Leading-logarithmic threshold resummation of Higgs production in gluon fusion at next-to-leading power

We sum the leading logarithms $$ {\alpha}_s^n{\ln}^{2n-1}\left(1-z\right) $$, n = 1, 2, . . . , near the kinematic threshold $$ z={m}_H^2/\hat{s}\to 1 $$ at next-to-leading power in the expansion in (1 − z) for Higgs production in gluon fusion. We highlight the new contributions compared to Drell-Yan production in quark-antiquark annihilation and show that the final result can be obtained to all orders by the substitution of the colour factor CF → CA, confirming previous fixed-order results. We also provide a numerical analysis of the next-to-leading power leading logarithms, which indicates that they are numerically relevant.