Related papers: Solving the strong CP problem
We show how the gauge invariant formulation of QCD in terms of loops is free from a hidden $\theta$ parameter and offers an alternative way to solve the $U(1)_A$ puzzle.
We review the physics case for CP-violating axions. In the first part, we focus on the Quantum Chromodynamics (QCD) axion and argue that new sources of CP violation beyond QCD misalign the axion solution to the strong CP problem and can…
We study spontaneous CP violation as a solution to the strong CP problem in left-right symmetric theories. The discrete CP symmetry is broken by a complex vacuum expectation value of a right-handed Higgs doublet. Heavy vectorlike down-type…
These lectures give an up to date description of CP violation and rare decays of K and B mesons and consist of ten chapters: i) Grand view of the field including CKM matrix and the unitarity triangle, ii) General aspects of the theoretical…
We propose a phenomenological model of lepton mixing and CP violation based on the flavor democracy of charge leptons and the mass degeneracy of neutrinos. A nearly bi-maximal flavor mixing pattern, which is favored by current data on…
Lepton charge asymmetries can be used as an alternative means of searching for new physics. They are interesting because they are small in the Standard Model and therefore, necessarily evidence new physics. In this work we explore the use…
Standard Model extensions with light axions are well-motivated by the observed Dark Matter abundance and the Peccei-Quinn solution to the Strong CP Problem. In general such axions can have large flavor-violating couplings to SM fermions,…
A $SU(N)_L\times SU(N)_R$ gauge theory for a scalar multiplet $Y$ transforming in the bi-fundamental representation $(N,\bar N)$ preserves, for $N>4$, an accidental $U(1)$ symmetry firstly broken at operator dimension $N$. Two…
Motivated by the intimate connection between the strong CP problem and the flavor structure of the Standard Model, we present a flavor model that revives and extends the classic ${m_u=0}$ solution to the strong CP problem. QCD is embedded…
The approximate conservation of $CP$ can be naturally understood if it arises as an automatic symmetry of the renormalizable Lagrangian. We present a specific realistic example with this feature. In this example, the global Peccei-Quinn…
Among solutions of the strong CP problem, the "invisible" axion in the narrow axion window is argued to be the remaining possibility among natural solutions on the smallness of $\bar{\theta}$. Related to the gravity spoil of global…
Current data from neutrino oscillation experiments are in good agreement with $\delta =-\frac{\pi}{2}$ and $\theta_{23}^{} = \frac{\pi}{4}$. We define the notion of "constrained maximal CP violation" (CMCPV) for predicting these features…
The axion solution to the strong CP problem makes use of a global Peccei-Quinn (PQ) U(1) symmetry which is susceptible to violations from quantum gravitational effects. We show explicitly how discrete gauge symmetries can protect the axion…
It is emphasized that the existence of a very light axion is consistent with the strong CP invariance and cosmological and astrophysical constraints. The attempt to embed the very light axion in superstring models is discussed.
We show how two principles - strong coupling and discrete symmetry - can work together to generate the flavour structure of the Standard Model. We propose that in the UV the full theory has a discrete flavour symmetry, typically only…
Can a theory of flavour capable of describing the spectrum of fermion (including neutrino) masses and mixings also contain within it the seeds for a solution of the SUSY flavour and CP problems? We argue that supergravity together with a…
We propose a new framework for solving the strong CP problem via a heavy axion, using mirror symmetry and grand unification. The mirror GUT sector remains unbroken and dynamically generates a calculable heavy mass scale via confinement…
We discuss the discovery potential for New Physics of various measurements of CP violation. If nature is supersymmetric, then the flavor problem is even more mysterious than in the standard model. We show how we can learn about the…
The consideration of chirality-preserving 2-fermion order parameters may shed new light on the strong CP problem and the breakdown of flavor symmetries. We describe two situations, one having the standard KM picture for weak CP violation…
We show that there are many candidates for the quintessence and/or the QCD axions in a class of chiral $U(1)$ gauge theories. Their qualities are high enough to serve as the dark energy and/or to solve the strong CP problem. Interestingly,…