Related papers: CP violating phases and a solution to the strong C…
I describe how the QCD vacuum structure, necessary to resolve the $U(1)_A$ problem, predicts the presence of a P, T and CP violating term proportional to the vacuum angle $\bar{\theta}$. To agree with experimental bounds, however, this…
I discuss how the solution of the $U(1)_A$ problem of QCD through the existence of the $\theta$-vacuum gave rise to the strong CP problem. After examining various suggested solutions to this problem, I conclude that the only viable solution…
We review the historical developments leading to the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix. Present status of the CKM matrix from direct measurements is summarized, giving also the present profile of the unitarity triangle. CP…
We consider order $\alpha_s$ corrections to the squared masses of the pseudo-Goldstone excitations about the ground state of dense quark matter. We show that these contributions tend to destabilize the vacuum, leading to a surprisingly…
The currently favored model of CP violation is based on phases in the Cabibbo-Kobayashi-Maskawa (CKM) matrix describing the weak charge-changing couplings of quarks. The present status of parameters of this matrix is described. Tests of the…
We propose a new method to extract the CP violating weak phase $\gamma$ (the phase of $V_{ub}^*$) in the CKM paradigm of the Standard Model, using $B^- \rightarrow D^0 \pi^- \rightarrow f \pi^-$ and $B^- \rightarrow \bar D^0 \pi^-…
We propose a new kind of CP violation effect -- the double-mixing CP asymmetry -- in a type of cascade decays that involves at least two mixing neutral mesons in the decay chain. It is induced by the interference between different…
We explore charged-Higgs cp-violating effects in a specific type III two-Higgs doublet model which is theoretically attractive as it accommodates the large mass of the top quark in a natural fashion. Two new CP-violating phases arise from…
In the standard model QCD Lagrangian, a term of CP violating gluon density is theoretically expected to have a physical coefficient $\bar{\theta}$ of the order of unity. However, the upper bound on the electric dipole moment of neutron…
In view of the observed strong hierarchy of quark masses, we propose a new description of flavor mixing which is particularly suited for models of quark mass matrices based on flavor symmetries. The necessary and sufficient conditions for…
We present a top-condensation model in which the CP symmetry is spontaneously broken at the electroweak scale due to the condensation of two composite Higgs doublets. In particular the CP-violating phase of the CKM matrix is generated. A…
We propose a three-zero texture for the down-quark mass matrix within a $SU(5)$ GUT-inspired Standard Model, enforced by a non-invertible selection rule originating from $\mathbb{Z}_2$ gauging of $\mathbb{Z}_N$ symmetries. Assuming CP…
Quantum Chromodynamics admits a CP-violating contribution to the action, the $\theta$ term, which is expected to give rise to a nonvanishing electric dipole moment of the neutron. Despite intensive search, no CP violations have been found…
CP-symmetry violates in oscillations of neutrinos in vacuum in presence of three generations. In this case there is an inherent complex phase in PMNS-matrix. When any two neutrino masses degenerate the CP-violation vanishes. In the present…
I explore the rich phase diagram of two-flavor QCD as a function of the quark masses. The theory involves three parameters, including one that is CP violating. As the masses vary, regions of both first and second order transitions are…
A model of quark masses and mixing angles is constructed within the framework of two large extra compact dimensions. A ``democratic'' pure phase mass matrix arises in a rather interesting way. This type of mass matrix has often been used as…
Three possibilities for the origin of CP violation are discussed: (1) the Standard Model in which all CP violation is due to one parameter in the CKM matrix, (2) the superweak model in which all CP violation is due to new physics and (3)…
Because 4-dimensional CP is a good symmetry of many higher-dimensional theories, this suggests the possible existence of a universal CP-violating phase originating from the process of compactification. Such a phase, if it existed, would not…
I discuss several aspects of CP non-invariance in the strongly interacting theory of quarks and gluons. I use a simple effective Lagrangian technique to map out the region of quark masses where CP symmetry is spontaneously broken. I then…
A brief review of CP violation in the $B$-meson system and of strategies to determine the angles $\alpha$, $\beta$ and $\gamma$ of the unitarity triangle of the CKM matrix is given. Both general aspects and some recent developments are…