Light Scalars Coupled to Photons and Non-Newtonian Forces
Light Scalars Coupled to Photons and Non-Newtonian Forces
A particle $\ensuremath{\phi}$ coupling to two photons couples also radiatively to charged particles, like protons. If the particle is a light scalar, this induced coupling leads to spin-independent non-Newtonian forces. We show that the experimental constraints on exotic, fifth-type forces lead to stringent constraints on the $\ensuremath{\phi}\ensuremath{\gamma}\ensuremath{\gamma}$ coupling. We discuss …