Probing Higgs-radion mixing in warped models through complementary searches at the LHC and the ILC

Abstract

We consider the Higgs-radion mixing in the context of warped space extra dimensional models with custodial symmetry and investigate the prospects of detecting the mixed radion. Custodial symmetries allow the Kaluza-Klein excitations to be lighter, and protect Zbb to be in agreement with experimental constraints. We perform a complementary study of discovery reaches of the Higgs-radion mixed state at the 13 and 14 TeV LHC and at the 500 and 1000 GeV ILC. We carry out a comprehensive analysis of the most significant production and decay modes of the mixed radion in the 80 GeV - 1 TeV mass range, and indicate the parameter space that can be probed at the LHC and the ILC. There exists a region of the parameter space which can be probed, at the LHC, through the diphoton channel even for a relatively low luminosity of 50 fb^{-1}. The reach of the 4-lepton final state, in probing the parameter space is also studied in the context of 14 TeV LHC, for a luminosity of 1000 fb^{-1}. At the ILC, with an integrated luminosity of 500 fb^{-1}, we analyze the Z-radion associated production and the WW fusion production, followed by the radion decay into bb and W+W-. The WW fusion production is favored over the Z-radion associated channel in probing regions of the parameter space beyond the LHC reach. The complementary study at the LHC and the ILC is useful both for the discovery of the radion and the understanding of its mixing sector.