  We study Higgs pair production with a subsequent decay to a pair of photons
and a pair of bottoms at the LHC. We use the log-likelihood ratio to identify
the kinematic regions which either allow us to separate the di-Higgs signal
from backgrounds or to determine the Higgs self-coupling. We find that both
regions are separate enough to ensure that details of the background modelling
will not affect the determination of the self-coupling. Assuming dominant
statistical uncertainties we determine the best precision with which the Higgs
self- coupling can be probed in this channel. We finally comment on the same
questions at a future 100 TeV collider.
