Related papers: Parity solves the Strong CP problem
In this talk, I present a pedagogical and historical review related to the CP symmetry. It includes the weak CP violation, the strong CP problem, "invisible" axions and cosmology, and Type-II leptogenesis.
The \mu parameter of the supersymmetric standard model is replaced by \lambda S, where S is a singlet chiral superfield, introducing a Peccei--Quinn symmetry into the theory. Dynamics at the electroweak scale naturally solves both the…
On general grounds based on quantum field theory the decay amplitude for $\Sigma^0 \to \Lambda \gamma$ consists of a parity conserving magnetic and a parity violating electric dipole transition moment. Because of the subsequent…
In higher-dimensional theories such as Brane World models with quasi-localized non-Abelian gauge fields the vacuum structure turns out to be trivial. Since the gauge theory behaves at large distances as a $4+\delta$-dimensional and thus the…
In this pedestrian approach I give my personal point of view on the various problems posed by dark matter in the universe. After a brief historical overview I discuss the various solutions stemming from high energy particle physics, and the…
The QCD axion is one of the most compelling solutions of the strong CP problem. There are major current efforts into searching for an ultralight, invisible axion, which is believed to be the only phenomenologically viable realization of the…
R-parity can be extended to a continuous global U(1)${}_R$ symmetry. We investigate whether an anomalous U(1)${}_R$ can be identified as the PQ symmetry suitable for solving the strong CP problem within supersymmetric extensions of the…
In the first part of this talk, after a brief presentation of the strong CP puzzle, the construction of axion models and their main phenomenological features are described. In the second part, the possibility to mix the Peccei-Quinn…
The cosmological constant (CC) problem is the biggest enigma of theoretical physics ever. In recent times, it has been rephrased as the dark energy problem in order to encompass a wider spectrum of possibilities. It is, in any case, a…
In this work, we critically reanalyze the explicit breaking of the Peccei-Quinn global symmetry -- and the corresponding corrections to the QCD axion potential -- induced by gravity. Specifically, we examine the role of gravitational…
It has been known for some time that asymptotic parity invariance of weak interactions can provide a solution to the strong CP problem without the need for the axion. Left-right symmetric theories which employ a minimal Higgs sector…
The theta dependent of pure gauge theories in four dimensions can be studied using a duality of large N gauge theories with string theory on a certain spacetime. Via this duality, one can argue that for every theta, there are infinitely…
It is explained that the Standard Model combined charge conjugation and parity transformation (CP) is a simultaneous complex conjugation outer automorphism transformation of gauge and space-time symmetries. Simple examples are given for the…
The strong CP problem is one of many puzzles in the theoretical description of elementary particle physics that still lacks an explanation. While top-down solutions to that problem usually comprise new symmetries or fields or both, we want…
We examine in the context of supersymmetric models whether the usual cosmological upper bound on the axion decay constant can be relaxed by assuming a period of stronger QCD in the early universe. By evaluating the axion potential in the…
The axion, originally postulated by Peccei and Quinn to solve the strong CP problem, has become of great interest in particle and astroparticle phenomenology. Yet it has a problem. It is widely assumed that the axion leaves the…
We argue that the Big Bang can be understood as a type of mirror. We show how reflecting boundary conditions for spinors and higher spin fields are fixed by local Lorentz and gauge symmetry, and how a temporal mirror (like the Bang) differs…
We explore whether the axion which solves the strong CP problem can naturally be much lighter than the canonical QCD axion. The $Z_\mathcal{N}$ symmetry proposed by Hook, with $\mathcal{N}$ mirror and degenerate worlds coexisting in Nature…
We construct phenomenologically viable supersymmetric models where CP is an approximate symmetry. The full high energy theory has exact CP and horizontal symmetries that are spontaneously broken with a naturally induced hierarchy of scales,…
This is an attempt to find a hidden virtue in Tolman's paradox by showing that it can give rise to quantum superposition. We consider tachyon exchange between two particles and show that it can generate superposition of eigenstates…