Fermilab
If dark matter can pull gravitationally, it has mass
So here is an article of 2006 with some interesting information. Now these experimental procedures are always interesting to me because of the type of detectors that were dreamt up in which to measure some aspect of the reality supposed, and realized, by noise in the background.
For scientists to "hear" a dark matter particle, it must hit an atom in one of the crystals at the heart of the CDMS detectors. The crystals are kept cold—close to absolute zero—to reduce atomic movement, keeping the crystals quiet. The detectors "listen" for vibrations inside the crystal, like ears listening for vibrations in the air.
The detectors contain two kinds of crystals, germanium and silicon. A germanium atom is larger than a silicon one: Its nucleus has 73 protons and neutrons compared to silicon's 28. This size difference helps CDMS sort out yet another source of background—neutrons. High-energy cosmic rays and radioactive decays in the matter surrounding the detectors can produce neutrons. Hitting atoms in the crystals, these neutrons cause a "sound" in the detectors similar to the one made by the predicted dark matter particles.See: Listening for whispers of dark matter
Model of the Cryogenic Dark Matter Search which translates actual data into sound and light. We have not yet had a dark matter interaction, but we have lots of particles hitting the detectors and that is what you are watching. A downloadable version is at my webpage http://www.hep.umn.edu/~prisca More info on our experiment can be found at http://cdms.berkeley.edu and http://www.soudan.umn.edu
So lets mover forward here to Dec 10, while waiting to hear on Dec 17 for more news.
The CDMS collaboration has completed the analysis of the final CDMS-II runs, which more than doubled the total data from all previous runs combined. The collaboration is working hard to complete the first scientific publication about these new results and plans to submit the manuscript to arXiv.org before the two primary CDMS talks scheduled for Thursday, Dec. 17, at Fermilab and at SLAC. See:The search for dark matter:has CDMS found something?
Update:
Latest Results in the Search for Dark Matter
Thursday, December 17, 2009
