相关论文: Domain walls in Nelson-Barr axion model

QCD was shown to have a nontrivial vacuum structure due to the topology of the theta = theta+2*pi*n parameter. As a result of this nontrivial topology, in the large N_c limit, quasi-stable QCD domain walls appear, characterized by a…

We investigate the possibility of parity being spontaneously violated in QCD at finite baryon density and temperature. The analysis is done for an idealized homogeneous and infinite nuclear matter where the influence of density can be…

The strong CP-violating parameter is small today as indicated by constraints on the neutron electric dipole moment. In the early universe, the QCD axion has not yet relaxed to its QCD-cancelling minimum and it is natural to wonder whether…

Using the well-known low-energy effective Lagrangian of QCD --valid for small (non-vanishing) quark masses and a large number of colors-- we study in detail the regions of parameter space where $CP$ is spontaneously broken/unbroken for a…

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 investigate the presence of domain walls in models described by three real scalar fields. We search for stable defect structures which minimize the energy of the static field configurations. We work out explict orbits in field space and…

We consider the low energy realization of QCD in terms of meson fields when an axial chemical potential is present; a situation that may be relevant in heavy ion collisions. We shall demonstrate that the presence of an axial charge…

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 propose a new scenario of baryogenesis, in which annihilation of axion domain walls generates a sizable baryon asymmetry. Successful baryogenesis is possible for a wide range of the axion mass and decay constant, $m \simeq 10^8 -10^{13}$…

We examine the collapse of an axion domain wall bounded by an axionic string. It is found that the collapse proceeds quickly and axion domain walls disappear. However axions are emitted in the collapse and its energy density increases…

After inflation occurs, a weakly coupled scalar field will in general not be in thermal equilibrium but have a distribution of values determined by the inflationary Hubble parameter. If such a field subsequently undergoes discrete symmetry…

Light scalar fields, with double well potentials and direct matter couplings, undergo density driven phase transitions, leading to the formation of domain walls. Such theories could explain dark energy, dark matter or source the nanoHz…

Domain walls are a type of topological defects that can arise in the early universe after the spontaneous breaking of a discrete symmetry. They can form in several beyond the Standard Model theories with an extended Higgs sector such as the…

We consider a dark matter (DM) model offering a very natural explanation of the observed relation, $\Omega_{\rm dark} \sim \Omega_{\rm visible}$. This generic consequence of the model is a result of the common origin of both types of matter…

We show that axion models with the domain wall number $k$ in $(3+1)$ dimensions, i.e., periodic scalar field theories admitting $k$ axion domain walls, exhibit an emergent ${\mathbb Z}_k$ 3-form symmetry for $k >1$ in addition to a…

The physical origin of the strong CP problem in QCD, rooted in the structures of the vacuum of the standard model, is reviewed. The chiral solution to this problem, with its accompanying axion, is explained and various characteristics of…

We propose a new mechanism for explaining the observed asymmetry between matter and antimatter, based on nonperturbative physics at the QCD scale. Our mechanism is a charge separation scenario, making use of domain walls separating the…

Axion is a promising candidate of dark matter. After the Peccei-Quinn symmetry breaking, axion strings are formed and attached by domain walls when the temperature of the universe becomes comparable to the QCD scale. Such objects can cause…

We build a model containing two scalar doublets and a scalar singlet with a specific discrete symmetry. After spontaneous symmetry breaking, the model has Standard Model-like phenomenology, as well as a hidden scalar sector which provides a…

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…