Two loop correction to interference in $gg \to ZZ$

Understand

We present results for the production of a pair of on-shell Z bosons via gluon fusion.

• This process occurs both through the production and decay of the Higgs boson, and through continuum production where the Z boson couples to a loop of massless quarks or to a massive quark.
• We calculate the interference of the two processes and its contribution to the cross section up to and including order O(alpha_s^3).
• The two-loop contributions to the amplitude are all known analytically, except for the continuum production through loops of top quarks of mass m.