55,976 research outputs found

    Low-lying states in even Gd isotopes studied with five-dimensional collective Hamiltonian based on covariant density functional theory

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    Five-dimensional collective Hamiltonian based on the covariant density functional theory has been applied to study the the low-lying states of even-even 148−162^{148-162}Gd isotopes. The shape evolution from 148^{148}Gd to 162^{162}Gd is presented. The experimental energy spectra and intraband B(E2)B(E2) transition probabilities for the 148−162^{148-162}Gd isotopes are reproduced by the present calculations. The relative B(E2)B(E2) ratios in present calculations are also compared with the available interacting boson model results and experimental data. It is found that the occupations of neutron 1i13/21i_{13/2} orbital result in the well-deformed prolate shape, and are essential for Gd isotopes.Comment: 11pages, 10figure

    Superspace Formulation in a Three-Algebra Approach to D=3, N=4,5 Superconformal Chern-Simons Matter Theories

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    We present a superspace formulation of the D=3, N=4,5 superconformal Chern-Simons Matter theories, with matter supermultiplets valued in a symplectic 3-algebra. We first construct an N=1 superconformal action, and then generalize a method used by Gaitto and Witten to enhance the supersymmetry from N=1 to N=5. By decomposing the N=5 supermultiplets and the symplectic 3-algebra properly and proposing a new super-potential term, we construct the N=4 superconformal Chern-Simons matter theories in terms of two sets of generators of a (quaternion) symplectic 3-algebra. The N=4 theories can also be derived by requiring that the supersymmetry transformations are closed on-shell. The relationship between the 3-algebras, Lie superalgebras, Lie algebras and embedding tensors (proposed in [E. A. Bergshoeff, O. Hohm, D. Roest, H. Samtleben, and E. Sezgin, J. High Energy Phys. 09 (2008) 101.]) is also clarified. The general N=4,5 superconformal Chern-Simons matter theories in terms of ordinary Lie algebras can be rederived in our 3-algebra approach. All known N=4,5 superconformal Chern-Simons matter theories can be recovered in the present superspace formulation for super-Lie-algebra realization of symplectic 3-algebras.Comment: 37 pages, minor changes, published in PR

    Subleading corrections to parity-violating pion photoproduction

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    We compute the photon asymmetry Bγ for near threshold parity-violating (PV) pion photoproduction through subleading order. We show that subleading contributions involve a new combination of PV couplings not included in previous analyses of hadronic PV. We argue that existing constraints on the leading order contribution to Bγ—obtained from the PV γ-decay of 18F—suggest that the impact of the subleading contributions may be more significant than expected from naturalness arguments

    The reduction of the closest disentangled states

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    We study the closest disentangled state to a given entangled state in any system (multi-party with any dimension). We obtain the set of equations the closest disentangled state must satisfy, and show that its reduction is strongly related to the extremal condition of the local filtering on each party. Although the equations we obtain are not still tractable, we find some sufficient conditions for which the closest disentangled state has the same reduction as the given entangled state. Further, we suggest a prescription to obtain a tight upper bound of the relative entropy of entanglement in two-qubit systems.Comment: a crucial error was correcte

    Chiral Symmetry and the Parity-Violating NNÏ€NN\pi Yukawa Coupling

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    We construct the complete SU(2) parity-violating (PV) π,N,Δ\pi, N, \Delta interaction Lagrangian with one derivative, and calculate the chiral corrections to the PV Yukawa NNπNN\pi coupling constant hπh_\pi through O(1/Λχ3){\cal O}(1/\Lambda_\chi^3) in the leading order of heavy baryon expansion. We discuss the relationship between the renormalized \hpi, the measured value of \hpi, and the corresponding quantity calculated microscopically from the Standard Model four-quark PV interaction.Comment: RevTex, 26 pages + 5 PS figure

    The Droplet State and the Compressibility Anomaly in Dilute 2D Electron Systems

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    We investigate the space distribution of carrier density and the compressibility of two-dimensional (2D) electron systems by using the local density approximation. The strong correlation is simulated by the local exchange and correlation energies. A slowly varied disorder potential is applied to simulate the disorder effect. We show that the compressibility anomaly observed in 2D systems which accompanies the metal-insulator transition can be attributed to the formation of the droplet state due to disorder effect at low carrier densities.Comment: 4 pages, 3 figure
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