The masses of the three generations of charged leptons are known to completely satisfy Koide＇s mass relation,but the question remains of whether such a relation exists for neutrinos.In this paper,by considering the seesaw mechanism as the mechanism generating tiny neutrino masses,we show how neutrinos satisfy Koide＇s mass relation,on the basis of which we systematically give exact values of both left-and right-handed neutrino masses.
Using the Bs meson wave function extracted from non-leptonic Bs decays, we reevaluate the rare decays Bs→l＋l- γ,（l=e,μ） in the Standard Model, including two kinds of contributions from the magnetic-penguin operator with virtual and real photons. We find that contributions to the exclusive decays from the magnetic-penguin operator b→sγ with real photons, which were regarded as negligible in the previous literature, are large and the branching ratios Bs→l＋l-γ are enhanced by a factor of almost 2. With the predicted branching ratios of the order of 10-8, it is expected that these radiative dileptonic decays will be detected in LHC-b and B factories in the near future.
