K-meson neutrinoless double muon decay as a probe of neutrino masses and mixings

Abstract

Recently an upper bound on the rate of the lepton number violating decay $K^{+}\to \hat{I}{¼}^{+}\hat{I}{¼}^{+}\ddot{I}{€}^{-}$ has been significantly reduced by the E865 experiment at BNL and further improvement is expected in the near future. We study this process as a possible source of information on neutrino masses and mixings. We find that it is insensitive to the light(eV domain) and heavy(GeV domain) neutrinos. However due to the effect of a resonant enhancement this decay is very sensitive to neutrinos $\hat{I}{½}_j$ in the mass region $245MeV\le m_{\hat{I}{½}_j}\le 389$ MeV. At present experimental sensitivity we deduce new stringent limits on the neutrino mixing matrix element $U_{\hat{I}¼j}$ for neutrino masses in this region.

10 pages, 2 figures, Latex