Quantum Flavordynamics (Weak Nuclear Force)
- This is basically the decay of a neutron into a proton by the emission of a W- boson.
- The up and down part of quarks is known as their flavour, they can effectively change flavours, in this case it is a down quark into an up quark.
- The W- has to be emitted for the flavour of the quark to change but it does not last long until it decays into an electron (e-) and an anti-electron neutrino (ν
- The W- boson (80GeV) is roughly 80x heavier than the neutron (1GeV) it decayed from meaning that it takes a lot of energy for this to happen so is seen happening inside stars which is basically just a big burning ball of protons.
- The energy for this change can also be borrowed from the vacuum provided the energy is paid back, to do this we refer to Heisenberg’s uncertainty principle:
ΔE x Δt<h
(amount of energy borrowed from vacuum) x (amount of time borrowed for) < Plancks constant
- This shows that the energy debt has to be paid back in 1e-25 seconds in which time the W- boson can move the distance of part a proton before it decays.
- This process is represented by the special unitary matrix two dimensional su(2) in mathematics. It is 2D because it is only changing ups and downs.