Dispersion relations and finite-size effects in high-energy electroweak interactions

Dispersion relations between the forward elastic scattering amplitude and the total inclusive cross section are shown to hold for (B + L)-violating instanton-induced interactions in the electroweak sector of the Standard Model and in the two-dimensional abelian Higgs model. The result is due to instanton-anti-instanton interactions, which are evaluated in the framework of the dilute instanton approximation. Within that framework finite instanton-size corrections are considered, and it is shown that their effect is not sufficient to suppress multiple gauge vector or Higgs scalar production below the threshold E0≅MH/αW. These processes may be sensitive to deviations from the dilute gas approximation. (orig.)