Flavour-Changing Neutral Current Top Decays in the Three Higgs Doublet Model

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Coleppa, Baradhwaj, Fuks, Benjamin, Khanna, Akshat
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914275447013376
author Coleppa, Baradhwaj
Fuks, Benjamin
Khanna, Akshat
author_facet Coleppa, Baradhwaj
Fuks, Benjamin
Khanna, Akshat
contents We study flavour-changing neutral current decays of the top quark in the democratic Three Higgs Doublet Model featuring a $Z_3$-symmetric scalar potential and Natural Flavour Conservation. In this framework, while such processes are absent at tree-level, the extended scalar sector induces new one-loop contributions to rare top decays. We compute the branching ratios for processes of the form $t \to q X$ (with $q = u, c$ and $X$ denoting a boson of the model), and explore the viable regions of the parameter space under theoretical consistency conditions and current experimental constraints. Several alignment-limit scenarios corresponding to different hierarchies among the CP-even Higgs states are analysed, and we find that the predicted branching ratios can significantly exceed their Standard Model expectations while remaining consistent with existing limits. In particular, we identify scenarios with light non-standard scalars that can lead to rates within the projected sensitivity of the High-Luminosity LHC. Our results therefore highlight rare top decays as a promising probe of the extended scalar sector of the Three Higgs Doublet Model.
format Preprint
id arxiv_https___arxiv_org_abs_2601_16647
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Flavour-Changing Neutral Current Top Decays in the Three Higgs Doublet Model
Coleppa, Baradhwaj
Fuks, Benjamin
Khanna, Akshat
High Energy Physics - Phenomenology
We study flavour-changing neutral current decays of the top quark in the democratic Three Higgs Doublet Model featuring a $Z_3$-symmetric scalar potential and Natural Flavour Conservation. In this framework, while such processes are absent at tree-level, the extended scalar sector induces new one-loop contributions to rare top decays. We compute the branching ratios for processes of the form $t \to q X$ (with $q = u, c$ and $X$ denoting a boson of the model), and explore the viable regions of the parameter space under theoretical consistency conditions and current experimental constraints. Several alignment-limit scenarios corresponding to different hierarchies among the CP-even Higgs states are analysed, and we find that the predicted branching ratios can significantly exceed their Standard Model expectations while remaining consistent with existing limits. In particular, we identify scenarios with light non-standard scalars that can lead to rates within the projected sensitivity of the High-Luminosity LHC. Our results therefore highlight rare top decays as a promising probe of the extended scalar sector of the Three Higgs Doublet Model.
title Flavour-Changing Neutral Current Top Decays in the Three Higgs Doublet Model
topic High Energy Physics - Phenomenology
url https://arxiv.org/abs/2601.16647