The Significance of the 750 GeV Fluctuation in the ATLAS Run 2 Diphoton Data

Abstract

We investigate the robustness of the resonance like feature centred at around a 750 GeV invariant mass in the 13 TeV diphoton data, recently released by the ATLAS collaboration. We focus on the choice of empirical function used to model the continuum diphoton background in order to quantify the uncertainties in the analysis due to this choice. We extend the function chosen by the ATLAS collaboration to one with two components. By performing a profile likelihood analysis we find that the local significance of a resonance drops from $3.9\sigma$ using the ATLAS background function, and a freely-varying width, to only $2\sigma$ with our own function. We argue that the latter significance is more realistic, since the former was derived using a function which is fit almost entirely to the low-energy data, while underfitting in the region around the resonance.

9 pages, 3 figs

Cited by in corpus (15)

• An extension of two-Higgs-doublet model and the excesses of 750 GeV diphoton, muon g-2 and $h\to \mu \tau$
• Left-right asymmetry and 750 GeV diphoton excess
• Diphoton excess at 750 GeV and LHC constraints in models with vector-like particles
• Diphoton Excess and Running Couplings
• Models of LHC Diphoton Excesses Valid up to the Planck scale
• Note on Spin-2 Particle Interpretation of the 750~GeV Diphoton Excess
• Resonant Diphoton Phenomenology Simplified
• Systematic Study of Diphoton Resonance at 750 GeV from Sgoldstino
• A Flippon Related Singlet at the LHC II
• Photo-production of a 750 GeV di-photon resonance mediated by Kaluza-Klein leptons in the loop
• Topological Structure of the Vacuum, Cosmological Constant and Dark Energy
• Diphoton decay for a 750 GeV scalar boson in a $SU(6)\otimes U(1{)}_X$ model
• Learning from the New Higgs-like Scalar before It Vanishes
• Minimal Dilaton Model and the Diphoton Excess
• Exploring high-mass diphoton resonance without new colored states