Center for Theoretical Physics of the Universe (CTPU-PTC)

Halo-independent determination of the unmodulated WIMP signal in DAMA and other model-independent approaches in the analysis of Dark Matter direct detection data

by Prof. Stefano Scopel

I will discuss recent progress in developing model-independent techniques that remove the two main sources of theoretical bias in the interpretation of Dark Matter direct detection data: the scaling law of the WIMP-nucleus cross section off different targets, and the WIMP velocity distribution in our Galaxy. In particular I will present a new technique to obtain a halo-independent determination of the time-independent part of the signal in an experiment that measures the yearly modulated component, disentangling for the first time the former from the background, and apply it to the DAMA data. I will also discuss strategies to make inferences on the thermal relic abundance of a Weakly Interacting Massive Particle (WIMP) when the same effective dimension-six operator that explains an experimental excess in direct detection is assumed to drive decoupling at freeze-out. In particular, due to a degeneracy between the WIMP local density and the WIMP-nucleon scattering cross section, a DM direct detection experiment is not directly sensitive to the physical cut-off scale of the effective theory, but the same degeneracy can be used to develop a consistency test on the possibility that the WIMP is a thermal relic in the first place.