Probing<i>CP</i>violation via Higgs boson decays to four leptons

Abstract

Since decays to four leptons is widely considered a promising way to search for the Higgs particle, we show how the same final state can also be used to search for signals of CP nonconservation. Energy asymmetries and triple correlations are related to parameters in the underlying CP-violating effective interaction at the ${\mathit{H}}^{0}$-W-W and ${\mathit{H}}^{0\mathrm{\ensuremath{-}}}$Z-Z vertices. It is argued that the expected size of the effects is extremely small in the standard model, and it is shown that the result also seems small to be observable in an extension of the standard model with an extra Higgs doublet.