Something?

What lives 20 picoseconds, travels one centimeter and then explodes in a shower of muons?

What the hell?

Don't know? Don't feel bad. Science doesn't know. Nobody fucking does. This mystery thingie has appeared in the detector (the old one) at Fermilab and science is baffled. If the result isn't some kind of screw-up then this appears to be a new particle with heavy implications for the Standard Model.

So what could it be? As it happens, Weiner and Nima Arkani-Hamed of the Institute for Advanced Study in Princeton, New Jersey, and colleagues have developed a theory of dark matter – the enigmatic stuff thought to make up a large proportion of the universe – to explain recent observations of radiation and anti-particles from the Milky Way.

Their model posits dark matter particles that interact among themselves by exchanging "force-carrying" particles with a mass of about 1 gigaelectronvolts.

The CDF muons appear to have come from the decay of a particle with a mass of about 1 GeV. So could they be a signature of dark matter? "We are trying to figure that out," says Weiner. "But I would be excited by the CDF data regardless."