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Related papers: Solving the flavour problem with hierarchical ferm…

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A brief overview of flavour-changing phenomena is presented. The main topics discussed are the universality and Lorentz structure of the leptonic charged-current couplings, our present knowledge of the quark-mixing matrix and the future…

High Energy Physics - Phenomenology · Physics 2010-11-23 A. Pich

It has recently been shown that when $N_f$ generations of chiral fermions are coupled in a specific manner to $N$ (with $N \geq 2N_f-1$) pairs of vectorlike fermions whose mass terms form a one-dimensional lattice-like structure in theory…

High Energy Physics - Phenomenology · Physics 2026-01-16 Gurucharan Mohanta , Ketan M. Patel

A general operator expansion is presented for quark and lepton mass matrices in unified theories based on a U(2) flavor symmetry, with breaking parameter of order $V_{cb} \approx m_s/m_b \approx \sqrt{m_c/m_t}$. While solving the…

High Energy Physics - Phenomenology · Physics 2009-10-30 R. Barbieri , L. J. Hall , S. Raby , A. Romanino

We investigate a framework of the Minimal Supersymmetric Standard Model (MSSM) in which the quark and lepton flavor structure and suppression of flavor-changing neutral currents (FCNCs) are governed by non-invertible selection rules. By…

High Energy Physics - Phenomenology · Physics 2025-12-29 Yuichiro Nakai , Hajime Otsuka , Yoshihiro Shigekami , Zhihao Zhang

Combining Pati-Salam (PS) and flavour symmetries in a renormalisable setup, we devise a scenario which produces realistic masses for the charged leptons. Flavour-symmetry breaking scalar fields in the adjoint representations of the PS gauge…

High Energy Physics - Phenomenology · Physics 2016-12-21 Thorsten Feldmann , Christoph Luhn , Paul Moch

Strongly coupled supersymmetric theories can give rise to composite quarks and leptons at low energy. We show that the internal structure of these particles can explain the origin of three generations and provide a qualitative understanding…

High Energy Physics - Phenomenology · Physics 2016-09-06 David B. Kaplan , Francois Lepeintre , Martin Schmaltz

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 rewrite the Yukawa interactions of the standard model in terms of flavour-dependent vacuum structure to address the family mass hierarchy and CP violation in both the quark sector and lepton sector. It is realized for the first time that…

High Energy Physics - Phenomenology · Physics 2022-01-17 Ying Zhang

The explicit breaking of chiral symmetry of the Wilson fermion action results in additive quark mass renormalization. Moreover, flavour singlet and non-singlet scalar currents acquire different renormalization constants with respect to…

High Energy Physics - Lattice · Physics 2016-10-12 Gunnar S. Bali , Enno E. Scholz , Jakob Simeth , Wolfgang Söldner

We extend the standard model with two extra Higgs doublets. Making use of a symmetry principle, we present flavour symmetries based on cycle groups $Z_N$ that oblige each Higgs doublet to contribute to the mass of only one generation, thus…

High Energy Physics - Phenomenology · Physics 2017-10-30 Nuno Rosa Agostinho , David Emmanuel-Costa , J. I. Silva-Marcos

We study the impact of an additional $U(1)'$ gauge symmetry with flavour-dependent charges for quarks and leptons on the LHC flavour anomalies observed in $B \to K^* \mu^+\mu^-$, $R(K) = B \to K \mu^+\mu^-/B \to K e^+e^-$, and $h \to…

High Energy Physics - Phenomenology · Physics 2015-04-15 Andreas Crivellin , Giancarlo D'Ambrosio , Julian Heeck

In the context of Supersymmetric Grand Unified theories with soft breaking terms arising at the Planck scale, it is generally possible to link flavor changing neutral current and CP violating processes occurring in the leptonic and hadronic…

High Energy Physics - Phenomenology · Physics 2009-11-10 M. Ciuchini , A. Masiero , L. Silvestrini , S. K. Vempati , O. Vives

We consider scenarios with a heavy $Z^\prime$ gauge boson with flavour non-universal quark and lepton couplings with the goal to illustrate how the cancellation of gauge anomalies generated by the additional U(1)$^\prime$ gauge symmetry…

High Energy Physics - Phenomenology · Physics 2020-03-18 Jason Aebischer , Andrzej J. Buras , Maria Cerdà-Sevilla , Fulvia De Fazio

We explore the possibility that the underlying flavour structure of the Standard Model could be determined by mass chains on a fractal geometry. We consider, as an example, the theory space on a Sierpinski-like geometry. The fermion mass…

High Energy Physics - Phenomenology · Physics 2025-09-08 Alejandro Ibarra , Aadarsh Singh , Sudhir K Vempati

These lectures provide an introductory overview of the dynamics of flavour-changing transitions. The main emphasis is put on present tests of the quark-mixing matrix structure and the phenomenological determination of its parameters. The…

High Energy Physics - Phenomenology · Physics 2008-02-03 A. Pich

In this talk, I present a new framework to understand the long-standing fermion mass hierarchy puzzle. We extend the Standard Model gauge symmetry by an extra local U(1)_S symmetry, broken spontaneously at the electroweak scale. All the SM…

High Energy Physics - Phenomenology · Physics 2015-05-14 S. Nandi

Working within the context of the minimal supersymmetric standard model, we compare current bounds from quark flavor changing processes with current and upcoming bounds on lepton flavor violation. We assume supersymmetry breaking…

High Energy Physics - Phenomenology · Physics 2018-03-07 Sebastian A. R. Ellis , Aaron Pierce

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

The flavour-changing neutral currents (FCNC) are derived at tree level if the electroweak gauge group depends on the fermion family, which are absent in the standard model. We study the lepton flavour violation (LFV) through the FCNC…

High Energy Physics - Phenomenology · Physics 2015-05-19 Kang Young Lee

In these proceedings we review the flavour phenomenology of 2HDMs with generic Yukawa structures. We first consider the quark sector and find that despite the stringent constraints from FCNC processes large effects in tauonic B decays are…

High Energy Physics - Phenomenology · Physics 2022-08-09 Andreas Crivellin , Christoph Greub , Ahmet Kokulu
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