  In a realistic theory with large extra dimensions and TeV scale gravity,
there are often other particles living in the extra dimensions in addition to
gravitons. A well motivated candidate is the flavon in a flavor theory which
explains the smallness of the fermion masses by the large volume of the extra
dimensions. The flavon interactions involve the Higgs field and can therefore
give rise to new mechanisms of Higgs boson production. We study these new Higgs
signals, including both real flavon emission and virtual flavon exchange. They
could provide powerful probes of the string scale which are comparable to the
extensively studied graviton production, if the flavons and the graviton feel
the same number of extra dimensions. If the flavons only live in a subspace of
the extra dimensions, they can yield even stronger bounds and may generate
spectacular displaced vertex signals. Our study also applies to a four
dimensional flavor theory with light flavons as well as to any theory with bulk
scalar fields coupled to the Higgs and fermions.
