First Results of the Phase II SIMPLE Dark Matter Search

We report results of a 14.1 kg d measurement with 15 superheated droplet detectors of total active mass 0.208 kg, comprising the first stage of a 30 kg d Phase II experiment. In combination with the results of the neutron-spin sensitive XENON10 experiment, these results yield a limit of |a{sub p}|<0.32 for M{sub W}=50 GeV/c{sup 2} on the spin-dependent sector of weakly interacting massive particle-nucleus interactions with a 50% reduction in the previously allowed region of the phase space, formerly defined by XENON, KIMS, and PICASSO. In the spin-independent sector, a limit of 2.3x10{sup -5} pb at M{sub W}=45 GeV/c{sup 2} is obtained.