PANIC2021 Conference

Searching for time-varying nuclear electric dipole moments using precision magnetic resonance

5 Sept 2021, 16:55

20m

Online

Talk Tests of symmetries and conservation laws Tests of symmetries and conservation laws

Speaker

Alex Sushkov (Boston University)

Description

The Cosmic Axion Spin Precession Experiments (CASPEr) search for ultralight axion-like dark matter. CASPEr-e is sensitive to the time-varying nuclear electric dipole moment, induced by the electric-dipole moment (EDM) coupling $g_d$. The detection scheme is based on a precision measurement of
${}^{207}$Pb solid-state nuclear magnetic resonance in a polarized ferroelectric crystal. We calibrated the detector and characterized the excitation spectrum and relaxation parameters of the nuclear spin ensemble with pulsed magnetic resonance measurements in a 4.4 T magnetic field. We swept the magnetic field near this value and searched for axion-like dark matter with Compton frequency within a 1 MHz band centered at 39.65 MHz. Our measurements place the upper bound $|g_d|<9.5\times {10}^{-4}{\text{GeV}}^{-2}$ (95% confidence level) in this frequency range. This constraint corresponds to an upper bound of $1.0\times {10}^{-21}\text{e}\cdot \text{cm}$ on the amplitude of oscillations of the neutron electric dipole moment, and $4.3\times {10}^{-6}$ on the amplitude of oscillations of CP-violating $\theta$ parameter of quantum chromodynamics. Our results demonstrate the feasibility of using solid-state nuclear magnetic resonance to search for axion-like dark matter in the nano-electronvolt mass range.

Presentation materials

AlexSushkov - Searching for time-varying nuclear electric dipole moments.pdf