Related papers: Axion Mediation
We review a class of models which generalize the traditional Peccei-Quinn (PQ) axion solution by a St\"uckelberg pseudoscalar. Such axion models represent a significant variant with respect to earlier scenarios where axion fields were…
We investigate bulk moduli stabilisation and supersymmetry breaking in local string/F-theory models where the Standard Model is supported on a del Pezzo surface or singularity. Computing the gravity mediated soft terms on the Standard Model…
We point out that in supersymmetric theories with extra dimensions, radius stabilization can give rise to a VEV for the $F$ component of the radius modulus. This gives an important contribution to supersymmetry breaking of fields that…
We give a general formulation of semi-direct gauge mediation of supersymmetry breaking where the messengers interact with the hidden sector only through a weakly gauged group. Using this general formulation, we provide an explicit proof…
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.…
We study models with contributions of similar size to the soft masses from anomaly- and gravity mediation, thereby curing the tachyonic slepton problem of anomaly mediation. A possible origin of this hybrid setup in a 5-dimensional brane…
The quantum chromodynamics (QCD) axion may solve the strong CP problem and explain the dark matter (DM) abundance of our Universe. The axion was originally proposed to arise as the pseudo-Nambu Goldstone boson of global $\mathrm{U}(1)_{\rm…
We study soft supersymmetry breaking parameters in a supersymmetric unified model which potentially solves the doublet-triplet splitting problem. In the model the doublet-triplet splitting is solved by the discrete symmetry which is allowed…
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…
We present a toy model which has the following properties: i) it is strongly coupled at a certain scale and breaks supersymmetry at this scale; ii) matter superfields of (one generation of) the Standard Model are effective low energy…
We propose two models where a U(1) Peccei-Quinn global symmetry arises accidentally and is respected up to high-dimensional operators, so that the axion solution to the strong CP problem is successful even in the presence of…
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 exhibit a simple and robust mechanism for mediation of supersymmetry breaking between geometrically separated D-branes in type II string theory. The mediation proceeds via RR p-forms that couple via linear Chern-Simons terms to the…
The $U(1)$ global symmetry to solve the strong $CP$ problem could be the remnant of multi-$U(1)$ symmetries from QCD and hidden strong dynamics. Both Peccei-Quinn $U(1)$ and dynamical $U(1)$ are described uniformly, based on which we…
We investigate effects of D-term contributions to the mixed modulus-anomaly mediated supersymmetry breaking scenario. In the original scenario, the tachyonic slepton problem in the pure anomaly mediated supersymmetry breaking is cured by…
The topological susceptibility of the QCD vacuum provides an understanding of $\theta$-vacua as vacua of a Chern-Simons gauge theory. In this way, it gives an immediate proof of the physicality of the boundary $\theta$-term. This makes the…
We study in detail a supersymmetric Peccei-Quinn model, which has a DFSZ and a KSVZ version. The fields breaking the Peccei-Quinn (PQ) symmetry correspond to flat directions (flaton fields) and have unsuppressed couplings when PQ symmetry…
In the effective field theory framework, we consider the effect of supersymmetry breaking via gaugino condensation and supergravity in the hidden sector gauge group on the hidden sector vacuum angle $\theta_h$. The $\theta_h$ parameter…
The main limitation for preinflationary breaking of Peccei-Quinn (PQ) symmetry is the upper bound on the Hubble rate during inflation from axion isocurvature fluctuations. This leads to a tension between high scale inflation and QCD axions…
We outline some general features of possible extensions of the Standard Model that include anomalous U(1) gauge symmetries, a certain number of axions and their mixings with the CP-odd Higgs sector. As previously shown, after the mixing one…