Hidden sector effects on double higgs production near threshold at the LHC

Understand

In this letter we study a novel effect of a hidden sector coupling to the standard model Higgs boson: an enhancement of the Higgs pair production cross section near threshold due to bound state effects.

• After summing the ladder contributions of the hidden sector to the effective $ggHH$ coupling, we find the amplitude for gluon-gluon scattering via a Higgs loop.
• We relate this amplitude to the double Higgs production cross section via the optical theorem.
• We find that enhancements of the order of 100 for the partonic cross section near the threshold region can be obtained for a hidden sector strongly coupled to the Higgs boson.