The Annual Modulation Signature for Dark Matter: DAMA/LIBRA-Phase1 Results and Perspectives
Table 3
Summary of the results obtained by investigating possible sources of systematics or side processes [1–4, 7, 8, 49, 57–62]. None able to give a modulation amplitude different from zero has been found; thus, cautious upper limits (90% C.L.) on the possible contributions to the measured modulation amplitude have been calculated and are shown here for DAMA/LIBRA-phase1 as done before for the seven annual cycles of DAMA/NaI [23, 24].
Source
Main comment
Cautious upper limit (90% C.L.)
Radon
Sealed Cu Box in HP Nitrogen atmosphere, 3 levels of sealing
<2.5 × 10−6 cpd/kg/keV
Temperature
Air conditioning + huge heat capacity
<10−4 cpd/kg/keV
Noise
Efficient rejection
<10−4 cpd/kg/keV
Energy scale
Routine + intrinsic calibrations
<1 − 2 × 10−4 cpd/kg/keV
Efficiencies
Regularly measured
<10−4 cpd/kg/keV
Background
No modulation above 6 keV; no modulation in the (2–6) keV multiple-hit events; this limit includes all possible sources of background
