The recent Xenon1T excess can be explained by solar neutrino scattering with electron via a light mediator, either scalar or vector, in addition to many other explanations from the dark sector. Since only the recoil electron is observable, a keV ster
ile neutrino instead of an active neutrino can appear in the final state. The sterile neutrino allows pseudoscalar mediator to explain the Xenon1T excess which was thought impossible. In addition, nonzero recoil energy lower bound arises from the sterile neutrino mass, which can be used to testify if the sterile neutrino is massive or not. We also briefly discuss the case of a sterile neutrino final state with light $Z$ mediator.
We show that the minimal 3-3-1 model cannot accommodate the neutrino masses at tree level using present experimental data. Nevertheless, a modified Zee and the Zee-Babu mechanisms for generating neutrino masses at 1-loop and 2-loop, respectively, are
automatically implemented in the minimal 3-3-1 model, without introducing new degrees of freedom to the model. We also present a systematic method for finding solutions to the leptonic sector masses and mixing. As a case study, we accommodate the charged and neutral leptons masses and the PMNS matrix in the 1-loop modified Zee mechanism contained in the minimal 3-3-1 model.
We performed a simulation on the DUNE experiment to probe the capability of future neutrino long-baseline experiments ability to constrain the parameter space of high-energy models by using the correlation between the atmospheric and reactor mixing a
ngles. As an example, we took the Tetrahedral Flavour Symmetry model, which predicts a strong relation between the non-zero value of $theta_{13}$ and deviation of $theta_{23}$ from the maximality. We show that in this case, the model can realistically be excluded in more than $3sigma$ for most of the parameter space. We also study the octant degeneracy at DUNE and its impact on the sensitivity of such models.
We found an analytical solution for the neutrino mass matrix in the most general case of the Zee model. Using the recent data on the neutrino parameters besides generating neutrino masses at 1-loop level we fit also the masses of the charged leptons
and the leptonic mixing matrix. We also show in what conditions the model is not compatible with neutrino data.
Taking into account the current global information on neutrino oscillation parameters we forecast the capabilities of future long baseline experiments such as DUNE and T2HK in settling the atmospheric octant puzzle. We find that a good measurement of
the reactor angle $theta_{13}$ plays a key role in fixing the octant of the atmospheric angle $theta_{23}$ with such future accelerator neutrino studies.
Here we study the pattern of neutrino oscillations emerging from a previously proposed warped model construction incorporating $Delta(27)$ flavor symmetry. In addition to a complete description of fermion masses, the model predicts the lepton mixing
matrix in terms of two parameters. The good measurement of $theta_{13}$ makes these two parameters nearly proportional, leading to an approximate one-parameter description of neutrino oscillations. There is a sharp fourfold degenerate correlation between $delta_{CP}$ and the atmospheric mixing angle $theta_{23}$, so that maximal $theta_{23}$ also implies maximal leptonic CP violation. The predicted electron neutrino and anti-neutrino appearance probabilities indicate that the model should be tested at the T2K, NO$ u$A and DUNE long baseline oscillation experiments.
