Nu Flavour: Novel Effective Field Theory and Simplified Model Approaches to Beyond-the-Standard Model Flavour Physics and Neutrino Phenomenology

I propose utilizing model-independent formalisms, e.g. effective field theories (EFT) and simplified models, to study Beyond-the-Standard Model (BSM) flavour physics and associated neutrino phenomenology. The proposal will consist of two parts, (a) and (b).

In (a) I will apply the highly novel all-orders formalism of the Geometric SMEFT (GeoSMEFT) to define and extract neutrino masses and mixings from available datasets, thereby ascertaining the extent to which BSM physics may already be effecting present measurements, and also any implied constraints on candidate ultraviolet (UV) flavour theories.

In (b) I will study the phenomenology of Simplified Models of Flavourful Leptoquarks (SMFL) and/or other simplified models invariant under residual family symmetries (RFS), which encode symmetry-breaking effects in UV flavour theories and which can account for potential B-decay anomalies at the LHC, in atmospheric neutrino cascades detectable at IceCube.

Proposals (a) and (b) will be executed in four Work Packages (WP) with the following titles: WP1: A derivation of mass and mixing quantities within the GeoSMEFT for both Majorana and Dirac neutrino paradigms, including the associated renormalization group flow (RGE) and matching to lower-energy EFTs.

WP2: A phenomenological GeoSMEFT extraction of neutrino mass and mixing parameters from available datasets.

WP3: An extension of the RFS formalism embedded in SMFL to account for RD(*) anomalies in addition to, and independently from, the presently addressed RK(*) anomalies.

WP4: The development of the cascade atmospheric neutrino formalism in the presence of flavoured BSM states, and in particular SMFL, and the subsequent calculation of associated conventional and prompt neutrino fluxes at IceCube.

WP1-WP4 will yield innovative techniques for studying BSM flavour and neutrino physics in a model-independent manner, and new phenomenological results of interest to the broader high-energy particle physics community.