New production mechanism of neutral Higgs bosons with right scalar tau neutrino as the LSP

Inspired by the neutrino oscillation data, we consider the lightest tau sne utrino <(nu)over tilde>tau(1) (which is mostly the right tan sneutrino) to be the lightest supersymmetric particle (LSP) in the framework of the minim al supersymmetric Standard Model. Both the standard and the non-standard tr ilinear scalar coupling terms are included for the right tan sneutrino inte ractions. The decay branching ratio of <(nu)over tilde>tau(2) --> <(nu)over tilde>(tau 1) + h(0) can become so large that the production rate of the l ightest neutral Higgs boson (h(0)) can be largely enhanced at electron or h adron colliders, either from the direct production of <(nu)over tilde>tau(2 ) or from the decay of charginos, neutralinos, sleptons, and the cascade de cay of squarks and gluinos, etc. Furthermore, because of the small LSP anni hilation rate, <(nu)over tilde>(tau 1) can be a good candidate for cold dar k matter. (C) 2000 Published by Elsevier Science B.V.