Anomalies in several short-baseline neutrino oscillation experiments suggest the possible existence of sterile neutrinos at about the eV scale that have appreciable mixing with the three known neutrinos. We find that if such a light sterile neutrino exists, through a combined study of the leptonic decays of μ-, τ-, π-, and K-, some semileptonic decays of τ- and the invisible decay width of the Z boson, it is possible to constrain the relevant mixing matrix elements. Furthermore, we compare the constraints, derived by using the method presented here, with the experimental results obtained from short-baseline neutrino oscillation experiments. We find that a single light sterile neutrino cannot satisfy the existing short-baseline neutrino oscillation constraints and explain the anomalies mentioned above. Along the way we provide a number of experimentally clean observables which can be used to directly study the light sterile neutrino independently of the neutrino oscillation experiments.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)