2006/06/30 by Alexander Friedland, Cecilia Lunardini · 2 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Neutrino Physics Research #Particle physics theoretical and experimental studies #hep-ex #hep-ph
paper · pdf · doi:10.1103/physrevd.74.033012
published as Phys.Rev. D74 (2006) 033012 · 10 pages, 3 figures; noticed typos corrected, results unchanged
arxiv created 2006/07/08 · openalex publication_date 2006/08/25 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The Super-Kamiokande atmospheric neutrino measurements leave substantial room for nonstandard interactions (NSI) of neutrinos with matter in the \ensuremathνe\mathrm\text\ensuremath-\ensuremathν_\ensuremathτ sector. Large values of the NSI couplings are accommodated if the vacuum oscillation parameters are changed from their standard values. Short and medium baseline neutrino beams can break this degeneracy by measuring the true vacuum oscillation parameters with the \ensuremathν_\ensuremathμ disappearance mode, for which the matter effects are negligible or subdominant. These experiments can also search for the \ensuremathνe\mathrm\text\ensuremath-\ensuremathν_\ensuremathτ flavor-changing effects directly, by looking for \ensuremathν_\ensuremathμ\mathrm\text\ensuremath-\ensuremathνe conversion caused by the intervening matter. We discuss both of these methods for the case of MINOS. We find that, while the present MINOS data on \ensuremathν_\ensuremathμ disappearance induce only minor changes on the constraints on the NSI parameters, the situation will improve markedly with the planned increase of the statistics by an order of magnitude. In that case, the precision will be enough to distinguish certain presently allowed NSI scenarios from the no-NSI case. NSI per quark of about 10% the size of the standard weak interaction could give a \ensuremathν_\ensuremathμ\mathrm\text\ensuremath-\ensuremathνe conversion probability of the order \ensuremath∼10^\ensuremath-2, measurable by MINOS in the same high statistics scenario. In this \ensuremathν_\ensuremathμ\mathrm\text\ensuremath-\ensuremathνe channel, the small effects of NSI could be comparable or larger than the vacuum contribution of the small angle \ensuremathθ13. The expected \ensuremathθ13 bound at MINOS should be more properly interpreted as a bound in the \ensuremathθ13-NSI parameter space.