Showing papers in "Physical Review Letters in 1974"
TL;DR: In this paper, strong, electromagnetic, and weak forces are conjectured to arise from a single fundamental interaction based on the gauge group SU(5), which is known as SU(4).
Abstract: Strong, electromagnetic, and weak forces are conjectured to arise from a single fundamental interaction based on the gauge group SU(5).
3,684 citations
TL;DR: In this article, the spontaneous generation of reversed fields in toroidal plasmas is shown to be a consequence of relaxation under constraints, and the onset of the reversed field and other features of this model agree well with observations on ZETA.
Abstract: The spontaneous generation of reversed fields in toroidal plasmas is shown to be a consequence of relaxation under constraints. With perfect conductivity a topological constraint exists for each field line and the final state is not unique. With small departures from perfect conductivity, topological constraints are relaxed and the final state becomes unique. The onset of the reversed field and other features of this model agree well with observations on ZETA.
1,740 citations
TL;DR: In this paper, the authors reported the observation of a heavy particle with mass 3.1$ GeV and width approximately zero at the Brookhaven National Laboratory's 30-GeV alternating-gradient synchrotron.
Abstract: We report the observation of a heavy particle $J$, with mass $m=3.1$ GeV and width approximately zero. The observation was made from the reaction $p+\mathrm{Be}\ensuremath{\rightarrow}{e}^{+}+{e}^{\ensuremath{-}}+x$ by measuring the ${e}^{+}{e}^{\ensuremath{-}}$ mass spectrum with a precise pair spectrometer at the Brookhaven National Laboratory's 30-GeV alternating-gradient synchrotron.
1,160 citations
TL;DR: In this paper, a general formalism for calculating renormalization effects which make strong interactions strong in simple gauge theories of strong, electromagnetic, and weak interactions is presented, where the superheavy gauge bosons arising in the spontaneous breakdown to observed interactions have mass perhaps as large as ${10}^{17}$ GeV, almost the Planck mass.
Abstract: We present a general formalism for calculating the renormalization effects which make strong interactions strong in simple gauge theories of strong, electromagnetic, and weak interactions. In an SU(5) model the superheavy gauge bosons arising in the spontaneous breakdown to observed interactions have mass perhaps as large as ${10}^{17}$ GeV, almost the Planck mass. Mixing-angle predictions are substantially modified.
1,111 citations
TL;DR: In this paper, a very sharp peak was observed in the cross section of the Hadron at a center-of-mass energy of 3105 ± 3.3 GeV.
Abstract: We have observed a very sharp peak in the cross section for ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathrm{hadrons}, {e}^{+}{e}^{\ensuremath{-}}$, and possibly ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ at a center-of-mass energy of 3105\ifmmode\pm\else\textpm\fi{}0003 GeV The upper limit to the full width at half-maximum is 13 MeV
1,008 citations
TL;DR: In this article, a simple rectangular potential well with a depth of ≈088ΔE g, where ΔE g is the difference in the semiconductor energy gaps is defined.
Abstract: Quantum levels associated with the confinement of carriers in very thin, molecular-beam—grown AlxGa1−xAs−GaAs-Alx Ga1−xAs heterostructures result in pronounced structure in the GaAs optical absorption spectrum Up to eight resolved exciton transitions, associated with different bound-electron and bound-hole states, have been observed The heterostructure behaves as a simple rectangular potential well with a depth of ≈088ΔE g , for confining electrons and ≈012ΔE g for confining holes, where ΔE g is the difference in the semiconductor energy gaps
976 citations
TL;DR: In this paper, the authors have calculated the value of the Callan-Symanzik β function to order g √ 5 for non-Abelian gauge theories with fermions.
Abstract: We have calculated the value of the Callan-Symanzik $\ensuremath{\beta}$ function to order ${g}^{5}$ for non-Abelian gauge theories with fermions. We discuss internal consistency of the calculation, and consider the approach to the aymptotic energy range in such theories.
894 citations
TL;DR: The superconducting phase transition is predicted to be weakly first order, because of effects of the intrinsic fluctuating magnetic field, according to a Wilson-Fisher $\ensuremath{\epsilon}$expansion analysis, as well as a generalized mean-field calculation appropriate to a type-I superconductor.
Abstract: The superconducting phase transition is predicted to be weakly first order, because of effects of the intrinsic fluctuating magnetic field, according to a Wilson-Fisher $\ensuremath{\epsilon}$-expansion analysis, as well as a generalized mean-field calculation appropriate to a type-I superconductor. Similar results hold for the phase transition from a smectic-$A$ to a nematic liquid crystal.
653 citations
TL;DR: The discovery of narrow resonances at 3.1 and 3.7 GeV and their interpretation as charmed quark-antiquark bound states suggest additional narrow states between 3.0 and 4.3 GeV as mentioned in this paper.
Abstract: The discovery of narrow resonances at 3.1 and 3.7 GeV and their interpretation as charmed quark-antiquark bound states suggest additional narrow states between 3.0 and 4.3 GeV. A model which incorporates quark confinement is used to determine the quantum numbers and estimate masses and decay widths of these states. Their existence should be revealed by γ-ray transitions among them.
633 citations
TL;DR: In this article, the authors identify the internal disruption as a growing sinusoidal $m=1$, $n=1$ oscillation and compare the properties of these oscillations with predictions for the $m = 1$ internal kink mode.
Abstract: Fluctuations in x-ray intensity from the ST tokamak show a characteristic sawtooth behavior. This behavior is identified as an internal disruption. The internal disruptions are preceded by growing sinusoidal $m=1$, $n=1$ oscillations. The properties of these oscillations are compared with predictions for the $m=1$ internal kink mode.
623 citations
TL;DR: In this article, the weak nonexponential relaxation of alloys was explained in terms of a cluster reaction and diffusion process, and the experimental observability of this slowing down was discussed.
Abstract: The weak nonexponential relaxation $\ensuremath{\propto}{t}^{\ensuremath{-}{a}^{\ensuremath{'}}}$ recently found in computer experiments on the phase separation of alloys is explained in terms of a cluster reaction and diffusion process. The nonlinear features of this process can be accounted for by a time-dependent diffusion constant. Estimates for the resulting exponents [${a}^{\ensuremath{'}}=\frac{1}{(3+d)}$] are consistent with the computer simulations. The experimental observability of this slowing down is discussed.
TL;DR: In this article, the Weinberg-Salam theory of weak interactions and an exactly-conserved-color gauge symmetry for strong interactions were examined for the effective non-leptonic weak interaction.
Abstract: The effective nonleptonic weak interaction is examined assuming the Weinberg-Salam theory of weak interactions and an exactly-conserved-color gauge symmetry for strong interactions. It is shown that the octet part of the nonleptonic weak interaction is more singular at short distances than the 27 part. The resulting enhancement of the octet term in the effective local weak Lagrangian, together with suggested mechanisms for the suppression of matrix elements of the 27 operator, may be sufficient to account for the observed $|\ensuremath{\Delta}I|=\frac{1}{2}$ rule.
IBM1
TL;DR: In this article, the authors report electronic transport properties in a GaAs-AlAs periodic structure known as a "superlattice" prepared by a molecular-beam epitaxy.
Abstract: We report electronic transport properties in a GaAs-AlAs periodic structure known as a "superlattice" prepared by a molecular-beam epitaxy. Its differential conductance in the superlattice direction first gradually decreases, followed by a rapid drop to negative values, then, at high fields, exhibits an oscillatory behavior with respect to applied voltages. This observation is interpreted in terms of the formation and expansion of a high-field domain. The voltage period of the oscillation provides the energy of the first-excited band which is in good agreement with that predicted by the theory.
TL;DR: On the basis of the theory of relativity, the principle of causality, and Le Chatelier's principle, it was shown in this article that the maximum mass of the equilibrium configuration of a neutron star cannot be larger than $3.2{M}_{[m?]}
Abstract: On the basis of Einstein's theory of relativity, the principle of causality, and Le Chatelier's principle, it is here established that the maximum mass of the equilibrium configuration of a neutron star cannot be larger than $3.2{M}_{[m?]}$. The extremal principle given here applies as well when the equation of state of matter is unknown in a limited range of densities. The absolute maximum mass of a neutron star provides a decisive method of observationally distinguishing neutron stars from black holes.
TL;DR: An exact solution to the one-dimensional electron gas with a particular attractive interaction strength for scattering across the Fermi "surface" is given in this paper, and scaling arguments are advanced to demonstrate that this solution applies generally for attractive backward scattering.
Abstract: An exact solution to the one-dimensional electron gas with a particular attractive-interaction strength for scattering across the Fermi "surface" is given. It is shown that conductivity enhancement occurs for physically interesting values of the coupling constants. Scaling arguments are advanced to demonstrate that this solution applies generally for attractive backward scattering. In addition, the spinless problem is solved exactly for arbitrary couplings.
TL;DR: In this article, the nonlinear frequency shift of a strong electromagnetic wave in a plasma, due to weak relativistic effects and the $\stackrel{\ensuremath{\rightarrow}}{\mathrm{v}}\ifmmode\times\else\texttimes\fi{}\stackrel{ensureMath{\right arrow}}{B}}$ force, can cause modulation and self-focusing instabilities.
Abstract: The nonlinear frequency shift of a strong electromagnetic wave in a plasma, due to weak relativistic effects and the $\stackrel{\ensuremath{\rightarrow}}{\mathrm{v}}\ifmmode\times\else\texttimes\fi{}\stackrel{\ensuremath{\rightarrow}}{\mathrm{B}}$ force, can cause modulation and self-focusing instabilities. These processes are explored, and their relation to self-focusing driven by the ponderomotive force is described.
TL;DR: In this paper, the anomalous properties of polytypes of charge-density waves, their periodic structure distortions, and the superlattices they induce are attributed to charge density waves.
Abstract: The previously termed "anomalous" properties of the various polytypes of ${d}^{1}$ Ta${\mathrm{S}}_{2}$, Ta${\mathrm{Se}}_{2}$, etc. are attributed to charge-density waves, their periodic structure distortions, and the superlattices they induce.
TL;DR: In this article, a new integral formalism for gauge fields is described, including gravitation equations related to, but not identical with, Einstein's equations, and further developments are presented.
Abstract: A new integral formalism for gauge fields is described. Further developments are presented, including gravitation equations related to, but not identical with, Einstein's equations.
IBM1
TL;DR: In this article, a simple formula involving the geometric mean of the electronegativities of the two components is proposed for the determination of the Fermi energies and hence the photoelectric thresholds of simple binary compounds, and is found to be surprisingly accurate for all presently available data.
Abstract: A simple formula involving the geometric mean of the electronegativities of the two components is proposed for the determination of the Fermi energies and hence the photoelectric thresholds of simple binary compounds, and is found to be surprisingly accurate for all presently available data. A theoretical basis for the use of the "postulate of the geometric mean" is also given.
TL;DR: The Rayleigh-Taylor instability in laser-driven spherical implosion can be stabilized by convective flow and firepolishing effect as mentioned in this paper, but the size of the stabilization effect depends on details of the thermal conductivity near the ablation surface.
Abstract: The Rayleigh-Taylor instability in laser-driven spherical implosions can be stabilized by convective flow and by the "fire-polishing" effect, but the size of the stabilization effect depends on details of the thermal conductivity near the ablation surface.
TL;DR: In this article, strong transient oscillations have been observed in proton-carbon-13 cross-polarization experiments in a ferrocene single crystal, which are manifestations of coherence effects caused by the dipolar coupling of the carbon-13 to the directly bound proton.
Abstract: Strong transient oscillations have been observed in proton-carbon-13 cross-polarization experiments in a ferrocene single crystal. These oscillations are in contrast with the usually observed exponential behavior of cross polarization. They are manifestations of coherence effects caused by the dipolar coupling of the carbon-13 to the directly bound proton. A simple model is described which explains the observations.
TL;DR: In this article, it was shown that nuclear matter is compressed during the encounter of heavy ions, and if the relative velocity of the nuclei is larger than the velocity of first sound in nuclear matter (compression sound for isospin $T=0$), nuclear shock waves occur.
Abstract: It is shown that nuclear matter is compressed during the encounter of heavy ions. If the relative velocity of the nuclei is larger than the velocity of first sound in nuclear matter (compression sound for isospin $T=0$), nuclear shock waves occur. They lead to densities which are 3-5 times higher than the nuclear equilibrium density ${\ensuremath{\rho}}_{0}$, depending on the energy of the nuclei. The implications of this phenomenon are discussed.
TL;DR: In this paper, steady-state self-focusing, self-trapping, and self-defocusing of a cw dye laser beam in sodium vapor for frequencies within several Doppler widths of the $D$-line resonance transitions were reported.
Abstract: We report steady-state self-focusing, self-trapping, and self-defocusing of a cw dye laser beam in sodium vapor for frequencies within several Doppler widths of the $D$-line resonance transitions. We measured the variation of the beam profile as the light propagates through the vapor. We observed a 20-mW beam self-trapped in a 12-cm-long filament having a half-power diameter of 70 \ensuremath{\mu}m.
TL;DR: In this article, an exact calculation of the acoustic-phonon-assisted jump rate has been carried out, and it is found that while the Miller-Abrahams approximation is adequate for the study of shallow-impurity conduction at helium temperatures, it is typically inappropriate for hopping between deep states in noncrystalline solids.
Abstract: An exact calculation of the acoustic-phonon-assisted jump rate has been carried out. It is found that while the Miller-Abrahams (single-phonon) approximation is adequate for the study of shallow-impurity conduction at helium temperatures, it is typically inappropriate for the study of hopping between deep states in noncrystalline solids. In particular, the multiphonon jump rate will display a nonactivated temperature dependence below the Debye temperature which is similar to the often-seen $\mathrm{exp}[\ensuremath{-}{(\frac{{T}_{0}}{T})}^{\frac{1}{4}}]$ behavior.
TL;DR: In this paper, the defects were produced in GaAs by 1-MeV electron irradiation and observed by transient-junction-capacitance techniques, and the data clearly relate the enhanced defect annealing rate to electronhole recombination processes at the defect.
Abstract: Recombination-enhanced annealing of defects in semiconductors has been observed directly for the first time. The defects were produced in GaAs by 1-MeV electron irradiation and observed by transient-junction-capacitance techniques. The data clearly relate the enhanced defect annealing rate to electron-hole recombination processes at the defect.
TL;DR: In this paper, the first experimental and theoretical investigation of the coupling of second-harmonic generation of light to surface plasmons in thin silver films was performed, and the results showed that a model based on polarization sources at the silver-air interface correctly predicts the observed harmonic enhancement of one and a half orders of magnitude because of excitation of the surface plasmon.
Abstract: We report the first experimental and theoretical investigation of the coupling of second-harmonic generation of light to surface plasmons in thin silver films. A model of second-harmonic generation due to polarization sources at the silver-air interface correctly predicts the observed harmonic enhancement of one and a half orders of magnitude because of excitation of the surface plasmon.
TL;DR: In this article, an intense electromagnetic wave propagating in a collisional plasma is found to be unstable to a thermal self-focusing instability by a selfconsistent solution of the hydrodynamic, heat conductivity, and wave propagation equations.
Abstract: An intense electromagnetic wave propagating in a collisional plasma is found to be unstable to a thermal self-focusing instability by a self-consistent solution of the hydrodynamic, heat conductivity, and wave propagation equations. The results are applied to ionospheric modifications and proposed power transmission experiments, and to laser-plasma interactions.