A Search for WIMPs with the First Five-Tower Data from CDMS

TL;DR

This paper reports the first results from the full five-tower CDMS II experiment, setting new upper limits on WIMP-nucleon interactions and improving constraints on dark matter models with WIMP masses above 42 GeV/c².

Contribution

First analysis of the complete five-tower CDMS II data, establishing the most sensitive upper limits on WIMP-nucleon cross sections for masses above 42 GeV/c².

Findings

Zero candidate events observed in the data.

Set an upper limit on the WIMP-nucleon cross section of 6.6×10⁻⁴⁴ cm² at 90% CL.

Improved constraints significantly restrict supersymmetric dark matter models.

Abstract

We report first results from the Cryogenic Dark Matter Search (CDMS II) experiment running with its full complement of 30 cryogenic particle detectors at the Soudan Underground Laboratory. This report is based on the analysis of data acquired between October 2006 and July 2007 from 15 Ge detectors (3.75 kg), giving an effective exposure of 121.3 kg-d (averaged over recoil energies 10--100 keV, weighted for a weakly interacting massive particle (WIMP) mass of 60 \gev). A blind analysis, incorporating improved techniques for event reconstruction and data quality monitoring, resulted in zero observed events. This analysis sets an upper limit on the WIMP-nucleon spin-independent cross section of 6.6$\times10^{-44}$ cm$^2$ (4.6$\times10^{-44}$ cm$^2$ when combined with previous CDMS Soudan data) at the 90% confidence level for a WIMP mass of 60 \gev. By providing the best sensitivity for dark matter WIMPs with masses above 42 GeV/c$^2$, this work significantly restricts the parameter space for some of the favored supersymmetric models.