4,523 research outputs found

    SU(N) Coherent States

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    We generalize Schwinger boson representation of SU(2) algebra to SU(N) and define coherent states of SU(N) using 2(2N11)2(2^{N-1}-1) bosonic harmonic oscillator creation and annihilation operators. We give an explicit construction of all (N-1) Casimirs of SU(N) in terms of these creation and annihilation operators. The SU(N) coherent states belonging to any irreducible representations of SU(N) are labelled by the eigenvalues of the Casimir operators and are characterized by (N-1) complex orthonormal vectors describing the SU(N) manifold. The coherent states provide a resolution of identity, satisfy the continuity property, and possess a variety of group theoretic properties.Comment: 25 pages, LaTex, no figure

    Nonuniversal Effects in the Homogeneous Bose Gas

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    Effective field theory predicts that the leading nonuniversal effects in the homogeneous Bose gas arise from the effective range for S-wave scattering and from an effective three-body contact interaction. We calculate the leading nonuniversal contributions to the energy density and condensate fraction and compare the predictions with results from diffusion Monte Carlo calculations by Giorgini, Boronat, and Casulleras. We give a crude determination of the strength of the three-body contact interaction for various model potentials. Accurate determinations could be obtained from diffusion Monte Carlo calculations of the energy density with higher statistics.Comment: 24 pages, RevTex, 5 ps figures, included with epsf.te

    Information Generating Function for the r-Power Distribution

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    In a previous paper the authors defined an information generating function for giving Kapur's entropy of order a and type beta for a given distribution P. In the present paper they deduce the corresponding generating function for the r-power distribution P (r) obtained from P. The generating function is specialized to the cases of Renyi's shannon's entropies. Entropy of P/sup (r)/ is also obtained for some special distributions P

    Fauna ediacárica del Grupo de Jodhpur (Supergrupo de Marwar) en la ciudad de Jodhpur, al oeste de Rajasthan, India: Implicación para la selección de posibles sitios geopatrimoniales

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    The Ediacaran fossil record of the Jodhpur Group in the surroundings of Jodhpur city, western Rajasthan, is revised. Their best exposures are considered as potential Geoheritage sites. A specific protection from quarrying is envisaged.Se revisa el registro fósil ediacárico del Grupo de Jodhpur en los alrededores de la ciudad de Jodhpur, al oeste de Rajastán. Sus mejores afloramientos son considerados como sitios potenciales de Geopatrimonio. Se prevé una protección específica contra la explotación de sus canteras

    On the polarization of the resonance lines of lithium and sodium atoms by electron impact

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    The polarization of the resonance lines of 6Li, 7Li and Na, excited by electron impact, are calculated using the Glauber approximation. The present results are in good agreement with experimental values and with other theoretical calculations in the energy range from 2 eV to 5 eV

    Searching for tetraquarks on the lattice

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    We address the question whether the lightest scalar mesons sigma and kappa are tetraquarks. We present a search for possible light tetraquark states with J^PC=0^++ and I=0, 1/2, 3/2, 2 in the dynamical and the quenched lattice simulations using tetraquark interpolators. In all the channels, we unavoidably find lowest scattering states pi(k)pi(-k) or K(k)pi(-k) with back-to-back momentum k=0,2*pi/L,.. . However, we find an additional light state in the I=0 and I=1/2 channels, which may be related to the observed resonances sigma and kappa with a strong tetraquark component. In the exotic repulsive channels I=2 and I=3/2, where no resonance is observed, we find no light state in addition to the scattering states.Comment: 3 pages, 1 figure, proceedings of Lepton-Photon 2009, Hambur

    Transplacental Japanese encephalitis virus (JEV) infection in mice during consecutive pregnancies

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    Transplacental transmission of Japanese encephalitis virus (JEV) has been demonstrated in consecutive pregnancies of mice. Pregnant mice inoculated intraperitoneally with JEV transmit the virus to the foetus. When such female mice were mated again after 6 months, the virus could be isolated from the foetuses of the ensuing pregnancy. The incidence of abortion was increased significantly though the neonatal deaths were considerably less than during the first pregnancy. Intra-uterine infection occurred in spite of the presence of HAI antibodies against JEV in the preconceptional sera of the mice. The findings of the present study indicate the value of such a system for further investigations of the pathogenesis of JEV infection during pregnancy in humans
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