Rather like players in a football game, particles interact by exchanging balls called gauge bosons. We say that gauge bosons carry forces between interacting particles.
Gauge bosons are themselves particles. Where does the energy come from to create them?
It turns out that in the quantum world, particles can pop in and out of existence as long as they do so quickly enough. The more mass they have, the sooner they must disappear and so the shorter the distance they can travel. This is Heisenbergs Uncertainty Principle in action.
Gauge bosons obey these rules and this determines the kind of forces they transmit.
The bosons that carry the weak force are almost a hundred times more massive than a neutron or proton.
The range of the weak force is about a hundred times less than the distance across an atomic nucleus.