Experiment for measuring the post-Maxwellian parameters of nonlinear electrodynamics of vacuum with laser-interferometer techniques

Abstract

An experiment is proposed to measure the post-Maxwellian parameters of the nonlinear electrodynamics of a vacuum. It is shown that the system for recording small differences of optical paths used in the Laser Interferometer Gravitational-Wave Observatory ͑LIGO͒ and in other laser interferometers for gravitational wave detectors permits us to measure the nonlinear electrodynamics corrections predicted by quantum electrodynamics. However, the use of LIGO or other full-scale laser interferometers of the gravitational wave detectors for this purpose does not seem sensible. Therefore it is suggested to perform this experiment on one of the laboratory prototypes used to develop interferometry for gravitational wave detection. The sensitivity of these laboratory prototypes is about the same as the sensitivity of the full-scale instruments, and the other parameters are most similar to the optimal values allowing us to observe the considered effect: the arm length l 0 of these prototypes is about several meters and in the Fabry-Perot interferometer about Nϳ2ϫ10 5 bounces can be realized. A further increase in the detector sensitivity is noted to offer also an opportunity of experimentally studying the nonlinearly electrodynamic corrections predicted by the Born-Infeld theory.

Light by light diffraction in vacuum

“…In fact, Quantum Electrodynamics (QED) predicts the existence of PhotonPhoton Scattering in Vacuum (PPSV) mediated by virtual charged particles running in loop diagrams [1], although the rate is negligible in all the experiments that have been performed up to now. On the other hand, additional, possibly larger contributions to the process may appear in non-standard models such as Born Infeld theory [2][3][4] or in new physics scenarios involving minicharged [5] or axion-like [6] particles. Therefore, the search for PPSV is important not only to demonstrate a still unconfirmed, fundamental quantum property of light, but also to either discover or constrain these kinds of new physics.…”

“…However, in Born-Infeld theory [2][3][4], or in models involving a new minicharged (or milli-charged) [5] or axionlike [6] particle, ξ L and ξ T will have different values, as computed in Ref. [9].…”

“…As a result, this experiment at present facilities can already either detect PPSV of non-standard origin, or substantially improve the limits on ξ L and ξ T . In the former case, the measurement of both ξ L and ξ T can be used to discriminate between different kind of new physics, such as Born Infeld theory [2][3][4] or models involving minicharged [5] or axion-like [6] particles, using the expressions for the corresponding contributions that have been computed in Ref. [9].…”

First results from the new PVLAS apparatus: A new limit on vacuum magnetic birefringence

“…Under these conditions the intensity I out (t) of the light emerging from the analyzer A is I out (t) = I 0 σ 2 + |ıη(t) + ıψ sin 2ϑ(t) + ıα(t)| 2 I 0 σ 2 + η(t) 2 + 2η(t)ψ sin 2ϑ(t) + 2η(t)α(t) (5) where I 0 represents the light power reaching the analyser, η(t) the ellipticity modulation generated by the PEM, σ 2 is the extinction ratio of the two polarizers and α(t) describes the slowly varying spurious ellipticities present in the apparatus. As can be seen, the introduction of the PEM linearises the ellipticity signal which would otherwise be quadratic.…”

“…In a general framework of non-linear electrodynamics at the lowest order described by a Lorentz invariant parity conserving Lagrangian correction [5] …”