![[فرمیون]]<ref group=nb>Since neutrino flavor [[eigenstatesویژہ قدر]] are not the same as neutrino mass eigenstates (see [[neutrino oscillation]]), the given masses are actually mass [[expectationمتوقع valueقدر]]s. If the mass of a neutrino could be measured directly, the value would always be that of one of the three mass eigenstates: ν<sub>1</sub>, ν<sub>2</sub>, and ν<sub>3</sub>. In practice, the mass cannot be measured directly. Instead it is measured by looking at the shape of the endpoint of the energy spectrum in [[particle decay]]s. This sort of measurement directly measures the expectation value of the mass; it is not sensitive to any of the mass eigenstates separately.</ref>