Why The LUX Results Matter To Dark Matter - And To WIMPs

Reading through the coverage of the first results from the world’s most sensitive search for dark matter, the Large Underground Xenon (LUX), you’d be forgiven for thinking that researchers working on dark matter had either discovered nothing at all or were on the verge of laying their (metaphorical) hands on the stuff. As with so much scientific research though, things are never as simple as they seem.

With the Higgs boson safely tucked under one arm, the next great hunt for physicists is the search for dark matter, even if scientists really don’t know very much about it at all. With their typical caution, the most any physicist will commit to is that there is something out there that is dark – in that it doesn’t show up in visible light or other electromagnetic waves – and that interacts with the universe in a similar way to visible matter.

After that, we’re firmly in the realm of theory. Dark matter might be made up of particles and those particles might be Weakly Interacting Massive Particles (WIMPs). WIMPs interact through the weak force and gravity, but not through electromagnetism – so they can’t be seen – and not through the strong nuclear force. Then again, dark matter might be made up of axions, a hypothetical elementary particle. Or it might be made up of something else entirely.

According to Dr. Chamkaur Ghag, an astroparticle physicist from University College London who works with the LUX project, WIMPs might be a “favoured theory”, but they’re far from the only theory out there.

“With experimental direct dark matter searches such as LUX, we try to be as model independent and “broadband” as possible, probing as many models as are feasible in the hunt for a signal,” he explained. “There are still many other models of course, and this is as it should be.”

So what exactly have LUX’ first results proved? Well, they have gone some way towards disproving other recent sets of results from the Coherent Germanium Neutrino Technology (CoGeNT) and the Cryogenic Dark Matter Search (CDMS) experiments, even if scientists at those projects aren’t entirely sure they agree yet...

Read the rest over at Forbes.