The Cryogenic Dark Matter Search (CDMS) uses low-temperature Ge and Si detectors to search for Weakly Interacting Massive Particles (WIMPs) via their elastic-scattering interaction with atomic nuclei while discriminating against interactions of background particles. CDMS data from 1998 and 1999 with a relaxed fiducial-volume cut (resulting in 15.8 kg-days exposure on Ge) are consistent with an earlier analysis with a more restrictive fiducial-volume cut. Twenty-three WIMP candidate events are observed, but these events are consistent with a background from neutrons. Resulting limits on the spin-independent WIMP-nucleon elastic-scattering cross-section are lower than those of any other experiment for WIMPs with masses between 10-70 GeV c-2. Under the assumptions of standard WIMP interactions and a standard halo, the results are incompatible with the annual-modulation signal of DAMA at 99.99% CL in the asymptotic limit.
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We thank Paul Luke of LBNL for his advice regarding surface-event rejection. We thank R. Abusaidi, J. Emes, D. Hale, G.W. Smith, J. Taylor, S. White, D.N. Seitz, J. Perales, M. Hennessy, M. Haldeman, and the rest of the engineering and technical staffs at our respective institutions for invaluable support. This work is supported by the Center for Particle Astrophysics, an NSF Science and Technology Center operated by the University of California, Berkeley, under Cooperative Agree ment No. AST-91-20005, by the National Science Foundation under Grant No. PHY-9722414, by the Department of Energy under contracts DEAC0376SF00098, DEFG03- 90ER40569, DEFG0391ER40618, and by Fer-milab, operated by the Universities Research Association, Inc., under Contract No. DEACOZ-76CH03000 with the Department of Energy.