Related papers: Vector-like quark doublets, weak-basis invariants …
We present a minimal extension of the Standard Model that can simultaneously account for the anomalies in semi-leptonic B meson decays and the muon g-2, give large CP violation in charm decays (up to the value recently measured by LHCb),…
We present a new form of CP violation (CPV) that can be realised in Two-Higgs Doublet Models (2HDMs) and was studied recently in [1]. By examining the vacuum manifold of a generic (convex) 2HDM potential, we identify scenarios that exhibit…
We study the patterns of flavour violation in renormalisable extensions of the Standard Model (SM) that contain vector-like quarks (VLQs) in a single complex representation of either the SM gauge group $G_{SM}$ or $G_{SM}' = G_{SM} \times…
Quark models with four-fermion interaction including derivatives of fields are exploited as prototypes for composite-Higgs extensions of the Standard Model. In the non-trivial case of two- and four-derivative insertions the dynamical…
Conditions for CP violation in the scalar potential sector of general N-Higgs-doublet models (NHDMs) are analyzed from a group theoretical perspective. For the simplest two-Higgs-doublet model (2HDM) potential, a minimum set of conditions…
CP violation plays a very important role in nature with implications both for Particle Physics and for Cosmology. Accounting for the observed matter anti-matter asymmetry of the Universe requires the existence of new sources of CP violation…
In this paper we study the direct CP asymmetry of the doubly Cabibbo-suppressed decay mode $D^0 \to K^+ \pi^- $ within standard model and two Higgs doublet model with generic Yukawa structure. In the standard model we derive the corrections…
Tests of CP violation by appropriate momentum correlations in $Z\to 3$ jets and in particular in $Z\to b\bar bX$ probe CP-violating effective couplings -- that manifest themselves as form factors -- which conserve the quark chirality and…
We give a procedure to construct a special class of symmetric quark mass matrices near the democratic limit of equal Yukawa couplings for each sector. It is shown that within appropriate weak-bases, the requirements of symmetry and…
We study CP violation in the lepton sector in extended models with right-handed neutrinos, without and with left-right symmetry, and with arbitrary mass terms. We find the conditions which must be satisfied by the neutrino and charged…
We investigate the quark sector of a four-Higgs-doublet model with an exact D_5 symmetry. In the framework of explicit CP violation, we considered the most general real vacuum, derived the quark mass matrices, and performed a numerical fit…
We consider supersymmetric extensions of the standard model with two pairs of Higgs doublets. We study the possibility that CP violation is generated spontaneously in the scalar sector via vacuum expectation values (VEVs) of the Higgs…
The invariant approach is a powerful method for studying CP violation for specific Lagrangians. The method is particularly useful for dealing with discrete family symmetries. We focus on the CP properties of unbroken $\Delta(27)$ invariant…
Models with new vector-like quarks can produce observable quark mixing effects which are forbidden in the Standard Model. We classify all such models and write down the effective Lagrangian that results from integrating out the new quarks.…
The Two-Higgs Doublet Model (2HDM) is a well-motivated theoretical framework that provides additional sources of CP Violation (CPV) beyond the Standard Model (SM). After studying the vacuum topology of a general (convex) 2HDM potential, we…
By using the relation between CP-violation phase and the mixing angles in Cabibbo-Kobayashi-Maskawa matrix postulated by us before, the rephasing invariant is recalculated. Furthermore, the problem about maximal CP violation is discussed.…
We obtain constraints on the mixing of vector-like quarks coupling predominantly to the third generation. We consider all (seven) relevant types of vector-like quarks, individually. The constraints are derived from oblique corrections and Z…
We consider the possibility of electroweak baryogenesis in a simple extension of the standard model with an extra singlet complex scalar and a vector-like down quark. We show that in the present model the first-order electroweak phase…
We propose a model of soft CP violation that evades the strong CP problem and can describe observed CP violation in the neutral kaon sector, both direct and indirect. Our model requires two ``duark'' mesons carrying quark number two that…
We show that in a Complementary two-Higgs doublet model(C2HDM) the CP violating phase in the CKM matrix can be generated spontaneously, dangerous FCNC can be naturally suppressed and the strong CP problem can also be avoided. The two Higgs…