Electron - Dark Matter Scattering in an Evacuated Tube

TL;DR

This paper proposes an experimental method to detect light dark matter particles via electron scattering in an evacuated tube, enabling direct measurement of dark matter mass and distinguishing it from background noise.

Contribution

It introduces a novel experimental setup using a high-current electron beam in an evacuated tube to detect light dark matter through elastic scattering.

Findings

Potential to measure dark matter mass directly

Clear separation of dark matter signal from residual gas scattering

Feasibility of detecting light dark matter particles in laboratory conditions

Abstract

The light dark matter model can explain both the primordial abundance of dark matter and the anomalous 511 keV gamma-ray signal from the galactic center. This model posits a light neutral scalar, \chi, with a mass in the range 1 MeV < Mchi < 10 MeV, as well as a light neutral spin-1 boson, U, which mediates the annihilation channel \chi\chi -> e+e-. Since the dark matter particle is light, its number density is relatively large if it accounts for a local dark matter density of 0.3 GeV/cm^3. We consider an experiment in which a low-energy, high-current electron beam is passed through a long evacuated tube, and elastic scattering of electrons off dark matter particles is observed. The kinematics of this process allow a clean separation of the signal process from scattering off residual gas in the tube, and also a direct measurement of Mchi.