Rare t-quark decays $t\to c{l}_j^{+}{l}_k^{-}$, $t\to c\widetilde{{\nu }_j}{\nu }_k$ in the minimal four color symmetry model

Abstract

The rare t-quark decays $t\to c{l}_j^{+}{l}_k^{-}$, $t\to c\widetilde{{\nu }_j}{\nu }_k$ 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 $\Gamma (t\to c{l^{+}}^{\prime }{l}^{-})={\sum }_{j,k}\Gamma (t\to c{l}_j^{+}{l}_k^{-})$ and the total width of the neutrino mode $\Gamma (t\to c{\tilde{\nu }}^{\prime }\nu )={\sum }_{j,k}\Gamma (t\to c\widetilde{{\nu }_j}{\nu }_k)$ are found. The corresponding branching ratios are shown to be $Br(t\to c{l^{+}}^{\prime }{l}^{-})\approx (3.5-0.4)10^{-5},$ $Br(t\to c{\tilde{\nu }}^{\prime }\nu )\approx (7.1-0.8)10^{-5}$ for the scalar leptoquark masses $m_S=180-250GeV$ and for the appropriate values $(\sin \beta \approx 0.2)$ of the mixing angle of the model. The search for such decays at LHC may be of interest.

Comments: 18 pages, 2 figures, 1 table, to be published in Modern Physics Letters A; corrected typos