Orateurs
Description
On behalf of the nEDM collaboration, we will discuss the measurement that established the best upper limit on the electric dipole moment of the neutron, dn < 1.8x10^(-26) e cm (90% CL) [1]. This result was obtained using the nEDM apparatus connected to the ultracold neutron source at the Paul Scherrer Institute (PSI). We will also present n2EDM, the next-generation experiment currently in the commissioning phase at PSI.
The absence of a neutron electric dipole moment (nEDM) at this sensitivity level constrains the CP-violating phase of QCD to an extremely small value, constituting the strong CP problem and motivating the existence of the Axion. Additionally, the neutron EDM is a highly sensitive probe of CP violation beyond the Standard Model.
Moreover, we performed a search in the nEDM data for an oscillating signal potentially due to an oscillating axion-like particles (ALPs) field. This search set upper limits on the axion couplings to gluons and neutrons in the mass range from 10^(-24) eV to 10^(-18) eV [2], and another limit in the mass range from 10^(-16) eV to 10^(-13) eV [3].
[1] C. Abel et al., Phys. Rev. Lett. 124, 081803 (2020)
[2] C. Abel et al., Phys. Rev. X 7, 041034 (2017)
[3] C. Abel et al., SciPost Phys. 15, 058 (2023)
