MHV Gluon Scattering in the Massive Scalar Background and Celestial OPE

TL;DR

This paper investigates the operator product expansion of gluons in a celestial conformal field theory coupled to a massive scalar, revealing that certain amplitude properties remain unchanged despite symmetry breaking.

Contribution

It extends the understanding of celestial OPEs by analyzing the effects of a massive scalar background on gluon interactions and soft theorems.

Findings

Subleading OPE terms match those in pure YM MHV sector.

Amplitudes satisfy known differential equations from pure YM theory.

Soft gluon theorems remain valid despite symmetry breaking.

Abstract

In this paper we study the OPE between two positive helicity outgoing gluons in the celestial CFT for the Yang-Mills theory chirally coupled to a massive scalar background. This theory breaks the translation as well as scale invariance. We compute the subleading terms in the OPE expansion and show that they are same as the subleading terms of the OPE expansions in the MHV sector. As a result the amplitudes of this theory also satisfy the set of differential equations obtained previously for MHV amplitudes in pure YM theory. This is not surprising because the symmetries coming from the leading and subleading soft gluon theorems do not change in the presence of a massive scalar background.