Comment by dschleef

This article goes to great contortions to avoid talking about electroweak theory or spontaneous symmetry breaking, both of which have decent Wikipedia articles, and are crucial to understanding what's going on here. Spontaneous symmetry breaking of the electroweak interaction and the Higgs mechanism is the reason _why_ the W and Z have mass. The article throws up a "who knows?" at this. When you write down the field equations for a massive boson field, you get an additional m^2 term in the denominator of the propagator, which contributes a e^(-r/m) term to the interaction force at low energy, such as the decay of a neutron or a weak-mediated nuclear decay.

Is there an ELI5 version of this? I think the article tries, and it's always cool to see physics described from a different vantage point.

My ELI5 version would be: fields with a massive gauge boson are "dragged down" in energy by the mass of the boson, so interactions propagate as if they have negative energy. What does a negative energy wave propagation look like? Similar negative energy wave propagations in physics are evanescent waves and electron tunneling, both of which have exponential drop-off terms, so it makes sense to see an exponential factor in massive boson interactions.