Interpreting the 750 GeV diphoton excess in the minimal dilaton model

Abstract

We try to interpret the 750 GeV diphoton excess in the minimal dilaton model, which extends the SM by adding one linearized dilaton field and vector-like fermions. We first show by analytic formulas in this framework that the production rates of the γγ, gg, Zγ, ZZ, WW∗, tt¯ , and hh signals at the 750 GeV resonance are only sensitive to the dilaton–Higgs mixing angle θS and the parameter η≡ vNX/ f, where f is the dilaton decay constant and NX denotes the number of the fermions. Then we scan the two parameters by considering various theoretical and experimental constraints to find the solutions to the diphoton excess. We conclude that the model can predict the central value of the diphoton rate without conflicting with any constraints. The signatures of our explanation at the LHC Run II and the vacuum stability at high energy scale are also discussed.