FITTING DIRECT INTERACTION PIECES INTO NEUTRINO PUZZLES

We develop a framework and unified, compact notation to include neutri no direct interaction effects with neutrino oscillations for a wide cl ass of low-energy, effective four-Fermi interactions. Modest flavor-vi olating interaction strengths can make significant changes in the boun daries in Delta M-2 <-> sin(2)2 theta and in tan(2)theta(13) <-> tan(2 )theta(23) parameter space. We draw examples from the L - R symmetric and MSSM + (R) over bar models and find the recently reported decay-at -rest mu <-> e transition probability can be described without oscilla tions in L-R symmetric models. (C) 1998 Published by Elsevier Science B.V. All rights reserved.