Probe of Extra Dimensions in Lepton Pair Production at the LHC: an update

Arkani-Hamed, Dimopoulous, and Dvali have proposed a model (ADD) of low-scale quantum gravity featuring large extra dimensions. In this model, the exchange of Kaluza-Klein towers of gravitons can enhance the production rate of lepton pairs at high invariant mass in proton-proton collisions at the LHC. By considering the present and future LHC energy regimes, we reanalyse the potential of the LHC to discover the effects of large extra dimensions and to discriminate between various theoretical models. Specifically, in latter case we explore the capability of the LHC to distinguish spin-2 Kaluza-Klein towers of gravitons exchange from other new physics effects which might be conveniently parametrized by the four-fermion contact interactions. We find that the LHC with planned energy 14 TeV and luminosity 100 fb(-1) will be capable of discovering (and identifying) graviton exchange effects in the large extra dimensions with the cutoff parameter of order M-S = 6.2 TeV (4.8 TeV) for d = 6 and M-S = 8.8 TeV (6.8 TeV) for d = 3.