Probing axion-like particles with RF cavities separated by thin barrier

We address the Light-Shining-Through-a-thin-Wall (LSthinW) laboratory setup to estimate the sensitivity of axion-like particle (ALP) detection using two radio-frequency (RF) cavities immersed in a static magnetic field. We analytically evaluate the asymptotic sensitivity in the off-shell regime for the lowest electromagnetic pump modes. We show that a sufficiently thin wall separating can lead to the improved sensitivity of the pure laboratory probes of ALP in the mass range $10^{-6}~{\rm eV} \lesssim m_a \lesssim 10^{-4}~{\rm eV}$.