Abstract:We study to what extent upcoming precision neutrino oscillation experiments will be able to exclude one of the most predictive models of neutrino mass and mixing: the Littlest Seesaw. We show that this model provides a good fit to current data, predicting eight observables from two input parameters, and provide new assessments of its predictions and their correlations. We then assess the ability to exclude this model using simulations of upcoming neutrino oscillation experiments including the medium-distance reactor experiments JUNO and RENO-50 and the long-baseline accelerator experiments DUNE and T2HK. We find that an accurate determination of the currently least well measured parameters, namely the atmospheric and solar angles and the CP phase δ, provide crucial independent tests of the model. For θ 13 and the two mass-squared differences, however, the model's exclusion requires a combination of measurements coming from a varied experimental programme. Our results show that the synergy and complementarity of future experiments will play a vital role in efficiently discriminating between predictive models of neutrino flavour, and hence, towards advancing our understanding of neutrino oscillations in the context of the flavour puzzle of the Standard Model.

Long-baseline neutrino oscillation experiments, in particular Deep Underground Neutrino Experiment (DUNE) and Tokai to Hyper-Kamiokande (T2HK), will lead the effort in the precision determination of the as yet unknown parameters of the leptonic mixing matrix. In this article, we revisit the potential of DUNE, T2HK and their combination in light of the most recent experimental information. As well as addressing more conventional questions, we pay particular attention to the attainable precision on {\delta}, which is playing an increasingly important role in the physics case of the long-baseline programme. We analyse the complementarity of the two designs, identify the benefit of a programme comprising distinct experiments and consider how best to optimise the global oscillation programme. This latter question is particularly pertinent in light of a number of alternative design options which have recently been mooted: a Korean second detector for T2HK and different beams options at DUNE. We study the impact of these options and quantify the synergies between alternative proposals, identifying the best means of furthering our knowledge of the fundamental physics of neutrino oscillation.Comment: 54 pages, 26 figure

We present results of a combined analysis in neutrino oscillations without unitarity assumption in the 3ν mixing picture. Constraints on neutrino mixing matrix elements are based on recent data from the reactor, solar and long-baseline accelerator neutrino oscillation experiments. The current data are consistent with the standard 3ν scheme. The precision on different matrix elements can be as good as a few percent at 3σ CL, and is mainly limited by the experimental statistical uncertainty. The νe related elements are the most precisely measured among all sectors with the uncertainties < 20%. The measured leptonic CP violation is very close to the one assuming the standard 3ν mixing. The deviations on normalization and the unitarity triangle closure are confined within $$ \mathcal{O} $$ O (10−3), $$ \mathcal{O} $$ O (10−2) and $$ \mathcal{O} $$ O (10−1), for νe, νμ and ντ sectors, respectively. We look forward to the next-generation neutrino oscillation experiments such as DUNE, T2HK, and JUNO, especially the precision measurements on ντ oscillations, to significantly improve the precision of unitarity test on the 3ν mixing matrix.

The eV-scale sterile neutrino has been proposed to explain some anomalous results in experiments, such as the deficit of reactor neutrino fluxes and the excess of νµ → νe in LSND. This hypothesis can be tested by future core-collapse supernova neutrino detection independently since the active-sterile mixing scheme affects the flavor conversion of neutrinos inside the supernova. In this work, we compute the predicted supernova neutrino events in future detectors -DUNE, Hyper-K, and JUNO -for neutrinos emitted during the neutronization burst phase when the luminosity of ν e dominates the other flavors. We find that for a supernova occurring within 10 kpc, the difference in the event numbers with and without sterile neutrinos allows to exclude the sterile neutrino hypothesis at more than 99% confidence level robustly. The derived constraints on sterile neutrinos mixing parameters are comparably better than the results from cosmology and on-going or proposed reactor experiments by more than two orders of magnitude in the sin 2 2θ 14 -∆m 2 41 plane.