Influence of the KK graviton decay into hh on the triple Higgs measurement at LHC

Abstract

Evidence for two KK graviton candidates has been previously reported at 380 GeV and 700 GeV. They would provide graviton factories in an e+e- collider. Following a Randall Sundrum interpretation, two extra resonances should appear at 1000 GeV and 1322 GeV. Recently ATLAS, in its search for triple Higgs coupling, has reported an excess in that mass region which comforts this prediction. Local cross sections are therefore clearly in excess of the standard predictions which implies muHH>1. While still marginally significant, this effect appears in a mass region with low background which allows to expect good prospects of discovery with RUN3 data. Such a result could therefore allow to confirm the existence of a series of KK graviton resonances observable at LHC. An optimised strategy, which includes H(95) is proposed to do so. Other opportunities appear in searches for heavier KK graviton recurrences decaying into ZZ/WW in semi-leptonic and fully hadronic modes. Prospects for measuring heavy KK graviton decays GKKi->G380G380 at HL-LHC are discussed. Indirect evidences for the RS model coming from precision measurements are also presented. KK lower mass limits for other KK particles are deduced from precision measurements at LEP/SLC and LHC.

arXiv comment18 pages, 14 figures, Work presented at LCW2025 and at IRN Terascale meeting at IJCLab Orsay, April 20-22nd 2026