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arXiv · 0802.2622

Scalar FCNC and rare top decays in a two Higgs doublet model "for the top"

Itzhak Baum·Gad Eilam·Shaouly Bar-Shalom
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Abstract

In the so called two Higgs doublet model for the top-quark (T2HDM), first suggested by Das and Kao, the top quark receives a special status, which endows it with a naturally large mass, and also potentially gives rise to large flavor changing neutral currents (FCNC) only in the up-quark sector. In this paper we calculate the branching ratio (BR) for the rare decays t->ch and h->tc (h is a neutral Higgs) in the T2HDM, at tree level and at 1-loop when it exceeds the tree-level. We compare our results to predictions from other versions of 2HDM's and find that the scalar FCNC in the T2HDM can play a significant role in these decays. In particular, the 1-loop mediated decays can be significantly enhanced in the T2HDM compared to the 2HDM of types I and II, in some instances reaching BR~10^-4 which is within the detectable level at the LHC.

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Itzhak Baum, Gad Eilam, Shaouly Bar-Shalom. 2008-02-25. Scalar FCNC and rare top decays in a two Higgs doublet model "for the top". https://doi.org/10.1103/physrevd.77.113008

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