相关论文: A new contribution to the flavour-changing lepton-…
We study the general properties of hierarchical fermion mass matrices in which the small eigenvalues are stable with respect to perturbations of the matrix entries and we consider specific applications to the charged lepton contribution to…
In a recent paper, we pointed out that mixing of the light neutrinos with heavy gauge singlet states could reconcile the Z-pole data from e+e- colliders and the nu_mu (anti-nu_mu) scattering data from the NuTeV experiment at Fermilab. We…
The fermion mass problem is briefly reviewed. The observed hierarchy of quark and charged lepton masses strongly suggests the existence of an approximately conserved chiral flavour symmetry beyond the Standard Model. It is argued that in…
We present a short review of a 6-dimensional model where a flavour puzzle of the Standard Model fermions finds an elegant solution. The mechanism is based on an idea that the three fermionic generations originate from a single 6D family.…
We construct extensions of the Standard Model with two Higgs doublets, where there are flavour changing neutral currents both in the quark and leptonic sectors, with their strength fixed by the fermion mixing matrices $V_{CKM}$ and…
The fermion mixing transformations are studied in the quantum field theory framework. In particular neutrino mixing is considered and the Fock space of definite flavor states is shown to be unitarily inequivalent to the Fock space of…
Upcoming searches for lepton flavour change (LFV) aim to probe New Physics(NP) scales up to $ \sim 10^4$ TeV, implying that they will be sensitive to NP at lower scales that is suppressed by loops or small couplings. We suppose that the NP…
We analyze lepton flavour violating transitions, leptonic magnetic dipole moments (MDMs) and electric dipole moments (EDMs) in a class of models characterized by the flavour symmetry A4 x Z3 x U(1)_{FN}, whose choice is motivated by the…
Flavour physics plays a central role in the search for physics beyond the Standard Model, posing fundamental questions whose answers may point to new physics scales far above the electroweak scale. The flavour structure of the Standard…
We discuss a mechanism of neutrinoless double beta decay, where neutrinos of different flavours come into play. This is realized by effective flavour-violating scalar interactions. As one consequence, we find that within the normal mass…
It is shown that it is possible to create successful models of flavor for both quarks and leptons using the discrete non-abelian group $T^{\prime}$ by itself. Two simple realizations are presented that can be used as the starting point for…
There are theoretical and phenomenological motivations that there may exist additional heavy Z' bosons with family non-universal couplings. Flavor mixing in the quark and lepton sectors will then lead to flavor changing couplings of the…
The inclusion of heavy neutral leptons to the Standard Model particle content could provide solutions to many open questions in particle physics and cosmology. The modification of the charged and neutral currents from active-sterile mixing…
The smallness of fermion masses and mixing angles has recently been been attributed to approximate global $U(1)$ symmetries, one for each fermion type. The parameters associated with these symmetry breakings are estimated here directly from…
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…
In this work I apply a recently proposed improvement procedure, originally conceived to reduce finite lattice spacing effects in transfer matrices for dilute Fermi systems, to tuning operators for the calculation of observables. I…
In this thesis, we study the role of flavours in leptogenesis. In a first time, we review the so-called one flavour picture, where only the lightest right-handed neutrino is taken into account, and where lepton flavours are neglected. After…
We consider an extension of the Standard Model with three right-handed neutrinos, endowed with a flavour symmetry $G_f$, $G_f=\Delta (3 \, n^2)$ or $G_f=\Delta (6 \, n^2)$, $n \geq 2$, and CP. For large active-sterile mixing, we study the…
In supersymmetric (SUSY) models the misalignment between fermion and sfermion families introduces unsuppressed flavor-changing processes. Even if the mass parameters are chosen to give no flavor violation, family dependent radiative…
In this talk we survey some of the recent promising developments in the search for the theory behind neutrino mass and mixing, and indeed all fermion masses and mixing. The talk is organized in terms of a neutrino mass models decision tree…