## Revisiting soliton contributions to perturbative amplitudes

It is often said that soliton contributions to perturbative processes in QFT are exponentially suppressed by a form-factor. We will provide a derivation of this form-factor by studying the soliton-antisoliton pair-production amplitude. This reduces to the calculation of a matrix element in the quantum mechanics on the soliton moduli space. We will investigate the conditions under which the latter leads to exponential suppression. We will also discuss how it suggests that the instanton-solitons of N = 2 SYM in 5D will not be suppressed and the implications for its relation to the (2,0) theory in 6D.