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We consider a flavour conserving two Higgs doublet model that consists of a type I (or X) quark sector and a generalized lepton sector where the Yukawa couplings of the charged leptons to the new scalars are not proportional to the lepton…

High Energy Physics - Phenomenology · Physics 2024-01-12 Francisco J. Botella , Fernando Cornet-Gomez , Carlos Miró , Miguel Nebot

In this work we address contributions from scalars to (g-2)_\mu. In order to explain the recently measured deviation by the BNL experiment on (g-2)_\mu, it is necessary that these scalars are either light or couple strongly with muons. Here…

High Energy Physics - Phenomenology · Physics 2009-11-07 C. A. de S. Pires , P. S. Rodrigues da Silva

Leptoquark (LQ) models are well motivated solutions to the $(g-2)_{\mu}$ anomaly. In the minimal LQ models, only specific representations can lead to the chiral enhancements. For the scalar LQs, the $R_2$ and $S_1$ can lead to the top quark…

High Energy Physics - Phenomenology · Physics 2023-06-14 Shi-Ping He

We study the anomalous muon and electron magnetic moments by introducing a scalar with CP-violating Yukawa couplings to the lepton sector. By fitting these two magnetic moments with the recent experimental measurements, we find that such a…

High Energy Physics - Phenomenology · Physics 2021-03-09 Ning Chen , Bin Wang , Chang-Yuan Yao

In addition to the long-standing anomalies seen in the muon $g-2$, $R_{K^{(*)}}$, and $R_{D^{(*)}}$ observables by various independent experiments, the CDF Collaboration has found another significant one in the $W$-boson mass. These…

High Energy Physics - Phenomenology · Physics 2022-12-16 Arvind Bhaskar , Anirudhan A. Madathil , Tanumoy Mandal , Subhadip Mitra

While the hunt for new states beyond the standard model (SM) goes on for various well motivated theories, the leptoquarks are among the most appealing scenarios at recent times due to a series of tensions observed in $B$-meson decays. We…

High Energy Physics - Phenomenology · Physics 2022-10-18 Priyotosh Bandyopadhyay , Anirban Karan , Rusa Mandal , Snehashis Parashar

A nonconventional $U(1)_{e-\mu}$ gauge model is proposed to explain the unexpected anomalous magnetic moments of the electron and muon (lepton $g-2$), where only the right-handed electron and muon in the standard model carry the…

High Energy Physics - Phenomenology · Physics 2021-02-24 Chuan-Hung Chen , Takaaki Nomura

Motivated by the long-standing tension in the muon anomalous magnetic moment (AMM) and persistent observations of B-physics anomalies in $R_{D^{(\ast)}}$ and $R_{K^{(\ast)}}$ ratios, we construct a simple two-loop radiative neutrino mass…

High Energy Physics - Phenomenology · Physics 2020-07-29 Shaikh Saad

We propose a leptoquark model with two scalar leptoquarks $S^{}_1 \left( \bar{3},1,\frac{1}{3} \right)$ and $\widetilde{R}^{}_2 \left(3,2,\frac{1}{6} \right)$ to give a combined explanation of neutrino masses, lepton flavor mixing and the…

High Energy Physics - Phenomenology · Physics 2021-07-28 Di Zhang

While the $S_3$ scalar leptoquark presents a possible tree-level explanation of the $b \to s \ell \ell$ flavour anomalies, it suffers from two conceptual problems which are often disregarded by model-builders. Firstly, the quantum numbers…

High Energy Physics - Phenomenology · Physics 2021-01-05 Joe Davighi , Matthew Kirk , Marco Nardecchia

We present a model based on $S_1$ scalar leptoquarks to solve the tension observed in the recently proposed non-leptonic optimized observables $L_{K^{*} \bar{K}^{*}}$ and $L_{K \bar{K}}$. These observables are constructed as ratios of…

High Energy Physics - Phenomenology · Physics 2023-09-20 Javier M. Lizana , Joaquim Matias , Ben A. Stefanek

We present a unified explanation for the $B$-decay anomalies in $R_{D^{(\ast)}}$ and $R_{K}$ together with the anomalous muon magnetic moment, consistent with the constraints from the current measurements of leptonic decay rates and…

High Energy Physics - Phenomenology · Physics 2016-11-02 Diganta Das , Chandan Hati , Girish Kumar , Namit Mahajan

The contributions of the scalar leptoquark doublets into widths of the $K^0_L \to e^{\mp} \mu^{\pm}$, $B^0 \to e^{\mp} \tau^{\pm}$ decays are calculated in MQLS model with Higgs mechanism of the quark-lepton mass splitting. The resulted…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. D. Smirnov

Leptoquark (LQ) models can be the solution to the $(g-2)_{\mu}$ anomaly because of the chiral enhancements. In this work, we consider the models extended by the LQ and vector-like quark (VLQ) simultaneously, which can be used to explain the…

High Energy Physics - Phenomenology · Physics 2022-06-24 Shi-Ping He

We compute the generic one-loop contribution involving scalar leptoquarks (LQ) to the $W$ and $Z$ leptonic decay widths. In our computation we include for the first time the finite terms and the corrections due to the external momenta of…

High Energy Physics - Phenomenology · Physics 2019-07-16 Pere Arnan , Damir Becirevic , Federico Mescia , Olcyr Sumensari

We consider the full flavor structure of the $S_1$ leptoquark model and derive conservative constraints on the elements of the left- and right-handed coupling matrices. We focus on the cases where the muon $g-2$ deviation is explained by…

High Energy Physics - Phenomenology · Physics 2023-10-31 Uladzimir Khasianevich , Dominik Stöckinger , Hyejung Stöckinger-Kim , Johannes Wünsche

We investigate the effects of the new scalars in a two-Higgs-doublet model on the weak magnetic dipole moments of the fermions at the $Z$ peak. Proportionality of the Yukawa couplings to the fermion masses, and to $\tan{\beta}$, makes such…

High Energy Physics - Phenomenology · Physics 2009-10-28 J. Bernabeu , D. Comelli , L. Lavoura , Joao P Silva

A systematic investigation on muon anomalous magnetic moment and related lepton flavor-violating process such as $\m\to e\g$, $\t\to e\g$ and $\t\to \m\g$ is made at two loop level in the models with flavor-changing scalar interactions. The…

High Energy Physics - Phenomenology · Physics 2014-11-17 Y. F. Zhou , Y. L. Wu

The recent measurement on the muon anomalous magnetic moment $a_\mu$ shows a $2.6\sigma$ deviation from the standard model value. We show that it puts an interesting bound on the mass of the second generation leptoquarks. To account for the…

High Energy Physics - Phenomenology · Physics 2009-12-31 Kingman Cheung

We derive constraints from flavor and LHC searches on charmphilic contributions to the muon anomalous magnetic moment with a single leptoquark. Only the scalar leptoquarks $S_1$ and $R_2$ are relevant for the present analysis. We find that…

High Energy Physics - Phenomenology · Physics 2021-04-09 Kamila Kowalska , Enrico Maria Sessolo , Yasuhiro Yamamoto