20,636 research outputs found

    The 25 October 2010 Mentawai tsunami earthquake (M_w 7.8) and the tsunami hazard presented by shallow megathrust ruptures

    Get PDF
    The 25 October 2010 Mentawai, Indonesia earthquake (M_w 7.8) ruptured the shallow portion of the subduction zone seaward of the Mentawai islands, off-shore of Sumatra, generating 3 to 9 m tsunami run-up along southwestern coasts of the Pagai Islands that took at least 431 lives. Analyses of teleseismic P, SH and Rayleigh waves for finite-fault source rupture characteristics indicate ∼90 s rupture duration with a low rupture velocity of ∼1.5 km/s on the 10° dipping megathrust, with total slip of 2–4 m over an ∼100 km long source region. The seismic moment-scaled energy release is 1.4 × 10^(−6), lower than 2.4 × 10^(−6) found for the 17 July 2006 Java tsunami earthquake (M_w 7.8). The Mentawai event ruptured up-dip of the slip region of the 12 September 2007 Kepulauan earthquake (M_w 7.9), and together with the 4 January 1907 (M 7.6) tsunami earthquake located seaward of Simeulue Island to the northwest along the arc, demonstrates the significant tsunami generation potential for shallow megathrust ruptures in regions up-dip of great underthrusting events in Indonesia and elsewhere

    Nonperturbative Determination of Heavy Meson Bound States

    Get PDF
    In this paper we obtain a heavy meson bound state equation from the heavy quark equation of motion in heavy quark effective theory (HQET) and the heavy meson effective field theory we developed very recently. The bound state equation is a covariant extention of the light-front bound state equation for heavy mesons derived from light-front QCD and HQET. We determine the covariant heavy meson wave function variationally by minimizing the binding energy Λˉ\bar{\Lambda}. Subsequently the other basic HQET parameters λ1\lambda_1 and λ2\lambda_2, and the heavy quark masses mbm_b and mcm_c can also be consistently determined.Comment: 15 pages, 1 figur

    Fractional flux periodicity of a twisted planar square lattice

    Full text link
    We present fractional flux periodicity in the ground state of planar systems made of a square lattice whose boundary is compacted into a torus. The ground-state energy shows a fractional period of the fundamental unit of magnetic flux depending on the twist around the torus axis.Comment: 4 pages, 2 figures, corrected typos (v3

    Coherent phenomena in mesoscopic systems

    Full text link
    A mesoscopic system of cylindrical geometry made of a metal or a semiconductor is shown to exhibit features of a quantum coherent state. It is shown that magnetostatic interaction can play an important role in mesoscopic systems leading to an ordered ground state. The temperature TT^{*} below the system exhibits long-range order is determined. The self-consistent mean field approximation of the magnetostatic interaction is performed giving the effective Hamiltonian from which the self-sustaining currents can be obtained. The relation of quantum coherent state in mesoscopic cylinders to other coherent systems like superconductors is discussed.Comment: REVTeX, 4 figures, in print in Supercond. Sci. Techno

    Sequestering CP Violation and GIM-Violation with Warped Extra Dimensions

    Get PDF
    We propose a model of spontaneous CP violation to address the strong CP problem in warped extra dimensions that relies on sequestering flavor and CP violation. We assume that brane-localized Higgs Yukawa interactions respect a U(3) flavor symmetry that is broken only by bulk fermion mass and Yukawa terms. All CP violation arises from the vev of a CP-odd scalar field localized in the bulk. To suppress radiative corrections to theta-bar, the doublet quarks in this model are localized on the IR brane. We calculate constraints from flavor-changing neutral currents (FCNCs), precision electroweak measurements, CKM unitarity, and the electric dipole moments in this model and predict theta-bar to be at least about 10^-12.Comment: 38 page

    Controlled Quantum Secret Sharing

    Full text link
    We present a new protocol in which a secret multiqubit quantum state Ψ\ket{\Psi} is shared by nn players and mm controllers, where Ψ\ket{\Psi} is the encoding state of a quantum secret sharing scheme. The players may be considered as field agents responsible for carrying out a task, using the secret information encrypted in Ψ\ket{\Psi}, while the controllers are superiors who decide if and when the task should be carried out and who to do it. Our protocol only requires ancillary Bell states and Bell-basis measurements.Comment: 6 pages, 0 figure, RevTeX4; published version with minor change
    corecore