Search for Low-Scale String Resonances with ATLAS at the Large Hadron Collider

Abstract

String theory requires the existence of extra spatial dimensions. They must be compactified since they have not yet been detected. If the size of these extra dimensions is large then it is possible that the string scale Ms could be on the order of TeV. In the Dp-brane model of string theory two-parton scattering in proton-proton collisions can create massive string resonances that could be detected at colliders such as the LHC. We simulate proton-proton collisions producing string resonances and compare with data taken with the ATLAS detector at a centre-of-mass energy of 13 TeV. We search the dijet invariant mass distribution for a significant signal over the expected background. We detect no excess in the data distribution over background and set a lower limit on the string scale of the first string resonance. We find with 95% confidence level that string resonances with an observed upper limit Ms < 8.30 TeV do not exist in ATLAS data with an integrated luminosity of 139 1/fb.