Are solar neutrino oscillations robust

By O. Miranda, M. Tórtola, J. Valle. 2004

180 citations recorded by the source corpus.

The robustness of the large mixing angle (LMA) oscillation (OSC) interpretation of the solar neutrino data is considered in a more general framework where non-standard neutrino interactions (NSI) are present. Such interactions may be regarded as a generic feature of models of neutrino mass. The 766.3 ton-yr data sample of the KamLAND collaboration are included in the analysis, paying attention to the background from the reaction ^13C(\alpha,n) ^16O. Similarly, the latest solar neutrino fluxes from the SNO collaboration are included. In addition to the solution which holds in the absence of NSI (LMA-I) there is a 'dark-side' solution (LMA-D) with sin^2 theta_Sol = 0.70, essentially degenerate with the former, and another light-side solution (LMA-0) allowed only at 97% CL. More precise KamLAND reactor measurements will not resolve the ambiguity in the determination of the solar neutrino mixing angle theta_Sol, as they are expected to constrain mainly Delta m^2. We comment on the complementary role of atmospheric, laboratory (e.g. CHARM) and future solar neutrino experiments in lifting the degeneracy between the LMA-I and LMA-D solutions. In particular, we show how the LMA-D solution induced by the simplest NSI between neutrinos and down-type-quarks-only is in conflict with the combination of current atmospheric data and data of the CHARM experiment. We also mention that establishing the issue of robustness of the oscillation picture in the most general case will require further experiments, such as those involving low energy solar neutrinos.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/7968f6cc2f9c3294e80446a86a5f934c71354365

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Citations in the corpus

Neutrino Oscillations and Non-standard Interactions (2017, methodology): “Since the LMA-D solution was introduced in the literature keeping ∆m(2)21 positive while allowing θ12 to vary in the range (0, π/2) [9] and this convention has become popular in the literature since then, we will use it along this review.”
Global Analyses of Neutrino Oscillation Experiments (2015, background): “• the determination of most the oscillation parameters discussed in the previous section is robust under the presence of NSI as large as allowed by the oscillation data itself with the exception of the octant of θ12; • a solution with θ12 > 45◦ (the “so-called” LMA-D solution [86]) still provides a ”
Probing new physics with coherent neutrino scattering off nuclei (2005, background): “y this case because, as it has been pointed out in the introduction, for this case is possible to have additional solutions to the solar neutrino problem, if the non-universal NSI contribution is big [11]. As before we consider only NSI parameters which include tau-neutrinos, since the NSI muon neut”
Determination of matter potential from global analysis of neutrino oscillation data (2013, background): “[73] it was found that the combination with CHARM scattering results [94, 95] for f = d substantially lifts the statistical difference between LMA and LMA-D.”
2020 global reassessment of the neutrino oscillation picture (2020, background): “† Other mechanisms, such as magnetic moments [16–18] or non-standard interactions [19–21] could be present only at a sub-leading level [7], for recent analyses see, e.”
Testing large non-standard neutrino interactions with arbitrary mediator mass after COHERENT data (2018, background): “In matter the degeneracy is broken, but can be restored with new physics in the form of NSI of the same magnitude as the weak scale, = O(1) [10].”
Updated constraints on non-standard interactions from global analysis of oscillation data (2018, background): “As can be seen, the main impact of including COHERENT data is to strongly disfavor the LMA-D solution for a wide range of η. LMA-D is allowed below 3σ only for −38◦ . η .”
Neutrino non-standard interactions: A status report (2019, background): “Similar degeneracy has also been observed in previous studies: in [17, 30, 34] (in the context of NSI) and also in [390] in the context of Lorentz violating parameters.”