Spin-2 Form Factors at Three Loop in QCD

TL;DR

This paper computes the complete three-loop QCD corrections to spin-2 form factors relevant for beyond Standard Model physics and Higgs searches, confirming the universality of infrared singularities in these processes.

Contribution

It provides the first full three-loop QCD corrections to spin-2 form factors, extending understanding of infrared structure in these amplitudes.

Findings

Infrared singularities match those of electroweak and Higgs form factors.

Results are applicable to LHC processes involving spin-2 particles.

Universality of infrared behavior in QCD amplitudes is confirmed.

Abstract

Spin-2 fields are often candidates in physics beyond the Standard Model namely the models with extra-dimensions where spin-2 Kaluza-Klein gravitons couple to the fields of the SM. Also, in the context of Higgs searches, spin-2 fields have been studied as an alternative to the scalar Higgs boson. In this article, we present the complete three loop QCD radiative corrections to the spin-2 quark-antiquark and spin-2 gluon-gluon form factors in SU(N) gauge theory with $n_f$ light flavors. These form factors contribute to both quark-antiquark and gluon-gluon initiated processes involving spin-2 particle in the hadronic reactions at the LHC. We have studied the structure of infrared singularities in these form factors up to three loop level using Sudakov integro-differential equation and found that the anomalous dimensions originating from soft and collinear regions of the loop integrals coincide with those of the electroweak vector boson and Higgs form factors confirming the universality of the infrared singularities in QCD amplitudes.