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dangerbird
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was it something that was figured out solely through atom smashers?
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Lok said:The latest experiment I've read about was deep inelastic scattering, using high energy electrons to study the nucleons. The results were as predicted: 3 particles(quarks), signs of internal structure among the particles. and the fractional charge predicted by the quark theories.
It's called "Gross-Llewellyn-Smith rum rule". You get it from the integral of the sum of the structure functions [itex]F_3[/itex] for neutrino and antineutrino.malawi_glenn said:one can not find that there are 3 quarks in a nucleon
Lok said:Wikipedia: In principle, some baryons could be composed of further quark-antiquark pairs in addition to the three quarks (or antiquarks) that make up basic baryons. Baryons containing a single additional quark-antiquark pair are called pentaquarks. Evidence for these states was claimed by several experiments in the early 2000s, though this has since been refuted. No evidence of baryon states with even more quark-antiquark pairs has been found.
I never heard of more than 3 quarks in a baryon, even though some theories predict them at relatively low energy levels, observable in nowadays experiments. I'm willing to wait for results in this direction, but i am skeptical about it.
The quarks that contribute to the quantum numbers of the hadrons are called valence quarks. Hadrons also contain virtual quark–antiquark pairs, known as sea quarks, originating from the gluons' strong interaction field.
The putative pentaquarks, as their name suggest, have 5 valence quarks (or 4 quarks, plus one antiquark). The concept of "valence quark is not limited to "naive quark models". The structure function I was referring to above have certainly little to do with "naive quark models". There is nothing wrong in principle with describing a hadron as a tower of Fock states, the valence part of which determines its quantum numbers. The reason people think of this picture in terms of "naive quark models" is only because in is difficult to calculate in practice.malawi_glenn said:again, you are only referring to the naive quark model, which treats the so called "valence quarks". You can read about the sea-quarks in any book on particle physics.
Lok said:We do still talk about theory here. If not Thanks for the input.
goooooooodmalawi_glenn said:why should they come from the moon? :-S
One simply produced muons by colliding particles at a target, and then filtered what was produced. One can use magnetic fields etc to pick up those particles that are interesting for ones purpose.
http://www.isis.rl.ac.uk/MUONS/index.htm?content_area=/MUONS/muonsIntro/whatMuons/whatMuons.htm&side_nav=/MUONS/muonsSideNav.htm&
Scientists use a variety of methods to study the structure of the nucleus, including electron microscopy, X-ray crystallography, and nuclear magnetic resonance spectroscopy.
The current understanding is that the nucleus is composed of protons and neutrons, which are held together by strong nuclear forces. These particles are further divided into quarks, which are believed to be the fundamental building blocks of matter.
Scientists use a technique called mass spectrometry to determine the number of protons and neutrons in a nucleus. This involves ionizing the nucleus and measuring the mass-to-charge ratio of the resulting particles.
Scientists use a combination of experimental data and theoretical models to determine the arrangement of protons and neutrons within the nucleus. This includes the use of nuclear models, such as the shell model and the liquid drop model.
Over the years, scientists have made significant advancements in understanding the structure of the nucleus. This includes the discovery of new subatomic particles, such as quarks and gluons, and the development of new experimental techniques, such as particle accelerators and detectors.