I passed along a rumor this week from the American Physical Society meeting in St. Louis that researchers at the Gran Sasso National Laboratories of the National Institute of Nuclear Physics (INFN) in Italy were set to reinforce their highly disputed claim to have discovered a dark matter particle. They were supposed to uncork their new data, from an experiment called DAMA/LIBRA, today at a conference. The only mention of it that I could find this morning, however, was in the comments section of the blog of Italian physicist Tommaso Dorigo, who apparently heard the talk and didn't even think it important enough to mention in his original post. He wrote: "I did listen to the talk about the DAMA-LIBRA experiment.⬨ And indeed, they claim to have a 8.2-sigma signal of a yearly oscillation in the signal yield." Sigma refers to standard deviations; 8.2-sigma means the odds are billions and billions to one against the signal being a random cluster in the data. Dorigo writes that he tuned out during the talk because it was hard to understand the speaker, who apparently talked over anyone who tried to ask questions. The analysis, he continued, "shows a clear component with yearly frequency. I believe the result is on solid ground. I am more skeptical about the interpretation: yes, DM [dark matter] fits in. But I would not be too surprised if DAMA ended up having discovered a yearly variation in their photomultiplier response. In other words, their equipment is probably doing something that they aren't factoring in. Hmm. Unless something dramatic happens or I get the sense that readers are clamoring for more information, I think I'll let this one drop. You can view the slides from the talk here, if it floats your boat.
-- Edited by JR Minkel at 04/16/2008 2:54 PM