Four-neutrino Ms 2 Mixing Typeset Using Revt E X 1

We present a simple scheme of mixing of four neutrinos that can accommodate the results of all neutrino oscillation experiments, the observed abundances of primordial elements and the current upper bound for the effective Majo-rana neutrino mass in neutrinoless double-β decay (assuming that massive neutrinos are Majorana particles). The scheme has maximal mixing in the ν µ , ν τ –ν 3 , ν 4 sector and small mixings in the ν e , ν s –ν 1 , ν 2 and ν e , ν µ –ν 1 , ν 3 (or ν e , ν µ –ν 1 , ν 4) sectors (MS 2). We discuss the implications of this scheme for short and long baseline oscillation experiments and for neutrinoless double-β decay and tritium β-decay experiments.