6533b854fe1ef96bd12aeac0
RESEARCH PRODUCT
Effects of non-standard neutrino-electron interactions on relic neutrino decoupling
T. PintoPasquale D. SerpicoGianpiero ManganoGennaro MieleOfelia PisantiSergio Pastorsubject
PhysicsNuclear and High Energy PhysicsParticle physicsNeutral currentPhysics::Instrumentation and DetectorsAstrophysics::High Energy Astrophysical PhenomenaHigh Energy Physics::PhenomenologyAstrophysics (astro-ph)FOS: Physical sciencesNeutrino decouplingElectronAstrophysicsCosmic neutrino backgroundHigh Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)Big Bang nucleosynthesisNucleosynthesisHigh Energy Physics::ExperimentNeutrinoNeutrino oscillationdescription
We consider the decoupling of neutrinos in the early Universe in presence of non-standard neutral current neutrino-electron interactions (NSI). We first discuss a semi-analytical approach to solve the relevant kinetic equations and then present the results of fully numerical and momentum-dependent calculations, including flavor neutrino oscillations. We present our results in terms of both the effective number of neutrino species (N_eff) and the impact on the abundance of He-4 produced during Big Bang Nucleosynthesis. We find that, for NSI parameters within the ranges allowed by present laboratory data, non-standard neutrino-electron interactions do not essentially modify the density of relic neutrinos nor the bounds on neutrino properties from cosmological observables, such as their mass. Nonetheless, the presence of neutrino-electron NSI may enhance the entropy transfer from electron-positron pairs into neutrinos instead of photons, up to a value of N_eff=3.12. This is almost three times the correction to N_eff=3 that appears for standard weak interactions.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2006-07-25 |