra.

Several rotational bands have been populated to high spin in the γ-soft nucleus ${}_{}{}^{131}{}_{}{}^{}\mathrm{La}$. We present expreimental evidence for a collective oblate rotational band based on a π${\mathrm{h}}_{11/2}$⊗(ν${\mathrm{h}}_{11/2}$${)}^2$ three-quasiparticle configuration. It is the rotational alignment of the pair of neutrons from the upper ${\mathrm{h}}_{11/2}$ midshell which drives the nucleus from a prolate (γ=0°) shape to a collectively rotating oblate (γ=-60°) shape. This band coexists with a prolate band that contains a pair of aligned protons from the lower ${\mathrm{h}}_{11/2}$ midshell.

The first high-resolution study of weakly bound cluster ions is reported. The millimeter- and submillimeter-wave rotational spectra of ${\mathrm{ArH}}_3$${\mathrm{}}^{+}$ and ${\mathrm{ArD}}_3$${\mathrm{}}^{+}$ have been observed in a magnetically confined, liquid-nitrogen–cooled glow discharge and a partial molecular structure has been derived from their analysis. ${\mathrm{ArH}}_3$${\mathrm{}}^{+}$ appears to be planar, with the Ar atom lying on a symmetry axis of the ${\mathrm{H}}_3$${\mathrm{}}^{+}$ equilateral triangle, 2.38 Å from the ${\mathrm{H}}_3$${\mathrm{}}^{+}$ centroid. SPlitting of some of the lines is strong evidence for tunneling motion.

Using three new coincidence experiments to study the dynamics of double photoionization of a complex atom we demonstrate that (1) indirect processes contribute up to 20% of the double ionization of Ar near threshold and (2) the population of final states depends on the symmetry of the electron-pair wave function as correctly predicted by the theory. The energy distribution of the photoelectrons is found to be essentially flat at 12.7 eV above threshold.

The first determination of the electric dipole moment of a molecular ion is reported. A tunable far-infrared laser was used to measure the Zeeman effect in low-J rotational transitions of ${\mathrm{ArH}}^{+}$ and ${\mathrm{ArD}}^{+}$, and the dipole was determined from the isotopic dependence of ${\mathrm{g}}_{\mathrm{r}}$. The result (μ=1.4±0.4 D) is in marginal agreement with ab initio calculations (2.2 D). It is shown that this method can ultimately provide molecular-ion dipole moments accurate to within a few percent. The adiabatic internuclear separations of both isotopes were also determined from the ${\mathrm{g}}_{\mathrm{r}}$ values.

The problem of two magnetic moments in a Fermi gas is studied with the numerical renormalization group used by Wilson for the Kondo problem. Even when the interaction energy of the moments is much smaller than the Kondo energy, the asymptotic low-temperature behavior is that of a correlated Kondo effect. An effective Hamiltonian for the low-temperature properties, which are nonuniversal, is deduced.

The string tension of spacelike Wilson loops is computed in SU(3) lattice gauge theory in the high-temperature deconfined phase. Its physical value is extracted following the continuum limit. An upper bound for the length scale where nonperturbative fluctuations become dominant is computed. The value of the string tension and the nonperturbative length scale are very close to their zero-temperature counterparts.

A resolution of one of the major dilemmas of preon dynamics, i.e., why ($m_q$,$m_l$)≪(1/$r_0$)≡${\Lambda }_0$, is provided. In a class of models, supersymmetry (SUSY) in its local rather than global form permits a breaking of SUSY and also a generation of composite-fermion masses, but both with a severe damping by powers of (${\Lambda }_0$/$M_{\mathrm{Planck}}$).

The polarization and magnetic moment of the ${\Sigma }^{+}$ hyperon have been measured for 137?0 ${\Sigma }^{+}$→p${\pi }^0$ decays from ${\Sigma }^{+}$ produced at 5 mrad by 400-GeV/c protons on Be. The polarization averages 24% in the range 140 to 350 GeV/c and is opposite in sign to that of similarly produced Λ. The moment is (2.479±0.012±0.022)${\mu }_N$, where the uncertainties are statistical and systematic, respectively.

We report evidence for an isoscalar state X(1110), observed via p¯n→${\rho }^{\mathrm{-}}$+X (→${\pi }^{+}$${\pi }^{\mathrm{-}}$) in p¯d annihilations at rest, of mass and width 1107±4 MeV/$c^2$ and 111±8 (statistical)±15 (systematic) MeV/$c^2$, respectively. The product branching ratio B(p¯n→${\rho }^{\mathrm{-}}$X)B(X →2π)=(3.6±0.5)% and $J^{\mathrm{PC}}$($I^G$${)=0\mathrm{}}^{++}$${(0\mathrm{}}^{+}$), $2^{++}$${(0\mathrm{}}^{+}$),. . . . As a $0^{++}$ the X(1110) would be a candidate for the ground ${}_{}{}^{13}{}_{}{}^{}\mathrm{P}_0^{}{}_{}{}^{}$ state of the I=0 natural-parity band of quasinuclear NN¯ states with the ζ(1480) being the ${}_{}{}^{13}{}_{}{}^{}\mathrm{P}_2^{}{}_{}{}^{}$${\mathrm{-}}^{13}$${\mathrm{F}}_2$. This interpretation predicts masses for the member states ${}_{}{}^{13}{}_{}{}^{}\mathrm{S}_1^{}{}_{}{}^{}$${\mathrm{-}}^{13}$${\mathrm{D}}_1$ and ${}_{}{}^{13}{}_{}{}^{}\mathrm{D}_3^{}{}_{}{}^{}$${\mathrm{-}}^{13}$${\mathrm{G}}_3$ of 1240 and 1850 MeV/$c^2$, respectively. Evidence for the ${}_{}{}^{13}{}_{}{}^{}\mathrm{S}_1^{}{}_{}{}^{}$${\mathrm{-}}^{13}$${\mathrm{D}}_1$ is discussed.

We propose a new theory to treat fluctuation phenomena in heavy-ion reactions. In practical terms, the method is an extension of the theories of the one-body density based on mean-field plus collisional dynamics. In an exploratory study of the ${}_{}{}^{20}{}_{}{}^{}$Ne${+\mathrm{}}^{20}$Ne reaction, we find considerable fragmentation with a rapidly falling mass spectrum.

The nitrogen KVV Auger spectrum of nitric oxide contains peaks corresponding to the decay of neutral, core-excited NO to final states of ${\mathrm{NO}}^{+}$. The position and shape of the peak resulting from decay to the ground state cannot be explained by the usual Franck-Condon analysis. Since the lifetime of the core-excited states is comparable to the characteristic vibrational time, it is necessary to include in the analysis the effects of interference between different vibrational states. When these are included, there is excellent agreement between the experimental and theoretical line shapes.

When a resonance mode is excited in a two-dimensional array of dielectric spheres, the local-field intensity is enhanced inside the spheres. This resonance frequency decreases with the increase of the dielectric constant. By use of these two properties, a new mechanism is proposed to realize optical bistability at a low laser power.

Hydrodynamic fluctuations in a dilute gas subjected to a constant heat flux are studied by both a computer simulation and the Landau-Lifshitz formalism. The latter explicitly incorporates the boundary conditions of the finite system, thus permitting quantitative comparison with the former. Good agreement is demonstrated.

An approximate theoretical analysis is given of a proposed technique for producing high transient electric fields within a mirror-confined hot-electron plasma. It is shown that exploitation of the ‘‘loss-cone’’ nature of the distribution function of the confined electrons, together with ion inertial effects and the plasma quasi-neutrality constraint, leads to a degree of control over the space-charge potentials that may permit application of the concept to high-energy particle accelerators.