I will consider multi-particle production rates in a weakly coupled quantum field theory with a massive elementary Higgs-like scalar. The theory enters the Higgsplosion regime when the n-particle production rates for n>>1 become unsuppressed. I will define what we mean by Higgsplosion and discuss its interpretations and consequences for the theory. In the second half of the talk I will explain how Higgsplosion can be justified using semiclassical methods, and present conclusions.
and the Physics Reports review of the semiclassical method in https://arxiv.org/abs/1810.01722