22,066 research outputs found

    Canonical Quantization of SU(3) Skyrme Model in a General Representation

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    A complete canonical quantization of the SU(3) Skyrme model performed in the collective coordinate formalism in general irreducible representations. In the case of SU(3) the model differs qualitatively in different representations. The Wess-Zumino-Witten term vanishes in all self-adjoint representations in the collective coordinate method for separation of space and time variables. The canonical quantization generates representation dependent quantum mass corrections, which can stabilize the soliton solution. The standard symmetry breaking mass term, which in general leads to representation mixing, degenerates to the SU(2) form in all self-adjoint representations.Comment: 24 RevTex4 pages, no figure

    Real-time evolution method and its application to 3α\alpha cluster system

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    A new theoretical method is proposed to describe the ground and excited cluster states of atomic nuclei. The method utilizes the equation-of-motion of the Gaussian wave packets to generate the basis wave functions having various cluster configurations. The generated basis wave functions are superposed to diagonalize the Hamiltonian. In other words, this method uses the real time as the generator coordinate. The application to the 3α3\alpha system as a benchmark shows that the new method works efficiently and yields the result consistent with or better than the other cluster models. Brief discussion on the structure of the excited 0+0^+ and 11^- states is also made

    High density quark matter in the NJL model with dimensional vs. cut-off regularization

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    We investigate color superconducting phase at high density in the extended Nambu--Jona-Lasinio model for the two flavor quarks. Because of the non-renormalizability of the model, physical observables may depend on the regularization procedure, that is why we apply two types of regularization, the cut-off and the dimensional one to evaluate the phase structure, the equation of state and the relationship between the mass and the radius of a dense star. To obtain the phase structure we evaluate the minimum of the effective potential at finite temperature and chemical potential. The stress tensor is calculated to derive the equation of state. Solving the Tolman-Oppenheimer-Volkoff equation, we show the relationship between the mass and the radius of a dense star. The dependence on the regularization is found not to be small for these phenomena in the color superconducting phase.Comment: 10 pages, 11 figures; a few points corrected and references adde

    NMR evidence for a strong modulation of the Bose-Einstein Condensate in BaCuSi2_2O6_6

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    We present a 63,65^{63,65}Cu and 29^{29}Si NMR study of the quasi-2D coupled spin 1/2 dimer compound BaCuSi2_2O6_6 in the magnetic field range 13-26 T and at temperatures as low as 50 mK. NMR data in the gapped phase reveal that below 90 K different intra-dimer exchange couplings and different gaps (ΔB/ΔA\Delta_{\rm{B}}/\Delta_{\rm{A}} = 1.16) exist in every second plane along the c-axis, in addition to a planar incommensurate (IC) modulation. 29^{29}Si spectra in the field induced magnetic ordered phase reveal that close to the quantum critical point at Hc1H_{\rm{c1}} = 23.35 T the average boson density nˉ\bar{n} of the Bose-Einstein condensate is strongly modulated along the c-axis with a density ratio for every second plane nˉA/nˉB5\bar{n}_{\rm{A}}/\bar{n}_{\rm{B}} \simeq 5. An IC modulation of the local density is also present in each plane. This adds new constraints for the understanding of the 2D value ϕ\phi = 1 of the critical exponent describing the phase boundary

    Exact Solution for Relativistic Two-Body Motion in Dilaton Gravity

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    We present an exact solution to the problem of the relativistic motion of 2 point masses in (1+1)(1+1) dimensional dilaton gravity. The motion of the bodies is governed entirely by their mutual gravitational influence, and the spacetime metric is likewise fully determined by their stress-energy. A Newtonian limit exists, and there is a static gravitational potential. Our solution gives the exact Hamiltonian to infinite order in the gravitational coupling constant.Comment: 6 pages, latex, 3 figure

    Leaf area index and topographical effects on turburlent diffusion in a deciduous forest

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    In order to investigate turbulent diffusion in a deciduous forest canopy, wind velocity measurements were conducted from late autumn of 2009 to early spring of 2010, using an observation tower 20 m in height located in the campus of Kanazawa University. Four sonic anemometers mounted on the tower recorded the average wind velocities and temperatures, as well as their fluctuations, at four different heights simultaneously. Two different types of data sets were selected, in which the wind velocities, wind bearings and atmospheric stabilities were all similar, but the Leaf Area Indexes (LAI's) were different. Vertical profiles of average wind velocities were found to have an approximately exponential profile in each case. The characteristic length scales of turbulence were evaluated by both von Karman's method and the integral time scale deduced from the autocorrelation from time-series analyses. Both methods produced comparable values of eddy diffusivity for the cases with some foliage during late autumn, but some discrepancy in the upper canopy layer was observed when the trees did not have their leaves in early spring. It was also found that the eddy diffusivities generally take greater values at higher positions, where the wind speeds are large. Anisotropy of eddy diffusivities between the vertical and horizontal components was also observed, particularly in the cases when the canopy does not have leaves, when the horizontal eddy diffusivities are generally larger than the vertical ones. On the other hand, the anisotropy is less visible when the trees have some foliage during autumn. The effects of topography on the turbulent diffusion were also investigated, including evaluation of the non-zero time-averaged vertical wind velocities. The results show that the effects are marginal for both cases, and can be neglected as far as diffusion in the canopy is concerned

    Formation of Deeply Bound Kaonic Atoms in (K^-,N) Reactions

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    We study theoretically the (K^-,N) reactions for the formation of the deeply bound kaonic atoms, which were predicted to be quasi--stable with narrow widths, using the Green function method. We consider various cases with different target nuclei and energies systematically and find the clear signals in the theoretical spectra for all cases considered in this article. The signals show very interesting structures, such as the RESONANCEDIPRESONANCE DIP instead of the resonance peak. We discuss the origins of the interesting structures and possibilities to get new information on the existence of the kaonic nuclei from the spectra of the atomic state formations.Comment: 11 pages, 9 figure

    Change of Electronic Structure Induced by Magnetic Transitions in CeBi

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    The temperature dependence of the electronic structure of CeBi arising from two types of antiferromagnetic transitions based on optical conductivity (σ(ω)\sigma(\omega)) was observed. The σ(ω)\sigma(\omega) spectrum continuously and discontinuously changes at 25 and 11 K, respectively. Between these temperatures, two peaks in the spectrum rapidly shift to the opposite energy sides as the temperature changes. Through a comparison with the band calculation as well as with the theoretical σ(ω)\sigma(\omega) spectrum, this peak shift was explained by the energy shift of the Bi 6p6p band due to the mixing effect between the Ce 4fΓ84f \Gamma_8 and Bi 6p6p states. The single-layer antiferromagnetic (++-) transition from the paramagnetic state was concluded to be of the second order. The marked changes in the σ(ω)\sigma(\omega) spectrum at 11 K, however, indicated the change in the electronic structure was due to a first-order-like magnetic transition from a single-layer to a double-layer (++++--) antiferromagnetic phase.Comment: 4 pages, to be published in J. Phys. Soc. Jpn. 73 Aug. (2004
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