Normally I live in London, but the past couple of weeks I’ve been visiting family in Chicago, which is quite a bit colder (but prettier). While I’ve been here, the Collision Detector at Fermilab (CDF), a particle physics experiment located at the Tevatron accelerator just outside the city has put out an intriguing paper.

In a nutshell, the paper uses a ton of data (5.3 inverse femtobarns in particle physics speak) to examine the decay of Top quarks, the heaviest of all the quarks. They find a rather puzzling asymmetry in the way the quarks decay into lighter particles. Even more strange, the asymmetry appears pronounced at higher collision energies, and non-existent at lower ones.

There’s some discussion about what this asymmetry might mean at the always interesting Résonaances blog, which put me on to the paper. The best guess among the theorists who comment on the blog seems to be that the accelerator is making something called a KK-gluon. These are heavy particles that arise from some theories predicting extra dimensions of space. Their decay into top quarks could explain the asymmetry and why it only appears at higher energies (energy=mass x c<font=-1>², so higher energy collisions would create heavier particles like KK gluons). So, if the effect is real, it may constitute evidence for extra-dimensions, a possibility the Large Hadron Collider at CERN near Geneva could also be in a position to weigh in on.

Or it could be a statistical fluke. I contacted John Ellis, a venerably bearded theorist at CERN and he said he’s “very much in wait-and-see mode”. Adam Falkowski, a Polish theorist who runs the Résonaances blog, suggests that the Tevatron physicists may have discovered a “fundon”–a particle generated by the imminent shutdown of their 24-year-old collider. He might be right, though to be fair, Fermilab, which operates the Tevatron, isn’t over-hyping the oddity.

Maybe its my proximity to Fermilab at the moment, but I do find the new paper intriguing. Hopefully another detector, either D0 at Fermilab or one of the new ones at the LHC, will confirm the result soon!

Photo Credit: Fermilab