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We employ a bottom-up and model-independent technique to search for non-Abelian discrete flavour symmetries capable of predicting viable CKM and PMNS matrices alongside of special patterns of leptoquark couplings. In particular, we analyze…

High Energy Physics - Phenomenology · Physics 2020-02-19 Jordan Bernigaud , Ivo de Medeiros Varzielas , Jim Talbert

In the Standard Model (SM), the coupling of the electroweak gauge bosons to the leptons is lepton flavour universal. Tests of this property constitute sensitive probes for new physics models that violate lepton flavour universality. Recent…

High Energy Physics - Experiment · Physics 2018-07-01 Christoph Langenbruch

We study the predictions for CP phases and absolute neutrino mass scale for broad classes of models with a U(2) flavor symmetry. For this purpose we consider the same special textures in neutrino and charged lepton mass matrices that are…

High Energy Physics - Phenomenology · Physics 2021-01-27 Matthias Linster , Jacobo Lopez-Pavon , Robert Ziegler

The mass and weak interaction eigenstates for the quarks of the third generation are very well aligned, an empirical fact for which the Standard Model offers no explanation. We explore the possibility that this alignment is due to an…

High Energy Physics - Phenomenology · Physics 2018-01-17 K. S. Babu , A. Friedland , P. A. N. Machado , I. Mocioiu

We show that new physics models without new flavor violating interactions can explain the recent anomalies in the $b\to s\ell^+\ell^-$ transitions. The $b\to s\ell^+\ell^-$ arises from a $Z'$ penguin which automatically predicts the $V-A$…

High Energy Physics - Phenomenology · Physics 2018-02-07 Jernej F. Kamenik , Yotam Soreq , Jure Zupan

We construct a three-Higgs doublet model with a flavour non-universal ${\rm U}(1)\times \mathbb{Z}_2$ symmetry. That symmetry induces suppressed flavour-changing interactions mediated by neutral scalars. New scalars with masses below the…

High Energy Physics - Phenomenology · Physics 2022-03-04 Dipankar Das , P. M. Ferreira , António P. Morais , Ian Padilla-Gay , Roman Pasechnik , J. Pedro Rodrigues

In models with an extra U(1)' gauge boson family non-universal couplings to the weak eigenstates of the standard model fermions generally induce flavor-changing neutral currents. This phenomenon leads to interesting results in various B…

High Energy Physics - Phenomenology · Physics 2009-09-15 Vernon Barger , Cheng-Wei Chiang , Jing Jiang , Paul Langacker

We analyze the class of models with an extra $U(1)_X$ gauge symmetry that can account for the $b \to s \ell \ell$ anomalies by modifying the Wilson coefficients $C_{9e}$ and $C_{9\mu}$ from their standard model values. At the same time,…

High Energy Physics - Phenomenology · Physics 2022-05-18 Disha Bhatia , Nishita Desai , Amol Dighe

In this letter we propose a strategy for discerning if new physics in the Wilson coefficient ${\cal C}_{9\mu}$ is dominantly lepton flavour universality violating or if it contains a sizable lepton flavour universal component (${\cal…

High Energy Physics - Phenomenology · Physics 2022-07-15 Marcel Algueró , Bernat Capdevila , Andreas Crivellin , Joaquim Matias

In combination with supersymmetry, flavor symmetry may relate quarks with leptons, even in the absence of a grand-unification group. We propose an SU(3)xSU(2)xU(1) model where both supersymmetry and the assumed A4 flavor symmetries are…

High Energy Physics - Phenomenology · Physics 2011-09-01 S. Morisi , E. Peinado , Yusuke Shimizu , J. W. F. Valle

We explore a novel mechanism to restrict TeV-scale leptoquark interactions and render the proton exactly stable to all orders in the effective field theory expansion. A scalar condensate breaks a lepton-flavoured $\mathrm{U}(1)_X$ gauge…

High Energy Physics - Phenomenology · Physics 2022-08-12 Joe Davighi , Admir Greljo , Anders Eller Thomsen

In order to simultaneously account for both $R_{D^{(\ast)}}$ and $R_{K^{(\ast)}}$ anomalies in $B$-decays, we consider an extension of the Standard Model by a single vector leptoquark field, and study how one can achieve the required lepton…

High Energy Physics - Phenomenology · Physics 2020-01-29 C. Hati , J. Kriewald , J. Orloff , A. M. Teixeira

There has been a steady interest in flavor anomalies and their global fits as ideal probes of new physics. If the anomalies are real, one promising explanation is a new $Z'$ gauge boson with flavor-changing coupling to bottom and strange…

High Energy Physics - Phenomenology · Physics 2018-03-14 Stefano Di Chiara , Andrew Fowlie , Sean Fraser , Carlo Marzo , Luca Marzola , Martti Raidal , Christian Spethmann

In the contest of a Two Higgs Doublet Model without flavor conservation, the presence of Flavor Changing Neutral Scalar Currents may affect in particular the couplings of the top quark. Some ideas on how to look for new signals from Flavor…

High Energy Physics - Phenomenology · Physics 2007-05-23 Laura Reina

The flavour lepton symmetry is gauged for both the Standard Model flavor group and its extension with three degenerate right-handed neutrinos. As a consequence of anomaly cancellation, exotic leptons are introduced which induce a see-saw…

High Energy Physics - Phenomenology · Physics 2017-05-18 P. Quilez

In the simplest examples of models with a discrete quark-lepton symmetry, an electroweak symmetry breaking sector with more than one Higgs doublet is necessary to obtain the correct mass relations between quarks and leptons. A two Higgs…

High Energy Physics - Phenomenology · Physics 2009-10-28 C. C. Lassig , R. R. Volkas

We construct a supersymmetric SU(5) x A_4 flavour GUT model in which an inverse neutrino mass hierarchy is realised without fine-tuning of parameters. The model shares some properties with the normal hierarchy model which we presented in…

High Energy Physics - Phenomenology · Physics 2013-12-18 Stefan Antusch , Christian Gross , Vinzenz Maurer , Constantin Sluka

We consider a class of models predicting new heavy neutral fermionic states, whose mixing with the light neutrinos can be naturally significant and produce observable effects below the threshold for their production. We update the indirect…

High Energy Physics - Phenomenology · Physics 2016-09-01 D. Tommasini , G. Barenboim , G. Bernabeu , C. Jarlskog

We analyse the violations of lepton-flavour universality in the ratios B(P -> l nu)/B(P -> l' nu) using a general effective theory approach, discussing various flavour-symmetry breaking patterns of physics beyond the SM. We find that in…

High Energy Physics - Phenomenology · Physics 2009-11-05 Alberto Filipuzzi , Gino Isidori

We explore a Z' boson with family-nonuniversal couplings to charged leptons. The general effect of Z-Z' mixing, of both kinetic and mass types, is included in the analysis. Adopting a model-independent approach, we perform a comprehensive…

High Energy Physics - Phenomenology · Physics 2013-11-05 Cheng-Wei Chiang , Yi-Fan Lin , Jusak Tandean