Related papers: Renormalization Group Evolution of Flavour Invaria…
Numerical correlations between fermion masses and mixings could indicate the presence of a flavor symmetry at high energies. In general, the search for these correlations using low-energy data requires an estimate of leading-log radiative…
In the Standard Model, Yukawa couplings parametrize the fermion masses and mixing angles with the exception of neutrino masses. The hierarchies and apparent regularities among the quark and lepton masses are, however, otherwise a mystery.…
To address fermion mass hierarchy and flavor mixings in the quark and lepton sectors, a minimal flavor structure without any redundant parameters beyond phenomenological observables is proposed via decomposition of the Standard Model Yukawa…
We consider a class of $\text{SO}(10)$ models with flavor symmetries in the Yukawa sector and investigate their viability by performing numerical fits to the fermion masses and mixing parameters. The fitting procedure involves a top-down…
We study the contraints on non-flavour-blind soft supersymmetry breaking terms coming from flavour and CP violating processes in the presence of hierarchical Yukawa couplings, and quantify how much these constraints are weakened in the…
Deriving the Yukawa couplings and the resulting fermion masses and mixing angles of the Standard Model (SM) from a more fundamental theory remains one of the central outstanding problems in theoretical high-energy physics. It has long been…
The scalar mass is determined in the simplest scalar-fermion Yukawa-model in the whole range of stability of the scalar potential. Two versions of the Functional Renormalisation Group (FRG) equations are solved, where also composite…
Most of the free parameters in the Standard Model (SM) -- a quantum field theory which has successfully elucidated the behaviors of strong, weak and electromagnetic interactions of all the known fundamental particles, come from the lepton…
Lepton flavour non-conserving processes are examined in the context of unified models with U(1)-family symmetries which reproduce successfully the low-energy hierarchy of the fermion mass spectrum and the Kobayashi - Maskawa mixing. These…
We construct a model in which the hierarchies of the quark and lepton masses and mixing are explained by the $\Gamma_6^\prime$ modular flavor symmetry. The hierarchies are realized by the Froggatt-Nielsen-like mechanism due to the residual…
General issues in the renormalization group evolution of fermion masses and mixings is discussed. An effective fixed point in the top quark Yukawa coupling can strongly constrain its value at the electroweak scale. Predictions following…
We present a new geometric approach to the flavour decomposition of an arbitrary soft supersymmetry-breaking sector in the MSSM. Our approach is based on the geometry that results from the quark and lepton Yukawa couplings, and enables us…
In the Yukawa model with two different mass scales the renormalization group equation is used to obtain relations between scattering amplitudes at low energies. Considering fermion-fermion scattering as an example, a basic one-loop…
We review recent work on the structure of the fermion mass matrices in supergravity effective superstrings. They are generally given at low energy by non-trivial functions of the gauge singlet moduli fields. Interesting structures appear in…
We present a model where all fermions are contained in a single irreducible representation of an SU(19) gauge symmetry group. If there is only one scalar field, Yukawa interactions are controlled by a single number rather than by one or…
Flavor mixings together with fermion mass spectra are studied in detail in the $SU(6) \times SU(2)_R$ model, in which state-mixings beyond the minimal supersymmetric standard model (MSSM) take place. Characteristic patterns of fermion…
In our recent attempt to explain flavor hierarchies [1], a gauged SU(2) flavor symmetry acting on left-handed fermions provides a ground to introduce three independent rank-one contributions to the Yukawa matrices: a renormalizable one for…
We study a number of models, based on a non-Abelian discrete group, that successfully reproduce the simple and predictive Yukawa textures usually associated with U(2) theories of flavor. These models allow for solutions to the solar and…
We present a new mechanism, which does not require any flavor symmetry, to explain the small Yukawa couplings and CKM mixing angles. The Yukawa matrices are assumed to be random at short distances and the hierarchical structure is generated…
A bottom-up approach has been adopted to identify a flavour model that agrees with present experimental measurements. The charged fermion mass hierarchies suggest that only the top Yukawa term should be present at the renormalisable level.…