A resonance without resonance: scrutinizing the diphoton excess at 750 GeV

TL;DR

This paper investigates a potential explanation for the 750 GeV diphoton excess by proposing a new heavy particle decaying into lighter pseudoscalars, analyzing collider data to assess its viability.

Contribution

It introduces a novel model where a heavy spinless particle decays into lighter pseudoscalars, connecting the excess to a new strongly interacting sector and anomaly couplings.

Findings

Parameter space consistent with 13 TeV and 8 TeV data identified

The proposed mechanism can produce the observed diphoton signals

Constraints on the new particle's properties derived from collider data

Abstract

Motivated by the recent diphoton excesses reported by both ATLAS and CMS collaborations, we suggest that a new heavy spinless particle is produced in gluon fusion at the LHC and decays to a couple of lighter pseudoscalars which then decay to photons. The new resonances could arise from a new strongly interacting sector and couple to Standard Model gauge bosons only via the corresponding Wess-Zumino-Witten anomaly. We present a detailed recast of the newest 13 TeV data from ATLAS and CMS together with the 8 TeV data to scan the consistency of the parameter space for those resonances.