TeV-scale string resonances at hadron colliders

We construct tree-level four-particle open-string amplitudes relevant to dilepton and diphoton production at hadron colliders. We expand the amplitudes into string resonance (SR) contributions and compare the total cross-section through the first SR with the Z^' search at the Tevatron. We establish a current lower bound based on the CDF Run I results on the string scale to be about 1.1-2.1 TeV, and it can be improved to about 1.5-3 TeV with 2 fb^-1. At the LHC, we investigate the properties of signals induced by string resonances in dilepton and diphoton processes. We demonstrate the unique aspects of SR-induced signals distinguishable from other new physics, such as the angular distributions and forward-backward asymmetry. A $95%$ C.L. lower bound can be reached at the LHC for MS>8.2-10 TeV with an integrated luminosity of $300$ fb^-1. We emphasize the generic features and profound implications of the amplitude construction.