Mixed QCD$\otimes$QED corrections to exclusive Drell Yan production using the $q_T$-subtraction method
Leandro Cieri, Daniel de Florian, Manuel Der, Javier Mazzitelli
TL;DR
Addressing the need for high-precision predictions, the paper extends the q_T-subtraction method to mixed QCDxQED corrections for colorless final states. It derives and presents all ingredients up to $O(alpha_s alpha)$, including the master subtraction formula and the abelianised coefficient functions, and applies the framework to exclusive Z production with Z decaying to neutrinos. The phenomenological study at LHC shows mixed corrections are typically below 1% but can be larger in certain kinematic regions, and the results reveal that naive factorisation of QCD and QED corrections is a poor approximation for differential observables. The work paves the way for fully exclusive mixed corrections and potential extensions to other massive colorless final states and resummation contexts.
Abstract
In this work we extend the $q_T$-subtraction formalism, originally developed for QCD corrections, to the case of mixed QCD$\otimes$QED corrections, and apply it to the fully exclusive calculation of the ${\cal{O}}(α_sα)$ contribution to the production of an off-shell $Z$ boson in hadronic collisions. We present explicit results for the subtraction term and the hard factor, therefore providing all the ingredients needed for the application of the formalism up to ${\cal{O}}(α_sα)$. To study the phenomenological impact we consider the decay of the off-shell $Z$ boson into a pair of neutrinos, and present kinematical distributions for the final-state leptons at LHC energies.
