8,595,655 research outputs found

    Proton-neutron alignment in the yrast states of 66^{66}Ge and 68^{68}Ge

    Full text link
    The 66^{66}Ge and 68^{68}Ge nuclei are studied by means of the shell model with the extended P+QQP+QQ Hamiltonian, which succeeds in reproducing experimentally observed energy levels, moments of inertia and other properties. The investigation using the reliable wave-functions predicts T=0, J=9 one-proton-one-neutron (1p1n1p1n) alignment in the g9/2g_{9/2} orbit, at high spins (141+14_1^+, 161+16_1^+ and 181+18_1^+) in these NZN \approx Z even-even nuclei. It is shown that a series of the even-JJ positive-parity yrast states (observed up to 261+26_1^+ for 68^{68}Ge) consists of the ground-state band and successive three bands with different types of particle alignments (two-neutron, 1p1n1p1n, two-proton-two-neutron) in the g9/2g_{9/2} orbit.Comment: 4 pages, 5 figures, to be published in Pyhs. Rev.

    Gluon fragmentation to 1D2^1D_2 quarkonia

    Full text link
    Gluon fragmentation to heavy JPC=2+J^{PC}=2^{-+} quarkonia is studied herein. We compute these D-wave states' polarized fragmentation functions and find that they are enhanced by large numerical prefactors. The prospects for detecting the lowest lying 1D2^1D_2 charmonium state at the Tevatron are discussed.Comment: 10 pages with 4 uuencoded figures, CALT-68-195

    Uniqueness of the compactly supported weak solutions of the relativistic Vlasov-Darwin system

    Full text link
    We use optimal transportation techniques to show uniqueness of the compactly supported weak solutions of the relativistic Vlasov-Darwin system. Our proof extends the method used by Loeper in J. Math. Pures Appl. 86, 68-79 (2006) to obtain uniqueness results for the Vlasov-Poisson system.Comment: AMS-LaTeX, 21 page

    One-step generation of high-quality squeezed and EPR states in cavity QED

    Full text link
    We show how to generate bilinear (quadratic) Hamiltonians in cavity quantum electrodynamics (QED) through the interaction of a single driven three-level atom with two (one) cavity modes. With this scheme it is possible to generate one-mode mesoscopic squeezed superpositions, two-mode entanglements, and two-mode squeezed vacuum states (such the original EPR state), without the need for Ramsey zones and external parametric amplification. The degree of squeezing achieved is up to 99% with currently feasible experimental parameters and the errors due to dissipative mechanisms become practically negligible

    Particle alignments and shape change in 66^{66}Ge and 68^{68}Ge

    Full text link
    The structure of the NZN \approx Z nuclei 66^{66}Ge and 68^{68}Ge is studied by the shell model on a spherical basis. The calculations with an extended P+QQP+QQ Hamiltonian in the configuration space (2p3/22p_{3/2}, 1f5/21f_{5/2}, 2p1/22p_{1/2}, 1g9/21g_{9/2}) succeed in reproducing experimental energy levels, moments of inertia and QQ moments in Ge isotopes. Using the reliable wave functions, this paper investigates particle alignments and nuclear shapes in 66^{66}Ge and 68^{68}Ge. It is shown that structural changes in the four sequences of the positive- and negative-parity yrast states with even JJ and odd JJ are caused by various types of particle alignments in the g9/2g_{9/2} orbit. The nuclear shape is investigated by calculating spectroscopic QQ moments of the first and second 2+2^+ states, and moreover the triaxiality is examined by the constrained Hatree-Fock method. The changes of the first band crossing and the nuclear deformation depending on the neutron number are discussed.Comment: 18 pages, 21 figures; submitted to Phys. Rev.

    Holomorphic submersions onto K\"ahler or balanced manifolds

    Full text link
    We study many properties concerning weak K\"ahlerianity on compact complex manifolds which admits a holomorphic submersion onto a K\"ahler or a balanced manifold. We get generalizations of some results of Harvey and Lawson (the K\"ahler case), Michelson (the balanced case), Popovici (the sG case) and others.Comment: 14 pages; second revised version; in press, Tohoku Math. J. vol 68, n.4 (2016

    Virtual moduli cycles and Gromov-Witten invariants of algebraic varieties

    Full text link
    We introduce a method of constructing the virtual cycle of any scheme associated with a tangent-obstruction complex. We apply this method to constructing the virtual moduli cycle of the moduli of stable maps from n-pointed genus g curves to any smooth projective variety. As an application, we give an algebraic definition of GW-invariants for any smooth projective variety.Comment: 68 pages, Amstex. Revised version. It appeared in J. of Amer. Math. Soc. Jan 9
    corecore