Related papers: Finite modular symmetries and the strong CP proble…
The QCD axion needs not be an exact pseudoscalar for solving the strong CP problem. Its imperfectness can play a profound role cosmologically. We propose effective operators, where the Peccei-Quinn field linearly couples to Standard Model…
Subtraction schemes provide a systematic way to compute fully-differential cross sections beyond the leading order in the strong coupling constant. These methods make singular real-emission corrections integrable in phase space by the…
These lectures discuss the $\theta$ parameter of QCD. After an introduction to anomalies in four and two dimensions, the parameter is introduced. That such topological parameters can have physical effects is illustrated with two dimensional…
The supersymmetric CP problem is studied within superstring-motivated extensions of the MSSM with an additional U(1)' gauge symmetry broken at the TeV scale. This class of models offers an attractive solution to the mu problem of the MSSM,…
We give a procedure to construct a special class of symmetric quark mass matrices near the democratic limit of equal Yukawa couplings for each sector. It is shown that within appropriate weak-bases, the requirements of symmetry and…
The even weight modular forms of level $N$ can be arranged into the common irreducible representations of the inhomogeneous finite modular group $\Gamma_N$ and the homogeneous finite modular group $\Gamma'_N$ which is the double covering of…
I discuss vacuum alignment and CP violation in technicolor theories of electroweak and flavor symmetry breaking. I review the surprising appearance of rational phase solutions in the technifermion sector and propose a new solution of the…
Considerable theoretical efforts have gone into expanding the reach of the QCD axion beyond its canonical mass--decay-constant relation. The $Z_\mathcal{N}$ QCD axion model reduces the QCD axion mass naturally, by invoking a discrete…
Possible effects of noncommutative geometry on weak CP violation and unitarity triangles are discussed by taking account of a simple version of the momentum-dependent quark mixing matrix in the noncommutative standard model. In particular,…
Axions and other pseudoscalar fields comprise an interesting class of ultralight dark matter candidates, that may independently play a role in solving the strong $CP$ problem. In the presence of $CP$-violating sources, these pseudoscalar…
Within a specific texture of the quark mass matrix the notion of a maximal violation of the $CP$ symmetry can be defined. The experimental constraints from weak decays imply that in reality one is close to the case of maximal $CP$…
We introduce the Anarchic Axion, a class of axion models which solves the Strong CP problem within current nEDM constraints with a lighter than usual QCD axion, thus populating new parameter space that ongoing and future experiments target.…
The QCD axion offers a natural resolution to the strong CP problem and provides a compelling dark matter candidate. If the QCD axion constitutes all the dark matter, the simplest models pick out a narrow range of masses around $100\,\mu{\rm…
Motivated UV frameworks generically predict the existence of multiple axion fields. Their interplay gives rise to novel collective phenomena - including level crossings and the formation of string bundles - which modify the predicted mass…
We propose a minimal set of weak-basis invariants in an extension of the SM where one up-type isosinglet vector-like quark is introduced, which allows us to obtain all the physical content of the CKM matrix. We present CP-odd invariants of…
Many problems in robotics require reasoning over a mix of continuous dynamics and discrete events, such as making and breaking contact in manipulation and locomotion. These problems are locally well modeled by linear complementarity…
A way of counting free parameters in the quark mass matrices of the standard model, including the constraints coming from weak basis transformations, is presented; this allow to understand the exact physical meaning of the parallel and…
We propose a unified model that simultaneously addresses the hierarchy problem and the strong CP problem by considering the most simple fundamental composite Higgs setup and showing that it can feature a viable emergent axion that could be…
Models that combine Abelian horizontal symmetries and spontaneous CP violation can (i) explain the smallness and hierarchy in quark parameters; (ii) satisfactorily suppress supersymmetric contributions to flavor changing neutral current…
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…