Using the Energy Spectrum at DAMA/LIBRA to Probe Light Dark Matter

TL;DR

This paper uses DAMA/LIBRA's energy spectrum data to place strong constraints on light WIMP dark matter models, showing that simple assumptions about WIMP properties cannot explain the observed signals.

Contribution

It demonstrates that detailed spectral analysis of DAMA/LIBRA data significantly restricts the parameter space for light WIMP dark matter.

Findings

Light WIMPs with Maxwellian velocity distributions are incompatible with DAMA/LIBRA data.

Most parameter space for spin-independent light WIMPs is excluded by unmodulated signal limits.

Alterations in astrophysical or particle physics assumptions could open new viable mass windows.

Abstract

A weakly interacting massive particle (WIMP) weighing only a few GeV has been invoked as an explanation for the signal from the DAMA/LIBRA experiment. We show that the data from DAMA/LIBRA are now powerful enough to strongly constrain the properties of any putative WIMP. Accounting for the detailed recoil spectrum, a light WIMP with a Maxwellian velocity distribution and a spin-independent (SI) interaction cannot account for the data. Even neglecting the spectrum, much of the parameter space is excluded by limits from the DAMA unmodulated signal at low energies. Significant modifications to the astrophysics or particle physics can open light mass windows.