Opening of the Higgs boson was a triumph for the standard model, which predicted the particle is formed, behaves and breaks during collisions in the Large Hadron Collider.
In fact, the standard model to accurately predict almost everything that we needed to write IT News
It would seem, should rejoice. But this situation is not very happy with the physicists, as the Standard Model is incomplete. It has no particles that could explain dark matter. It does not include an explanation of why the universe more matter than antimatter. And it does not provide any mechanism that could provide the neutrino mass.
The discovery of a new particle, which was not predicted by the Standard Model, would be a clear sign that we are ready to advancing beyond. But we do not necessarily look for a new particle to break up the Standard Model; as we have said, the model also predicts the behavior and the decay particles. So the search for strange decays could also shed some light.
At the end of this week, scientists from the two large detectors LHC reported that finally revealed one of these decays. Unfortunately, it occurred under conditions that are indistinguishable from those predicted by the Standard Model.
This decay includes a set of particles called neutral B-mesons. B-mesons – a particle that contain heavy Bottom antiquark (or pretty), which weighs almost four times more than the proton. In neutral B-mesons Bottom antiquark is paired with another quark, strange. In fact, they are an exotic version of the neutron, built with heavy quarks.
These particles can decay completely different ways, the most common of which is the production of a single muon (heavy cousin of the electron) and a neutrino. (Quarks and antiquarks in these particles can not be annihilated, as Bottom-antiquark can do this only with the bottom quark). However, there are rare decay mode, which includes the heaviest known particles (top quark, top quark), which leads to the production of muon and antimuon. The standard model predicts that these pathways are quite rare. In the case of anti-Bottom / odd B-meson, we expect that this will happen four times every billion decays. In the case of anti-Bottom / odd B-meson, we expect that this will happen only once in 10 billion decays.
Find something like this is not so simple. You need to
It was expected that neutral B-mesons live long enough to move a few centimeters from the collision of protons; Two of the muon decay of the concrete had to go to the outer boundaries of particle detectors. Scientists both detectors also modeled a lot of B-meson decays and false signals and trained the software to distinguish between them.
A more widespread decay of antibottom / country combinations have been found with a significance level of more than six standard deviations (6σ) and level, which completely fits into the predictions of the Standard Model. Finding antibottom / charming decay gained only 3,2σ – not enough to proclaim the discovery. The level of detection was slightly higher predicted by the Standard Model, but because of the lack of these decays are still fit into the model predictions.
To summarize: there is no indication of the existence of physics beyond the Standard Model, but we know that she must be. And it’s frustrating. Unidentified heavy particles, such as those that might explain dark matter could behave like the top quark and increase the number of decays in this way. Smaller numbers would allow to limit the idea of what additional physics could be expected. Instead, scientists will conduct research on the basis of existing theoretical developments.
Source: hi-news.ru
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