Resonant absorption of bosonic dark matter in molecules

TL;DR

This paper introduces a novel bosonic dark matter detector using resonant absorption in molecules, leveraging molecular spectroscopy and photon detection to improve sensitivity and enable detailed dark matter velocity mapping.

Contribution

It proposes a new molecular spectroscopy-based detector for bosonic dark matter, capable of high sensitivity, background rejection, and velocity distribution reconstruction.

Findings

Potential to improve coupling sensitivity by orders of magnitude

Excellent energy resolution and background rejection capabilities

Possibility to reconstruct dark matter velocity distribution

Abstract

We propose a new class of bosonic dark matter (DM) detectors based on resonant absorption onto a gas of small polyatomic molecules. Bosonic DM acts on the molecules as a narrow-band perturbation, like an intense but weakly coupled laser. The excited molecules emit the absorbed energy into fluorescence photons that are picked up by sensitive photodetectors with low dark count rates. This setup is sensitive to any DM candidate that couples to electrons, photons, and nuclei, and may improve on current searches by several orders of magnitude in coupling for DM masses between 0.2 eV and 20 eV. This type of detector has excellent intrinsic energy resolution, along with several control variables---pressure, temperature, external electromagnetic fields, molecular species/isotopes---that allow for powerful background rejection methods as well as precision studies of a potential DM signal. The proposed experiment does not require usage of novel exotic materials or futuristic technologies, relying instead on the well-established field of molecular spectroscopy, and on recent advances in single-photon detection. Cooperative radiation effects, which arise due to the large spatial coherence of the nonrelativistic DM field in certain detector geometries, can tightly focus the DM-induced fluorescence photons in a direction that depends on the DM's velocity, possibly permitting a detailed reconstruction of the full 3D velocity distribution in our Galactic neighborhood, as well as further background rejection.