  We study the effect of final state interactions at the threshold of Higgs
boson pair production in the Glashow-Weinberg-Salam model. We consider three
major processes of the pair production in the model: lepton pair annihilation,
ZZ fusion, and WW fusion. We find that the corrections caused by the effect for
these processes are markedly different. According to our results, the effect
can cause non-negligible corrections to the cross sections for lepton pair
annihilation and small corrections for ZZ fusion, and this effect is negligible
for WW fusion.
