Warped gravitons at the CERN LHC and beyond

We study the production and decay of Kaluza-Klein (KK) gravitons at the CERN Large Hadron Collider (LHC), in the framework of a warped extra dimension in which the standard model (SM) fields propagate. Such a scenario can provide solutions to both the Planck-weak hierarchy problem and the flavor puzzle of the SM. In this scenario, the production via qq̄ annihilation and decays to the conventional photon and lepton channels are highly suppressed. However, we show that graviton production via gluon fusion followed by decay to longitudinal $Z/W$ can be significant; vector boson fusion is found to be a subdominant production mode. In particular, the golden $ZZ$ decay mode offers a distinctive 4-lepton signal that could lead to the observation at the LHC with 300 fb^-1 (SLHC with 3 ab^-1) of a KK graviton with a mass up to ~2 (~3) TeV for the ratio of the AdS₅ curvature to the Planck scale modestly above unity. We argue that (contrary to the lore) such a size of the curvature scale can still be within the regime of validity of the framework. Upgrades beyond the SLHC luminosity are required to discover gravitons heavier than ~4 TeV, as favored by the electroweak and flavor precision tests in the simplest such models.