TeV-Scale String Resonances at Hadron Colliders

Abstract 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.