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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Miranda, O. G., Papoulias, D. K., Tortola, M., & Valle, J. W. F. (2020). XENON1T signal from transition neutrino magnetic moments. Phys. Lett. B, 808, 135685–5pp.
Abstract: The recent puzzling results of the XENONIT collaboration at few keV electronic recoils could be due to the scattering of solar neutrinos endowed with finite Majorana transition magnetic moments (TMMs). Within such general formalism, we find that the observed excess in the XENONIT data agrees well with this interpretation. The required TMM strengths lie within the limits set by current experiments, such as Borexino, specially when one takes into account a possible tritium contamination.
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de Salas, P. F., Gariazzo, S., Martinez-Mirave, P., Pastor, S., & Tortola, M. (2021). Cosmological radiation density with non-standard neutrino-electron interactions. Phys. Lett. B, 820, 136508–9pp.
Abstract: Neutrino non-standard interactions (NSI) with electrons are known to alter the picture of neutrino de coupling from the cosmic plasma. NSI modify both flavour oscillations through matter effects, and the annihilation and scattering between neutrinos and electrons and positrons in the thermal plasma. In view of the forthcoming cosmological observations, we perform a precision study of the impact of non universal and flavour-changing NSI on the effective number of neutrinos, Neff. We present the variation of Neff arising from the different NSI parameters and discuss the existing degeneracies among them, from cosmology alone and in relation to the current bounds from terrestrial experiments. Even though cosmology is generally less sensitive to NSI than these experiments, we find that future cosmological data would provide competitive and complementary constraints for some of the couplings and their combinations.
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Addazi, A. et al, Martinez-Mirave, P., Mitsou, V. A., Palomares-Ruiz, S., Tortola, M., & Zornoza, J. D. (2022). Quantum gravity phenomenology at the dawn of the multi-messenger era-A review. Prog. Part. Nucl. Phys., 125, 103948–119pp.
Abstract: The exploration of the universe has recently entered a new era thanks to the multi-messenger paradigm, characterized by a continuous increase in the quantity and quality of experimental data that is obtained by the detection of the various cosmic messengers (photons, neutrinos, cosmic rays and gravitational waves) from numerous origins. They give us information about their sources in the universe and the properties of the intergalactic medium. Moreover, multi-messenger astronomy opens up the possibility to search for phenomenological signatures of quantum gravity. On the one hand, the most energetic events allow us to test our physical theories at energy regimes which are not directly accessible in accelerators; on the other hand, tiny effects in the propagation of very high energy particles could be amplified by cosmological distances. After decades of merely theoretical investigations, the possibility of obtaining phenomenological indications of Planck-scale effects is a revolutionary step in the quest for a quantum theory of gravity, but it requires cooperation between different communities of physicists (both theoretical and experimental). This review, prepared within the COST Action CA18108 “Quantum gravity phenomenology in the multi-messenger approach”, is aimed at promoting this cooperation by giving a state-of-the art account of the interdisciplinary expertise that is needed in the effective search of quantum gravity footprints in the production, propagation and detection of cosmic messengers.
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Miranda, O. G., Tortola, M., & Valle, J. W. F. (2016). New Ambiguity in Probing CP Violation in Neutrino Oscillations. Phys. Rev. Lett., 117(6), 061804–5pp.
Abstract: If neutrinos get mass via the seesaw mechanism the mixing matrix describing neutrino oscillations can be effectively nonunitary. We show that in this case the neutrino appearance probabilities involve a new CP phase phi associated with nonunitarity. This leads to an ambiguity in extracting the “standard” three-neutrino phase delta(CP), which can survive even after neutrino and antineutrino channels are combined. Its existence should be taken into account in the planning of any oscillation experiment aiming at a robust measurement of delta(CP).
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