New constraints on R-parity violation from K and B systems

We derive new upper limits on several products (two at a time) of lepton number violating lambda'-type couplings from the consideration of Delta S = 2 and Delta B = 2 box graphs. Each box contains one scalar lepton and one W-boson or one charged-Higgs-boson as internal lines. Most of these bounds are more stringent than previously obtained. Some of these product couplings drive K-L (and some other B-d) decays to two charged leptons at enhanced rates. Some of them can explain the rare K+-->pi(+)nu nu(-) event recently observed at BNL. [S0556-2821(98)50307-4].