  There are two simple ways that the Higgs boson H of the Standard Model (SM)
may be more difficult to observe than expected at the Large Hadron Collider
(LHC) or the Tevatron. One is well-known, i.e. H decays invisibly, into
dark-matter scalar particles for example. The other is that H mixes with a
heavy singlet scalar S which couples to new colored fermions and scalars. Of
the two mass eigenstates, the lighter one could (accidentally) have a
suppressed effective coupling to two gluons, and the heavy one could be
kinematically beyond the reach of the LHC.
