Neutrino decay and solar neutrino seasonal effect

We consider the possibility of solar neutrino decay as a sub-leading effect on their propagation between production and detection. Using current oscillation data, we set a new lower bound to the ν2 neutrino lifetime at τ2/m2≥7.2×10−4s.eV−1 at 99% C.L. Also, we show how seasonal variations in the solar neutrino data can give interesting additional information about neutrino lifetime.