Related papers: Solving the strong CP problem with non-conventiona…
We propose a simultaneous solution to the strong CP problem and the SUSY phase problem based on parity symmetry realized when the supersymmetric standard model is embedded into a left-right symmetric framework at a scale near 2 x 10^{16}…
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…
The Standard Model contains a natural source for CP asymmetries in weak decays, which is described by the KM mechanism. Beyond $\epsilon _K$ it generates only elusive manifestations of CP violation in {\em light-}quark systems. On the other…
We revisit the minimal Nelson-Barr model for solving the strong CP problem through the idea of spontaneous CP breaking. The minimal model suffers from the quality problem, which means that the strong CP angle is generated by…
Generically, non-Standard-Model particles contribute to processes with order-one charge-parity (CP) violating phases, as CP is not a fundamental symmetry of nature. The exploration of CP violation becomes therefore a sensitive search for…
One may argue that QCD solves the strong CP problem by itself, without having to introduce new symmetries and particles. To test this idea, a lattice simulation is performed. The problem is investigated in the CP$^3$ model first. It is…
We analyse the properties of generic models based on an SU(3) family symmetry providing a full description of quark charged lepton and neutrino masses and mixing angles. We show that a precise fit of the resulting fermion textures is…
In a world devoid of axions, the smallness of the strong CP phase can have implications for leptonic CP violation being probed by neutrino experiments. For example, if nature adopted an axionless solution to the strong CP problem, the same…
We analyse the CP problem in the context of a supersymmetric extension of the standard model with universal strength of Yukawa couplings. A salient feature of these models is that the CP phases are constrained to be very small by the…
The tiny neutrino masses can be explained naturally by extending the standard model with right-handed Majorana neutrinos in low-scale seesaw mechanism, and the CP violation effect induced by Majorana phase is interesting and worth studying…
We study how to incorporate CP violation in the Froggatt--Nielsen (FN) mechanism. To this end, we introduce non-renormalizable interactions with a flavor democratic structure to the fermion mass generation sector. It is found that at least…
We argue that the Nelson-Barr solution to the Strong CP Problem can be naturally realized in an E$_6$ Grand-Unified Theory. The chiral SM fermions reside in three generations of E$_6$ fundamentals together with heavy vectorlike down quarks,…
The absence of a neutron electric dipole moment (EDM) constrains the quantum chromodynamics (QCD) theta angle to be less than one part in ten billion, posing the Strong $CP$ problem. We revisit two classes of proposed solutions. First, we…
We address the question of whether the CP violating phase in the CKM mixing matrix can be the only source of all CP violation. We show that in supersymmetric models with new flavour structure beyond the Yukawa matrices, the CKM phase can…
In this manuscript, a general FCNC-free and CP-violating pattern of quark-mass matrices in the 2HDM derived in our previous investigations is revised. This revised pattern is to be diagonalized analytically with no symmetries imposed. The…
We propose a mechanism for relaxing a gauge theory CP violating phase in discrete steps to very small values. The idea is that the CP violating phase includes the magnetic dual of a $4$-form flux which can discharge by the nucleation of…
The spontaneous violation of the CP symmetry in the next-to-minimal supersymmetric standard Model (NMSSM) is investigated. It is found that the spontaneous violation of the CP symmetry can occur in the Higgs sector of the NMSSM for a wide…
It is pointed out that the strong CP problem may have a natural solution in the context of a recently proposed dualized version of the Standard Model where Higgs fields and generations emerge naturally. Although fermions have finite…
We study the minimal version of the supersymmetric standard model with spontaneous CP breaking. In this model, the KM matrix is real and contributions to $\varepsilon$ arise from box diagrams involving squarks. We analyze the region of the…
We analyse a possible connection between CP violations in the quark and lepton sectors, parametrised by the CKM and PMNS phases. If one assumes that CP breaking arises from complex Yukawa couplings, both in the quark and lepton sectors, the…