Two classes of interesting results this morning from the EuroPhysics conference. I’ll try to explain their significance later when time permits.
- The LHC experiments ATLAS and CMS put new and much stronger limits on certain classes of supersymmetric theories. [However, other types of supersymmetry are not very constrained by these measurements; so the end of supersymmetry is by no means nigh, despite what you may read elsewhere.]
- The Tevatron’s DZero experiment repeated the CDF measurement of the top quark forward-backward asymmetry. [In the proton-antiproton collisions of the Tevatron, top quarks are more likely to head in the proton direction than in the antiproton direction; this tendency is much larger than expected.] Like CDF, DZero sees an excess 2 standard deviations above the Standard Model prediction, although unlike CDF they do not see significant variation of the asymmetry with the total energy of the event [more precisely, with the top-antitop invariant mass]. This excess asymmetry remains the most significant experimental disagreement with the predictions of the Standard Model. But it is still far from convincing.
Sadly, the slides of the DZero talk about AFB are not available. Thanks for sharing the news.