Constraining interactions mediated by axion-like particles with ultracold neutrons
Abstract
We report a new limit on a possible short range spin-dependent interaction from the precise measurement of the ratio of Larmor precession frequencies of stored ultracold neutrons and Hg199 atoms confined in the same volume. The measurement was performed in a ~1μT vertical magnetic holding field with the apparatus searching for a permanent electric dipole moment of the neutron at the Paul Scherrer Institute. A possible coupling between freely precessing polarized neutron spins and unpolarized nucleons of the wall material can be investigated by searching for a tiny change of the precession frequencies of neutron and mercury spins. Such a frequency change can be interpreted as a consequence of a short range spin-dependent interaction that could possibly be mediated by axions or axion-like particles. The interaction strength is proportional to the CP violating product of scalar and pseudoscalar coupling constants gSgP. Our result confirms limits from complementary experiments with spin-polarized nuclei in a model-independent way. Limits from other neutron experiments are improved by up to two orders of magnitude in the interaction range of 10-6<λ<10-4m. Mehr anzeigen
Persistenter Link
https://doi.org/10.3929/ethz-b-000101442Publikationsstatus
publishedExterne Links
Zeitschrift / Serie
Physics Letters BBand
Seiten / Artikelnummer
Verlag
ElsevierThema
CP violation; Short range spin-dependent interaction; Axion; Axion-like particle; Ultracold neutrons; Neutron electric dipole momentOrganisationseinheit
03864 - Kirch, Klaus / Kirch, Klaus
Förderung
149211 - Measurement of the neutron electric dipole moment (SNF)