zefram c,
The following partial reply is based on Weak Interactions from chapter 7 of Donald H. Perkins' Introduction to High Energy Physics, 4th edition, starting at page 194.
I begin this reply by first giving some introduction to the concepts of H+ and H-.
From H+/H- theory: all fermions are made of odd number of H+/H-. All bosons are made of even number H+/H-. The number of H+/H- are not necessarily equal. If they are equal, the results are neutrally charged particles. Regardless of their LOE, each H+ or H- has an absolute value for charge as 1/6.
The electron is made of 7H- and 1H+. The muon and tau leptons are made of higher LOE of H+/H-.
The neutrino is made of 1H+ and 1H-. Likewise, Higher LOEs for muon-neutrino and tau-neutrino.
The up quark is made of 5H+ and 1H-. Likewise, Higher LOEs for charm and top)
The down quark is made of 1H+ and 3H-. Likewise, Higher LOEs for strange and bottom.
The vacuum is made of even and odd H+/H- of different LOEs of which energy can be borrowed for a short time in a given interaction.
The tree diagram for vacuum fluctuation is (positron, 7H+1H-) + (electron, 1H+7H-)-->(2 photons or 1 Z0, 8H+8H-). Other tree diagrams are the following:
(7H+1H-) + (W-, 2H+8H-) --> (9H+9H-), a higher LOE of neutrino. But (9H+9H-) is an excited state of neutrino, so (8H+8H-) can be returned to the vacuum, to get a stable neutrino (1H+1H-). Higher LOE means more mass or more energy.
For the weak charged current interaction: (1H+1H-) + (neutron, 7H+7H-) -->(intermediate, (W+, 8H+2H-) + (6H-)) + (borrow from vacuum, 4H+4H-) --> (intermediate, 12H+12H-) --> (proton, 11H+5H-) + (electron, 1H+7H-)
For the weak neutral current interaction: (1H+1H-) + (7H+7H-) --> (Z0, 8H+8H-) --> (1H+1H-) + (7H+7H-).