Probing neutrino physics with supernovae and rare decay searches
- Autores: Federica Pompa
- Directores de la Tesis: Michel Sorel (dir. tes.), Olga Mena Requejo (codir. tes.), Nadia Yahlali (tut. tes.)
- Lectura: En la Universitat de València ( España ) en 2024
- Idioma: español
- Tribunal Calificador de la Tesis: Roxanne Guenette (presid.), Mariam Tortola (secret.), L. Enrique Fernandez Martinez (voc.)
- Programa de doctorado: Programa de Doctorado en Física por la Universitat de València (Estudi General)
- Materias:
- Enlaces
- Tesis en acceso abierto en: TESEO
- Resumen
The observation of non-zero neutrino masses through flavor oscillations is the only direct evidence of particle physics beyond the Standard Model (BSM). The mechanism behind the generation of these masses, their absolute values, and whether neutrinos are Dirac or Majorana particles remains unknown. Recent advances in neutrino physics from both theoretical and experimental sides suggest that next-generation neutrino observatories could significantly enhance our understanding of fundamental physics. This thesis explores the expected advancements in supernova (SN) neutrinos and neutrino-less double beta decay (0vbb) searches.
The 99% of the energy released by a SN explosion is emitted in the form of all flavors MeV (anti)neutrinos. During their propagation towards the Earth, SN neutrinos experience a time delay due to their non-zero mass and can, in principle, decay, altering the expected flux on Earth. The detection of the initial phase of the SN neutrino emission, the neutronization burst, characterized by the presence of a sharp peak in the luminosity time spectra of the produced SN electron neutrinos, allows to reduce the SN model uncertainties affecting the modeling of the SN dynamics. Improved sensitivities on both neutrino mass and lifetime, with respect to the present bounds established by SN1987A data, could be achieved by the future DUNE and Hyper-Kamiokande projects, thanks to the large statistics collected and the combination of multiple interaction channels.
0vbb currently represents the only feasible way to probe Majorana neutrinos. It violates lepton number symmetry (LNV) and can be described through the approach of the effective field theory (EFT). Within a theoretical framework, different mechanisms can contribute to 0vbb. A well-motivated realization of 0vbb, directly connected to neutrino masses and their ordering, is given by the mass mechanism, through which a Majorana neutrino mass term is generated via the exchange of light Majorana neutrinos. Future projects, like LEGEND-1000 and nEXO, aim to fully cover the minimal inverted mass ordering (IO) region. Their combined performance would be sufficient to confirm or exclude, at 3sigma level, a 0vbb signal in the entire IO for almost all the nuclear model (NM) calculations available in the literature. Combination of future experiments could also discriminate among different NMs by exploiting complementary detection techniques and isotopes. However, the lack of knowledge on the underlying dominant contribution to 0vbb, and the complexity in describing the nuclear physics of the process, results in large uncertainties that constitute the most limiting theoretical factor in case of a future 0vbb signal observation. The ability to reconstruct the 0vbb electron kinematics would allow to discriminate the dominant LNV mechanism generating 0vbb. A ton-scale Xenon-gas detector with Barium-tagging capabilities would discriminate different LNV mechanisms with just few 0vbb events detected.
