Virtual corrections to gg → ZH in the high-energy and large-mt limits

We compute the next-to-leading order virtual corrections to the partonic cross-section of the processgg → ZH, in the high-energy and large-mtlimits. We use Padé approximants to increase the radius of convergence of the high-energy expansion in$$ {m}_t^2/s $$mt2/s,$$ {m}_t^2/t $$mt2/tand$$ {m}_t^2/u $$mt2/uand show that precise results can be obtained down to energies which are fairly close to the top quark pair threshold. We present results both for the form factors and the next-to-leading order virtual cross-section.

Anomalous dimensions of effective theories from partial waves

On-shell amplitude methods have proven to be extremely efficient for calculating anomalous dimensions. We further elaborate on these methods to show that, by the use of an angular momentum decomposition, the one-loop anomalous dimensions can be reduced to essentially a sum of products of partial waves. We apply this to the SM EFT, and show how certain classes of anomalous dimensions have their origin in the same partial-wave coefficients. We also use our result to obtain a generic formula for the one-loop anomalous dimensions of nonlinear sigma models at any order in the energy expansion, and apply our method to gravity, where it proves to be very advantageous even in the presence of IR divergencies.