Breakdown of Effective Field Theory for a Gluon Initiated Resonance

TL;DR

This paper investigates how high transverse momentum production of a gluon-initiated resonance can reveal the underlying dynamics and energy scales, using an EFT framework and a 750 GeV diphoton resonance as a case study.

Contribution

It demonstrates how to extract the scale of non-renormalizable operators or loop particles from collider data, comparing EFT and UV completion approaches.

Findings

Strong constraints on EFT scale with ~100 events

EFT expansion converges slowly with dimension-5 and -7 operators

Mass of vector-like quarks can be inferred from data

Abstract

Gauge invariance dictates that a resonance produced from initial state gluons must be produced through a non-renormalizable operator or a loop process. Should such a resonance be discovered, uncovering the dynamics that give rise to its couplings to gluons will be crucial to understanding the nature of the new state. Here we study how the production of this resonance at high transverse momentum in association with one (or more) jets can be used to directly measure the scale of the operator or the mass of the particles in the loop. We use a 750 GeV diphoton resonance as an example application, and we study how the non-renormalizable operator case can be described by a slowly converging effective field theory (EFT) expansion with operators of dimension five and seven. We show that with O(100) events, one can put strong constraints on the scale of the EFT, particularly in theories with strong coupling. We also compare the EFT analysis to that of a UV completion with vector-like quarks, and outline how the mass of said quarks could be measured.