Beta decay and the sun

[call me greg]

First of all, in beta decay (+ or -) I know it emites an electron/positron and an electron antineutrino/neutrino, however I noticed on some A-level work one of the bosons was involved with the beta decay, I was wondering what role it plays in the decay process...

 

Also my physics teacher said "beta+ decay doesn't occur in nature", and I questioned that thinking about what happens in the sun when two protons fuse and will surely undergo beta+ decay to create deuterium (which would then allow a proton to fuse to make helium-3, or deuterium to make helium-4), I'm sure I'm right in thinking his statement needs reworking?

[mathematic]

Strictly speaking he is correct. The two protons don't fuse to He2, which would then decay. It is one reaction.

 

 

 

http://en.wikipedia.org/wiki/Proton%E2%80%93proton_chain_reaction

[RichIsnang]

Beta decay is mediated by the weak force, so it involves bosons.

And doesn't sodium 22 undergo beta + decay? It definately emits positrons.

[swansont]

Also my physics teacher said "beta+ decay doesn't occur in nature"

 

Your physics teacher is mistaken, but probably not egregiously so. Most of the processes we see are beta-, because naturally occurring heavy isotopes which alpha-decay leave daughters that are neutron-rich, so they will eventually leave you with beta- decays. "Found in nature" is a somewhat ambiguous qualifier. Found on earth, or anywhere in the universe? Found on its own, or can there be a natural process that produces them, even if they decay quickly?

 

But K-40 undergoes beta+ decays, although electron capture is more likely. It also undergoes beta-, so it hits the beta trifecta.

http://prola.aps.org/abstract/PR/v126/i5/p1818_1

 

N-13 also beta+ decays, and in present in the fusion cycle. I imagine it's also produced by cosmic rays, since the production method is a proton hitting O-16 and knocking out an alpha

http://en.wikipedia.org/wiki/Nitrogen-13

 

I also imagine a lot of beta+ decayers are produced in a supernova.