  A search for signatures of extra dimensions in the diphoton invariant-mass
spectrum has been performed with the CMS detector at the LHC. No excess of
events above the standard model expectation is observed using a data sample
collected in proton-proton collisions at sqrt(s) = 7 TeV corresponding to an
integrated luminosity of 2.2 inverse femtobarns. In the context of the
large-extra-dimensions model, lower limits are set on the effective Planck
scale in the range of 2.3-3.8 TeV at the 95% confidence level. These limits are
the most restrictive bounds on virtual-graviton exchange to date. The most
restrictive lower limits to date are also set on the mass of the first graviton
excitation in the Randall-Sundrum model in the range of 0.86-1.84 TeV, for
values of the associated coupling parameter between 0.01 and 0.10.
