Speaker
Ms
Fang-Min Cai
(CCNU)
Description
We update the Standard Model predictions for the branching ratios of the top-quark rare decays $t \to cg(g)$ in the Standard Model and focus on evaluating the maximum they can be in the aligned two-Higgs-doublet model (A2HDM), their properties are also discussed briefly in the 2HDM with $\mathcal{Z}_2$ symmetries. With the constraints on the alignment parameters from flavour observables, we find that the branching ratios of $t \to cg$ and $t \to cgg$ are in the same order and can reach about $3.79\times 10^{-9}$ and $6.80\times 10^{-9}$ in the A2HDM, respectively; while the branching ratio of $t \to cgg$ is nearly three orders of magnitude as large as the one of $t \to cg$ in the SM. Moreover, there are no significant enhancements in the 2HDM than that in the SM for these two decays. Compared with the measurements in the high-luminosity colliders in the near future, both the branching ratios of $t \to cg$ and $t \to cgg$ within the A2HDM are out of the sensitivity of the HL-LHC and FCC-hh.
| Presentation type | Oral |
|---|
Primary author
Ms
Fang-Min Cai
(CCNU)
Co-authors
Dr
Funatsu Shuichiro
(CCNU)
Prof.
Xin-Qiang Li
(CCNU)
Prof.
Ya-Dong Yang
(Zhengzhou university)
