1,697 research outputs found

    Effective Lagrangian with vector mesons : Linear response theory

    Full text link
    The soliton breathing mode is investigated in the framework of linear response theory within a Skyrme model vector meson stabilized. The effective Lagrangian considered includes the ρ\rho (introduced following the standard prescription of nonlinear chiral symmetry) and the ω\omega mesons. The monopole response function is found to have a pronounced peak which is identified to the P11P11 (Roper) resonance. The results are compared to those obtained within the local approximation.Comment: 8 pages of plain Latex and 2 figures (available from the author), preprint LPN 93-12 and IPNO/TH 93-4

    Neutrino-photon reactions for energies above mem_e

    Get PDF
    We show that neutrino-photon reactions above mem_e are dominated by the reaction νγνe+e\nu \gamma \to \nu e^+ e^-. We calculate its cross-section and see that it is larger by several orders of magnitude than the cross-sections of other neutrino-photon processes, for energies above mem_e. We also discuss potential astrophysical and cosmological consequences.Comment: 7 pages, 2 figure

    Addendum to Finite-size effects on multibody neutrino exchange

    Get PDF
    The interaction energy of the neutrons due to massless neutrino exchange in a neutron star has recently been proved, using an effective theory, to be extremely small and infrared-safe. Our comment here is of conceptual order: two approaches to compute the total interaction energy density have recently been proposed. Here, we study the connection between these two approaches. From CP invariance, we argue that the resulting interaction energy has to be even in the parameter b=GFnn/2b=-G_F n_n /\sqrt{2}, which expresses the static neutrino potential created by a neutron medium of density nnn_n.Comment: Latex file (Revtex), 9 pages, 1 figure, one reference change