Undergrad When is weak interaction a force?

[snorkack]

When is weak interaction actually a force, rather than merely cause of some process?
Not in beta decay - it is process.

There are simpler weak interaction processes around: elastic scatterings that change only momentum but not taste. But those are still processes and are over as the particles depart.
Electrons are stuck in atoms for a long time. They undergo electron capture - but the eventual capture is still a process, and over as the neutrino departs.

But an electron should also undergo elastic scattering from nucleus by weak force.
The electron also undergoes elastic scattering from nucleus by the far stronger electromagnetic force.
But weak force has different symmetries and selection rules! Not only does weak force operate differently on left and right helicity particles - which electromagnetic force cannot - but weak force operates only on left helicity particles.

So consider a s electron in an atom. The type of orbitals that for part of orbit enter the nucleus into weak force range
No orbital angular momentum, so no spin-orbit interaction.

Suppose the nucleus also has no spin - neutrons and protons paired - so no interaction of electron spin with nuclear spin.
How will the weak force distort the orbitals? What kind of asymmetry does it introduce into the orbital that does not follow from the electromanetic potetial?

 

[mfb]

There are simpler weak interaction processes around: elastic scatterings that change only momentum but not taste. But those are still processes and are over as the particles depart.

How is that fundamentally different to elastic electron/electron scattering for example?

I think you are just unnecessarily trying to make your own definitions of words.

 

[snorkack]

How is that fundamentally different to elastic electron/electron scattering for example?

I think you are just unnecessarily trying to make your own definitions of words.

In case of elastic electromagnetic scattering, you cannot easily detect whether the force was repulsive or attractive. Because the true location of electron suffers Heisenberg uncertainty, if you see an electron deflected to the right, you cannot tell apart an electron that passed to the right of an electron and was repelled from an electron that passed to the left of a positron and was attracted.
In case of electrostatic interaction, it is strong enough to bind bound systems. Confirming the force is attractive.

But there are no known systems bound by weak force.
So, how can the effects of weak force be resolved?
Observe systems bound by other forces, and examine them for perturbations caused by weak force.

So what are the perturbations of atoms caused by weak interaction between electron and nucleus?

 

[mfb]

Because the true location of electron suffers Heisenberg uncertainty, if you see an electron deflected to the right, you cannot tell apart an electron that passed to the right of an electron and was repelled from an electron that passed to the left of a positron and was attracted.

You can, by looking for the electron or positron recoil.

But there are no known systems bound by weak force.

So what?

So what are the perturbations of atoms caused by weak interaction between electron and nucleus?

There is an extremely small impact on the energy levels from Z exchange. I'm not sure if that has been measured. It also means atoms are not perfectly parity invariant. Here is a discussion.

 

[ORF]

Hi,

So what are the perturbations of atoms caused by weak interaction between electron and nucleus?

The range of the weak interaction is shorter than the size of an atom (although s-orbitals overlap the nucleus...)

Regards,
ORF