No “Light Shining through a Wall”: Results from a Photoregeneration Experiment

Recently, axionlike particle search has received renewed interest. In particular, several groups have started “light shining through a wall” experiments based on magnetic field and laser both continuous, which is very demanding in terms of detector background. We present here the 2σ limits obtained so far with our novel setup consisting of a pulsed magnetic field and a pulsed laser. In particular, we have found that the axionlike particle two photons inverse coupling constant M is >8×10⁵  GeV provided that the particle mass m_a∼1  meV. Our results definitively invalidate the axion interpretation of the original PVLAS optical measurements with a confidence level greater than 99.9%.