Constraining the couplings of massive pseudoscalars using gravity and optical experiments

Abstract

The simultaneous exchange of two pseudoscalars between fermions leads to a spin-independent force between macroscopic objects. Previous work has demonstrated that one can combine this interaction with tests of the weak equivalence principle, gravitational inverse square law, and studies of laser beam propagation in magnetic fields, to set significant new constraints on the Yukawa couplings of massless pseudoscalars to nucleons. Here we extend these results to massive pseudoscalars, and derive new constraints which relate the strengths of these couplings to the pseudoscalar mass.

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

“…These experiments, however, deal with the unpolarized test bodies. As to the potential arising between two fermions belonging to different test bodies from the exchange of a single axion with a pseudoscalar coupling, it is spin-dependent [29]. Thus, there is no net force in Casimir experiments due to a single axion exchange.…”

“…[24][25][26] were extended [29] to the more realistic case of massive axions. From the gravitational experiments of Eötvos-and Cavendish-type rather strong constraints on g ap,p and g an,p were obtained [29] for the axion masses m a ≤ 9.9µeV. Further work on constraining interactions mediated by light pseudoscalar particles from the laboratory experiments was done in Ref.…”

“…It is not surprising, then, that these experiments have not been used in the past to obtain constraints on the axion-like pseudoscalar particles. Nevertheless, a simultaneous exchange of two massless [40] or two massive [29] pseudoscalar particles between two fermions leads to a spin-independent interaction potential (this was used in Ref. [29] for constraining the parameters of an axion from the gravitational experiments of Eötvos-and Cavendish-type dealing with unpolarized test bodies).…”

“…Nevertheless, a simultaneous exchange of two massless [40] or two massive [29] pseudoscalar particles between two fermions leads to a spin-independent interaction potential (this was used in Ref. [29] for constraining the parameters of an axion from the gravitational experiments of Eötvos-and Cavendish-type dealing with unpolarized test bodies). Here we use the same approach in application to the experiment on measuring the thermal Casimir-Polder force.…”

Submillimeter tests of the gravitational inverse-square law

“…The exchange of two massive pseudoscalar bosons having γ 5 couplings to fermions a and b with coupling constants g a and g b , produces a long-range, spin-independent exchange potential [25,26],…”