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We present an analysis on flavour anomalies in semileptonic rare $B$-meson decays using an effective field theory approach and assuming that new physics affects only one generation in the interaction basis and non-universal mixing effects…

High Energy Physics - Phenomenology · Physics 2026-03-09 Jorge Alda , Alejandro Mir , Siannah Penaranda

We propose a modification of the electroweak theory, where the fermions with the same electroweak quantum numbers are combined in multiplets and are treated as different quantum states of a single particle. The developed approach enables…

High Energy Physics - Phenomenology · Physics 2019-06-25 A. E. Lobanov

We show how any flavour conserving $Z'$ model can be made flavour violating and non-universal by introducing mass mixing of quarks and leptons with a fourth family of vector-like fermions with non-universal $Z'$ couplings. After developing…

High Energy Physics - Phenomenology · Physics 2017-09-13 Stephen F. King

We consider all relevant dimension six operators to perform a model independent analysis of flavour changing single top production at the LHC.

High Energy Physics - Phenomenology · Physics 2007-05-23 P. M. Ferreira , R. Santos

Four-fermion operators have been utilized in the past to link the quark-exchange processes in the interaction of hadrons with the effective meson-exchange amplitudes. In this paper, we apply the similar idea of a Fierz rearrangement to the…

High Energy Physics - Phenomenology · Physics 2015-06-15 Chueng-Ryong Ji , Bernard L. G. Bakker , Ho-Meoyng Choi , Alfredo Suzuki

We survey some of the recent promising developments in the search for the theory behind neutrino mass and tri-bimaximal mixing, and indeed all fermion masses and mixing. We focus in particular on models with discrete family symmetry and…

High Energy Physics - Phenomenology · Physics 2015-05-14 Stephen F King

Even without grand unification, proton decay can be a powerful probe of physics at the highest energy scales. Supersymmetric theories with conserved R-parity contain Planck-suppressed dimension 5 operators that give important contributions…

High Energy Physics - Phenomenology · Physics 2015-06-25 Daniel T. Larson

We consider a class of models of neutrino mixing with $S_4$ flavour symmetry and generalised CP symmetry, broken to $Z_2$ and $Z_2 \times {\rm CP}$ residual symmetries in the charged lepton and neutrino sectors, respectively. In this…

High Energy Physics - Phenomenology · Physics 2018-03-30 J. T. Penedo , S. T. Petcov , A. V. Titov

Tribimaximal lepton mixing can be obtained assuming A4 flavour symmetry. Many possibilities have been explored in the literature and we give a classification in terms of A4 representations. We propose some phenomenological and theoretical…

High Energy Physics - Phenomenology · Physics 2010-11-11 S. Morisi

These proceedings review the status of present and future bounds on muonic lepton flavour violating transitions in the context of an effective-field theory defined below the electroweak scale. A specific focus is set on the phenomenology of…

High Energy Physics - Phenomenology · Physics 2018-07-02 Giovanni Marco Pruna

New Physics models in which the Standard Model particle content is enlarged via the addition of sterile fermions remain among the most minimal and yet most appealing constructions, particularly since these states are present as building…

High Energy Physics - Phenomenology · Physics 2018-12-20 Asmaa Abada , Ana M. Teixeira

Motivated by the recent strong experimental evidence of large \nu_mu-\nu_tau neutrino mixing, we explore current bounds on the analogous mixing in the charged lepton sector. We present a general formalism for dimension-6 fermionic effective…

High Energy Physics - Phenomenology · Physics 2008-11-26 Deirdre Black , Tao Han , Hong-Jian He , Marc Sher

It has been recently claimed that the symmetry group S4 yields to the Tri-bimaximal neutrino mixing in a "natural" way from the group theory point of view. Approving of this feature as an indication, we build a supersymmetric model of…

High Energy Physics - Phenomenology · Physics 2010-05-12 Federica Bazzocchi , Luca Merlo , Stefano Morisi

We present a concise review of the recent important experimental developments on neutrino mixing (hints for sterile neutrinos, large $\theta_{13}$, possible non maximal $\theta_{23}$, approaching sensitivity on $\delta_{CP}$) and their…

High Energy Physics - Phenomenology · Physics 2015-06-11 G. Altarelli

We amend the incorrect discussion in Nucl. Phys. B 886 (2014) 569 [1] concerning the numerical examples considered there. In particular, we discuss the viability of minimal radiative models of Resonant Leptogenesis and prove that no…

High Energy Physics - Phenomenology · Physics 2015-06-25 P. S. Bhupal Dev , Peter Millington , Apostolos Pilaftsis , Daniele Teresi

The generation of exponential flavor hierarchies from extra-dimensional wavefunction overlaps is re-examined. We find, surprisingly, that coexistence of anarchic fermion mass matrices with such hierarchies is intrinsic and natural to this…

High Energy Physics - Phenomenology · Physics 2010-04-15 Kaustubh Agashe , Takemichi Okui , Raman Sundrum

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 present a model of neutrino mixing based on the flavour group $\Delta(27)$ in order to account for the observation of a non-zero reactor mixing angle ($\theta_{13}$). The model provides a common flavour structure for the charged-lepton…

High Energy Physics - Phenomenology · Physics 2014-06-10 P. F. Harrison , R. Krishnan , W. G. Scott

When lepton flavour effects in thermal leptogenesis are active, they introduce important differences with respect to the case in which they are neglected, the so-called one-flavour approximation. We investigate analytically and numerically…

High Energy Physics - Phenomenology · Physics 2010-10-27 Andrea De Simone , Antonio Riotto

We propose two new simple lepton flavor models in the framework of the $S_4$ flavor symmetry. The neutrino mass matrices, which are given by two complex parameters, lead to the inverted mass hierarchy. The charged lepton mass matrix has the…

High Energy Physics - Phenomenology · Physics 2016-01-27 Yusuke Shimizu , Morimitsu Tanimoto