Related papers: Hidden Vector 'Coordinates' in Particle Physics
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…
Grand unified theories with fermions transforming as irreducible representations of a discrete nonabelian flavor symmetry can lead to realistic fermion masses, without requiring very small fundamental parameters. We construct a specific…
The fundamental properties of the lepton sector include the neutrino masses and flavor mixings. Both are difficult to observe because of the extremely small neutrino masses and neutrino-matter cross sections. In these lectures, we focus on…
The behavior of fermions in the presence of Lorentz and CPT violation is studied. Allowing for operators of any mass dimension, we classify all Lorentz-violating terms in the quadratic Lagrange density for free fermions. The result is…
We briefly review some recent developments in theoretical models of fermion masses, mixings and CP violation with discrete non-Abelian symmetries. Then, we explain the main ideas of a recently proposed Minimal S_3 Invariant Extension of the…
$B$-physics data and flavor symmetries suggest that leptoquarks can have masses as low as few ${\cal{O}}(\mbox{TeV})$, predominantly decay to third generation quarks, and highlight $pp \to b \mu \mu$ signatures from single production and…
Lepton and quark flavor invariants are studied, both in the Standard Model with a dimension five Majorana neutrino mass operator, and in the seesaw model. The ring of invariants in the lepton sector is highly non-trivial, with non-linear…
We argue that neutrino flavor parameters may exhibit features that are very different from those of quarks and charged leptons. Specifically, within the Froggatt-Nielsen (FN) framework, charged fermion parameters depend on the ratio between…
We review flavour and CP violations in the lepton sector as probes of new physics beyond the standard model and its minimal extensions accommodating massive neutrinos. After recalling the main experimental bounds and the future…
Heavy Neutral Leptons are naturally present in many well-motivated extensions of the Standard Model. If their mass is of few dozens of GeVs, they can be long-lived and lead to events with displaced vertices, giving rise to promising…
The oscillating probabilities of lepton flavor changing neutrino oscillation processes, where neutrinos are detected by charged-current and neutral-current interactions, are calculated in a quantum field-theoretical approach to neutrino…
Present situation in the flavour mixing of quarks and leptons is briefly reviewed and a new approach called the Minimal Flavour Mixing (MFM) is considered in detail. According to MFM the whole of the flavour mixing is basically determined…
We propose an extra-dimension framework on the orbifold $S^1/Z_2$ for understanding the origin of the fermion mass and mixing hierarchies. Introducing the flavor symmetry $G_F(=${\it non-Abelian}$\times${\it Abelian}) as well as the extra…
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…
Recent work on local F-theory models shows the potential for new categories of flavor models. In this paper we investigate the perturbative effective theory interpretation of this result. We also show how to extend the model to the neutrino…
Flavor physics is about particle mass-degeneracy-deviations (DMD) and mixing and especially about hierarchies of those deviations. On the one hand there is no established theory of particle flavor at present; on the other hand there are…
The high-energy astrophysical neutrinos recently discovered by IceCube opened a new way to test Lorentz and CPT violation through the astrophysical neutrino mixing properties. The flavor ratio of astrophysical neutrinos is a very powerful…
Assuming that neutrinos are not Majorana fermions and the right handed Dirac neutrino does not exist, we propose a model in which the second and the third generations of the leptons are composites, while the first generation is fundamental.…
We propose a simple clockwork model of flavor which successfully generates the Standard Model flavor hierarchies from random order-one couplings. With very few parameters we achieve distributions of models in excellent agreement with…
Family symmetries are possibly the most conservative extension of the Standard Model that attempt explanations of the pattern of fermion masses and mixings. The observed large mixing angles in the lepton sector may be the first signal for…