A Double Take on New Physics in Double Higgs Production

Gluon-initiated double Higgs production is the most important channel to extract the Higgs self-coupling at hadron colliders. However, new physics could enter into this channel in several distinctive ways including, but not limited to, the Higgs self-coupling, a modified top Yukawa coupling, and an anomalous Higgs-top quartic coupling. In this work we initiate a study on the interplay of these effects in the kinematic distributions of the Higgs bosons. More specifically, we divide the transverse momentum and the total invariant mass spectra into two bins and use the differential rates in each bin to constrain the magnitude of the aforementioned effects. Significantly improved results could be obtained over those using total cross section alone. However, some degeneracy remains, especially in the determination of the Higgs trilinear coupling. Therefore, an accurate measurement of the Higgs self-coupling in this channel would require precise knowledge of the magnitudes of other new physics effects. We base our analysis on a future 100 TeV proton-proton collider.