Unveiling New Physics Models Through Meson Decays and Their Impact on Neutrino Experiments

As neutrino experiments enter into the precision era, it is desirable to identify deviations from data in comparison to theory as well as provide possible models as explanation. Particularly useful is the description in terms of non-standard interactions (NSI), which can be related to neutral (NC-NSI) or charged (CC-NSI) currents. Previously, we have developed the code eft-neutrino that connects NSI with generic UV models at tree-level matching. In this work, we integrate our code with other tools, increasing the matching between the UV and IR theories to one-loop level. As working example, we consider the pion and kaon decay, the main production mechanisms for accelerator neutrino experiments. We provide up-to-date allowed regions on a set of Wilson coefficients related to pion and kaon decay. We also illustrate how our chain of codes can be used in particular UV models, showing that promising large value for CC-NSI can be misleading when considering a specific UV model.