Physical constraints derived from FCNC in the 3-3-1-1 model

Duy Nguyen Tuan; Takeo Inami; Huong Do Thi

doi:10.1140/epjc/s10052-021-09583-x

2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2021) 81: 813
https://doi.org/10.1140/epjc/s10052-021-09583-x

Regular Article - Theoretical Physics

Physical constraints derived from FCNC in the 3-3-1-1 model

Duy Nguyen Tuan¹^,2^a, Takeo Inami¹^,3 and Huong Do Thi¹

¹ Institute of Physics, VAST, 10 Dao Tan, Ba Dinh, Hanoi, Vietnam
² Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam
³ Theoretical Research Division, Nishina Center, RIKEN, 351-0198, Wako, Japan

^a ntdem@iop.vast.ac.vn

Received: 8 February 2021
Accepted: 28 August 2021
Published online: 14 September 2021

Abstract

We investigate several phenomena related to FCNCs in the $3-3-1-1$ $\text {3-3-1-1}$ model. The sources of FCNCs at the tree-level from both the gauge and Higgs sectors are clarified. Experiments on the oscillation of mesons most stringently constrain the tree-level FCNCs. The lower bound on the new physics scale is imposed more tightly than in the previous, $M_{new} > 12$ $\text {M}_{\text {new}}>12$ TeV. Under this bound, the tree-level FCNCs make a negligible contribution to the $Br (B_{s} \to μ^{+} μ^{-})$ $\text {Br}(B_s \rightarrow \mu ^+ \mu ^-)$ , $Br (B \to K^{*} μ^{+} μ^{-})$ $\text {Br}(B \rightarrow K^{*} \mu ^+ \mu ^-)$ and $Br (B^{+} \to K^{+} μ^{+} μ^{-})$ $\text {Br}(B^{+}\rightarrow K^{+}\mu ^{+}\mu ^{-})$ . The branching ratio of radiative decay $b \to s γ$ $b \rightarrow s \gamma$ is enhanced by the ratio $\frac{v}{u}$ $\frac{v}{u}$ via diagrams with the charged Higgs mediation. In contrast, the charged currents of new gauge bosons significantly contribute to the decay process $μ \to e γ$ $\mu \rightarrow e \gamma$ .

© The Author(s) 2021

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