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

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.

added two references. 15 pages, 14 figures

References in corpus (2)

• Flavor changing neutral decay effects in models with two Higgs boson doublets: Applications to LHC Physics
• Top quark rare decays in a two Higgs doublet model for the top

Cited by in corpus (16)

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• Search for top quark decays $t\to qH$ with $H\to \gamma \gamma$ using the ATLAS detector
• Search for top quark decays $t\to qH$, with $H\to \gamma \gamma$, in $\sqrt{s}=13$ TeV $pp$ collisions using the ATLAS detector
• Search for flavor-changing neutral current interactions of the top quark and Higgs boson in final states with two photons in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Signatures of NP models in top FCNC decay t --> c(u) l+ l-
• New flavor physics in di- and tri-lepton events from single-top at the LHC and beyond
• Multi-lepton probes of new physics and lepton-universality in top-quark interactions
• Search for flavour-changing neutral-current couplings between the top quark and the Higgs boson in multi-lepton final states in 13 TeV $pp$ collisions with the ATLAS detector
• Flavour-changing neutral scalar interactions of the top quark
• Search for flavor-changing neutral $tqH$ interactions with $H\to \gamma \gamma$ in $pp$ collisions at $\sqrt{s}$ = 13 TeV using the ATLAS detector
• Search for flavour-changing neutral current interactions of the top quark and the Higgs boson in events with a pair of $\tau$-leptons in pp collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Flavour-changing top quark decays in the alternative left-right model
• Search for flavor-changing neutral current interactions of the top quark mediated by a Higgs boson in proton-proton collisions at 13 TeV
• Probing the anomalous tqgamma couplings in photon-proton collisions
• Investigation of the FCNC couplings between the top quark and the photon in $\gamma \gamma$ and ${\gamma }^{\ast }{\gamma }^{\ast }$ collisions at the CLIC
• Sensitivity analysis for the anomalous $tq\gamma$ couplings via $\gamma q\to t\gamma$ subprocess in photon-proton collisions at the FCC-$\mu$p