Related papers: Flavour Violating Axions
We present a short overview of recent work on the topic of flavour violation in the presence of a sequential fourth generation (4G) of quarks and leptons. We discuss the implications of this simple extension of the Standard Model (SM3) for…
Minimal Flavour Violation in its strong or weak versions, based on $U(3)^3$ and $U(2)^3$ respectively, allows suitable extensions of the Standard Model at the TeV scale to comply with current flavour constraints in the quark sector. Here we…
We explore the possibility that lepton family numbers and baryon number are such good symmetries of Nature because they are the global remnant of a spontaneously broken gauge symmetry. An almost arbitrary linear combination of these…
While solving the supersymmetric flavour problem, a U(2) flavour symmetry might be at the origin of the pattern of fermion masses and mixings. The consequences of this hypothesis are spelled out concerning the parameters of the CKM matrix…
Lepton Flavor Universality Violation (LFUV) in $b\rightarrow s l^+ l^-$ processes is investigated in the context of a 331 model. It is shown that in order to explain the experimentally observed deviations from the Standard Model in these…
Analyticity and unitarity constrain certain classe of new physics models by linking flavor-conserving and flavor-violating four-fermion interactions. In this work, we explore how these theoretical relations impact flavor-violating rare top…
In a supersymmetric model with hierarchical squark masses we analyze a pattern of flavour symmetry breaking centered on the special role of the top Yukawa coupling and, by extension, of the full Yukawa couplings for the up-type quarks. For…
Recent hints for lepton-universality violation in $b\to c\ell\nu$ and $b\to s\ell\ell$ transitions could imply the existence of lepton-flavour violating $b$ decays. The LHCb experiment is well suited for the search for these decays due to…
Lepton charge asymmetries can be used as an alternative means of searching for new physics. They are interesting because they are small in the Standard Model and therefore, necessarily evidence new physics. In this work we explore the use…
High precision electroweak tests, such as deviations from the Standard Model expectations of the Lepton Flavor Universality breaking in K->lnu (with l= e or mu), represent a powerful tool to test the Standard Model and, hence, to constrain…
We investigate to what extent a generic, generation-dependent $U(1)$ symmetry acting on the quark Yukawa operators can reduce the number of free parameters by forcing some entries in the Yukawa matrices to vanish. The maximal reduction…
We study a class of DFSZ-like models for the QCD axion that can address observed anomalies in stellar cooling. Stringent constraints from SN1987A and neutron stars are avoided by suppressed couplings to nucleons, while axion couplings to…
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, such…
We systematically investigate the possible phenomenological impact of residual flavour groups in the charged lepton sector. We consider all possible flavour charge assignments for abelian residual symmetries up to Z8. The allowed flavour…
We outline a systematic strategy which should help in this decade to identify New Physics beyond the Standard Model by means of quark flavour violating processes and thereby to extend the picture of short distance physics down to the scales…
We study flavour physics and CP violation in the context of low energy Supersymmetry with non-universal soft mass terms for sfermions. Large deviations from Standard Model predictions are allowed in B-physics, as shown in two explicit…
New physics in the rare top decays $t \to q \ell^+\ell^-$ is currently very weakly constrained. We show that in a large class of Standard Model extensions, existing experimental constraints on new physics in flavor-conserving processes…
Flavour symmetries in the dark sector are a theoretically motivated and phenomenologically appealing concept. The dark matter particle can be stabilised with the help of flavour symmetries, without the need to introduce an additional…
New sub-GeV vector bosons with couplings to muons but not electrons have been discussed in order to explain the muon's magnetic moment, the gap of high-energy neutrinos in IceCube or the proton radius puzzle. If such a light Z' not only…
The flavor puzzles remain among the most compelling open questions in particle physics. The striking hierarchies observed in the masses and mixing of charged fermions define the Standard Model (SM) flavor puzzle, a profound structural…