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

Data, collected by the ≃100 kg NaI(Tl) DAMA set-up at the Gran Sasso National Laboratory of I.N.F.N. during two further yearly cycles (DAMA/NaI-3 and DAMA/NaI-4; statistics of 38475 kg·day), have been analysed in terms of WIMP annual modulation signature. The results agree with those previously achieved. The cumulative analysis of all the available data (DAMA/NaI-1 to 4; statistics of 57986 kg·day) favours the possible presence of a WIMP with Mw=(52+10−8) GeV and ξσp=(7.2+0.4−0.9)·10−6 pb at 4 σ C.L., when standard astrophysical assumptions are considered. The allowed mass extends up to 105 GeV (1 σ) when the uncertainty on the mean value of the local velocity v0 is taken into account and up to 132 GeV (1 σ) in case a possible bulk halo rotation is taken into account. Moreover, the allowed regions extend to lower ξσp values when the upper limits on the recoil differential counting rate obtained from DAMA/NaI-0 is included in the cumulative analysis (favouring, in case of standard assumptions, Mw=(44+12−9) GeV and ξσp=(5.4±1.0)·10−6 pb at ≃4 σ C.L.). The 3 σ C.L. allowed regions in the ξσp, Mw plane summarize the obtained main physical results.