Quantum electrodynamics (QED) predicts an anisotropy of the refractive index of the
vacuum in the magnetic field. This unique property of the vacuum is referred to as
vacuum magnetic birefringence (VMB), which is induced by the non-linear interaction
of photons mediated by the virtual electron-positron pairs in the vacuum. In addition,
Axion like particles and milli-charged particles are also predicted to induce VMB.
Experimental observation of VMB is a good probe for new physics beyond the standard
model as well as a precision test of QED. The OVAL experiment searches for VMB
with a high repetitive pulsed magnet and a high finesse optical cavity. In this talk, I
would like to show the latest result of the OVAL experiment.