Probing neutrino nonstandard interactions with atmospheric neutrino data

By N. Fornengo, M. Maltoni, R. Tomàs, J. Valle. 2001

158 citations recorded by the source corpus.

We reconsider the atmospheric neutrino anomaly in light of the latest data from Super-Kamiokande contained events and from Super-Kamiokande and MACRO upgoing muons. We reanalyze the proposed solution to the atmospheric neutrino anomaly in terms of nonstandard neutrino-matter interactions (NSI's) as well as the standard ${\ensuremath{\nu}}_{\ensuremath{\mu}}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ oscillations (OSC's). Our statistical analysis shows that a pure NSI mechanism is now ruled out at 99%, while the standard ${\ensuremath{\nu}}_{\ensuremath{\mu}}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ OSC mechanism provides a quite remarkably good description of the anomaly. We therefore study an extended mechanism of neutrino propagation which combines both oscillation and nonstandard neutrino-matter interactions, in order to derive limits on flavor-changing and nonuniversal neutrino interactions. We obtain that the off-diagonal flavor-changing neutrino parameter $\ensuremath{\varepsilon}$ and the diagonal nonuniversality neutrino parameter ${\ensuremath{\varepsilon}}^{\ensuremath{'}}$ are confined to $\ensuremath{-}0.05l\ensuremath{\varepsilon}l0.04$ and $|{\ensuremath{\varepsilon}}^{\ensuremath{'}}|l0.17$ at 99% C.L. These limits are model independent and they are obtained from pure neutrino-physics processes. The stability of the neutrino oscillation solution to the atmospheric neutrino anomaly against the presence of nonstandard neutrino interactions establishes the robustness of the near-maximal atmospheric mixing and massive-neutrino hypothesis. The best agreement with the data is obtained for $\ensuremath{\Delta}{m}^{2}=2.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3} {\mathrm{eV}}^{2},$ ${\mathrm{sin}}^{2}(2\ensuremath{\theta})=0.99,$ $\ensuremath{\varepsilon}=\ensuremath{-}9.1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3},$ and ${\ensuremath{\varepsilon}}^{\ensuremath{'}}=\ensuremath{-}1.9\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3},$ although the ${\ensuremath{\chi}}^{2}$ function is quite flat in the $\ensuremath{\varepsilon}$ and ${\ensuremath{\varepsilon}}^{\ensuremath{'}}$ directions for $\ensuremath{\varepsilon},{\ensuremath{\varepsilon}}^{\ensuremath{'}}\ensuremath{\rightarrow}0.$

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/a7843d89bafb4786d95a7a1ac4b927dc3586495e

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Citations in the corpus

Probing new physics with coherent neutrino scattering off nuclei (2005, background): “In the atmospheric case, although a two families analysis [12] gives strong constraints, the three family case [13] showed that NSI interactions can be big.”
Oscillations of neutrinos and mesons in quantum field theory (2001, background): “anisms, such as oscillations of massless neutrinos due to a violation of the Equivalence Principle [235], to resonant spin-ﬂavor precession [12, 44], to ﬂavor-changing (or non-universal) interactions [118] or to dissipation [199, 52] (comparative reviews can be found in [195, 220, 132]). Finally, we”
Determination of matter potential from global analysis of neutrino oscillation data (2013, background): “The magnitude and the presence of non-standard forms of the matter potential can be tested in solar neutrino experiments (and in combination with KamLAND) [14–27], as well and in the propagation of atmospheric and long-baseline neutrinos [28–54].”
Neutrino Oscillations and Non-standard Interactions (2017, background): “Assuming a two–flavor neutrino system, it was shown [127] that the presence of large NSI couplings together with the standard mechanism of neutrino oscillation can spoil the excellent description of the atmospheric neutrino anomaly given by neutrino oscillations.”