EXCESS workshop: Descriptions of rising low-energy spectra

Understand

Many low-threshold experiments observe sharply rising event rates of yet unknown origins below a few hundred eV, and larger than expected from known backgrounds.

• Due to the significant impact of this excess on the dark matter or neutrino sensitivity of these experiments, a collective effort has been started to share the knowledge about the individual observations.
• For this, the EXCESS Workshop was initiated.
• In its first iteration in June 2021, ten rare event search collaborations contributed to this initiative via talks and discussions.