相关论文: A Vacuum Accumulation Solution to the Strong CP Pr…

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…

The non-perturbative solution to the strong CP problem with magnetic monopoles as originally proposed by the author is described. It is shown that the gauge orbit space with gauge potentials and gauge tranformations restricted on the space…

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…

The Supersymmetric Standard Model is a benchmark theoretical framework for particle physics, yet it suffers from a number of deficiencies, chief among which is the strong CP problem. Solving this with an axion in the context of selected new…

We exploit the non-perturbative result that the $\theta$ angle which defines the vacuum structure is not a $c$-number free parameter, as suggested by the instanton semi-classical approximation, but instead one of the points of the spectrum…

I discuss how anomalies affect classical symmetries and how, in turn, the non-trivial nature of the gauge theory vacuum makes these quantum corrections troublesome. Although no solution seems in sight for the cosmological constant problem,…

We exhibit a solution to the strong CP problem in which ultraviolet physics renders the QCD theta angle physically unobservable. Our models involve new strong interactions beyond QCD and particles charged under both the new interactions and…

The vacuum of quantum chromodynamics has an incredibly rich structure at the nonperturbative level, which is intimately connected with the topology of gauge fields, and put to a test by the strong CP problem. We investigate the…

We discuss a mechanism through which the multi-vacua theories, such as String Theory, could solve the Hierarchy Problem, without any UV-regulating physics at low energies. Because of symmetry the number density of vacua with a certain…

We consider an enlarged color sector which solves the strong CP problem via new massless fermions. The spontaneous breaking of a unified color group into QCD and another confining group provides a source of naturally large axion mass $m_a$…

These TASI lectures where given in 2018 and provide an introduction to the Strong CP problem and the axion. I start by introducing the Strong CP problem from both a classical and a quantum mechanical perspective, calculating the neutron eDM…

We propose a new solution to the strong-CP problem. It involves the existence of an unbroken gauged $U(1)_X$ symmetry whose gauge boson gets a Stuckelberg mass term by combining with a pseudoscalar field $\eta (x)$. The latter has…

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…

We present a model that solves the strong CP problem via an axion parametrically heavier than the standard one. Within this picture the Standard Model quarks are embedded into a larger non-abelian Grand Color group that at high scales…

We present a connection between two known solutions to the strong-CP problem: the standard introduction of axions and the extra-dimensional one, relying on topological arguments. Using an equivalent lower-dimensional set-up with a warped…

We show that the de Sitter quantum breaking bound when applied to QCD exposes the necessity of the axion solution to the strong CP problem. The Peccei-Quinn mechanism emerges as a consistency requirement independent of the naturalness…

We analyse the impact of quantum gravity on the possible solutions to the strong CP problem which utilize the spontaneously broken discrete symmetries, such as parity and time reversal invariance. We find that the stability of the solution…

It is shown that the quark mass aligns QCD $\theta$ vacuum in such a way that the strong CP is conserved, resolving the strong CP problem.

We present a novel framework of the post-inflationary composite axion to address the strong CP problem without the cosmological domain wall problem. Conventional composite axion models lead to the domain wall number greater than one,…

Axion fields provide the most elegant solution to the strong CP problem. In string compactifications it is difficult to obtain an axion whose decay constant is consistent with current cosmological bounds. We examine this question in…