Scotogenic top-quark FCNC decays

Chen, Chuan-Hung; Nomura, Takaaki

doi:10.48550/arxiv.2204.01214

Cited by 1 publication

(3 citation statements)

References 32 publications

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“…In terms of the chiral structures of the initial-and final-state quarks, the effective interactions for t → q(h, γ, Z) can be parametrized as [28]:…”

Section: A Top-fcnc Processesmentioning

confidence: 99%

“…Some interesting extensions of the SM proposed to enhance the top-FCNC decays can be found in Refs. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%

“…one SU (2) L -singlet vector-like quark [28], and two singlet vector-like Dirac-type neutral leptons [95], where the Z 2 -odd quark is responsible for the top-FCNC processes, and the The induced top-FCNC and LFV processes including lepton g − 2 are studied in detail in Sec. III.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Top-quark FCNC decays, LFVs, lepton $g-2$, and $W$ mass anomaly with inert charged Higgses

Chen¹,

Chiang²,

Su³

2023

Preprint

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The observed flavor-changing neutral-current (FCNC) processes in the standard model (SM) arise from the loop diagrams involving the weak charged currents mediated by the W -gauge boson.Nevertheless, the top-quark FCNCs and lepton-flavor violating processes resulting from the same mechanism are highly suppressed. We investigate possible new physics effects that can enhance the suppressed FCNC processes, such as t → q(h, V ) with V = γ, Z, g, h →, and → γ.To achieve the assumption that the induced-FCNCs are all from quantum loops, we consider the scotogenic mechanism, where a Z 2 symmetry is introduced and only new particles carry an odd Z 2 parity. With the extension of the SM to include an inert Higgs doublet, an inert charged Higgs singlet, a vector-like singlet quark, and two neutral leptons, it is found that, with relevant constraints taken into account, the t → c(h, Z), h → µτ , and τ → γ decays can be enhanced up to the expected sensitivities in experiments. The branching ratios of h → µ + µ − /τ + τ − from only new physics effects can reach up to O(10 −3 ). Intriguingly, the resulting muon g − 2 can fit the combined data within 2σ errors, whereas the electron g − 2 can have either sign with a magnitude of O(10 −13 − 10 −12 ). In addition, we examine the oblique parameters in the model and find that the resulting W -mass anomaly observed by CDF II can be accommodated.

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“…In terms of the chiral structures of the initial-and final-state quarks, the effective interactions for t → q(h, γ, Z) can be parametrized as [28]:…”

Section: A Top-fcnc Processesmentioning

confidence: 99%

“…Some interesting extensions of the SM proposed to enhance the top-FCNC decays can be found in Refs. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%