Rare t-quark decays $t \to c l_j^{+} l_k^{-}$, $t \to c \tilde{ν_j} ν_k$ in the minimal four color symmetry model

Abstract

The rare t-quark decays $t \to c l_j^{+} l_k^{-}$, $t \to c \tilde{ν_j} ν_k$ via the scalar leptoquark doublets are investigated in the minimal four color symmetry model with the Higgs mechanism of the quark-lepton mass splitting. The partial widths of these decays are calculated and the total width of the charged lepton mode $ Γ(t \to c {l^{+}}' l^{-})= \sum_{j,k} Γ(t \to c l_{j}^{+} l_{k}^{-})$ and the total width of the neutrino mode $ Γ(t \to c \tildeν' ν)= \sum_{j,k} Γ(t \to c \tilde{ν_{j}} ν_{k})$ are found. The corresponding branching ratios are shown to be $ Br(t \to c {l^{+}}' l^{-}) \approx (3.5 - 0.4) 10^{-5}, $ $ Br(t \to c {\tildeν}' ν) \approx (7.1 - 0.8) 10^{-5} $ for the scalar leptoquark masses $ m_{S}= 180 - 250 GeV $ and for the appropriate values $ (\sinβ \approx 0.2) $ of the mixing angle of the model. The search for such decays at LHC may be of interest.