New CDMS Low Threshold Result

CDMS has released the latest result from its CDMSlite, in which the detectors are run with a very low energy threshold. To do this, CDMS has to give up its particle ID information by applying a much higher bias voltage to the detectors than usual and then only measuring the phonon signal.

The measurement isn’t background free, and several germanium escape peaks are seen, but they use the optimum interval method to extract a limit. The limit turns out to be the best so far from any direct detection experiment between WIMP masses of 1.6 and 5.5 GeV. Few low background experiments are able to measure events at a threshold close to that of CDMSlite, so the measurement doesn’t need to be background free to give world leading limits.