[en] The mass scale M_s of superstring theory is an arbitrary parameter that can be as low as few TeVs if the Universe contains large extra dimensions. We propose a search for the effects of Regge excitations of fundamental strings at the CERN Large Hadron Collider (LHC), in the process pp→γ+jet. The underlying parton process is dominantly the single photon production in gluon fusion, gg→γg, with open string states propagating in intermediate channels. If the photon mixes with the gauge boson of the baryon number, which is a common feature of D-brane quivers, the amplitude appears already at the string disk level. It is completely determined by the mixing parameter--and it is otherwise model (compactification) independent. Even for relatively small mixing, 100 fb^-1 of LHC data could probe deviations from standard model physics, at a 5σ significance, for M_s as large as 3.3 TeV