A couple of questions about the weak force.

[Juxtaroberto]

Is the weak force responsible for all radioactive decay, or just beta? If it is also responsible for alpha and gamma, how does it work? If not, what causes the other two?

(Also, related to this, I know that alpha radiation is two protons and two neutrons being expelled from the nucleus, and that beta is either an electron or a positron being expelled from either a neutron or a proton, respectively (or more aptly, one of their quarks), so what exactly is gamma radiation? It is a high energy photon, but being expelled from where, and by what mechanism?)

How is it that the weak force powers the sun? I've heard this repeated many times but I don't think I've found an explanation for it. If the sun is powered by fusion, where does the weak force come in? I think it's the reason why the sun puts out neutrinos, I remember neutrinos in the Feynman diagrams regarding the weak force, but how exactly does it all work?

Sorry for all the questions, and thanks in advance.

 

[Juxtaroberto]

No, nothing? Is it in the wrong section? I figured since I was asking the question from a quantum point of view, i.e. the role of the W+, W-, and Z bosons, that it belonged here.

 

[Matterwave]

The strong force mediates some reactions, but pretty much anything where you have leptons involved, that's a weak force interaction I believe. So beta decay is weak-force, and proton-proton fusion is weak force because anti-neutrinos and positrons are created.

Gamma decay is just when a nucleus goes to a lower energy state and emits a high energy gamma-ray. This can result from the nucleus breaking apart, e.g. fission.

My knowledge of this is quite limited though, someone else can probably answer better.

 

[Avodyne]

The weak force is responsible for beta decay, the strong force together with the electromagnetic force for alpha decay, and the electromagnetic force for gamma decay.

 

[Parlyne]

In Hydrogen fusion, it is necessary to transmute protons into neutrons. Any process in which this occurs necessarily involves the weak force.

 

[Juxtaroberto]

The weak force is responsible for beta decay, the strong force together with the electromagnetic force for alpha decay, and the electromagnetic force for gamma decay.

Thanks! In the case of beta decay, I know that one of the quarks, with the help of a mediating W boson, decays and releases an electron or positron. What exactly is the process that causes alpha decay? I'm assuming that it happens because the nucleus is large enough that the EM overpowers the strong, which is trying to keep the nucleus together? Is there anything more to it?

And in gamma, does the photon comes from the nucleus, not one of the electrons? When this photon is released, what exactly happens to the proton/neutron that releases it? Can you give a real life example? I'm sorry to ask so many questions, I'm just really curious about this.

In Hydrogen fusion, it is necessary to transmute protons into neutrons. Any process in which this occurs necessarily involves the weak force.

I see what you're saying. Just like that other poster said, whenever leptons are created, the weak force is involved?

 

[dextercioby]

Just like that other poster said, whenever leptons are created, the weak force is involved?

Yes, or more generally the electroweak interaction.

 

[jtbell]

Except that particle-antiparticle pair production (e.g. electron plus positron) proceeds via the electromagnetic interaction.

 

[Parlyne]

Except that particle-antiparticle pair production (e.g. electron plus positron) proceeds via the electromagnetic interaction.

Yeah, it's better to say that any process that produces a single charged lepton must proceed through the weak force.