Down Quark: Composed of Up Quark and Electron?

[daisey]

TL;DR

Is the Down Quark an Elementary Particle or a composition of other Elementary Particles?

I have no formal Physics training, just what I've read over time. And I've always read and understood that Quarks are Elementary Particles. I was reading on the web today where someone who seemed to know what he was talking about stated that Down Quarks are not really elementary particles, but instead composed of an Up Quark and an Electron. Is this true, maybe possible, or hogwash?

The exact quote: "...the down quark is not an elementary particle, it is composed of an up quark and an electron. When the electron is released from the one of the down quarks, it leaves the up quark."

 

[phinds]

I was reading on the web today ...

That has all the credence here on PF as "some guy on a bus told me ... ".

The down quark is one of the elementary particles listed in the Standard Model (which is VERY easy to verify online)

 

[Orodruin]

Summary:: Is the Down Quark an Elementary Particle or a composition of other Elementary Particles?

I was reading on the web today

I read somewhere is not a proper reference. Where? Please provide links.

That said, the down quark is elementary in the standard model of particle physics.

Now, that does not necessarily mean the person was wrong. We have no means of knowing exactly what was said - just your interpretation of what was said. This is why proper reference is important.

 

[daisey]

I read somewhere is not a proper reference. Where? Please provide links.

That said, the down quark is elementary in the standard model of particle physics.

Now, that does not necessarily mean the person was wrong. We have no means of knowing exactly what was said - just your interpretation of what was said. This is why proper reference is important.

That has all the credence here on PF as "some guy on a bus told me ... ".

The down quark is one of the elementary particles listed in the Standard Model (which is VERY easy to verify online)

Orodruin: Thanks for asking. Let me explain in detail if you prefer. I was researching why there are sometimes more neutrons than protons in a nucleus (such as Potassium). The statement I refer to was embedded in an answer.

Here is a link to the article, which I didn't post at first because some forums don't approve of links to external sites: https://www.quora.com/How-does-oversupply-of-neutral-neutrons-make-an-atom-unstable

For some reason on that Quora site you get answers from different people every time you visit. But here is the full text of his answer (copy and paste). I emboldened the text in question.

[Moderator Note -- Body of that Quora answer deleted because it contained personal information]

 

[Gaussian97]

The answer to your question reveals another level of detail provided by Gordon’s Theory of Everything adding to our current understanding of physics. Note that Gordon’s Theory of Everything does not change our current physics… It just gives a better model of how our current physics works.

My advice: If you ever read something like this, run.

 

[daisey]

My advice: If you ever read something like this, run.

I guess that means the answer to my original question is: Hogwash. I thought that might be the case. I did visit Wikipedia before coming here, and it still said it was an Elementary Particle. But I thought maybe it was something newly discovered. Apparently not. Thanks for your help!

 

[Orodruin]

M.S. Biomedical Engineering

So, no actual physics credibility.

Firstname X Surname

Surname’s Theory of Everything

... naming his personal theory after himself ...

Note that Surname’s Theory of Everything does not change our current physics… It just gives a better model of how our current physics works.

Yes it does ... and it shows that he clearly understands absolutely zero of how our current physics models actually work.

He also proposes a model that according to himself makes no new testable predictions so it cannot be distinguished. That is not actually a new model.

Even if that was not the case it would not be new. Every single person that has studied physics has at one point or the other had that thought. We just continued to learn how physics actually work and why it cannot be.

I guess that means the answer to my original question is: Hogwash.

Complete and utter horse manure.

Now, that said, posting the link would have sufficed. There is no call for copy pasting personal information about the poster.

[Moderator Note -- Body of that Quora answer deleted because it contained personal information]

 

[berkeman]

Thread is closed temporarily for Moderation...

 

[berkeman]

Thread reopened after deleting the personal information from the Quora link.

 

[SBoh]

It reminds me Heisenberg's neutron model, which assumed neutron as composite state of proton and electron. Of course, the model was failed by his own the uncertainty principle. Energy of beta decay electrons is too low compared to required energy to bind electron in size of neutron. (dx is very small, so dp should be very large). It is same for your question about down quark as up quark plus electron. It is physically not possible.

For point if down quark is composite particle, I would say that we do not know yet.
Up to energy scale we have studied, quarks behave as they are elementary particles (no inner structure).
There are several models which suggest inner structure of quarks and leptons.
But, it is not like down quark as up quark plus electron.
Those models expect smaller elementary particles, and they form quarks and leptons.
So, in this kind of models, there could be excited states of leptons and quarks at very high energy scale.
If we discover those excited state particles, the model could be next Standard Model.
However, there is no observation so far.

 

[jtbell]

Models involving quarks and leptons being "made out of" preons or rishons go back to when I was in grad school in the late 1970s to early 1980s. Nothing has come of them as far as I know, as far as experimental evidence is concerned.

 

[PeroK]

I guess that means the answer to my original question is: Hogwash. I thought that might be the case. I did visit Wikipedia before coming here, and it still said it was an Elementary Particle. But I thought maybe it was something newly discovered. Apparently not. Thanks for your help!

There's an interesting psychology with such people. Imagine two children learning to play chess and one of them discovers something like a Knight fork. They imagine that no one before them could possibly have thought of something so clever and they must already be one of the best players in the world.

It's equally absurd to think - especially in this day and age with the volume of physics knowledge out there - that a few simple ideas have never been thought of.

On the contrary, the posts above show that all these ideas- dating back to Heisenberg - have been analysed and tested to death and what remains in the standard model has been through a truly enormous theoretical and experimental mill.

 

[daisey]

First of all, thanks to PeroK, jtbell, and Sboh for their thoughtful answers. Unfortunately over my 12 years as a member I've noticed most responses on this forum are NOT thoughtful, so this will be my last post. It appears it's not possible to delete an account here.

Like I stated in my original question, I know very little about physics, and most members here have forgotten more about Physics than I have ever learned. What little I do know has been gathered mostly from reading books and conversation here. Yes, I am aware the Standard Model is currently our best understanding of Physics. And when I read this author's statement about the Down Quark being an Up Quark + Electron, I knew that disagreed with what I learned of the Standard Model, but wondered if this was new discovery, a wild theory, or absolutely 100% impossible.

I try to never dismiss something just because (like others here apparently do) it doesn't fit with what's in my textbook about the Standard Model. I suspect the designers of those little objects flying around US Warships which have been in the news lately would say that our Standard Model is AT BEST incomplete. And with all due respect, some of the other members here who might be considered by their human peers to be knowledgeable and in fact idiots. At least I can admit that I am.