Quark signal

The quark signal (often shortened in quark T) is a Quark, a Elementary particle of the Physique of the particles.

Properties

Like all the quarks, the quark signal is a Fermion. It is about a quark of 3rd generation having a electric Charge of ⅔ E, the most massive quark with a mass of 170,9 ± 1,8 GeV. C ^-2 (almost as far as a Atom of Gold which contains 79 protons, 118 neutrons and 79 electrons is 183,5 GeV. C ^-2).

The antiparticle of the quark signal is the antiquark signal , of electric charge - ⅔ E.

The quark signal interacts mainly via the strong Interaction but can disintegrate only by that of the weak Interaction, almost exclusively in a Boson W and a quark '' bottom ''. The standard Modèle predicts a lifespan to him approximately 10⁻²⁵s, that is to say approximately 20 times less than the order of magnitude of the durations of the strong interactions. Consequently, the quark signal hadronise not.

History

In the years preceding the discovery by the quark signal , one realized that certain measurements of precision of the masses and the couplings of the Boson S vectors of the électrofaible Interaction were very sensitive to the value of the mass of the quark signal . These effects allowed the indirect detection of the quark signal , even if this one could not be produced at the time. These effects led Gerald 'T Hooft and Martinus Veltman to be predicted in 1994 a mass of the quark signal ranging between 145 and 185 GeV (what was worth partly the to them Nobel Prize of physics in 1999).

The quark signal was directly detected on March 2nd, 1995 by the Tevatron of the Fermilab; to date (2007), it is about the only place in the world where the particle can be produced (by thousands in one year), by collisions proton-antiproton with an energy of 1,8 TeV.Il appears in company of its antiparticle and disintegrates immediately in a quark B and a boson W, which disintegrates in its turn in positon and electronic neutrino or muon and muon neutrino.

After the discovery of the other quark of 3rd generation (the quark bottom ) in 1977, an attempt was made to name them “beauty” and “truth”; this use was not maintained and the quark were named bottom and signal .

A rare and very massive particle

Twelve years after its discovery the quark signal is one of the subjects of study of the high-energy physics (physics Terascale ). Why is it so massive? What can it reveal us origins of the mass of the particles? Its mass is connected by mathematics to that of boson of Higgs. The measurement of the mass of the quark signal must be specified (currently accuracy of 1%). It is of course that massive wide does not want to say. Its lifespan does not enable him to take part in containment.

The Broad High-energy particle Collider (LHC, CERN, Switzerland) would have, since 2008, to produce 7 times more quark signal than the Tevatron (by million).

See too

Internal bonds

External bonds

Characteristic of the quark '' signal '' ( Particle Dated Group )

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