There’s a minor kerfuffle at the moment over the XENON experiment’s early data (arxiv paper) which did not detect any dark matter in 11 days of data acquisition. This conflicts with earlier claims by the DAMA experiment and recent maybe-kinda-sorta detections by the CoGeNT and CDMA experiments.
As a result, a couple of members of other collaborations have posted a response on the arxiv saying, basically, that they don’t believe the sensitivity claimed for the XENON detector in the energy range in question, and that their result can’t really be said to rule out the possibility of dark matter in that area as well as they claim. This has generated a little buzz, and some back-and-forth in the news story.
So is this the catfight of the century? Not really. This is more or less the way things are done, as far as I can tell– people make claims to have seen things all the time, and those claims are questioned in very strong terms. That’s how science works.
Is there any merit to the questions being raised about XENON? Almost certainly– these types of detectors are fearsomely complicated devices, and the data analysis of such devices almost always include some steps that verge on Black Art– simulations used to estimate sensitivity, complicated algorithms to decide what data to keep and what to discard, etc. There will almost always be differences of opinion on these issues, especially with a detector as new as the XENON project’s.
The one thing that’s a little different here is that this is being done via dueling arxiv preprints, rather than an exchange of informal letters, private discussions within a collaboration, or even testy questions at conferences. And, of course, these days we have science-themed media outlets who watch the arxiv for signs of this sort of thing, making it more of a story than it might otherwise be. As the Physics World piece says, “The real test of the XENON100 collaboration’s analysis will be its peer review.” What’s going on here is just the first steps of that process of peer review.
It does seem a little odd to have the debate conducted through strongly worded pre-prints, but that probably just indicates that other channels failed for one reason or another. Many of the scientists involved are members of more than one collaboration, and some of these issues may have been raised during pre-posting discussions within the collaboration, and not dealt with to their satisfaction. It’s tough to say without more knowledge of the people and politics than I have.
(Full disclosure: I co-authored a paper with Dan McKinsey at Yale, one of the authors of the response pre-print, and a person quoted in the Physics World story, and I got endorsements of my NSF proposal a few years back from both McKinsey and Elena Aprile of XENON. My interactions with both of them were (and are) very positive, but that’s about where my knowledge of the issues involved end.)
(Also, technically, the detector involved uses liquid xenon, not gaseous xenon. I couldn’t resist, though.)