Search for Heavy Neutrino in K->mu nu_h(nu_h-> nu gamma) Decay at ISTRA+ Setup

Authors :: collaboration, ISTRA
Duk, V. A.
Bolotov, V. N.
Khudyakov, A. A.
Lebedev, V. A.
Makarov, A. I.
Novikov, V. P.
Polyarush, A. Yu.
Akimenko, S. A.
Britvich, G. I.
Filin, A. P.
Inyakin, A. V.
Kholodenko, S. A.
Leontiev, V. M.
Obraztsov, V. F.
Polyakov, V. A.
Romanovsky, V. I.
Stenyakin, O. V.
Tchikilev, O. G.
Uvarov, V. A.
Yushchenko, O. P.
Source :: Phys.Lett.B710:307-317,2012
Publication Year :: 2011
Abstract: Heavy neutrino nu_h with m_h < 300MeV/c^2 can be effectively searched for in kaon decays. We put upper limits on mixing matrix element |U_mu_h}|^2 for radiatively decaying nu_h from K->mu nu_h (nu_h -> nu gamma) decay chain in the following parameter region: 30MeV/c^2 < m_h < 80MeV/c^2; 10^{-11}sec < tau_h < 10^{-9}sec. For the whole region |U_{mu h}|^2 < 5 x 10^{-5} for Majorana type of nu_h and | U_{\mu h}|^2 < 8 x 10^{-5} for the Dirac case.<br />Comment: Published in Phys. Lett. B