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We discuss our recently proposed S3(down)xS3(up) flavour-permutation-symmetric mixing observables, giving expressions for them in terms of (moduli-squared) of the mixing matrix elements. We outline their successful use in providing…

High Energy Physics - Phenomenology · Physics 2008-05-23 P. F. Harrison , D. R. J. Roythorne , W. G. Scott

We introduce an effective lagrangian including negative and positive parity heavy mesons containing a heavy quark, light pseudoscalars, and light vector resonances, with their allowed interactions, using heavy quark spin-flavour symmetry,…

High Energy Physics - Phenomenology · Physics 2009-10-22 R. Casalbuoni , A. Deandrea , N. Di Bartolomeo F. Feruglio , R. Gatto , G. Nardulli

We consider the phenomenology of new neutral gauge bosons with flavour non-diagonal couplings to fermions, inherent in 6D models explaining successfully the hierarchy of masses as well as the mixing for quarks, charged leptons and neutrinos…

High Energy Physics - Phenomenology · Physics 2016-06-29 Jean-Marie Frère , Maxim Libanov , Simon Mollet , Sergey Troitsky

We consider the leptonic and semileptonic (SL) lepton flavour violating (LFV) decays of the charged leptons in the minimal supersymmetric standard model (MSSM). The formalism for evaluation of branching fractions for the SL LFV…

High Energy Physics - Phenomenology · Physics 2008-11-26 Takeshi Fukuyama , Amon Ilakovac , Tatsuru Kikuchi

We implement electroweak renormalisation schemes involving the effective weak mixing angle to NLO in Standard Model Effective Field Theory (SMEFT). After developing the necessary theoretical machinery, we analyse a select set of electroweak…

High Energy Physics - Phenomenology · Physics 2023-12-15 Anke Biekötter , Benjamin D. Pecjak , Tommy Smith

We analyze possible lepton-flavor-violating decays of the $Z^0$ particle in a minimal extension of the Standard Model, in which one right-handed neutral field for each family has been introduced. Such rare leptonic decays are induced by…

High Energy Physics - Phenomenology · Physics 2009-10-22 J. G. Koerner , A. Pilaftsis , K. Schilcher

Four-fermi models in dimensionality $2<d<4$ exhibit an ultra-violet stable renormalization group fixed point at a strong value of the coupling constant where chiral symmetry is spontaneously broken. The resulting field theory describes…

High Energy Physics - Lattice · Physics 2016-08-31 Simon Hands , Aleksandar Kocic , John B. Kogut

We examine for standard-like orbifold compactification models the constraints due to quarks and leptons generation non-universality of soft supersymmetry breaking interactions. We follow the approach initiated by Ibanez and Lust and…

High Energy Physics - Theory · Physics 2010-04-06 P. Brax , M. Chemtob

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

We discuss $Z$ mediated flavour changing neutral currents within a model where the hierarchical quark and lepton masses are explained via a fourth vector-like family, together with a scalar sector consisting of two Higgs doublets augmented…

High Energy Physics - Phenomenology · Physics 2022-02-08 A. E. Cárcamo Hernández , S. F. King , H. Lee

We study renormalisable models with minimal field content that can provide a viable Dark Matter candidate through the standard freeze-out paradigm and, simultaneously, accommodate the observed anomalies in semileptonic $B$-meson decays at…

High Energy Physics - Phenomenology · Physics 2021-12-22 Giorgio Arcadi , Lorenzo Calibbi , Marco Fedele , Federico Mescia

In this work we consider the Standard Model Effective Field Theory extended with right-handed neutrinos, the $\nu$SMEFT, and calculate the full set of one-loop anomalous dimensions that are proportional to Yukawa couplings. These…

High Energy Physics - Phenomenology · Physics 2024-08-06 Marco Ardu , Xabier Marcano

In a supersymmetric scenario, we study masses and mixings for leptons through the ${\bf Q}_{6}$ flavour symmetry. In the simplest case, the ${\bf M}_{\nu}$ effective neutrino mass matrix, that comes from the type I see-saw mechanism, breaks…

High Energy Physics - Phenomenology · Physics 2016-09-30 J. C. Gómez-Izquierdo , F. González-Canales , M. Mondragon

Functional renormalisation group approach is applied to a imbalanced many- fermion system with a short-range attractive force. Composite boson field is introduced to describe the pairing between different flavour fermions. A set of…

Quantum Gases · Physics 2015-06-22 Boris Krippa

Whenever an anomaly in the flavour sector appears, analyses are performed examining whether it can be explained by adding a small number of carefully-chosen flavour non-universal four-fermion SMEFT operators. These analyses are typically…

High Energy Physics - Phenomenology · Physics 2026-03-05 Alakabha Datta , Jean-François Fortin , Jacky Kumar , David London , Danny Marfatia , Nicolas Sanfaçon

The Standard Model (SM) predicts the universality of lepton couplings with the electroweak gauge bosons. Semileptonic decays of $b$-hadrons provide a powerful framework for testing the SM and probing possible New Physics effects. In…

High Energy Physics - Experiment · Physics 2026-04-30 Davide Fazzini

We posit that the distinct patterns observed in fermion masses and mixings are due to a minimally broken $\mathrm{U}(2)_{q+e}$ flavor symmetry acting on left-handed quarks and right-handed charged leptons, giving rise to an accidental…

High Energy Physics - Phenomenology · Physics 2024-02-28 Stefan Antusch , Admir Greljo , Ben A. Stefanek , Anders Eller Thomsen

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 suggest a new class of tests for searching for lepton flavor non-universality (LFNU) using ratio observables and based on correlations among the underlying LFNU new physics (NP) effects in several (seemingly independent) di-lepton and…

High Energy Physics - Phenomenology · Physics 2020-11-09 Yoav Afik , Shaouly Bar-Shalom , Jonathan Cohen , Amarjit Soni , Jose Wudka

Lepton flavor-violating processes offer interesting possibilities to probe new physics at multi-TeV scale. We discuss those in the framework of effective field theory, emphasizing the role of gluonic operators. Those operators are obtained…

High Energy Physics - Phenomenology · Physics 2017-08-09 Alexey A. Petrov , Dmitry V. Zhuridov