Probing Lepton Flavor Triality with Higgs Boson Decay

Abstract

If neutrino tribimaximal mixing is explained by a non-Abelian discrete symmetry such as $A_4$, $T_7$, $\Delta (27)$, etc., the charged-lepton Higgs sector has a $Z_3$ residual symmetry (lepton flavor triality), which may be observed directly in the decay chain $H^0\to {\psi }_2^0{\bar{\psi }}_2^0$, then ${\psi }_2^0({\bar{\psi }}_2^0)\to l_i^{+}{l}_j^{-}(i\ne j)$, where $H^0$ is a standard-model-like Higgs boson and ${\psi }_2^0$ is a scalar particle needed for realizing the original discrete symmetry. If kinematically allowed, this unusual and easily detectable decay is observable at the LHC with 1 fb${}^{-1}$ for E_{cm} = 7 TeV.

Comments: PRD version