Including QCD radiation corrections in transplanckian scattering

Abstract

In the context of Large Extra Dimensions the fundamental Planck scale can be as low as the TeV scale. If this is the way of nature, quantum gravity effects could be visible at the LHC or other High energy colliders. A model independent signal is given by elastic scattering at small angles and transplanckian energy, which can be computed in the eikonal approximation. It is interesting both from a phenomenological and a theoretical point of view to study the corrections to this process due to the QCD radiation. To include it, we generalize a shock-wave method proposed by 't Hooft, so that we are able to obtain the amplitude at first order in the gauge interaction but resummed to all orders in gravity. From this result we can learn many interesting things, for example we can extract the true scale of the process which agrees with an earlier guess of Emparan, Masip and Rattazzi. The problem of radiation in transplanckian scattering is briefly introduced, we then report and comment the recent results and mention the perspectives for the near future.