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unixronin: Galen the technomage, from Babylon 5: Crusade (Default)
Unixronin

December 2012

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Wednesday, May 19th, 2010 10:12 pm

An interesting new result from the DZero experiment at Fermilab has found relatively massive asymmetry between creation of normal matter particles and antiparticles resulting from proton-antiproton collisions in the Tevatron.

Previous asymmetries were already known in matter-antimatter creation.  Known as charge-parity violation, the effect is fully consistent with the Standard Model that underlies all of our current theoretical background on the structure of matter.  However, CP violation is far too small an effect to account for the overwhelming abundance of normal matter present in the Universe.  Put another way, the total amount of mass-energy believed present in the Universe is not large enough — by a very large margin — for CP violation alone to yield the observed quantity of normal matter.

The new Tevatron result shows an asymmetry on the order of 1% — which is to say, a high-energy event such as matter-antimatter annihilation is 1% more likely to produce normal matter than antimatter.  That doesn't sound like a lot, but in particle physics, it's huge, and in fact the result agrees very well with the observed amount of normal matter present in the Universe.  However, such a large asymmetry cannot be explained by the Standard Model.

Combine this with the fact that the Large Hadron Collider now gives us the capability to search the entire range of mass-energies within which, according to the Standard Model as it stands, it is believed possible for the Higgs boson to be found (although that exhaustive search has not yet been done), and it looks as though things could be about to get interesting again in high-energy physics, because if the Standard Model is shown to be wrong, we will have to rethink an awful lot of theory.  Either that, or someone is going to have to come up with a way to reconcile this DZero data with the Standard Model as it now exists.

First, of course, this result will have to be confirmed and replicated.  But now we have at least two other tools able to do that — the Collider Detector at Fermilab, and the LHCb experiment at the Large Hadron Collider.

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Thursday, May 20th, 2010 06:12 am (UTC)
There've been hints from time to time over the past few years that the Standard Model doesn't quite cover all of physical reality, that it needs anything from a mild amount of tinkering to a complete overhaul to reconcile what we've been observing in experiments such as these with the best theoretical models we have of physical reality. We just may get the Second 30 Years That Shook Physics soon.