Search for highly-excited string states with ATLAS

Using fully simulated data samples, we have set limits on the string ball cross section versus lower-mass threshold for string ball production. Assuming a data sample with an integrated luminosity of 100~pb$^{-1}$ at a proton-proton centre of mass energy of 10~TeV, cross section values greater than 185~fb over the threshold mass range of 3.0 to 5.4~TeV/c$^2$ have been excluded at the 95%confidence level. Based on a simple model for string ball production, values of the string scale of less than 1.6~TeV and the Planck scale of less than 2.4~TeV could be excluded.