The simple explanation is based upon-(Generalized) Pauli-Principle (GPP), which requires that the ( overall) wave-function must be anti-symmetric for two-identical Fermions under exchange of their relevant quantum-numbers. It must be noted that 'proton' and 'neutron' are not distinct Fermions in strong-interaction due to Iso-spin-symmetry, but correspond to two rotated-states of the same object, the nucleon and further that strong-nuclear-force is invariant under such rotation in the Iso-spin-space in exact analogy with ordinary-spin-angular momentum. Hence, under simultaneous exchange of space-, spin- and I-spin labels, the two nucleon-state must be anti-symmetric. This condition is satified for the n-p-bound state ('deuteron') because the eigen-function in iso-spin space could be anti-symmetric ('iso-singlet-state') even though the space-spin-part of the wave-function is symmetric (Spin-triplet, S-state). (Recall that for proton, the z-component of I-spin is +(1/2), while that for the neutron is -(1/2). Further, there is no charged-partner of the deuteron, which enforces its iso-singlet-nature.). However, |p,p> or the |n,n> state is symmetric under exchange of I-spin quantum-numbers as these belong to the Iso-triplet case , which leads to the violation of the GPP even though the space-spin-part of the wave-function is symmetric.

In the context of nuclear-bound states, the quark-substructure of the nucleons may be irrelevant at the energy-scale of nucleon-binding with B.E.~ few MEV. Furthermore, e.m.interactions can be neglected compared to the strong-force between the nucleons.

Dear Ali,

You would find it easier to understand if you took into account that protons and neutrons are not elementary particles, but systems of elementary particles, just like the solar system is not a celestial body, but a system of celestial bodies.

It was experimentally confirmed at the SLAC accelerator in the 1960's that protons and neutrons have an inner structure comprising 3 scatterable massive and charged elementary particles named up quark and down quark (uud for the proton and udd for the neutron).

It is these charged elementary particles that interact in atomic nuclei. If you examine the ratio of their inner charged particles, it will become obvious why combinations like pp or nn cannot exist.

These 2 papers may help you understand their inner structures. Most formal references in the reference sections can be accessed:

https://www.omicsonline.org/open-access/the-last-challenge-of-modern-physics-2090-0902-1000217.pdf

http://ijerd.com/paper/vol8-issue1/B08011033.pdf

Many thanks for the prompt reply. I know what really there are in nuclear structure, I mean quarks.

u = 3/2+

d= 1/2 -

But ...

Do u mean something like coulomb repulsion ? right ?

If u mean coulomb repulsion, I think its not true. Since the order of magnitude of strong and weak nuclear force is much larger than coulomb force.

What say you ?

Dear Ali,

I mean a combination Coulomb force and magnetic predominantly repulsive interaction.

If you check with the calculations in this paper, you will see that Coulomb force attraction at inner quarks distances within nucleons is of the right magnitude. You can do the calculations yourself:

http://ijerd.com/paper/vol7-issue9/E0709029053.pdf

As for the predominantly repulsive interaction, its mechanics is summarily described in this paper between the electron and the hydrogen atom nucleus (a proton). The same mechanics is at play within the proton between the quarks and their carrier-photons:

https://www.omicsonline.org/open-access/gravitation-quantum-mechanics-and-the-least-action-electromagneticequilibrium-states-2329-6542-1000152.pdf

Actually, it seems that the quarks fall into a least action electromagnetic equilibrium resonance state between Coulomb force attraction and counteracting predominantly repulsive magnetic interaction.

I have another paper coming up in a few months that will explain in more details.

Best Regards

André

The simple explanation is based upon-(Generalized) Pauli-Principle (GPP), which requires that the ( overall) wave-function must be anti-symmetric for two-identical Fermions under exchange of their relevant quantum-numbers. It must be noted that 'proton' and 'neutron' are not distinct Fermions in strong-interaction due to Iso-spin-symmetry, but correspond to two rotated-states of the same object, the nucleon and further that strong-nuclear-force is invariant under such rotation in the Iso-spin-space in exact analogy with ordinary-spin-angular momentum. Hence, under simultaneous exchange of space-, spin- and I-spin labels, the two nucleon-state must be anti-symmetric. This condition is satified for the n-p-bound state ('deuteron') because the eigen-function in iso-spin space could be anti-symmetric ('iso-singlet-state') even though the space-spin-part of the wave-function is symmetric (Spin-triplet, S-state). (Recall that for proton, the z-component of I-spin is +(1/2), while that for the neutron is -(1/2). Further, there is no charged-partner of the deuteron, which enforces its iso-singlet-nature.). However, |p,p> or the |n,n> state is symmetric under exchange of I-spin quantum-numbers as these belong to the Iso-triplet case , which leads to the violation of the GPP even though the space-spin-part of the wave-function is symmetric.

In the context of nuclear-bound states, the quark-substructure of the nucleons may be irrelevant at the energy-scale of nucleon-binding with B.E.~ few MEV. Furthermore, e.m.interactions can be neglected compared to the strong-force between the nucleons.

Dear André,

Many thanks.

Cool...

I'll wait for your paper, and im going to read both paper that u mentioned ,for now :)

Dear Bimal Mahapatra,

In the first place, Thanks for the prompt reply.

Exactly u right . Im agreed with u, But Mr Michaud has another idea, i have to read those paper first...

Dear Ali,

You should not be disappointed with the coming paper.

Its title will be "The Hydrogen Atom Fundamental Resonance States". It is meant to explain how Schrödinger's wave function can be reconciled with electromagnetism and also how wave functions could be (and should be) developed to describe the inner resonance states inside nucleons in a possibly more logical way than QCD. A work in progress.

Best Regards

André