Signs of Dark Matter from Minnesota Mine->
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by
thomst
thomst writes "Ron Cowen of Science News reports that on May 2nd, at the American Physical Society meeting in Anaheim, CA, Juan Collar, team leader of COGENT, an experimental effort to detect WIMPs (Weakly Interacting Massive Particles), presented a paper detailing 15 months of data collected via a pure germanium detector located deep in a Minnesota mine which seems to confirm similar results reported by a European effort called DAMA/LIBRA. The results are particularly intriguing, because they appear to show a seasonal variation in the density of WIMPs that accords with models that predict that Earth should encounter more WIMPs in Summer (when its path around the Sun moves in the same direction as the Milky Way revolves) than in Winter (when it goes the opposite direction). The most interesting thing about the COGENT experiment is that the mass of the WIMP candidates it records is significantly less than most particle physicists had predicted, according to popular models. If the interactions recorded by COGENT are eventually confirmed as WIMP encounters, wholesale revisions to the so-called "Standard Model" may be required. (Cowen wrote an earlier article about COGENT last year that goes into a lot more detail about how COGENT works, what its team expects it to find, and why."
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