How Does Nucleon Shape Relate to Quark Number and Electric Quadrupole Moment?

[jk22]

If a nucleon is let say made of 3 quarks then they rather build a triangle than a tetrahedron, so they are flat ? Why is there not 4 quarks ?

 

[mfb]

They don't have any particular arrangement. They don't even have a well-defined position in a proton (except from "everywhere in the proton", if you prefer that view).

4 quarks cannot form a color-neutral hadron. Two quarks and two antiquarks can, you get short-living tetraquarks in that case.

 

[snorkack]

A proton and electron in a protium atom are on a line at any moment, except when the electron is at the cusp. But they do not have a preferred spatial direction at their ground state of 1s - over time, the electron can be in any direction. The He nucleus and two electrons are always on a flat triangle, but in their ground state (both 1s) do not have a preferred spatial orientation either.

 

[PeroK]

If a nucleon is let say made of 3 quarks then they rather build a triangle than a tetrahedron, so they are flat ? Why is there not 4 quarks ?

You could try this.

https://www.physicsforums.com/insights/a-beginners-guide-to-baryons/

 

[snorkack]

Do spin 1/2 baryons such as nucleons possesses electric quadrupole moment?
Do spin 3/2 baryons such as omega hyperon and delta resonances possesses electric quadrupole moment?