239,759 research outputs found

    Dynamic Model and Phase Transitions for Liquid Helium

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    This article presents a phenomenological dynamic phase transition theory -- modeling and analysis -- for superfluids. As we know, although the time-dependent Ginzburg-Landau model has been successfully used in superconductivity, and the classical Ginzburg-Landau free energy is still poorly applicable to liquid helium in a quantitative sense. The study in this article is based on 1) a new dynamic classification scheme of phase transitions, 2) new time-dependent Ginzburg-Landau models for general equilibrium transitions, and 3) the general dynamic transition theory. The results in this article predict the existence of a unstable region H, where both solid and liquid He II states appear randomly depending on fluctuations and the existence of a switch point M on the lambda-curve, where the transitions changes types

    Exploration of Resonant Continuum and Giant Resonance in the Relativistic Approach

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    Single-particle resonant-states in the continuum are determined by solving scattering states of the Dirac equation with proper asymptotic conditions in the relativistic mean field theory (RMF). The regular and irregular solutions of the Dirac equation at a large radius where the nuclear potentials vanish are relativistic Coulomb wave functions, which are calculated numerically. Energies, widths and wave functions of single-particle resonance states in the continuum for ^{120}Sn are studied in the RMF with the parameter set of NL3. The isoscalar giant octupole resonance of ^{120}Sn is investigated in a fully consistent relativistic random phase approximation. Comparing the results with including full continuum states and only those single-particle resonances we find that the contributions from those resonant-states dominate in the nuclear giant resonant processes.Comment: 16 pages, 2 figure

    Neutrino mixing matrix in the 3-3-1 model with heavy leptons and A4A_4 symmetry

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    We study the lepton sector in the model based on the local gauge group SU(3)c⊗SU(3)L⊗U(1)XSU(3)_c\otimes SU(3)_L\otimes U(1)_X which do not contain particles with exotic electric charges. The seesaw mechanism and discrete A4A_4 symmetry are introduced into the model to understand why neutrinos are especially light and the observed pattern of neutrino mixing. The model provides a method for obtaining the tri-bimaximal mixing matrix in the leading order. A non-zero mixing angle Ve3V_{e3} presents in the modified mixing matrix.Comment: 10 page

    Realistic Gluino Axion Model Consistent with Supersymmetry Breaking at the TeV Scale

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    The recently proposed model of using the dynamical phase of the gluino to solve the strong CP problem is shown to admit a specific realization in terms of fundamental singlet superfields, such that the breaking of supersymmetry occurs only at the TeV scale, despite the large axion scale of 10^{9} to 10^{12} GeV. Phenomenological implications are discussed.Comment: 12 pp, 2 fig

    Supersymmetric Higgs Triplets and Bilinear R-Parity Nonconservation

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    The supersymmetric standard model of particle interactions is extended to include two Higgs triplet superfields at the TeV scale, carrying two units of lepton number. Realistic tree-level Majorana neutrino masses are obtained in the presence of soft, i.e. bilinear, R-parity nonconservation.Comment: 5 pages, no figur

    Quantization of static space-times

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    A 4-dimensional Lorentzian static space-time is equivalent to 3-dimensional Euclidean gravity coupled to a massless Klein-field. By canonically quantizing the coupling model in the framework of loop quantum gravity, we obtain a quantum theory which actually describes quantized static space-times. The Kinematical Hilbert space is the product of the Hilbert space of gravity with that of imaginary scalar fields. It turns out that the Hamiltonian constraint of the 2+1 model corresponds to a densely defined operator in the underlying Hilbert space, and hence it is finite without renormalization. As a new point of view, this quantized model might shed some light on a few physical problems concerning quantum gravity.Comment: 14 pages, made a few modifications, added Journal-re

    Recoverable Information and Emergent Conservation Laws in Fracton Stabilizer Codes

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    We introduce a new quantity, that we term recoverable information, defined for stabilizer Hamiltonians. For such models, the recoverable information provides a measure of the topological information, as well as a physical interpretation, which is complementary to topological entanglement entropy. We discuss three different ways to calculate the recoverable information, and prove their equivalence. To demonstrate its utility, we compute recoverable information for fracton models using all three methods where appropriate. From the recoverable information, we deduce the existence of emergent Z2Z_2 Gauss-law type constraints, which in turn imply emergent Z2Z_2 conservation laws for point-like quasiparticle excitations of an underlying topologically ordered phase.Comment: Added additional cluster model calculation (SPT example) and a new section discussing the general benefits of recoverable informatio

    Breakdown of Landau-Ginzburg-Wilson theory for certain quantum phase transitions

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    The quantum ferromagnetic transition of itinerant electrons is considered. It is shown that the Landau-Ginzburg-Wilson theory described by Hertz and others breaks down due to a singular coupling between fluctuations of the conserved order parameter. This coupling induces an effective long-range interaction between the spins of the form 1/r^{2d-1}. It leads to unusual scaling behavior at the quantum critical point in 1<d≤31<d\leq 3 dimensions, which is determined exactly.Comment: 4 pp., REVTeX, no figs, final version as publishe
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