I've most often seen the statement that the annihilation of a particle and its antiparticle occurs when they 'collide' with one another. So in other words when they get very close to one another right?
How close do they need to be (for annihilation to occur)?
Charged normal/anti particles will naturally attract one another and lead to such a collision, but I imagine that non-charged pairs could be in some manner coaxed within close proximity - and short of a collision. In this situation can 'annihilation' be moderated to control the rate at which the energy is released, or does annihilation always occur as a sudden and full release of energy?
I did find a question very similar to my question here:
But it doesn't directly answer my main question nor the question of whether the annihilation event can be moderated.