Related papers: Anomalous mass dimensions and Schwinger-Dyson equa…
It is argued on general ground and demonstrated in the particular example of the Chiral Schwinger Model that there is nothing wrong with apparently anomalous chiral gauge theory. If quantised correctly, there should be no gauge anomaly and…
The effective potential for the Wilson loop in the SU(2) gauge theory with N_f massive fundamental and N_a massive adjoint fermions on S^1 x M^4 is computed at the one-loop level, assuming periodic boundary conditions for the gauge field…
In this work we present symmetry transformations relating bosons to fermions which cannot be represented as a supersymmetric algebra. We present a symmetry transformation relating a complex scalar and a fermion in four dimensions and…
We consider the analog in one spatial dimension of the Bose-Fermi transmutation for planar systems. A quantum mechanical system of a spin 1/2 particle coupled to an abelian gauge field, which is classically invariant under gauge…
We extend our previous study of the SU(3) gauge theory with N_f=2 flavors of fermions in the sextet representation of color. Our tool is the Schroedinger functional method. By changing the lattice action, we push the bulk transition of the…
In holographic models of QCD, the running of the anomalous dimension of the quark bilinear operator leads to chiral symmetry breaking when gamma=1 and the Breitenlohner-Freedman bound is violated. In that case, the running drives the sigma…
The gauge symmetry of the Standard Model is SU(3)_c x SU(2)_L x U(1)_Y for unknown reasons. One aspect that can be addressed is the low dimensionality of all its subgroups. Why not much larger groups like SU(7), or for that matter, SP(38)…
The condition for the existence of a bound state between two fermions exchanging massive scalars is derived. For low scalar mass, we reproduce the scalar field model result. The high scalar mass result exhibits a somewhat different…
We study fermions, such as gravitinos and gauginos in supersymmetric theories, propagating in a five-dimensional bulk where the fifth dimensional component is assumed to be an interval. We show that the most general boundary condition at…
While radiative corrections of infrared origin normally depress high energy amplitudes (Sudakov form factors), we find that in some cases resummation of leading effects produces exponentials with positive exponents, giving rise to…
We show how a sparticle spectrum characteristic of anomaly mediation can arise from a theory whose Lagrangian contains no explicit mass scale. The scale of supersymmetry breaking is governed by the gravitino mass, which is the vacuum…
The effect of anomalous couplings in $\gamma \gamma \to W^+ W^-$ is studied for different energies of the $\gamma \gamma$ mode of the next linear collider. The analysis based on the maximum likelihood method exploits the variables in the…
We elucidate and extend the conditions that map gauge-Yukawa theories at low energies into time-honoured gauged four-fermion interactions at high energies. These compositeness conditions permit to investigate theories of composite dynamics…
We study 4-dimensional SU(N) gauge theory with one adjoint Weyl fermion and fundamental matter - either bosonic or fermionic. Symmetries, their 't Hooft anomalies, and the Vafa-Witten-Weingarten theorems strongly constrain the possible bulk…
Exchange of unparticle stuff of dimension $d_\U$ with FCNC interaction can induce $M^{12,u}$ and $\Gamma^{12,u}$ causing meson and anti-meson mixing with the relation $\Gamma^{12,u}/M^{12,u} = 2 \tan(\pi d_\U)$. We show that this type of…
We work out in the forward limit and up to order $e^6$ in perturbation theory the collinear divergences. In this kinematical regime we discover new collinear divergences that we argue can be only cancelled using quantum interference with…
We extend the phase diagram of SU(N) gauge-fermion theories as function of number of flavours and colours to the region in which asymptotic freedom is lost. We argue, using large $N_f$ results, for the existence of an ultraviolet…
The fundamental chiral nature of the observed quarks and leptons and the emergence of the gauge group itself are most puzzling aspects of the standard model. Starting from general considerations of topological properties of gauge field…
The idea of the self-breaking of the standard model gauge symmetry is applied to a gauge theory in a warped space. We systematically examine the gauge couplings of bulk and brane fermions. The constraint on the masses of bulk fermions is…
The index theorems relate the gauge field and metric on a manifold to the solution of the Dirac equation on it. In the standard approach, the Dirac operator must be massless in order to make the chirality operator well-defined. In physics,…