Non-universal gravitational couplings of neutrinos in matter

When neutrinos travel through a normal matter medium, the electron neutrinos couple differently to gravity compared to the other neutrinos, due to the presence of electrons in the medium and the absence of the other charged leptons. The matter-induced gravitational couplings of the neutrinos under such conditions are calculated and their contribution to the neutrino index of refraction in the presence of a gravitational potential is determined.Comment: Latex, 10 page

Gravitational coupling of neutrinos in a medium

In a medium that contains electrons but not the other charged leptons, such as normal matter, the gravitational interactions of neutrinos are not the same for all the neutrino flavors. We calculate the leading order matter-induced corrections to the neutrino gravitational interactions in such a medium and consider some of their physical implications.Comment: 21 pages, Latex, uses axodraw.sty (typos corrected; two references added. To appear in Phys. Rev. D

Momentum-dependent contributions to the gravitational coupling of neutrinos in a medium

When neutrinos travel through a normal matter medium, the electron neutrinos couple differently to gravity compared to the other neutrinos, due to the presence of electrons in the medium and the absence of the other charged leptons. We calculate the momentum-dependent part of the matter-induced gravitational couplings of the neutrinos under such conditions, which arise at order $g^2/M^4_W$, and determine their contribution to the neutrino dispersion relation in the presence of a gravitational potential $\phi^{\mathrm{ext}}$. These new contributions vanish for the muon and tau neutrinos. For electron neutrinos with momentum $K$, they are of the order of the usual Wolfenstein term times the factor $(K^2/M^2_W)\phi^{\mathrm{ext}}$, for high energy neutrinos. In environments where the gravitational potential is substantial, such as those in the vicinity of Active Galactic Nuclei, they could be the dominant term in the neutrino dispersion relation. They must also be taken into account in the analysis of possible violations of the Equivalence Principle in the neutrino sector, in experimental settings involving high energy neutrinos traveling through a matter background.Comment: Minor corrections in the references; one reference adde

Neutrino Energy Reconstruction and the Shape of the CCQE-like Total Cross Section

We show that because of the multinucleon mechanism effects, the algorithm used to reconstruct the neutrino energy is not adequate when dealing with quasielastic-like events, and a distortion of the total flux unfolded cross section shape is produced. This amounts to a redistribution of strength from high to low energies, which gives rise to a sizable excess (deficit) of low (high) energy neutrinos. This distortion of the shape leads to a good description of the MiniBooNE unfolded CCQE-like cross sections published in Phys.Rev. D81 (2010) 092005. However, these changes in the shape are artifacts of the unfolding process that ignores multinucleon mechanisms.Comment: 11 pages, 6 figures. Some references and comments adde

Una nueva especie afrotropical de Ormyrus Westwood, 1832 (Hymenoptera, Chalcidoidea, Ormyridae)

Anew species, Ormyrus fernandinus sp. n. (Hymenoptera, Chalcidoidea, Ormyridae), is described from the island of Bioko (Equatorial Guinea). Collected with Malaise trap, the biology of the new species is unknown. The differential morphological features of the new species with respect to known afrotropical Ormyrus species, and its phylogenetic relationships are discussed.Se describe una nueva especie, Ormyrus fernandinus sp. n. (Hymenoptera, Chalcidoidea, Ormyridae), de la isla de Bioko (Guinea Ecuatorial). La especie fue colectada con trampa Malaise por lo que se desconoce su biología. Se discuten los caracteres distintivos fundamentales de la nueva especie en relación a las especies de Ormyrus conocidas en la region Afrotropical, y sus relaciones filogenéticas