New limits to interaction rates from the UK dark matter experiment

Direct detection of Weakly Interacting Massive Particles (WIMP's) is possible if they have a scattering cross-section with with nucleons comparable to that of a neutrino. Low background underground detector searches are underway worldwide and we report here on an improvement of an order of magnitude in out published limits to the spin-dependent dark matter interaction rate. A 2 σ upper limit of the rate of 0.14 events/kg.keV.day (at 7-10 KeV equivalent photon energy) is achieved by use of event time profile information to reject most of the radioactive background. (authors)