We show that the dominant channel proposed for the determination of the Higgs boson trilinear coupling, $pp\to HH+X$ via gluon fusion, exhibits an interference structure that is independent of the collider energy for collider energies in the range $8\mathrm{TeV}\le \sqrt{s}\le 100\mathrm{TeV}$ and is almost maximally destructive. This insensitivity to the collider energy remains approximately true for a variety of other two Higgs production mechanisms although the magnitude of the interference varies widely.

• Received 7 May 2015

DOI:https://doi.org/10.1103/PhysRevD.92.093003