Research

After the discovery of the third nonvanishing neutrino mixing angle in 2012, the 3-neutrino mixing paradigm has been confirmed. The goal of future oscillation experiments will be to be able to measure with unprecedent precision oscillation parameters. Indeed, there are still a few open questions in the oscillation framework which need to be answered: in which octant the atmospheric mixing angle θ23 lies, which is the neutrino mass hierarchy and which is the amount of CP violation in neutrino oscillation. However, there exist a large number of new physics models which modify the oscillation probabilities. The astonishing predicted capabilities of the future long-baseline experiments DUNE and T2HK may be able to catch some of the faint effects of new physics in neutrino oscillation; for this reason, we expect that such experiments will be able to probe BSM models. In our research, we explore new approaches that may be used in this context.

The discovery of neutrino oscillations confirmed that neutrinos are not massless. It is difficult to ignore the fact that the range of fermion masses now spans at least 12 orders of magnitude, from the lightest neutrino to the top quark. Why are neutrino masses so small compared to those of charged leptons? Why is neutrino mixing so different from quark mixing, characterized by two large and one small angles? Is there a way to connect these puzzles with Grand Unification Theories and the matter-antimatter asymmetry of the Universe (Leptogenesis)? Is there an organizing principle (flavor symmetries) behind all of this? In our research, we explore all of these questions.

Modular Invariance is a promising tool proposed in 2017 to study neutrino masses and mixing: it is a very constraining type of flavour symmetry, with stringy origins. As opposed to traditional flavour symmetries, in most cases only one flavon (modulus) is needed to break the symmetry group, and the Yukawa couplings of the SM become pre-determined functions (modular forms) of the complex VEV of the modulus, up to a limited number of free parameters. In our reserach we employ this framework to study its phenomenological consequences.

Grand Unified Theories (GUT) supplemented with the help of family symmetries could provide a simple explanation so that their role in deciphering the flavor problem cannot be neglected. In fact, while GUT groups relate the properties of particles belonging to different species, thus establishing a connections among mass matrices of leptons and quarks, flavor symmetries act on the members of particles of the same species but different families, enabling a strong connection between the matrix elements of a given mass matrix.  
In our research we study different GUTs and their phenomenology in the context of neutrino masses and mixing.