56383156
Improving the Discovery Potential of Future Light-Shining-through-a-Wall Experiments
Planning for the next generation of light-shining-through-wall experiments has started. It is therefore timely to investigate possible ways to optimize their setups. The goals are to improve the sensitivity towards smaller couplings and increase the mass range to which the experiments are sensitive. We discuss possible magnet arrangements and the eects of the unavoidable gaps in the magnetic field profile. Furthermore, we discuss requirements on the diameter of the laser beam and aperture of the magnets in order to achieve high-quality cavities. Several well motivated extensions of the Standard Model predict the existence of very weakly
119160303
Chiral anomaly beyond Lorentz invariance
The chiral anomaly in the context of an extended standard model with Lorentz invariance violation is studied. Taking into account bounds from measurements of the speed of light, we argue that the chiral anomaly and its consequences are general results valid even beyond the relativistic symmetry.
119184475
Effects of heavy bosonic excitations on QED vacuum
We discuss the contribution of axion-like excitations (ALE) to the vacuum birefringence in the limit mA ≳ ω, where mA is the mass of the excitation and ω the energy of test photons interacting with an external (intense) magnetic field. The relevance of this term with respect to the QED contribution depends on the ratio gA/mA and, from present bounds on the mass and the coupling constant gA, we find that in the present low energy regime, it ranges from 10-14 to 102 suggesting an interesting alternative to explore.
118495032
SU(2) Kinetic Mixing Terms and Spontaneous Symmetry Breaking
The non-Abelian generalization of the Holdom model, i.e. a theory with two gauge fields coupled to the kinetic mixing term g tr(Fμν(A)Fμν(B)) is considered. Contrarily to the Abelian case, the group structure G×G is explicitly broken to G. For SU(2) this fact implies that the residual gauge symmetry as well as the Lorentz symmetry is spontaneously broken. We show that this mechanism provides masses for the involved particles. Also, the model presents instanton solutions with a redefined coupling constant.
118294407
Illuminating WISPs with Photons
Physics beyond the Standard Model naturally gives rise to very light and weakly interacting particles, dubbed WISPs (Weakly Interacting Slim Particles). A prime example is the axion, that has eluded experimental detection for more than thirty years. In this talk we will review some of the strongly motivated candidates for such particles, the observational hints for them and the present status of searches with photon regeneration experiments, as well as possible future improvements.
117024657
Electrodynamics with an Infrared Scale and PVLAS experiment
We consider an infrared Lorentz violation in connection with recent results of PVLAS experiment. Our analysis is based in a relation that can be established, under certain conditions, between an axial-like-particle theory and electrodynamics with an infrared scale. In the PVLAS case, the conditions imply two dispersion relations such that the infrared scale $|\vec \theta|$, the inverse axion-photon coupling constant $M^{-1}$ and the external magnetic field ${\vec B}$ can be connected through the formula $|{\vec \theta}|= {|\vec B|}/M$. Our analysis, which only requires a non-dynamical (auxiliar) axial-like field leads to $|{\vec\theta}| \leq 5.4 \times 10^{-7}$ meV and $M^{-1} \sim 1.2 \times 10^{-3}$ GeV $^{-1}$.
13266160
GAUGE INVARIANCE AND SECOND CLASS CONSTRAINTS IN 3-D LINERIZED MASSIVE GRAVITY
A recently introduced approach for the dynamical analysis and quantization of field theoretical models with second class constraints is ilustrated applied to linearized gravity in 3-D. The canonical structure of two different models of linerized gravity in 3-D, the intermediate and the self dual models, is discussed in detail. It is shown that the first order self dual model whose constraints are all second class may be regarded as a gauge fixed version of the second order gauge invariant intermediate model. In particular it is shown how to construct the gauge invariant hamiltonian of the intermediate model starting from the one of the self dual model. The relation with the t opologically massive linearized gravity is also discussed.
118915291
Canonical equivalence between massive spin 1 theories
The model of Cremmer-Scherck and Proca are considered in dimensions greater than 3+1. It is obtained that the Proca model correspond to a gauged fixed version of the Cremmer-Scherck one, and we show their canonical equivalence.