Speaker
Description
Many experiments have been conducted to search for charged lepton flavor violation (CLFV) and have yielded very strong constraints. At the same time, there has been much interest in neutrino nonstandard interactions (NSI), which could also in general be flavor-violating. However, the direct constraints on NSI are typically rather weak due to the present limitations of neutrino experiments. As noted previously by various authors, the stronger constraints on CLFV can be used to establish indirect constraints on flavor-violating NSI under certain assumptions about the new physics; in particular, if the new physics takes the form of tree-level, mass-dimension-six effective operators, the $SU(2)_L$ symmetry will establish a close connection between CLFV and flavor-violating NSI. Working in this established paradigm, we seek to update some of these constraints using recent experimental results; we find that for many effective operators, the CLFV places constraints on NSI that would push it beyond the sensitivity of most neutrino experiments, although still at levels of interest to those studying the role of neutrinos in supernovae. We find that some operators, however, are subject only to weaker indirect constraints which are comparable to the direct ones.