Constraints on the parameters of axion from measurements of thermal Casimir-Polder force

Abstract

Stronger constraints on the pseudoscalar coupling constants of an axion and axion-like particles with a proton and a neutron are obtained from measurements of the thermal Casimir-Polder force between a Bose-Einstein condensate of ${}^{87}$Rb atoms and a SiO${}_2$ plate. For this purpose the additional force acting between a condensate cloud and a plate due to two-axion exchange is calculated. The obtained constraints refer to the axion masses from 0.1meV to 0.3eV which overlap with the region from 0.01meV to 10meV considered at the moment as the most prospective.

Comments: 15 pages, 2 figures; several typos are corrected; to appear in Phys. Rev. D