Dark Matter attempts for CoGeNT and DAMA

TL;DR

This paper investigates whether signals from CoGeNT and DAMA/LIBRA can be explained by dark matter interactions, considering various models and experimental constraints, and finds limited compatibility between the signals.

Contribution

The study systematically analyzes multiple dark matter interaction models to assess their ability to simultaneously explain CoGeNT and DAMA/LIBRA signals within experimental constraints.

Findings

Limited simultaneous explanation of CoGeNT and DAMA/LIBRA signals.

Inelastic spin-independent scattering can reconcile CoGeNT data with other constraints.

Spin-dependent inelastic scattering can explain DAMA/LIBRA signal independently.

Abstract

Recently, the CoGeNT collaboration presented a positive signal for an annual modulation in their data set. In light of the long standing annual modulation signal in DAMA/LIBRA, we analyze the compatibility of both of these signal within the hypothesis of dark matter (DM) scattering on nuclei, taking into account existing experimental constraints. We consider the cases of elastic and inelastic scattering with either spin-dependent or spin-independent coupling to nucleons. We allow for isospin violating interactions as well as for light mediators. We find that there is some tension between the size of the modulation signal and the time-integrated event excess in CoGeNT, making it difficult to explain both simultaneously. Moreover, within the wide range of DM interaction models considered, we do not find a simultaneous explanation of CoGeNT and DAMA/LIBRA compatible with constraints from other experiments. However, in certain cases part of the data can be made consistent. For example, the modulation signal from CoGeNT becomes consistent with the total rate and with limits from other DM searches at 90% CL (but not with the DAMA/LIBRA signal) if DM scattering is inelastic spin-independent with just the right couplings to protons and neutrons to reduce the scattering rate on xenon. Conversely the DAMA/LIBRA signal (but not CoGeNT) can be explained by spin-dependent inelastic DM scattering.