We study squark flavour violation in the anomaly mediated supersymmetry broken (AMSB) minimal supersymmetric standard model. Analytical expressions for the three-generational squark mass matrices are derived. We show that the anomaly-induced soft breaking terms have a decreasing amount of squark flavour violation when running from the GUT to the weak scale. Taking into account intergenerational...

We discuss the relationship between a symmetry in the neutrino flavour evolution equations and neutrino flavour oscillations in the collective precession mode. This collective precession mode can give rise to spectral swaps (splits) when conditions can be approximated as homogeneous and isotropic. Multi-angle numerical simulations of supernova neutrino flavour transformation show that when this...

We investigate a class of actions for lattice QCD with staggered quarks aimed at reducing the flavour symmetry violations associated with using staggered fermions. These actions replace the gauge field link fields in the quark action with covariantly smeared fields. As such they are an extension of actions considered by the MILC collaboration. We show that such actions systematically reduce fla...

We present a detailed and complete calculation of the gluino and scalar quarks contribution to the flavour-changing top quark decay into a charm quark and a photon, gluon, or a Z 0 boson within the minimal supersymmetric standard model including flavour changing gluino-quarks-scalar quarks couplings in the right-handed sector. We compare the results with the ones presented in an earlier paper w...

A new mechanism for spontaneous breaking of flavour symmetry is demonstrated. An exactly flavour symmetric model with degenerate bare nonets and with sufficiently strong tri-linear meson couplings is shown to lead to selfconsistency equations which are unstable. Instead there exists a stable solution, which break flavour symmetry spontaneously in the mass spectrum. For a C-degenerate meson spec...

We explore realizations of minimal flavour violation (MFV) for the lepton sector. We find that it can be realized within those seesaw models where a separation of the lepton number and lepton flavour violating scales can be achieved. We present a simple implementation of the MFV hypothesis that allows to reconstruct the flavour structure of the model from the values of the light neutrino masses...

We point out that the interactions of goldstinos with matter supermultiplets are a potential source of flavour violation, if fermion and sfermion mass matrices are not aligned and supersymmetry is spontaneously broken at a low scale. We study the impact of those couplings on low-energy processes such as μ → eγ, μ → eee, K → μ+μ−, K-K transitions and analogous ones. Moreover, we address the issu...

The gauge sector of the Standard Model (SM) exhibits a flavour symmetry which allows for independent unitary transformations of the fermion multiplets. In the SM the flavour symmetry is broken by the Yukawa couplings to the Higgs boson, and the resulting fermion masses and mixing angles show a pronounced hierarchy. In this work we connect the observed hierarchy to a sequence of intermediate eff...

The flavour violating neutrinoless muon decays in the presence of nuclei, are discussed. We focus on the theoretical aspects of µ − (A, Z) → e − (A, Z) * (muon to electron conversion), one of the most prominent flavour changing reactions, emphasizing its connection with the physics beyond the standard model. This process offers the most severe limits of the lepton flavour violation. By using th...

Soft supersymmetry-breaking terms provide a wealth of new potential sources of flavour violation, which are tightly constrained by precision experiments. This has posed a challenge to construct flavour models which both explain the structure of the Standard Model Yukawa couplings and also predict soft-breaking patterns that are compatible with these constraints. While such models have been stud...