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Related papers: Simplified Models of Flavourful Leptoquarks

200 papers

In a generic supersymmetric extension of the Standard Model, whether unified or not, a simple and well motivated U(2) symmetry, acting on the lightest two generations, completely solves the flavour changing problem and necessarily leads to…

High Energy Physics - Phenomenology · Physics 2009-10-28 Riccardo Barbieri , George Dvali , Lawrence Hall

In our recent attempt to explain flavor hierarchies [1], a gauged SU(2) flavor symmetry acting on left-handed fermions provides a ground to introduce three independent rank-one contributions to the Yukawa matrices: a renormalizable one for…

High Energy Physics - Phenomenology · Physics 2024-06-06 Admir Greljo , Anders Eller Thomsen , Hector Tiblom

Measurements of the ratio of $B \to K^* \mu \mu $ to $B \to K^* e e $ branching fractions, $R_{K^*}$, by the LHCb collaboration strengthen the hints from previous studies with pseudoscalar kaons, $R_K$, for the breakdown of lepton…

High Energy Physics - Phenomenology · Physics 2018-02-12 Gudrun Hiller , Ivan Nisandzic

We study two-site deconstructions of the $SU(2)_L$ gauge group factor of the SM. Models based on this approach can explain the hierarchies of the quark masses and CKM mixing between third and light families if these fields are localised on…

High Energy Physics - Phenomenology · Physics 2024-08-12 Bernat Capdevila , Andreas Crivellin , Javier M. Lizana , Stefan Pokorski

As an extension of the Standard Model (SM), the 3HDM (Three-Higgs-Doublet Model) defines additional relationships among the fermions. In the visible leptonic Yukawa sector of the 3HDM, we investigate the existence of flavor symmetries under…

High Energy Physics - Phenomenology · Physics 2024-10-10 Bartosz Dziewit , Joris Vergeest , Marek Zrałek

The impact of rare lepton decays ($\mu \to e \gamma$, $\tau \to \mu \gamma$, >...) and rare $B$ and $K$ decays ($B\to \ell^+\ell^-$, $B\to \ell\nu$, $K\to \pi \nu\nu$, $K\to\ell\nu$, ...) in probing the existence of an underlying flavour…

High Energy Physics - Phenomenology · Physics 2008-11-26 Gino Isidori

A grand unified $SU(5)$ theory is constructed with a hierarchical breaking of a $U(2)$ flavor symmetry. The small parameters of the squark and slepton mass matrices, necessary to solve the supersymmetric flavor-changing problem, and the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Riccardo Barbieri , Lawrence Hall

We study the effect of scalar leptoquarks in the lepton flavour violating $B$ meson decays induced by the flavour changing transitions $b \to q l_i^+ l_j^-$ with $q=s,d$. In the standard model these transitions are extremely rare as they…

High Energy Physics - Phenomenology · Physics 2016-06-08 Suchismita Sahoo , Rukmani Mohanta

We consider the flavor structure of supersymmetric theories that can account for the deviation of the observed time-dependent CP asymmetry in B --> phi K_S from the standard model prediction. Assuming simple flavor symmetries and effective…

High Energy Physics - Phenomenology · Physics 2008-11-26 Kaustubh Agashe , Christopher D. Carone

We present a model of fermion masses based on a minimal, non-Abelian discrete symmetry that reproduces the Yukawa matrices usually associated with U(2) theories of flavor. Mass and mixing angle relations that follow from the simple form of…

High Energy Physics - Phenomenology · Physics 2014-11-17 Alfredo Aranda , Christopher D. Carone , Richard F. Lebed

We consider a flavoured $B-L$ gauge symmetry under which only the third generation fermions are charged. Such a symmetry can survive at low energies (~TeV) while still allowing for two superheavy right-handed neutrinos, consistent with…

High Energy Physics - Phenomenology · Physics 2017-11-20 Rodrigo Alonso , Peter Cox , Chengcheng Han , Tsutomu T. Yanagida

We propose a natural $ S_4 \times SO(10) $ supersymmetric grand unified theory of flavour with an auxiliary $\mathbb{Z}_4^2 \times \mathbb{Z}_4^R$ symmetry, based on small Higgs representations (nothing larger than an adjoint) and hence a…

High Energy Physics - Phenomenology · Physics 2017-11-03 Fredrik Björkeroth , Francisco J. de Anda , Stephen F. King , Elena Perdomo

The $R_{K^{(*)}}$ anomaly can be explained by tree level exchange of leptoquarks. We study the consequences of subjecting these models to the principle of minimal flavor violation (MFV). We consider MFV in the linear regime, and take the…

High Energy Physics - Phenomenology · Physics 2017-12-06 Daniel Aloni , Avital Dery , Claudia Frugiuele , Yosef Nir

Motivated by the disagreement between the experimental data and lattice calculations on the decay constant of the $D_{s}$ meson, we investigate leptoquark (LQ) contributions to the purely leptonic decays of a pseudoscalar (P). We…

High Energy Physics - Phenomenology · Physics 2009-02-12 Rachid Benbrik , Chuan-Hung Chen

We initiate the study of the generalized global flavor symmetries of the Standard Model. The presence of nonzero triangle diagrams between the $U(3)^5$ flavor currents and the $U(1)_Y$ hypercharge current intertwines them in the form of a…

High Energy Physics - Phenomenology · Physics 2022-12-27 Clay Cordova , Seth Koren

We propose an extra-dimension framework on the orbifold $S^1/Z_2$ for understanding the origin of the fermion mass and mixing hierarchies. Introducing the flavor symmetry $G_F(=${\it non-Abelian}$\times${\it Abelian}) as well as the extra…

High Energy Physics - Phenomenology · Physics 2022-11-09 Y. H. Ahn , Sin Kyu Kang , Hyun Min Lee

Pursuing a bottom-up approach to explore which flavor symmetry could serve as an explanation of the observed fermion masses and mixings, we discuss an extension of the standard model (SM) where the flavor structure for both quarks and…

High Energy Physics - Phenomenology · Physics 2011-05-05 C. Hagedorn , M. Lindner , R. N. Mohapatra

We consider the phenomenological signatures of Simplified Models of Flavourful Leptoquarks, whose Beyond-the-Standard Model (SM) couplings to fermion generations occur via textures that are well motivated from a broad class of ultraviolet…

High Energy Physics - Phenomenology · Physics 2022-09-07 Jordan Bernigaud , Monika Blanke , Ivo de Medeiros Varzielas , Jim Talbert , José Zurita

We quantitatively analyze a quark-lepton flavour model derived from a six-dimensional supersymmetric theory with $SO(10)\times U(1)$ gauge symmetry, compactified on an orbifold with magnetic flux. Two bulk $\mathbf{16}$-plets charged under…

High Energy Physics - Phenomenology · Physics 2018-04-25 Wilfried Buchmuller , Ketan M. Patel

The gauge interactions of any supersymmetric extension of the standard model involve new flavor mixing matrices. The assumptions involved in the construction of minimal supersymmetric models, both $SU(3) \times SU(2) \times U(1)$ and grand…

High Energy Physics - Phenomenology · Physics 2009-10-28 Nima Arkani-Hamed , Hsin-Chia Cheng , L. J. Hall