A search for signatures of extra spatial 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 √s=7  TeV corresponding to an integrated luminosity of 2.2  fb−1. In the context of the large-extra-dimensions model, lower limits are set on the effective Planck scale ...