750 GeV Diphotons from a D3-brane

TL;DR

This paper explores string-inspired models involving a D3-brane near an E-type Yukawa point to explain the 750 GeV diphoton excess observed at the LHC, predicting specific decay channels and production mechanisms.

Contribution

It introduces a novel class of strongly coupled string-based models with a D3-brane that naturally accommodate the 750 GeV diphoton signal and predict additional decay channels.

Findings

Models predict diphoton resonance at 750 GeV

Additional decay channels to ZZ and Z gamma are expected

String-based models can naturally explain the observed excess

Abstract

Motivated by the recently reported diphoton excess at 750 GeV observed by both CMS and ATLAS, we study string-based particle physics models which can accommodate this signal. Quite remarkably, although Grand Unified Theories in F-theory tend to impose tight restrictions on candidate extra sectors, the case of a probe D3-brane near an E-type Yukawa point naturally leads to a class of strongly coupled models capable of accommodating the observed signature. In these models, the visible sector is realized by intersecting 7-branes, and the 750 GeV resonance is a scalar modulus associated with motion of the D3-brane in the direction transverse to the Standard Model 7-branes. Integrating out heavy 3-7 string messenger states leads to dimension five operators for gluon fusion production and diphoton decays. Due to the unified structure of interactions, these models also predict that there should be additional decay channels to ZZ and Z gamma. We also comment on models with distorted unification, where both the production mechanism and decay channels can differ.