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Related papers: Constraining Flavour Symmetries At The EW Scale II…

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A classification is given of Higgs-flavor models. In these models, there are several Higgs doublets in an irreducible multiplet R_{Phi} of a non-abelian symmetry G_{Phi}, under which the quarks and leptons do not transform (thus giving…

High Energy Physics - Phenomenology · Physics 2013-05-30 S. M. Barr , Thomas W. Kephart

We show that supplementing the Standard Model by only a second Higgs doublet, a combined explanation of $h\to e\tau$, $h\to \mu\tau$, $b\to s \ell^+ \ell^-$, the $W$ mass and $R({D^{(*)}})$ as well as the excess in $t\to bH^+(130\,{\rm…

High Energy Physics - Phenomenology · Physics 2024-07-16 Andreas Crivellin , Syuhei Iguro

The origin of fermion mass hierarchies and mixings is one of the unresolved and most difficult problem in high-energy physics. One possibility to address the flavour problem is by extending the Standard Model to include a family symmetry.…

High Energy Physics - Phenomenology · Physics 2015-06-18 Stephen F. King , Alexander Merle , Stefano Morisi , Yusuke Shimizu , Morimitsu Tanimoto

We systematically investigate the possible phenomenological impact of residual flavour groups in the charged lepton sector. We consider all possible flavour charge assignments for abelian residual symmetries up to Z8. The allowed flavour…

High Energy Physics - Phenomenology · Physics 2025-09-24 Lorenzo Calibbi , Claudia Hagedorn , Michael A. Schmidt , James Vandeleur

The fundamental constraint on two Higgs doublet models comes from the requirement of sufficiently suppressing flavor-changing neutral currents. There are various standard approaches for dealing with this problem, but they all tend to share…

High Energy Physics - Phenomenology · Physics 2011-09-13 Jason Evans , Brian Feldstein , William Klemm , Hitoshi Murayama , Tsutomu T. Yanagida

We study flavour issues in nonsupersymmetric intersecting brane models. Specifically, the purpose of the present paper is twofold: (i) to determine whether realistic flavour structures can be obtained in these models, and (ii) to establish…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. Abel , O. Lebedev , J. Santiago

Flavour changing neutral current processes, being strongly suppressed in the Standard Model (SM), provide a unique window to new physics at scales much above the electroweak scale. Here, we summarize the recent progress in flavour physics…

High Energy Physics - Phenomenology · Physics 2011-03-23 Monika Blanke , Andrzej J. Buras

We consider an abelian extension of the Standard Model (SM) comprising a new gauge group $U(1)^\prime$, with the neutral gauge boson $Z^\prime$ having flavour violating couplings to quarks and leptons. The fermion content is the same as in…

High Energy Physics - Phenomenology · Physics 2025-11-27 Pietro Colangelo , Fulvia De Fazio , Davide Milillo

Apparent regularities in fermion masses and mixings are often associated with physics at a high flavor scale, especially in the context of discrete flavor symmetries. One of the main reasons for that is that the correct vacuum alignment…

High Energy Physics - Phenomenology · Physics 2013-03-14 Martin Holthausen , Manfred Lindner , Michael A. Schmidt

We do not know why there are three fermion families in the Standard Model (SM), nor can we explain the observed pattern of fermion masses and mixing angles. Standard grand unified theories based on the SU(5) and SO(10) groups fail to shed…

High Energy Physics - Phenomenology · Physics 2020-12-16 Renato M. Fonseca

The concept of lepton flavour universality (LFU), according to which the three lepton families are equivalent except for their masses, is a cornerstone prediction of the Standard Model (SM). LFU can be violated in models beyond the SM by…

High Energy Physics - Experiment · Physics 2019-05-22 Elena Graverini

In the frame of two Higgs doublet model we try to explain the lepton masses and mixing matrix elements assuming that neutrinos are Dirac particles. Discrete family symmetry groups, which are subgroups of U(3) up to the 1025 order are…

High Energy Physics - Phenomenology · Physics 2016-06-21 Bartosz Dziewit , Jacek Holeczek , Monika Richter , Sebastian Zając , Marek Zrałek

We study Two-Higgs-Doublet Models (2HDM) where Abelian symmetries have been introduced, leading to a drastic reduction in the number of free parameters in the 2HDM. Our analysis is inspired in BGL models, where, as the result of a symmetry…

High Energy Physics - Phenomenology · Physics 2018-09-12 Joao M. Alves , Francisco J. Botella , Gustavo C. Branco , Fernando Cornet-Gomez , Miguel Nebot , Joao P. Silva

We explore Two Higgs Doublet Models with non-standard flavor structures. In analogy to the four, well studied, models with natural flavor conservation (type 1, type 2, lepton-specific, flipped), we identify four models that preserve an…

High Energy Physics - Phenomenology · Physics 2018-11-08 Wolfgang Altmannshofer , Brian Maddock

We analyse how $U(3)^5$ and $U(2)^5$ flavour symmetries act on the Standard Model Effective Field Theory, providing an organising principle to classify the large number of dimension-six operators involving fermion fields. A detailed…

High Energy Physics - Phenomenology · Physics 2025-04-23 Darius A. Faroughy , Gino Isidori , Felix Wilsch , Kei Yamamoto

We observe that a recently proposed supersymmetric model with Q6 flavor symmetry admits a new CP violating ground state. A new sum rule for the quark mixing parameters emerges, which is found to be consistent with data. Simple extensions of…

High Energy Physics - Phenomenology · Physics 2011-05-25 K. S. Babu , Kenji Kawashima , Jisuke Kubo

Composite Higgs extensions of the Standard Model provide an explanation for the large hierarchies between the Yukawa couplings. We study their realisation in the context of fundamental partial compositeness where the Standard Model fermions…

High Energy Physics - Phenomenology · Physics 2023-07-24 Florian Goertz , Álvaro Pastor-Gutiérrez , Jan M. Pawlowski

We construct an extension of the Standard Model (SM) which is based on grand unification with Pati-Salam symmetry. The setup is supplemented with the idea of spontaneous flavour symmetry breaking which is mediated through flavon fields with…

High Energy Physics - Phenomenology · Physics 2015-06-03 Thorsten Feldmann , Florian Hartmann , Wolfgang Kilian , Christoph Luhn

It is presented an analysis on lepton flavour violating transitions, leptonic magnetic dipole moments and electric dipole moments in a class of models characterized by the flavour symmetry A4 x Z3 x U(1)_FN, whose choice is motivated by the…

High Energy Physics - Phenomenology · Physics 2009-07-22 Luca Merlo

The introduction of a Flavour Symmetry can represent an interesting way in which one can try to find an answer to some intriguing problems in Flavour Physics, like the hierarchy between the fermion masses or the particular values of mixing…

High Energy Physics - Phenomenology · Physics 2009-05-07 Alfredo Urbano