Search for WIMP annual modulation signature: Results from DAMA/NaI-3 and DAMA/NaI-4 and the global combined analysis

Data, collected by the similar or equal to 100 kg NaI(TI) DAMA set-up at th e Gran Sasso National Laboratory of I.N.F.N. during two further yearly cycl es (DAMA/NaI-3 and DAMA/NaI-4; statistics of 38475 kg (.) day), have been a nalysed in terms of WIMP annual modulation signature. The results agree wit h those previously achieved. The cumulative analysis of all the available d ata (DAMA/NaI-1 to 4; statistics of 57986 kg(.)day) favours the possible pr esence of a WIMP with M-W = (52(-8)(+10)) GeV and xi sigma(p) = (7.2(-0.9)( +0.4)) (.) 10(-6) pb at 4 sigma C.L., when standard astrophysical assumptio ns are considered. The allowed mass extends up to 105 GeV (1 sigma) when th e uncertainty on the mean value of the local velocity v(0) is taken into ac count and up to 132 GeV(1 a) in case a possible bulk halo rotation is taken into account. Moreover, the allowed regions extend to lower xi sigma(p) va lues when the upper limits on the recoil differential counting rate obtaine d from DAMA/NaI-0 is included in the cumulative analysis (favouring, in cas e of standard assumptions, M-w = (44(-9)(+12)) GeV and xi sigma(p) = (5.4 /- 1.0) (.)10(-6) pb at similar or equal to 4 sigma C.L.). The 3 sigma C.L. allowed regions in the xi sigma(p), M-w plane summarize the obtained main physical results. (C) 2000 Elsevier Science B.V. All rights reserved.