Noble liquids have properties that suit the goal of detecting the recoils expected from dark matter.
For instance, nuclear and electronic recoils can be distinguished to a very high level, low energy thresholds can be reached (thanks to high scintillation yields), they are transparent to their own light, and we can produce massive detectors at decent price.
Xenon is a natural player, as argon.
I guess because of the properties xenon is the candidate, but helium, argon or neon could also serve as dark matter detectors right?.. which is more efficient as a detector? the heavier one like xenon or the lighter one like neon?
There are detectors made of argon, neon and xenon so far. I guess (this goes beyond what I know as a theorist) helium is not manageable because of the too low boiling point.
Great... thanks for clearing up my doubt :)
I hope I did, as I am unsure about my own answer. But it sounds logical to me ;)