Higher harmonics in vacuum from nonlinear QED effects without low-mass intermediate particles.
We show that in the presence of a slowly rotating strong transverse magnetic field there is an infinite spectrum of harmonic wave functions An due to the first order QED correction (in alpha2) given by the Euler-Heisenberg Lagrangian. The frequency shifts are integer multiples +/- omega(0)n of the magnetic field angular frequency rotation omega(0)=2pinu(m), and the several modes n are coupled to the nearest harmonics n+/-1. This is a new effect due to QED vacuum fluctuations, not exploited before, that can explain, both qualitatively and quantitatively, the recent experimental results of the PVLAS collaboration without the need of a low-mass intermediate particle, hence may dismiss the recent claim of the discovery of the axion.
Tito Mendonça
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CFP and CFIF, Instituto Superior Técnico, 1096 Lisboa, Portugal.
Dias de Deus
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J
Castelo Ferreira
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