7,255 research outputs found

    Massive Overlap Fermions on Anisotropic Lattices

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    We formulate the massive overlap fermions on anisotropic lattices. We find that the dispersion relation for the overlap fermion resembles the continuum form in the low-momentum region once the bare parameters are properly tuned. The quark self-energy and the quark field renormalization constants are calculated to one-loop in bare lattice perturbation theory. We argue that massive domain wall quarks might be helpful in lattice QCD studies on heavy-light hadron spectroscopy.Comment: 21 pages, 5 figures, one reference added compared with v.

    Localization of fermionic fields on braneworlds with bulk tachyon matter

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    Recently, Pal and Skar in [arXiv:hep-th/0701266] proposed a mechanism to arise the warped braneworld models from bulk tachyon matter, which are endowed with a thin brane and a thick brane. In this framework, we investigate localization of fermionic fields on these branes. As in the 1/2 spin case, the field can be localized on both the thin and thick branes with inclusion of scalar background. In the 3/2 spin extension, the general supergravity action coupled to chiral supermultiplets is considered to produce the localization on both the branes as a result.Comment: 9 pages, no figure

    Gauged Q ball in a piecewise parabolic potential

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    Q ball solutions are considered within the theory of a complex scalar field with a gauged U(1) symmetry and a parabolic-type potential. In the thin-walled limit, we show explicitly that there is a maximum size for these objects because of the repulsive Coulomb force. The size of Q ball will increase with the decrease of local minimum of the potential. And when the two minima degenerate, the energy stored within the surface of the Q ball becomes significant. Furthermore, we find an analytic expression for gauged Q ball, which is beyond the conventional thin-walled limit.Comment: 1 figure

    Reconstruction of 5D5D Cosmological Models From Equation of State of Dark Energy

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    We consider a class of five-dimensional cosmological solutions which contains two arbitrary function μ(t)\mu(t) and ν(t)\nu(t). We found that the arbitrary function μ(t)\mu(t) contained in the solutions can be rewritten in terms of the redshift zz as a new arbitrary function f(z)f(z). We further showed that this new arbitrary function f(z)f(z) could be solved out for four known parameterized equations of state of dark energy. Then the 5D5D models can be reconstructed and the evolution of the density and deceleration parameters of the universe can be determined.Comment: 10 pages, 4 eps figures, ws-ijmpd.cls styl

    Scaling of the CKM Matrix in the 5D MSSM

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    We discuss a five-dimensional Minimal Supersymmetric Standard Model compactified on a S1/Z2S^1/Z_2 orbifold, looking at, in particular, the one-loop evolution equations of the Yukawa couplings for the quark sector and various flavor observables. Different possibilities for the matter fields are discussed, that is, where they are in the bulk or localised to the brane. The two possibilities give rise to quite different behaviours. By studying the implications of the evolution with the renormalisation group of the Yukawa couplings and of the flavor observables we find that, for a theory that is valid up to the unification scale, the case where fields are localised to the brane, with a large tanβ\tan\beta, would be more easily distinguishable from other scenarios.Comment: 12 pages, 8 figures, Extra comments adde

    Method and System for Scatter Correction in X-Ray Imaging

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    Approaches for deriving scatter information using inverse tracking of scattered X-rays is disclosed. In certain embodiments scattered rays are tracked from respective locations on a detector to a source of the X-ray radiation, as opposed to tracking schemes that proceed from the source to the detector. In one such approach, the inverse tracking is implemented using a density integrated volume that reduces the integration steps performed

    Counterdiabatic driving for pseudo- and antipseudo- Hermitian systems

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    In this work, we study the counterdiabatic driving scheme in pseudo- and antipseudo- Hermitian systems. By discussing the adiabatic condition for non-Hermitian system, we show that the adiabatic evolution of state can only be realized in the non-Hermitian system which possesses real energy spectrum. Therefore, the counterdiabatic driving scheme to reproduce an exact evolution of an energy eigenstate needs either real energy spectrum or dropping its parts of dynamic phase and Berry phase. In this sense, we derive the adiabatic conditions and counterdiabatic driving Hamiltonians for the pseudo-Hermitian Hamiltonian which possesses either real or complex energy spectrum and the antipseudo-Hermitian Hamiltonian which possesses either imaginary or complex energy spectrum. We also find the condition to get self-normalized energy eigenstates in pseudo- and antipseudo- Hermitian system and derive the well-defined population of bare states on this energy eigenstate. Our results are illustrated by studying the counterdiabatic driving for a non-Hermitian three level system, and a perfect population transfer with loss or gain is realized.Comment: 9pages, 6figure

    Electric field tunable multi-state tunnel magnetoresistances in 2D van der Waals magnetic heterojunctions

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    Magnetic tunnel junction (MTJ) based on van der Waals (vdW) magnetic layers has been found to present excellent tunneling magnetoresistance (TMR) property, which has great potential applications in field sensing, non-volatile magnetic random access memories, and spin logics. Although MTJs composed of multilayer vdW magnetic homojunctions have been extensively investigated, the ones composed of vdW magnetic heterojunction is still to be explored. Here we use first-principles approaches to reveal that the magnetic heterojunction MTJs have much more distinguishable TMR values than the homojunction ones. In the MTJ composed of bilayer CrI3/bilayer Cr2Ge2Te6 heterojunction, we find there are eight stable magnetic states, leading to seven distinguishable electronic resistances. As a result, six sizable TMRs larger than 600% can be obtained (the maximum TMR is up to 120,000%). The number of distinguishable memories is more than two times larger than that of a four-layered homojunction MTJ. The underlying relationships among magnetic state, spin-polarized band structures, and transmission spectrums are further revealed to explain the multiple TMR values. We also find that the magnetic states and thus TMRs can be efficiently modulated by an external electric field. This study opens an avenue to the design of high-performance MTJ devices based on vdW heterojunctions.Comment: 6 figure
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