713 research outputs found

    Chern-simon type photon mass from fermion electric dipole moments at finite temperature in 3+1 dimensions

    Full text link
    We study the low energy effective field theory of fermions with electric and magnetic dipole moments at finite temperature. We find that at one loop there is an interaction term of the Chern-Simon form LI=mμ AνF~μν{\cal L_I}=m_\mu\>A_\nu {\tilde F}^{\mu\nu}. The four vector mμ≃diμimi2 ∂μ (lnT)m_\mu \simeq d_i \mu_i m_i^2 ~{\partial_\mu}\>(ln T) is interpreted as a Chern- Simon type mass of photons, which is determined by the electric (magnetic) dipole moments did_i (μi\mu_i) of the fermions in the vacuum polarisation loop diagram. The physical consequence of such a photon mass is that, photons of opposite circular polarisations, propagating through a hot medium, have different group velocities. We estimate that the time lag between the arrival times of the left and right circularly polarised light signals from pulsars. If the light propagates through a hot plasma (where the temperature in some regions is T∼100MeVT \sim 100 MeV) then the time lag between the two circularly polarised signals of frequency ω\omega will be Δt(ω)≃10−6/ω\Delta t(\omega) \simeq 10^{-6} /\omega. It may be possible to observe this effect in pulsar signals which propagate through nebula at high temperatures.Comment: plain TeX, 9 page

    Central charge and renormalization in supersymmetric theories with vortices

    Full text link
    Some quantum features of vortices in supersymmetric theories in 1+2 dimensions are studied in a manifestly supersymmetric setting of the superfield formalism. A close examination of the supercurrent that accommodates the central charge and super-Poincare charges in a supermultiplet reveals that there is no genuine quantum anomaly in the supertrace identity and in the supercharge algebra, with the central-charge operator given by the bare Fayet-Iliopoulos term alone. The central charge and the vortex spectrum undergo renormalization on taking the expectation value of the central-charge operator. It is shown that the vortex spectrum is exactly determined at one loop while the spectrum of the elementary excitations receives higher-order corrections.Comment: 9 pages, revte

    Open Access Publishing in Business Research: The Authors’ Perspective

    Get PDF
    Open access (OA) publishing is now accepted as an integral part of the emerging trends within scholarly communication. Business librarians, like their subject specialist colleagues in other disciplines, are increasingly called upon to interpret scholarly communication trends to their faculty. This study surveys 1,293 business faculty from American schools of business accredited by the Association to Advance Collegiate Schools of Business. Issues explored include business faculty publishing practices within the discipline and how these affect academic advancement, obtaining articles for their own research, electronic publishing, self-archiving, and their perceptions about OA publishing generally.With support from the Emerald Publishing Research Award 2009

    Ten-year consistency in neurological test performance of children without focal neurological deficit

    Full text link
    To assess \u27soft-sign\u27 persistence and its correlates outside a referred sample, 159 members of a local birth cohort of the United National Collaborative Perinatal Project were traced and their performance on six neurological test scales was measured at age 17 by examiners blind to their status at age seven. A comparison group was also formed, who had been \u27sign-free\u27 at age seven. On four of the six tests (dysdiadochokinesis, mirror movements, dysgraphesthesia and motor slowness) index boys did significantly worse than the comparison boys; by contrast, index girls scored significantly worse than comparisons only on motor slowness

    Self-DUal SU(3) Chern-Simons Higgs Systems

    Get PDF
    We explore self-dual Chern-Simons Higgs systems with the local SU(3)SU(3) and global U(1)U(1) symmetries where the matter field lies in the adjoint representation. We show that there are three degenerate vacua of different symmetries and study the unbroken symmetry and particle spectrum in each vacuum. We classify the self-dual configurations into three types and study their properties.Comment: Columbia Preprint CU-TP-635, 19 page

    Failure of Gauge Invariance in the Nonperturbative Formulation of Massless Lorentz-Violating QED

    Full text link
    We consider a Lorentz-violating modification to the fermionic Lagrangian of QED that is known to produce a finite Chern-Simons term at leading order. We compute the second order correction to the one-loop photon self-energy in the massless case using an exact propagator and a nonperturbative formulation of the theory. This nonperturbative theory assigns a definite value to the coefficient of the induced Chern-Simons term; however, we find that the theory fails to preserve gauge invariance at higher orders. We conclude that the specific nonperturbative value of the Chern-Simons coefficient has no special significance.Comment: 8 pages, very minor change

    Massless Scalar QED with Non-minimal Chern Simons Coupling

    Full text link
    2+1 dimensional massless scalar QED with (ϕ∗ϕ)3(\phi^*\phi)^3 scalar self-coupling is modified by the addition of a non- minimal Chern-Simons term that couples the dual of the electromagnetic field strength to the covariant current of the complex scalar field. The theory is shown to be fully one- loop renormalizable. The one loop effective potential for the scalar field gives rise to spontaneous symmetry breaking which induces masses for both the scalar and vector fields. At high temperature there is a symmetry restoring phase transition.Comment: 18 pages, latex, preprint WIN-93-1
    • …
    corecore