Dark Matter-Electron Scattering from Aromatic Organic Targets

Understand

Sub-GeV dark matter (DM) which interacts with electrons can excite electrons occupying molecular orbitals in a scattering event.

• In particular, aromatic compounds such as benzene or xylene have an electronic excitation energy of a few eV, making them sensitive to DM as light as a few MeV.
• These compounds are often used as solvents in organic scintillators, where the de-excitation process leads to a photon which propagates until it is absorbed and re-emitted by a dilute fluor.
• The fluor photoemission is not absorbed by the bulk, but is instead detected by a photon detector such as a photomultiplier tube.