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welatiger
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Is the discovery of Higgs boson contradict the Compositeness model and the preon existence ?!
welatiger said:Is the discovery of Higgs boson contradict the Compositeness model and the preon existence ?!
mathman said:The Higgs boson was considered part of the Standard Model, so nothing has changed.
Note: Your sentence is unclear - could you define the terms?
To be honest, I never heard of the compositeness model.welatiger said:You Know that in the compositeness model, the spontaneous symmetry breaking is due to the preon but not the Higgs boson.
mathman said:To be honest, I never heard of the compositeness model.
welatiger said:Dear all
The compositness model was first proposed by A.Salam 1970, mainly due to the hairechary problem, you can read about it in wiki pages.
arivero said:Do you mean, you have never heard of _any_ compositeness model? Fascinating.
It is not just Wikipedia. It is the overwhelming consensus of the physics community that there is no evidence for compositeness of leptons and quarks.arivero said:Perhaps the point is if there is someone here in the forum.who is interested on composites. If nobody can comment beyond the wikipedia, it is probably not worth to raise the topic here.
mathman said:It is not just Wikipedia. It is the overwhelming consensus of the physics community that there is no evidence for compositeness of leptons and quarks
DimReg said:If a particle is composite, it has to have a finite radius
DimReg said:I'm not sure how I would rigorously prove this for a general case. However, as a model you can use the infinite spherical well potential, so inside the radius the particle is free to move but a very strong restoring force holds the particle in if it tries to leave that radius (also, you do the usual trick of reducing a two body problem to a one body problem). The ground state energy (actually all energy levels) goes as r^-2, where r is the radius of the well. Clearly this diverges when r goes to 0.
But most importantly, there isn't some derived rule that says that the string has to be an extended object, it is the postulated form a particle takes, and thus by construction the string in string theory is extended.
There is currently no direct experimental evidence for the compositeness of quarks and leptons. However, theoretical models such as the Standard Model of particle physics suggest that these particles may be made up of even smaller building blocks called subquarks or preons.
Observing the compositeness of quarks and leptons would require experiments with extremely high energies, which are currently beyond our technological capabilities. However, indirect evidence for compositeness can be obtained through precision measurements of particle properties and interactions.
If quarks and leptons are found to be composite particles, it would revolutionize our understanding of the fundamental building blocks of matter. It would also have implications for the development of new theories and models in particle physics.
Yes, there are alternative theories that suggest quarks and leptons are not composite particles. Some theories propose that they may be made up of smaller, indivisible units called primons, while others suggest they may be fundamental particles with no internal structure.
Scientists are currently conducting experiments at particle accelerators such as the Large Hadron Collider (LHC) to search for evidence of compositeness. These experiments involve studying the properties and interactions of particles at high energies to look for any deviations from the predictions of the Standard Model.