Improved constraints on the coupling constants of axion-like particles to nucleons from recent Casimir-less experiment

We obtain improved constraints on the coupling constants of axion-like particles to nucleons from a recently performed Casimir-less experiment. For this purpose, the differential force between a Au-coated sphere and either the Au or the Si sector of a rotating disc, arising due to two-axion exchange, is calculated. Over a wide region of axion masses, from 1.7×10-3  eV to 0.9 eV, the obtained constraints are up to a factor of 60 stronger than the previously known ones following from the Cavendish-type experiment and measurements of the effective Casimir pressure