|Image: Event display of candidate event for this ultra-rare decay observed in the LHCb experiment|
Scientists at the Large Hadron Collider (LHC) at CERN, near Geneva, have spotted one of the rarest particle decays ever seen in nature. The result is very damaging to new theories like the extremely popular Supersymmetry (or SUSY for short).Current knowledge about the most fundamental matter particles (quarks and leptons, such as an electron) and the forces between them is embedded in the so-called Standard Model. The particle masses are a consequence of their interactions with the Higgs field. Exciting the Higgs field in particle collisions at the LHC recently resulted in the discovery of the Higgs boson.However, the Standard Model is not the ultimate theory; it does not include gravity nor explain 95% of the Universe, which is in the form of Dark Matter and Dark Energy. See:
SUPERSYMMETRY SQUEEZED AS LHC SPOTS ULTRA RARE PARTICLE DECAY
The worst thing about the BBC article is the headline, “Supersymmetry theory dealt a blow” (though that’s presumably the editor’s fault, as much as or more than the author’s) and the ensuing prose, “The finding deals a significant blow to the theory of physics known as supersymmetry.” What’s wrong with it? It’s certainly true that the measurement means that many variants of supersymmetry (of which there are a vast number) are now inconsistent with what we know about nature. But what does it mean to say a theory has suffered a blow? and why supersymmetry? See: “Supersymmetry Dealt a Blow”?
|The graph showing evidence of the Bs0 → μ+ μ- decay. The result was presented Monday 12 November at the HCP Conference in Kyoto (photo courtesy of the LHCb Collaboration).|
Today, at the Hadron Collider Physics Symposium in Kyoto, the LHCb collaboration has presented the evidence of a very rare B decay, the rarest ever seen. The result further shrinks the region in which scientists can still look for supersymmetry. See: A rare sight
|A typical B0s →μμ decay candidate event is shown above. The two muon tracks from B0s decay are seen as a pair of purple tracks traversing the whole detector in the left image above.|