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A window into
new physics
The standard model of particle physics is extremely successful in describing nature on microscopic scales, yet it is not completely compatible with theories of the macroscopic universe. Researchers in the Recept project are probing the possibility of new physics beyond the standard model by testing a prediction called lepton universality, as Dr Vladimir Gligorov explains. The standard model of particle physics
RECEPT project
is extremely successful at describing nature on microscopic scales, in the sense that it predicts the properties of a wide range of particles. A contradiction emerges when researchers attempt to reconcile the behaviour of these particles as described by the standard model with theories of the macroscopic universe, such as the Big Bang. “There are numerous difficulties, one of which is the problem of dark matter and dark energy. Essentially, on macroscopic cosmological scales, there is a mis-match between the quantity of visible matter and the mass of matter that you would infer from how the galaxies move around. This is why people hypothesise the existence of dark matter, that could exist outside the standard model,” says Dr Vladimir Gligorov. Based at Cern in Geneva, where the Large Hadron Collider (LHC) is located, Dr Gligorov is the Principal Investigator of the Recept project, a collaborative international initiative aiming to test the predictions of the standard model, which could lead to new insights into fundamental physics questions. “Are there particles or forces beyond the standard model which resolves the early universe?” he asks.
This research involves monitoring the behaviour of particles, using data from the LHCb experiment at Cern, and then looking for evidence of new physics. Despite being based at Cern, LHCb is very much a collaborative initiative, bringing together researchers from 16 countries. The data is generated at the
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that have been described, and while it can be difficult to produce these particles in the laboratory, Dr Gligorov says it is still possible to investigate them indirectly. “Even if new particles and forces are too heavy to be produced directly in the laboratory, they could interact virtually with the existing particles that you do produce,” he explains.
“The more you can automate, the more you save your energy for the things that matter. LHCb’s real-time algorithms allow us to infer not only whether an LHC collision looked interesting but also which parts of this collision are most relevant for further analysis.” LHC then distributed across the globe via the worldwide computing grid, essentially a network of data centres in different countries, giving researchers across the world access to important data. “It’s very democractic everybody involved in the collaboration has equal access to all this data,” says Dr Gligorov. A number of new particles and forces have been postulated to explain the inconsistencies
Researchers in the project are using this kind of approach to test a specific prediction of the standard model called lepton universality. “This is very interesting because it’s something that the standard model predicts very precisely,” says Dr Gligorov. “The standard model states that there are six leptons, three of which are charged leptons – the electron, the muon and the tau. There are also three
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