Choice of dispersion relation to calculate the QCD correction to Γ(H→${\mathit{l}}^{+}$${\mathit{l}}^{\mathrm{-}}$)

We use the operator product expansion of quark vacuum polarization functions to show that the dispersion relation of Kniehl and Sirlin will yield the correct result to all orders in ${\mathrm{\alpha }}_{\mathit{s}}$ when applied to the QCD correction to the leptonic decay width of the Higgs boson. i© 1996 The American Physical Society.