Constraining Muon decay parameters from CEvNS measurements at Spallation Sources

Abstract: The talk will present a study of the sensitivity of COHERENT-like experiments to non-standard neutrino interactions within the vWEFT framework, i.e. low-energy EFT with additional right-handed Dirac neutrinos. Our analysis incorporates, for the first time, flavor-general New Physics effects in neutrino production (from pion and muon decays) and neutrino detection, through Coherent Elastic Neutrino-Nucleus Scattering (CEvNS). As a special case, we will highlight how CEvNS data provide an alternative probe for muon decay parameters, for neutrino experiments where muon decay is a source of neutrinos. We will further illustrate how the results can be conveniently formulated in compact form and the ease with which they can be implemented in existing or future analyses using effective nuclear charges. Finally, We will discuss numerical results based on current COHERENT data, and also present estimates for the sensitivity of future measurements.