We search for dark matter in the form of axionlike particles (ALPs) in the
mass range $5.576741 \,\mathrm{neV/c^2}$ – $5.577733\,\mathrm{neV/c^2}$ by
probing their possible coupling to fermion spins through the ALP field
gradient. This is achieved by performing proton nuclear magnetic resonance
spectroscopy on a sample of methanol as a technical demonstration of the Cosmic
Axion Spin Precession Experiment Gradient (CASPEr-Gradient) Low-Field
apparatus. Searching for spin-coupled ALP dark matter in this mass range with
associated Compton frequencies in a 240 Hz window centered at 1.348570 MHz
resulted in a sensitivity to the ALP-proton coupling constant of
$g_{\mathrm{ap}} \approx 3 \times 10^{-2}\,\mathrm{GeV}^{-1}$. This
narrow-bandwidth search serves as a proof-of-principle and a commissioning
measurement, validating our methodology and demonstrating the experiment’s
capabilities. It opens the door to probing large swaths of hitherto unexplored
mass-coupling parameter space in the future by using hyperpolarized samples.

Este artículo explora los viajes en el tiempo y sus implicaciones.

Descargar PDF: