Color-kinematics duality for Sudakov form factor in non-supersymmetric pure Yang–Mills theory

We study the duality between color and kinematics for Sudakov form factors of ${\rm tr}(F^2)$ in non-supersymmetric pure Yang-Mills theory. construct integrands that manifest color-kinematics up to two loops. The resulting numerators are given terms Lorentz products momenta polarization vectors, which have same powers loop as from Feynman rules. checked by $d$-dimensional unitarity cuts valid any dimension. find massless-bubble tadpole topologies needed at loops realize duality. Interestingly, two-loop solution contains a large number free parameters suggesting may hold higher orders.