de Salas, P. F., Forero, D. V., Ternes, C. A., Tortola, M., & Valle, J. W. F. (2018). Status of neutrino oscillations 2018: 3 sigma hint for normal mass ordering and improved CP sensitivity. Phys. Lett. B, 782, 633–640.
Abstract: We present a new global fit of neutrino oscillation parameters within the simplest three-neutrino picture, including new data which appeared since our previous analysis[1]. In this update we include new long-baseline neutrino data involving the antineutrino channel in T2K, as well as new data in the neutrino channel, data from NO nu A, as well as new reactor data, such as the Daya Bay 1230 days electron antineutrino disappearance spectrum data and the 1500 live days prompt spectrum from RENO, as well as new Double Chooz data. We also include atmospheric neutrino data from the IceCube DeepCore and ANTARES neutrino telescopes and from Super-Kamiokande. Finally, we also update our solar oscillation analysis by including the 2055-day day/night spectrum from the fourth phase of the Super-Kamiokande experiment. With the new data we find a preference for the atmospheric angle in the upper octant for both neutrino mass orderings, with maximal mixing allowed at Delta chi(2)= 1.6 (3.2) for normal (inverted) ordering. We also obtain a strong preference for values of the CP phase delta in the range [pi, 2 pi], excluding values close to pi/2at more than 4 sigma. More remarkably, our global analysis shows a hint in favorof the normal mass ordering over the inverted one at more than 3 sigma. We discuss in detail the status of the mass ordering, CP violation and octant sensitivities, analyzing the interplay among the different neutrino data samples.
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Bandyopadhyay, P., Chun, E. J., Mandal, R., & Queiroz, F. S. (2019). Scrutinizing right-handed neutrino portal dark matter with Yukawa effect. Phys. Lett. B, 788, 530–534.
Abstract: Analyzing the neutrino Yukawa effect in the freeze-out process of a generic dark matter candidate with right-handed neutrino portal, we identify the parameter regions satisfying the observed dark matter relic density as well as the current Fermi-LAT and H.E.S.S. limits and the future CTA reach on gamma-ray signals. In this scenario the dark matter couples to the Higgs boson at one-loop level and thus could be detected by spin-independent nucleonic scattering for a reasonable range of the relevant parameters.
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Ellis, J., Mavromatos, N. E., Sakharov, A. S., & Sarkisyan-Grinbaum, E. K. (2019). Limits on neutrino Lorentz violation from multimessenger observations of TXS 0506+056. Phys. Lett. B, 789, 352–355.
Abstract: The observation by the IceCube Collaboration of a high-energy (E greater than or similar to 200 TeV) neutrino from the direction of the blazar TXS 0506+056 and the coincident observations of enhanced gamma-ray emissions from the same object by MAGIC and other experiments can be used to set stringent constraints on Lorentz violation in the propagation of neutrinos that is linear in the neutrino energy: Delta v = -E/M-1, where Delta v is the deviation from the velocity of light, and M-1 is an unknown high energy scale to be constrained by experiment. Allowing for a difference in neutrino and photon propagation times of similar to 10 days, we find that M-1 greater than or similar to 3 x 10(16) GeV. This improves on previous limits on linear Lorentz violation in neutrino propagation by many orders of magnitude, and the same is true for quadratic Lorentz violation.
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de Salas, P. F., Pastor, S., Ternes, C. A., Thakore, T., & Tortola, M. (2019). Constraining the invisible neutrino decay with KM3NeT-ORCA. Phys. Lett. B, 789, 472–479.
Abstract: Several theories of particle physics beyond the Standard Model consider that neutrinos can decay. In this work we assume that the standard mechanism of neutrino oscillations is altered by the decay of the heaviest neutrino mass state into a sterile neutrino and, depending on the model, a scalar or a Majoron. We study the sensitivity of the forthcoming KM3NeT-ORCA experiment to this scenario and find that it could improve the current bounds coming from oscillation experiments, where three-neutrino oscillations have been considered, by roughly two orders of magnitude. We also study how the presence of this neutrino decay can affect the determination of the atmospheric oscillation parameters sin(2) theta(23) and Delta m(31)(2), as well as the sensitivity to the neutrino mass ordering.
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Barenboim, G., Denton, P. B., Parke, S. J., & Ternes, C. A. (2019). Neutrino oscillation probabilities through the looking glass. Phys. Lett. B, 791, 351–360.
Abstract: In this paper we review different expansions for neutrino oscillation probabilities in matter in the context of long-baseline neutrino experiments. We examine the accuracy and computational efficiency of different exact and approximate expressions. We find that many of the expressions used in the literature are not precise enough for the next generation of long-baseline experiments, but several of them are while maintaining comparable simplicity. The results of this paper can be used as guidance to both phenomenologists and experimentalists when implementing the various oscillation expressions into their analysis tools.
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