291 research outputs found

    Amplification of coupling for Yukawa potentials

    Get PDF
    It is well known that Yukawa potentials permit bound states in the Schrodinger equation only if the ratio of the exchanged mass to bound mass is below a critical multiple of the coupling constant. However, arguments suggested by the Darwin term imply a more complex situation. By numerically studying the Dirac equation with a Yukawa potential we investigate this amplification effect.Comment: 7 pages, 2 figure

    Translations between Quaternion and Complex Quantum Mechanics

    Full text link
    While in general there is no one-to-one correspondence between complex and quaternion quantum mechanics (QQM), there exists at least one version of QQM in which a {\em partial} set of {\em translations} may be made. We define these translations and use the rules to obtain rapid quaternion counterparts (some of which are new) of standard quantum mechanical results.Comment: 15 pages, LaTeX, ULTH-93-3

    Wave packets and quantum oscillations

    Full text link
    We give a detailed analysis of the oscillation formula within the context of the wave packet formalism. Particular attention is made to insure flavor eigenstate creation in the physical cases (Delta p not equal 0). This requirement imposes non instantaneous particle creation in all frames. It is shown that the standard formula is not only exact when the mass wave packets have the same velocity, but it is a good approximation when minimal slippage occurs. For more general situations the oscillation formula contains additional arbitrary parameters, which allows for the unknown form of the wave packet envelope.Comment: 15 pages [8 figs], AMS-Te

    REPLY TO HEP-PH/0211241 "On the extra factor of two in the phase of neutrino oscillations"

    Full text link
    Arguments continue to appear in the literature concerning the validity of the standard oscillation formula. We point out some misunderstandings and try to explain in simple terms our viewpoint.Comment: 4 pages [1 colored LaTex-fig], AMS-Te

    The cosmological dependence of weak interactions

    Get PDF
    A model for the cosmological time dependence of weak interactions is discused and some experimental tests suggested

    Representations of U(1,q) and Constructive Quaternion Tensor Products

    Full text link
    The representation theory of the group U(1,q) is discussed in detail because of its possible application in a quaternion version of the Salam-Weinberg theory. As a consequence, from purely group theoretical arguments we demonstrate that the eigenvalues must be right-eigenvalues and that the only consistent scalar products are the complex ones. We also define an explicit quaternion tensor product which leads to a set of additional group representations for integer ``spin''.Comment: 28 pages, Latex, Dipartimento di Fisica, Universita di Lecce INFN-Sezione di Lecc

    Empresa social e economia solidária: perspectivas no campo da inserção laboral de portadores de transtorno mental

    Get PDF
    O processo da reforma psiquiátrica requer a implementação de políticas públicas que garantam a inserção laboral de portadores de transtorno mental. Para tal, é necessário que o trabalho seja compreendido como promotor de autonomia, de emancipação e de cidadania. O objetivo deste estudo é refletir acerca de concepções teóricas relacionadas à inserção social pelo trabalho, a fim de explorar o campo da inclusão de portadores de transtorno mental no mundo do trabalho. Foram escolhidos os conceitos de empresa social e de economia solidária como fundamentais para o estudo. Na empresa social, o sujeito é entendido como ser social, enfocando-se seu processo de formação no sentido da emancipação. Na economia solidária, objetiva-se o desenvolvimento de uma forma de economia mais justa que tem como característica a igualdade e a solidariedade. Sugerimos que a discussão desses conceitos possa contribuir para embasar a implantação de projetos de inclusão social pelo trabalho.El proceso de reforma psiquiátrica requiere de la implementación de políticas públicas que garanticen la inserción laboral de portadores de transtorno mental. Para ello, es necesario que el trabajo sea comprendido como promotor de autonomía, emancipación y ciudadanía. El objetivo de este estudio es reflexionar acerca de concepciones teóricas relacionadas con la inserción social mediante el trabajo, apuntando a explorar el campo de la inclusión de portadores de transtorno mental en el mundo laboral. Se eligieron los conceptos de empresa social y de economía solidaria como fundamentales para el estudio. En la empresa social, el sujeto es entendido como ser social, enfocándose su proceso de formación con sentido emancipatorio. En la economía solidaria, se objetiva el desarrollo de una economía más justa que tiene como característica la igualdad y solidaridad. Sugerimos que la discusión de tales conceptos aporte como base de implantación de proyectos de inclusión social mediante el trabajo.The psychiatric reform process requires the implementation of public policies that guarantee the work inclusion of individuals with mental disorders. To do this, work must be understood as a promoter of autonomy, emancipation and citizenship. The objective of this study is to reflect on the theoretical concepts related to social insertion through work, with the purpose of exploring the inclusion of individuals with mental disorders in the work market. The concepts social company and solidary economy where selected as fundamental for the study. In the social company, the subject is considered to be a social being, focusing on the development process towards emancipation. In solidary economy, the objective is to develop an economy that is more just, equal and solidary. Further discussions on these concepts should be developed to support the implementation of projects for social inclusion through work

    Barrier Paradox in the Klein Zone

    Get PDF
    We study the solutions for a one-dimensional electrostatic potential in the Dirac equation when the incoming wave packet exhibits the Klein paradox (pair production). With a barrier potential we demonstrate the existence of multiple reflections (and transmissions). The antiparticle solutions which are necessarily localized within the barrier region create new pairs with each reflection at the potential walls. Consequently we encounter a new paradox for the barrier because successive outgoing wave amplitudes grow geometrically.Comment: 10 page
    corecore