Dark matter discovered? (APS April 2008)
Has dark matter been discovered? Rumors floating about suggest that the DAMA-LIBRA collaboration will announce that they have detected dark matter after repetition of their controversial experiment which released results in 2000.
The DArk MAtter (DAMA) experiment, situated in an underground laboratory in Gran Sasso, Italy, will announce the results of a new experiment using the same technology that led to the 2000 result. The collaboration has been very quiet for the past few years but will break silence on Wednesday, April 16, at the NO-VE neutrino oscillation workshop in Venice, Italy. Sources here at the APS meeting tell me that DAMA plans to claim they have again seen a signal for dark matter detection. People here don't have more details at this time.
The DAMA result was controversial because it relies on looking for a small variation in a signal in a sodium iodide detector which has a lot of background noise. Other attempts since to see dark matter have not found anything with the properties DAMA claimed. Might the signal have been due to a systematic error? To see the signal, the detector needs to run for at least a year and look for variation over the year due to the motion of the Earth through the cosmic dark matter background. The quantity of data measured in this new experiment is as much as what led to the original claim of dark matter observation in 2000.
Whatever the DAMA-LIBRA collaboration says, physicists will not be entirely convinced of any claim for detection of dark matter until it is repeated in other types of experiments. However, prepare for another media storm if the announcement is indeed what the rumors are saying. I am certain the collaboration will be much more prepared to answer their challengers and will have a much tighter argument ready if they do indeed try to claim a result.
One of the reasons I'm telling this story is that it highlights another aspect of the value of conferences for physicists. They hear about all kinds of things that are going through the strength of personal connections instead of just having to wait for official publications. A lot of work gets done over a beer in the evenings, and a lot of news spreads through casual conversations.
See all posts from the American Physical Society April 2008 conference here.