Results from Tevatron Collider Suggest Previously Undiscovered Particle or Force
Researchers at Illinois’ Fermilab Tevatron are cautiously optimistic that a bump in their data may herald the discovery either a new force, such as gravity or magnetism, or a new elementary particle. And no, it doesn’t seem to be the Higgs boson.
A new analysis of 10,000 collisions between proton and anti-protons created jets of heavier particles, which was to be expected. What was surprising was that 250 more times than expected, those particles were much heavier than they should have been, clocking in around 144 billion electron volts. This suggests that a new particle was created and decayed before it hit the detector, or a new force acted on the particles.
The paper, as yet unpublished but available online, found the anomaly while looking at the detection of W and Z bosons. Ars Technica explains:
[W and Z bosons] are sometimes produced in pairs during the collisions, but neither of them live very long before decaying. As a result, the particles themselves don’t reach the detectors; instead, their decay products do. But it is possible to trace the path of these more stable products back to their point of origin, and sum up all the energy they carry in order to figure out when they originated from the decay as a single particle, and how much that particle must weigh (we’ve done a detailed description of this process).
Since we know how much the W and Z boson weigh, we can figure out when jets of particles originated in a single location, and calculate the weight of their source, matching it to the W and Z bosons. If all goes well, there should be a peak in the data at the right energy to match these known particles. What the new paper does is repeat the whole process and try to determine if there are any bumps at energies that don’t match up with the production of W and Z bosons.
It seems that there was such a bump, suggesting that something beyond W and Z bosons was at work in the experiment. Instead of a nice, smooth decline, a bump appeared, suggesting something new.
Though exciting, the data has not yet passed muster to qualify as a “discovery.” Though the team determined that there is a less than 1% chance that their findings are a statistical fluctuation, they have yet to be peer-reviewed.
In the meantime, some scientists are turning their attention toward the Large Hadron Collider. In the race to understand these new findings, the LHC is likely to be a part of the investigation. But for the Tevatron, this might be its swan song; The collider is slated to be shut down in September due to budgetary constraints.
(PopSci via Slashdot, Ars Technica, image via Wikipedia)
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