Related papers: Solving the strong CP problem with non-conventiona…
We show that a recently proposed solution to the Hierarchy Problem simultaneously solves the Strong CP Problem, without requiring an axion or any further new physics. Consistency of black hole physics implies a non-trivial relation between…
CP violation is observed to date only in K^0 decays and is parameterizable by a single quantity epsilon. Because it is one of the least understood phenomena in the Standard Model and holds a clue to baryogenesis, it must be investigated…
We explore a concrete realization of a Nelson-Barr model addressing the strong CP problem with suppressed unfavorable corrections. This model has a scalar field that spontaneously breaks discrete symmetry, and its phase component can…
CP violation in $B$ decays is reviewed in the Standard Model (SM) and beyond the SM. The present explanation of CP violation in terms of a phase in the Cabibbo-Kobayashi-Maskawa (CKM) matrix can be tested through a variety of CP asymmetries…
The strong CP violation problem has a long history emanating from its discovery 60 years ago in the decay of neutral kaons and subsequent experimental and theoretical studies over several decades. We review herein experimental data that…
The leading order contribution to the direct CP asymmetry in tau^{+/-} -> K^{+/-} pi^0 nu_{tau} decay rates is evaluated within the Standard Model. The weak phase required for CP violation is introduced through an interesting mechanism…
Recent neutrino oscillation experiments suggest that the PMNS matrix in the lepton sector has a $CP$ violating phase as the CKM matrix in the quark sector. However, origin of these phases in both matrices are not clarified by now. Although…
Recent improvements to the limit of Delta M_{B_s} imply that pure superweak theories, while not excluded, no longer provide a good fit to the data. A class of general superweak theories is introduced in which all flavor changing…
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…
Since CP violation in weak decays is successfully described by the KM mechanism, the strong CP problem cannot easily be accommodated. This leads us to reconsider the issue. If the axion and massless up quark are abandoned, we must extend…
We propose a model of soft CP violation in which the CP violating mechanism naturally lies only in the charged Higgs sector. The charged Higgs mechanism not only accounts for the measured value of the CP-violating parameter $\epsilon$ but…
We explore charged-Higgs CP-violating effects in an intriguing two-Higgs doublet model which accords special status to the top quark. In this model the heaviness of the top quark originates naturally from the much larger VEV of the second…
Using the worldline method, we derive an effective action of the bosonic sector of the Standard Model by integrating out the fermionic degrees of freedom. The CP violation stemming from the complex phase in the CKM matrix gives rise to…
It is shown that a two-Higgs doublet model with Vacuum CP Violation and Approximate Global $U(1)$ Family Symmetries (AGUFS) may provide one of the simplest and attractive models in understanding origin and mechanisms of CP violation at the…
The origin of the matter-antimatter asymmetry in the Universe is a fundamental question of physics. Electroweak baryogenesis is a compelling scenario for explaining it but it requires beyond the Standard Model sources of the CP symmetry…
The QCD Lagrangian contains a CP violating gluon density term with a physical coefficient $\bar{\theta}$. The upper bound on the electric dipole moment of neutron implies that the value of $\bar{\theta}$ should be extremely small rather…
We study a decay rate asymmetry of the top quark in the supersymmetric standard model, taking into account the constraints from the electric dipole moments of the neutron and the electron. One CP-violating phase contained in the…
CP is a symmetry of pure gauge theories, that is without scalar interactions. Actually its violation originates in the Standard Model from the completely arbitrary Yukawa couplings. Thus, as the unification principle would wash out the…
The current laws of physics do not explain the observed imbalance of matter and antimatter in the universe. Sakharov proposed that an explanation would require the violation of CP symmetry between matter and antimatter. The only CP…
The possibility of CP violation is studied in the Higgs sector of a supersymmetric standard model with multiple Higgs singlets. The tree-level Lagrangian in this model is assumed to conserve the CP symmetry. We find that CP violation is…