Electron - Up Quark Interactions

[metastable]

I have some questions about forces acting between electrons (-1 charge) and up quarks (+2/3 charge).

I did attempt to make sure its a valid line of questioning by privately asking mfb...

in general asking about quark compositeness is no problem. It is an active field of research.

& I'll ask all the questions up front so as not to annoy the moderators with my follow up questions.

So here goes:

Is there an attractive force acting between up quarks (+2/3 charge) and electrons (-1 charge)?

If so, is it possible anywhere in the universe to prepare or observe any type of stable or short lived metastable exotic atom composed of an up quark and an electron (along the lines of positronium, in the sense of being short lived system between oppositely charged particles).

Is it possible to prepare or observe any type of stable or short lived metastable exotic atom involving multiple up quarks and electrons, specifically with 4 up quarks and 3 electrons (+2/3) + (+2/3) + (+2/3) + (+2/3) + (-1) + (-1) + (-1) = (-1/3 charge), and how would such a system's properties be expected to differ from the properties of a down quark (-1/3 charge, 1/2 spin)? Or with 3 up quarks and 2 electrons (+2/3) + (+2/3) + (+2/3) + (-1) + (-1) = (0 charge), and how would such a system's properties be expected to differ from the properties of a neutrino (0 charge, 1/2 spin)?

Would it be possible to bind such a system with other systems (analogously to binding metastable positronium with hydrogen to form positronium hydride).

Finally, in this article about the so-called "proton spin crisis..." are those results thought to indicate more than a total of 3 particles with spin in a proton?

https://en.wikipedia.org/wiki/Proton_spin_crisis

"The proton spin crisis (sometimes called the "proton spin puzzle") is a theoretical crisis precipitated by an experiment in 1987[1] which tried to determine the spin configuration of the proton. The experiment was carried out by the European Muon Collaboration (EMC).[2]

Physicists expected that the quarks carry all the proton spin. However, not only was the total proton spin carried by quarks far smaller than 100%, these results were consistent with almost zero (4–24%[3]) proton spin being carried by quarks. This surprising and puzzling result was termed the "proton spin crisis".[4] The problem is considered one of the important unsolved problems in physics.[5]"

 

[Orodruin]

Is there an attractive force acting between up quarks (+2/3 charge) and electrons (-1 charge)?

There are two interactions being mediated between an up quark and an electron. The electromagnetic attractive force and the weak interactions.

If so, is it possible anywhere in the universe to prepare or observe any type of stable or short lived metastable exotic atom composed of an up quark and an electron (along the lines of positronium, in the sense of being short lived system between oppositely charged particles).

No. That would break quark confinement. The overall state would have a non-trivial QCD colour.

specifically with 4 up quarks and 3 electrons

Again, that would break quark confinement by giving you a non-trivial QCD colour state.