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

Abstract

We derive new upper limits on several products (two at a time) of lepton number violating λ'-type couplings from the consideration of ΔS=2 and ΔB=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⁺→π⁺νν̅ event recently observed at BNL.