Related papers: Anomalous solutions to the strong CP problem
A recent paper "What can solve the strong CP problem?" goes counter to conventional wisdom by arguing that the universe was in an initial state that combines different eigenstates of $\theta$ (of the theta vacuum of QCD), and asserts that…
In this talk, we introduce a new scenario of grand unified theory (GUT) with anomalous $U(1)_A$ gauge symmetry. Since generic interactions (including non-renormalizable interactions) are introduced, once we fix the symmetry of the theory,…
The strong CP problem is inseparably connected with the topology of gauge fields and the mechanism of color confinement, which requires nonperturbative tools to solve it. In this talk I present results of a recent lattice investigation of…
I briefly review solutions to the strong CP problem based on axions, parity invariance, CP-invariance, and present a new idea based on CP as part of a spontaneously broken flavour symmetry such as a U(1) or modular invariance.
A non-axion solution to the Strong CP Problem is proposed that works even in the context of gravity-mediated supersymmetry breaking. Both $\epsilon'/\epsilon$ and indirect CP violation in the $B-\bar{B}$ are predicted to be unobservably…
We investigate a controversial issue on the measure of CP violation in strong in teractions. In the presence of nontrivial topological gauge configurations, the $\theta$-term in QCD has a profound effect: it breaks the CP symmetry. The…
We propose an attractive scenario of grand unified theories in which doublet-triplet splitting is beautifully realized in SO(10) unification using Dimopoulos-Wilczek mechanism. The anomalous U(1)_A gauge symmetry plays essential roles in…
We point out that the long-standing strong CP problem may be resolved by an anthropic argument. The key ideas are: (i) to allow explicit breaking(s) of the Peccei-Quinn symmetry which reduces the strong CP problem to the cosmological…
The anomalous U(1)_A symmetry provides a generic method of getting accidental symmetries. Therefore, it can play a crucial role in solving the doublet-triplet splitting and the \mu-problems via the `pseudo-Goldstone' mechanism: U(1)_A can…
We note that in (2+1)-dimensional gauge theories with even number of massless fermions, there is anomalous $Z_2$ symmetry if theory is regularized in a parity-invariant way. We then consider a parity invariant $U(1)_V\times U(1)_A$ model,…
We present the supersymmetric $SU(5)$ models which provide a simple ``all order'' solution to the doublet-triplet splitting problem through the missing doublet mechanism. The crucial role is played by the anomalous $U(1)_A$ gauge symmetry…
We suggest a new solution to the strong CP problem. The solution is based on the proper use of the boundary conditions for the QCD generating functional integral. We expand the perturbative boundary conditions to both perturbative and…
We consider theories of gauged quark flavor and identify non-invertible Peccei-Quinn symmetries arising from fractional instantons when the resulting gauge group has non-trivial global structure. Such symmetries exist solely because the…
We use a non-invertible symmetry to construct a three-zero texture for the down-type quark mass matrix, which can resolve the strong CP problem without invoking the axion, in four-dimensional spacetime with three quark families in QCD. We…
We construct a model based on a new $U(1)_X$ gauge symmetry and a discrete $Z_2$ symmetry under which the new gauge boson is odd. The model contains new complex scalars which carry $U(1)_X$ charge but are singlets of the Standard Model. The…
The existence of an anomalous U(1) symmetry is shown to play a crucial role in the supersymmetric radiative seesaw model for neutrino masses. It explains the smallness of some couplings related to neutrino mass generation in a favorable way…
We have proposed a very attractive scenario of Grand Unified Theories (GUTs). It employs the supersymmetry (SUSY) and an anomalous U(1) symmetry whose anomaly is canceled via the Green-Schwarz mechanism. In this scenario, the…
I discuss supersymmetric extensions of the Standard Model containing an extra U(1)' gauge symmetry which provide a solution to the mu-problem and at the same time protect the proton from decaying via dimension 4 operators. Moreover, all…
We present a solution to the strong CP problem, which relies on the horizontal gauge symmetry and CP invariance in a full theory. Similar to other Nelson-Barr type solutions, CP violation in both the strong and weak sectors in the Standard…
It is shown that in the scheme with a rotating fermion mass matrix (i.e. one with a scale-dependent orientation in generation space) suggested earlier for explaining fermion mixing and mass hierarchy, the theta-angle term in the QCD action…