Related papers: Vector-like quark doublets, weak-basis invariants …
The combination of precise determinations of $V_{us}$ and $V_{ud}$ hints towards a violation of the CKM first row unitarity at about $3\sigma$ level. Conversely, the recent measurement of the $W$-boson mass by the CDF Collaboration exhibits…
The special features of CP violation in the Standard Model are presented. The significance of measuring CP violation in B, K and D decays is explained. The predictions of the Standard Model for CP asymmetries in B decays are analyzed in…
We study the Standard-Model extensions that have the following features: they violate Lorentz invariance explicitly at high energies; they are unitary, local, polynomial and renormalizable by weighted power counting; they contain the vertex…
Nelson-Barr models solve the strong CP problem based on spontaneous CP violation and generically requires vector-like quarks (VLQs) mixing with standard quarks to transmit the CP violation. We devise an explicit parametrization for the case…
We examine certain extensions of the standard model in which $CP$ violation is spontaneous and the strong $CP$ problem is resolved. In these models, the $3 \times 3$ quark mixing matrix is neither real nor unitary. However, to a precision…
We review the theory and phenomenology of isosinglet vector-like quarks (VLQs). In recent years, interest in VLQs has been increasing, due to their contributions to new physics effects that can be tested in experiments at LHC and…
In the electroweak sector of the Standard Model, CP violation arises through a very particular interplay between the three quark generations, as described by the Cabibbo--Kobayashi--Maskawa (CKM) mechanism and the single Jarlskog invariant…
I put forward a model with vectorlike isosinglet quarks in which soft breaking of CP leads to strong CP violation only arising at two-loop level.
We find a minimal set of constraints which are independent of the choice of weak quark basis and necessary and sufficient for CP conservation for four quark families, including also the case of degenerate quark masses. These invariant…
We explore CP violation in a Left-Right Model that reproduces the quark mass and CKM rotation angle hierarchies in a relatively natural way by fixing the bidoublet Higgs VEVs to be in the ratio m_b:m_t. Our model is quite general and allows…
CP-odd invariants provide a basis independent way of studying the CP properties of Lagrangians. We propose powerful methods for constructing basis invariants and determining whether they are CP-odd or CP-even, then systematically construct…
We work in a model where all CP violating phenomena have a common source. CP is spontaneously broken at a large scale $V$ through the phase of a complex singlet scalar. An additional $SU(2)_L$ singlet vector-like down-type quark relates…
In the minimal left-right symmetric model, there are only two intrinsic CP violating phases to account for all CP violation in both the quark and lepton sectors, if CP is broken spontaneously by the complex phases in the VEV's of the scalar…
We build a class of two-Higgs-doublet models in which the flavour-changing couplings of the neutral scalars are related in an exact way to elements of the quark mixing matrix. In this framework, we explore the different possibilities for CP…
We investigate the leading effects of extending the Standard Model of electroweak interactions by an extra iso-singlet up- and down- type quark pair on various distributions and total branching ratio of the inclusive B-> X_s l^+ l^- (l…
We analyse the general constraints on unified gauge models with spontaneous CP breaking that satisfy the conditions that (i) CP violation in the quark sector is described by a realistic complex CKM matrix, and (ii) there is no significant…
When extending the SM, e.g. with vector-like quarks (VLQ), one inevitably encounters more than one CP violating complex phases. In this work, we develop a method useful in reducing the number of complex phases in scenarios with one and two…
We review the highlights of quark mixing, particle-antiparticle mixing, CP violation and rare K- and B-decays in the Standard Model. The top quark discovery, the precise measurement of its mass, the improved knowledge of the couplings…
This work analyses a class of extensions of the Standard Model through the lens of a novel exact parameterisation. This parameterisation is specially suitable to the analysis of extensions of the Standard Model with non-unitary mixing…
In the quark sector, Jarlskog rephasing invariant parameter $J_{CP}$ has important implications for the CP violation as well as phase structure of the quark mass matrices. In fact all CP violating effects in this sector are proportional to…