Search for annual and daily dark-matter modulations with Ge detectors at Baksan

An energy threshold of 2 keV was achieved for the 1-kg HP Ge detector in a long-term experiment aimed at searches for cold-dark-matter (CDM) particles. Data from two (Ge-76 and natural Ge) detectors were accumulated and analyzed for a period from May 1995 to March 1997. The effective passive and active shielding, together with pulse-shape discrimination, allowed one to achieve a background of 0.26 count/(kg keV d) for both detectors. New restrictions on the masses of weakly interacting massive particles (WIMP) and on the cross section for their elastic scattering on nuclei are obtained. The Dirac neutrino as a WIMP is ruled out in the range 13 GeV-4.5 TeV, Annual and daily modulations of the CDM signal are investigated. The possibility of detecting CDM particles by means of their inelastic interaction with Ge-73 is considered.