Bounds on the conformal scale of a minimally coupled dilaton and multi-leptonic signatures at the LHC

We explore the potential for the discovery of a dilaton O(200 − 500) GeV in a classical scale/conformal invariant extension of the Standard Model by investigating the size of the corresponding breaking scale Λ at the LHC, extending a previous analysis. In particular, we address the recent bounds on Λ derived from Higgs boson searches. We investigate if such a dilaton can be produced via gluon-gluon fusion at the LHC, presenting rates for its decay either into a pair of Higgs bosons or into two heavy gauge bosons, which can give rise to multi-leptonic final states. A detailed analysis via PYTHIA-FastJet has been carried out of the dominant Standard Model backgrounds at the LHC, at a centre of mass energy of 14 TeV. We show that early data of ∼ 20 fb−1 can certainly probe the region of parameter space where such a dilaton is allowed. A conformal scale of 5 TeV is allowed by the current data, for almost all values of the dilaton mass investigated.