  We study the Z boson pair production mediated by the Kaluza-Klein (KK)
graviton in large extra dimensions (LED) at the CERN Large Hadron Collider
(LHC). We use the partial wave unitarity to discuss the constraints on the
process energy scale in order to give a self-consistent calculation. We find
that the LED contributions can enhance the Z boson pair production cross
sections significantly when the fundamental scale $M_S$ of the large extra
dimensions is up to several TeV. We also show that the kinematic distributions
of the LED signals are greatly different from the standard model ones and the
LHC can probe the $M_S$ values up to $4.3\sim 5.6$ TeV at $3\sigma$ level
depending on the number of the extra dimensions.

High Energy Physics - Phenomenology