A closer look to the sgoldstino interpretation of the diphoton excess

TL;DR

This paper reexamines the sgoldstino explanation for the diphoton excess within gauge mediation, identifying a narrow parameter space where it remains viable despite previous constraints, involving light scalar messengers and enhanced couplings.

Contribution

It demonstrates the viability of the sgoldstino interpretation in a specific parameter region with light scalar messengers, challenging standard gauge mediation assumptions.

Findings

Viable sgoldstino explanation in a near-critical parameter region.

Enhanced sgoldstino coupling due to lighter scalar messengers.

Non-perturbative regime when messenger masses differ by a factor of ~4π.

Abstract

We revisit the sgoldstino interpretation of the diphoton excess in the context of gauge mediation. While the bound on the gluino mass might seem to make the sgoldstino contribution to the diphoton excess unobservable, we show that the interpretation is viable in a thin, near critical region of the parameter space. This regime gives rise to drastic departures from the standard gauge mediation picture. While the fermion messengers lie in the (10-100) TeV range, some scalar messengers are significantly lighter and are responsible for the sgoldstino production and decay. Their effective coupling to the sgoldstino is correspondingly enhanced, and a non-perturbative regime is triggered when light and heavy messenger masses differ by a factor $\sim4\pi$. We also comment on the possible role of an R-axion and on the possibility to decouple the sfermions in this context.