We summarize the Hybrids, Exotics, and Dibaryon section. We begin with a brief discussion of hybrid properties and some comments on qq̄qq̄ states and dibaryons. The bulk of this summary is devoted to discussion of the...
We summarize the Hybrids, Exotics, and Dibaryon section. We begin with a brief discussion of hybrid properties and some comments on qq̄qq̄ states and dibaryons. The bulk of this summary is devoted to discussion of the interesting results report in these sessions; the GAMS 1−+→ηπ0 state, the Lepton‐F C(1480)→φπ0 state, various γγ→VV’ results, and the CERN WA62 U(3.1)→Λp̄π+π− state along with theoretical interpretations of these results. We conclude with some comments on future directions in exotic hadrons.
The dynamical process for dipolar ordering in ferroelectric crystals oftris-sarcosine calcium chloride has been studied through the dielectric and electron paramagnetic resonance anomalies in the critical region, for ...
The dynamical process for dipolar ordering in ferroelectric crystals oftris-sarcosine calcium chloride has been studied through the dielectric and electron paramagnetic resonance anomalies in the critical region, for which a collective fluctuation of local-order parameters is considered to be responsible. Although different aspects of the phase transition are dealt with, these anomalies provide complementary information about the quasi-one-dimensional mode of order parameters. Induced by B2usoft phonons in the para-electric phase, it may be regarded as acondensatestabilized by the short-range correlation among constituent order parameters. In real crystals where randomly distributed defects violate the translational symmetry of the lattice, the condensate at long wavelengths either may be pinned or may slide free from defects. Depending on the defect density in sample crystals, the anomalies were observed as composed of these two condensate modes characterized by distinct frequencies. The significance of lattice defects for the polarization fluctuation at the ferroelectric phase transition is discussed.
Recent Dirac-Hartree-Slater and Dirac-Hartree-Fock calculations of ionization cross-sections, fluorescence and Coster-Kronig yields and X-ray emission rates offer a “self-consistent” theoretical data base for relati...
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Recent Dirac-Hartree-Slater and Dirac-Hartree-Fock calculations of ionization cross-sections, fluorescence and Coster-Kronig yields and X-ray emission rates offer a “self-consistent” theoretical data base for relative intensities of proton-induced L X-rays. Interpolation schemes for use with tables of these quantities are described. Theoretical intensity ratios for major line groups agree with compiled experimental data to within a few percent, justifying use of the data base in PIXE.
We propose a new pairing mechanism for high- T c superconductivity in doped La 2 CuO 4 compounds. In this mechanism, the attractive interaction between the electrons in a Cooper pair is induced through holes which are...
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We propose a new pairing mechanism for high- T c superconductivity in doped La 2 CuO 4 compounds. In this mechanism, the attractive interaction between the electrons in a Cooper pair is induced through holes which are spinless neutral bosons. The basic requirements of the model are the existence of CuO 2 planes containing a number of holes and a large intrasite Coulomb repulsion U . We find superconducting state with s -wave symmetry. For small values of the hole concentration δ, T c increases with an increase in δ and t (transfer integral). With δ = 0.15 and t = 1 eV, we obtain T c ∼ 75 K . We expect a maximum in the T c vs δ curve for some value of δ.
The superconducting order parameter Δ( T ) and the maximum Josephson tunneling current J s ( T ) for an antiferromagnetic superconductor (AFS) are calculated both in the paramagnetic and the antiferromagnetic phases....
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The superconducting order parameter Δ( T ) and the maximum Josephson tunneling current J s ( T ) for an antiferromagnetic superconductor (AFS) are calculated both in the paramagnetic and the antiferromagnetic phases. The effects of the molecular field, impurities and the elastic scattering from spin-fluctuations have been included. The enhancement in J s ( T ) and Δ( T ) by the antiferromagnetic (AF) ordering observed in SmRh 4 B 4 by Vaglio et al. [1] can be understood with a reasonable choice of parameters. We also predict depression in J s ( T ) and Δ( T ) by AF ordering in some materials.
Starting from realistic interatomic pair potentials, a temperature-quench Monte Carlo simulation method is used to calculate the mean atomic volume and pair distribution functions at each temperature step in the trans...
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Starting from realistic interatomic pair potentials, a temperature-quench Monte Carlo simulation method is used to calculate the mean atomic volume and pair distribution functions at each temperature step in the transition from the liquid state to the glassy state under zero pressure for the metallic binary alloy Ca0.7Mg0.3. Then, by using the results obtained from this calculation and those reported in the literature for monatomic systems, we demonstrate (i) that the Wendt-Abraham parameter, characterizing the liquid-glass transition, changes significantly in going from the pure metals to their binary alloys, and (ii) how to determine the glass transition temperature in a simple manner for a given system.
A correlation function for second virial coefficients of4He calculated on the basis of an accurate interatomic potential is presented. Such a correlation is more physically based than one fitted directly to the raw da...
A correlation function for second virial coefficients of4He calculated on the basis of an accurate interatomic potential is presented. Such a correlation is more physically based than one fitted directly to the raw data. The intermediate step of fitting a realistic potential form to the virials as well as other precise data serves the function of smoothing the raw data, thus avoiding systematic error trends. A flexible correlation function is then fitted to the calculated virials.
The laser-induced vibrational excitation of an adatom bound to a harmonic lattice at T =0 K is studied by integrating the classical generalized Langevin equation numerically. The anharmonicity of the adatom-surface bo...
The laser-induced vibrational excitation of an adatom bound to a harmonic lattice at T =0 K is studied by integrating the classical generalized Langevin equation numerically. The anharmonicity of the adatom-surface bond plays an important role in inducing quasiperiodic and chaotic adatom motion.
Using proton‐beam irradiation at 15 MeV, the emission spectra from 3He and 4He doped samples of solid hydrogen and deuterium have been observed from 350–750 nm at 4.2 K. Such samples simulate the conditions of solid...
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Using proton‐beam irradiation at 15 MeV, the emission spectra from 3He and 4He doped samples of solid hydrogen and deuterium have been observed from 350–750 nm at 4.2 K. Such samples simulate the conditions of solid tritium or tritiated hydrogens after about six days of helium accretion. The spectra are very similar to pure helium gas spectra acquired at 4.2 K and closer still to spectra acquired using helium gas in the upper portion of a sample cell partially filled with solid hydrogen. The helium collects as macroscopically large bubbles whose pressure has been determined. The pure 4He gas spectrum at 4.2 K contains a band near 460 nm previously assigned to an unspecified excimer–dimer radiative transition. The pressure and isotope dependence of this band is presented which lends support to that interpretation. A mechanism is proposed for the transition.
A theory of the longitudinal electron spin susceptibility χs for an antiferromagnetic superconductor (AFS) has been given. For the AFS, we have assumed a homogeneous superconducting order parameter and a one-dimensio...
A theory of the longitudinal electron spin susceptibility χs for an antiferromagnetic superconductor (AFS) has been given. For the AFS, we have assumed a homogeneous superconducting order parameter and a one-dimensional electron band that satisfies the nesting condition ɛk=-ɛk+Q, where Q is the wave vector characterizing the antiferromagnetic (AF) order. First we have studied the dependence of χs on the scattering rates for the scattering of conduction electrons from the nonmagnetic, spin-orbit, and magnetic impurities by regarding HQ as a parameter and neglecting the spin-fluctuation effects (HQ is the AF field). The effect of impurities is found to be significant. Then we have investigated the temperature dependence of χs by taking TN
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