The New Physics” challenges of the Standard Model




“Physics beyond the Standard Model “covers theoretical developments to explain the shortcomings of the Standard Model, for example, the origin of mass, the phenomenon of neutrino oscillations, asymmetry of matter and antimatter, the nature of dark energy and dark matter, as well as those areas where the standard model is not consistent with GTR: the singularity of the Big Bang and the event horizon of a black hole .

Recent observations presented at the conference Europhysics, dedicated to high-energy particle physics in Grenoble, France, for the top quark (t-quarks, quarks or true) – the heaviest known fundamental particles – can turn the Standard Model.

These collisions at the Tevatron particle accelerator at Fermilab in Batavia, Illinois, suggest that some of the top-quark interactions are based on the as yet unknown force and bind an unknown particle that is not represented among possible in the Standard Model – the top gluon. According to one interpretation, the top quark associated with their negative partner, the antitop, would act as a variation of the elusive Higgs boson, transferring mass to other particles.

Regina Demin, a physicist at the University of Rochester in New York, and his colleagues analyzed data from particle collisions in eight years at the two Tevatron detectors, known as DZero. Top quarks are produced in the collisions, may fly in the direction of the proton or antiproton beam accelerator. Demin and her team discovered that in the direction of the proton beam is sent more particles than predicted by the Standard Model. Physics beyond the Standard Model will have to explain this discrepancy.

According to Nature, a possible new model was proposed by Christopher Hill, Fermilab theorist, who 10 years ago, in 2003, proposed a model of how the top quark and its antiparticle can impart a lot of W-and Z-bosons, particles carrying the weak nuclear force responsible for radioactive decay. The paper presents the analogy of some low-temperature superconductors, materials with no electrical resistance at temperatures a few degrees above absolute zero. In some superconductors form a pair of electrons associated vibrations of the material particles. Bound electrons limit the distance at which the effect is material, the electromagnetic force, an effect that gives the effective mass of photons – particles of light, carriers of the long-range electromagnetic force, which normally have no weight.

Likewise, Hill suggested that the top quark and antitop quarks can pair throughout the cosmos, being bound by the power that is transferred as yet unknown particles – top-gluons.

“It was as if the entire universe acts as a superconductor,” – says physicist Matthew Schwartz of Harvard University in Cambridge, Massachusetts, who posted the survey online. Schwartz believes that Hill’s model can also explain the asymmetry of the top quark observed at the Tevatron.

The theory, according to Nature, explains the origin of mass in the universe team effort, first, top-gluon, which can interact with both top quark and antitop, giving them the weight as well as strength, the bonding electrons in superconductors, gives the next photons weight. Second, a pair of top-antitop itself could explain the origin of mass in the rest of the universe, including, for example, W-and Z-bosons, carriers of the weak nuclear force. The relatively large mass, acquired the W-and Z-particles limits the range of the weak force, breaking the symmetry between this force and the long-range electromagnetic force, which, according to the theorists, there is a very high energies.

Asymmetry that is observed on the DZero, are not enough to bring proof of the existence of top-gluon, but there are other findings that independent researchers at the other detector Tevatron, CDF.

Schwartz’s theory is easy to check. Top-gluon has an estimated energy in the range of the world’s most powerful particle accelerator – the Large Hadron Collider – so can be found throughout the year, according to Schwartz. Dmitri Denisov, a spokesman for DZero, agrees that the results agree with those of other experiments. However, warns that the standard model of particle physics is so complex that it is difficult to be described by equations. The observed asymmetry of the top quark is compared with an imperfect substitute for the present standard model, and the supposed discrepancy may well be due to the uncertainty of the model.

A team of researchers working with the detector LHC Compact Muon Solenoid, reported on July 21 that he sees no evidence of asymmetry of the top quark. But Schwartz notes that the asymmetry of the LHC see more complex than at the Tevatron because the LHC starts with an initially symmetric configuration: the colliding proton beam to the other beam of protons. So it’s hard to make out, pick a top quark is one of the directions.
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