Experimental bounds on induced vacuum magnetic birefringence can be used to improve present photon-photon scattering limits in the electronvolt energy range. Measurements with the Polarizzazione del Vuoto con Laser apparatus [ E. Zavattini et al. Phys. Rev. D 77 032006 (2008)] at both λ=1064 and 532 nm lead to bounds on the parameter Ae, describing nonlinear effects in QED, of Ae(1064)<6.6×10-21 T-2@1064 nm and Ae(532)<6.3×10-21 T-2@532 nm, respectively, at 95% confidence level, compared to the predicted value of Ae=1.32×10-24 T-2. The total photon-photon scattering cross section may also be expressed in terms of Ae, setting bounds for unpolarized light of σγγ(1064)<4.6×10-62 m2 and σγγ(532)<2.7×10-60 m2. Compared to the expected QED scattering cross section these results are a factor of ≃2×107 higher and represent an improvement of a factor about 500 on previous bounds based on ellipticity measurements and of a factor of about 1010 on bounds based on direct stimulated scattering measurements.
Zavattini, E., Zavattini, G., Ruoso, G., Raiteri, G., Polacco, E., Milotti, E., et al. (2008). Limits on low energy photon-photon scattering from an experiment on magnetic vacuum birefringence. PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY, 78(3) [10.1103/PhysRevD.78.032006].
Limits on low energy photon-photon scattering from an experiment on magnetic vacuum birefringence
Della Valle, Federico;
2008-01-01
Abstract
Experimental bounds on induced vacuum magnetic birefringence can be used to improve present photon-photon scattering limits in the electronvolt energy range. Measurements with the Polarizzazione del Vuoto con Laser apparatus [ E. Zavattini et al. Phys. Rev. D 77 032006 (2008)] at both λ=1064 and 532 nm lead to bounds on the parameter Ae, describing nonlinear effects in QED, of Ae(1064)<6.6×10-21 T-2@1064 nm and Ae(532)<6.3×10-21 T-2@532 nm, respectively, at 95% confidence level, compared to the predicted value of Ae=1.32×10-24 T-2. The total photon-photon scattering cross section may also be expressed in terms of Ae, setting bounds for unpolarized light of σγγ(1064)<4.6×10-62 m2 and σγγ(532)<2.7×10-60 m2. Compared to the expected QED scattering cross section these results are a factor of ≃2×107 higher and represent an improvement of a factor about 500 on previous bounds based on ellipticity measurements and of a factor of about 1010 on bounds based on direct stimulated scattering measurements.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
https://hdl.handle.net/11365/1035060