This manifests itself through nuclear decay,
(7.7) |
The standard coupling for this theory is called the Fermi coupling, , after its discoverer. After the theory was introduced it was discovered that there were physical particles that mediate the weak force, the and the bosons. These are very heavy particles (their mass is about 80 times the proton mass!), which is why they have such a small range – fluctuations where I need to create that much mass are rare. The bosons are charged, and the boson is neutral. The typical decay referred to above is mediated by a boson as can be seen in the Feynman diagram figure 7.1 . The reason for this choice is that it conserves charge at each point (the charge of a proton and a is zero, the charge of an electron and a neutrino is -1, the same as that of a ).