相关论文: Constraints on Variant Axion Models

The invisible variant axion model is very attractive as it is free from the domain wall problem. This model requires at least two Higgs doublets at the electroweak scale, with one Higgs doublet carrying a nonzero Peccei-Quinn (PQ) charge…

The strongest upper bounds on the axion mass come from astrophysical observations like the neutrino burst duration of SN1987A, which depends on the axion couplings to nucleons, or the white-dwarf cooling rates and red-giant evolution, which…

We perform for the first time a dedicated analysis of cosmological constraints on DFSZ QCD axion models. Such constructions are especially interesting in light of the recent Xenon-1T excess and of hints from stellar cooling. In DFSZ models,…

We study a class of DFSZ-like models for the QCD axion that can address observed anomalies in stellar cooling. Stringent constraints from SN1987A and neutron stars are avoided by suppressed couplings to nucleons, while axion couplings to…

Two particular classes of axion models are presented, each one yielding a lower bound on the axion decay constant, based though on different considerations. In the first class only some, and not all, of the right-handed quarks have PQ…

We discuss phenomenological criteria for defining "axion windows", namely regions in the parameter space of the axion-photon coupling where realistic models live. Currently, the boundaries of this region depend on somewhat arbitrary…

We systematically calculate the axion-photon coupling for non-minimal DFSZ models. Thereby we can classify every calculated model and study the resulting distributions, relevant for axion experiments like haloscopes, helioscopes or…

A number of observations of stellar systems show a mild preference for anomalously fast cooling compared with what predicted in the standard theory, which leads to a speculation that there exists an additional energy loss mechanism…

The QCD axion has important connections to early universe cosmology. For example, it is often said that isocurvature limits rule out a combination of high axion decay constant, $f_a$, and high inflationary Hubble scale, $H_I$. High scales…

The invisible variant axion model is very attractive as it is free from the domain wall problem. This model requires two Higgs doublets at the electroweak scale where one Higgs doublet carries a nonzero Peccei-Quinn (PQ) charge and the…

Type-Z models, where charged leptons, up type quarks, and down type quarks each couple to a different scalar, are only possible when there are three or more Higgs doublets. We consider the Type-Z three Higgs doublet model imposed by a…

We show that there is a constraint on the parameter space of two Higgs doublet models that comes from the existence of the stable vortex-domain wall systems. The constraint is quite universal in the sense that it depends on only two…

It is pointed out that there exist a few problems to be overcome toward an observable sub-eV QCD axion in superstring compactification. We give a general expression for the axion decay constant. For a large domain wall number $N_{DW}$, the…

Various authors have noted that in particular models, the upper bound on the axion decay constant may not hold. We point out that within supersymmetry, this is a generic issue. For large decay constants, the cosmological problems associated…

A major goal of axion searches is to reach inside the parameter space region of realistic axion models. Currently, the boundaries of this region depend on somewhat arbitrary criteria, and it would be desirable to specify them in terms of…

We revisit the domain wall problem for QCD axion models with more than one quark charged under the Peccei-Quinn symmetry. Symmetry breaking during or after inflation results in the formation of a domain wall network which would cause cosmic…

We study collider implications of variant axion models which naturally avoid the cosmological domain wall problem. We find that in such models the branching ratio of $h \to \gamma\gamma$ can be enhanced by a factor of 5 up to 30 as compared…

We present new anomaly free gauge models where the gauge field only has axial vector couplings to both quarks and leptons. We use the left-right symmetric universal seesaw models as the basis for this construction with an extra $U(1)_a$ as…

We analyze the Higgs sector in the Next-to-Minimal Supersymmetric Standard Model, emphasizing the possibility of a light CP-odd scalar (axion) in the spectrum. We compute the coupling of the Standard-Model-like Higgs boson to a pair of…

In this paper, we investigate axion physics in 4D F-theory MSSM models. We derive the axion coupling term with QCD gauge fields and the axion potential from a top-down perspective, from both IIB superstring and the dual M-theory picture.…