Sergio Cruz-Alzaga | Searcharxiv

arXiv2025

Muon-Decay Parameters from COHERENT

We demonstrate that measurements of Coherent Elastic Neutrino-Nucleus Scattering (CE$ν$NS) at spallation sources are valuable probes of muon-decay physics. Using COHERENT data we derive the first direct constraint on the Michel parameters governing the $\barν_μ$ energy distribution. We also discuss future sensitivities, the implications for the Lorentz structure of the interactions mediating muon decay and the application to other neutrino-production mechanisms like pion decay.

hep-ph↗

arXiv2025

EFT analysis of New Physics at COHERENT with Dirac neutrinos

We study the sensitivity of COHERENT-like experiments to non-standard contributions within the so-called $ν$WEFT framework. The latter is the most general low-energy effective field theory that includes not only the light SM fields but also additional right-handed Dirac neutrinos. Our analysis includes for the first time flavor-general New Physics effects in neutrino production (pion and muon decays) and neutrino detection (through Coherent Elastic Neutrino-Nucleus Scattering). Despite the generality, the results can be written in compact form and are easy to implement in existing or future analyses using effective nuclear charges. We use current COHERENT data to set constraints on the corresponding effective operators, and we estimate the sensitivity of future measurements.

hep-ph↗