Discovery and Identification of Contactlike Interactions in Fermion-pair Production at ILC

Non-standard scenarios described by effective contactlike interactions can be revealed only by searching for deviations of the measured observables from the Standard Model (SM) predictions. If deviations were indeed observed within the experimental uncertainty, the identification of their source among the different non-standard interactions should be needed. We here consider the example of the discrimination of gravity in compactified extra dimensions (ADD model) against the four-fermion contact interactions (CI). We present assessments of the identification reach on this scenario, that could be obtained from measurements of the differential cross sections for the fermionic processes $e^+e^-\to{\bar f}f$, with $f=e,\mu,\tau,c,b$, at the planned ILC.