Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: syhprum on 23/09/2016 17:18:04

Title: How strong is the evidence that the Electron is not a composite particle
Post by: syhprum on 23/09/2016 17:18:04
I have read suggestions that the Electron is a composite particle hence my question
Title: Re: How strong is the evidence that the Electron is not a composite particle
Post by: CPT ArkAngel on 23/09/2016 21:12:55
I would say that the best evidence is the electron-positron annihilation resulting in photons. There are some experiments that suggest the fragmentation of the charge and others suggesting the separation of the electron quantum states. Theoretically speaking, the fact that the electron has proper mass, spin, charge and other characteristics is a strong sign of composite elements due to relativity and Mach's principle.
Title: Re: How strong is the evidence that the Electron is not a composite particle
Post by: evan_au on 23/09/2016 23:15:46
High-energy electrons were used to probe the structure of protons and neutrons, and provided the first evidence for quarks. At these energies, there was no evidence for an internal structure of electrons.

So, in a sense, electrons are "more" elementary than protons.

Recent experiments at the LHC at 7 TeV have failed to find oscillations of electrons and muons that would point to an internal structure.

Preons was a theory that tried to find the fundamental components of the known subatomic particles.
It is quite possible (even likely?) that in the extraordinary energies of the big bang, that new particles would have existed which are inaccessible to us in the LHC.

See: https://en.wikipedia.org/wiki/Preon#Motivations
Title: Re: How strong is the evidence that the Electron is not a composite particle
Post by: CPT ArkAngel on 24/09/2016 00:52:17
You are right. Fractional charges are accepted by standards and there is some experiments pointing toward separation of quantum states for the electron but I don't remember where I read this. Certainly electrons are simpler than protons.
Title: Re: How strong is the evidence that the Electron is not a composite particle
Post by: evan_au on 24/09/2016 10:47:18
There is a fractional Hall effect, but this relates to macroscopic systems, not individual charges.
https://en.wikipedia.org/wiki/Fractional_quantum_Hall_effect

Ever since the original oil drop experiment, there have been researchers looking for fractional charges. But I haven't heard of any recent confirmed finds.
https://en.wikipedia.org/wiki/Elementary_charge#Charges_less_than_an_elementary_charge
Title: Re: How strong is the evidence that the Electron is not a composite particle
Post by: CPT ArkAngel on 24/09/2016 14:32:51
The Quarks have 1/3 and 2/3 of a charge.
Title: Re: How strong is the evidence that the Electron is not a composite particle
Post by: JoeBrown on 24/09/2016 20:47:59
You understand the largest machines in the world were built and are operated looking for "stronger" evidence that support THE constitutional concept of atomic structure.

Electrons and "positrons" are the smallest massive objects known to exist for any length.  Anything smaller decay near instantaneously into space (my postulation) and/or become parts of other atomic structures (which seems the general consensus).

There's approximately n*100 different theories, stringing various forces together, that make atomic structures  (n=number of string theorists, also a postulation (or guess, in this instance)).

Many would be happy if there was but one definitive answer to such question.