2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/47838We investigate the rare decay processes of the K mesons, K_{L,S} -> π^0 ν\barν and K^{+} -> π^+ ν\barν in LR model with lepton family number being well conserved. In these processes, scalar operators (\bar{s}d)(\barν_τν_τ), which are derived from box diagram in LR model, play an important role due to an enhancement factor M_{K}/m_{s} in the matrix element $<π|\bar{s}d|K>$. It is emphasized that the K_{L} decay process through the scalar operator is not the CP violating mode, so the B(K_L -> π^{0} ν\barν) remains non-zero even in the CP conserved limit. We present the pion energy spectrum for these processes and discuss the effects of LR model.6 pages, ps figures included, psfig.sty, and here.sty are required. Talk presented by Y. Kiyo at Workshop on ``Fermion Mass and CP Violation'', Hiroshima, 5-6 March 1998High Energy Physics - Phenomenologytext