Chapter 9

Signature for signals from the dark universe

The DAMA Collaboration

R Bernabei^1 ,MAmato^2 , P Belli^1 , R Cerulli^1 ,CJDai^3 ,HLHe^3 ,

GIgnesti^2 , A Incicchitti^2 , H H Kuang^3 ,JMMa^3 ,

F Montecchia^1 , D Prosperi^2

(^1) Department of Physics, University of Rome ‘Tor Vergata’ and

INFN, Rome, Italy

(^2) Department of Physics, University of Rome ‘La Sapienza’ and

INFN, Rome, Italy

(^3) IHEP, Chinese Academy, Beijing, China
The DAMA experiment is located at the Gran Sasso National Laboratories of the
INFN and is searching for dark matter (DM) particles using various scintillators as
target-detector systems. In particular the results, presented here, were obtained by
analysing, in terms of the WIMP annual modulation signature, the data collected
with the highly radiopure (∼100 kg NaI(Tl)) set-up during four annual cycles
(total statistics of 57 986 kg day).

9.1 Introduction

In the past few years, the many experimental and theoretical studies have changed
the main question on the DM problem from its existence to the nature of its
constituents. The stringent limit on the baryonic part (arising from a comparison
between the measured relative abundance of light elements with their expectations
in the nucleosynthesis scenario) and the results achieved in investigations of the
cosmic microwave background (which have ruled out the pure hot DM scenario)
support the view that—whatever the DM composition turns out to be (even if a
cosmological constant different from zero is definitively demonstrated)—a large
amount of CDM is necessary. This can be in the form of WIMPs or axions.

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