Next-to-Next-to-Leading Order QCD Corrections in Models of TeV-Scale Gravity

We compute the next-to-next-to-leading order QCD corrections to the graviton production in models of TeV-scale gravity, within the soft-virtual approximation. For the Arkani-Hamed, Dimopoulos and Dvali (ADD) model we evaluate the contribution to the Drell-Yan cross section, and we present distributions for the di-lepton invariant mass at the LHC with a center-of-mass energy $\sqrt{s_H}=14\text{TeV}$. We find a large $K$ factor ($K\simeq 1.8$) for large values of invariant mass, which is the region where the ADD graviton contribution dominates the cross section. The increase in the cross section with respect to the previous order result is larger than $10\%$ in the same invariant mass region. We also observe a substantial reduction in the scale uncertainty. For the Randall-Sundrum (RS) model we computed the total single graviton production cross section at the LHC. We find an increase between $10\%$ and $13\%$ with respect to the next-to-leading order prediction, depending on the model parameters. We provide an analytic expression for the NNLO $K$ factor as a function of the lightest RS graviton mass.