Direct collider signatures of large extra dimensions

Abstract

The realization of low (TeV) scale strings usually requires the existence of large (TeV) extra dimensions where gauge bosons live. The direct production of Kaluza-Klein excitations of the photon and Z-boson at present and future colliders is studied in this work. At the LEPII, NLC and Tevatron colliders, these Kaluza-Klein modes lead to deviations from the standard model cross-sections, which provide lower bounds on their mass. At the LHC the corresponding resonances can be produced and decay on-shell, triggering a characteristic pattern in the distribution of the dilepton invariant mass.

Figures (5)

• Figure 1: Ratio $\left|{N_T(s)-N_T^{\rm SM}(s) \over \sqrt{N_T^{\rm SM}(s)}} \right|$ from the total cross section at LEPII. We assumed a luminosity times efficiency of 200 $pb^{-1}$.
• Figure 2: Ratio $\left|{N_T(s)-N_T^{\rm SM}(s) \over \sqrt{N_T^{\rm SM}(s)}} \right|$ from the total cross section at NLC-500 and NLC-1000. We assumed a luminosity times efficiency of 75 $fb^{-1}$ and 200 $fb^{-1}$, respectively.
• Figure 3: Number of $l^+ l^-$-pair events with centre--of--mass energy above 400 GeV (600 GeV) expected at the Tevatron run-I (run-II) with integrated luminosity $\int {\cal L}dt= 110\ pb^{-1}$ ($\int {\cal L}dt= 2\ fb^{-1}$) and efficiency times acceptance of $\sim$ 50%, as a function of $R^{-1}$.
• Figure 4: Ratio $\left|{N_T(s)-N_T^{\rm SM}(s) \over \sqrt{N_T^{\rm SM}(s)}}\right|$ from the total cross section at the LHC for dilepton--invariant mass above 400 GeV as a function of $R^{-1}$. We assumed a luminosity (times acceptance) times efficiency of 5 $fb^{-1}$.
• Figure 5: First resonances in the LHC experiment due to a KK state for one and two extra dimensions at 3 TeV.