NLO EW and QCD corrections to polarized ZZ production in the four-charged-lepton channel at the LHC

Ansgar Denner,Giovanni Pelliccioli

doi:10.1007/jhep10(2021)097

Abstract

Measuring the polarization of electroweak bosons at the LHC allows for important tests of the electroweak-symmetry-breaking mechanism that is realized in nature. Therefore, precise Standard Model predictions are needed for the production of polarized bosons in the presence of realistic kinematic selections. We formulate a method for the calculation of polarized cross-sections at NLO that relies on the pole approximation and the separation of polarized matrix elements at the amplitude level. In this framework, we compute NLO-accurate cross-sections for the production of two polarized Z bosons at the LHC, including for the first time NLO EW corrections and combining them with NLO QCD corrections and contributions from the gluon-induced process.

Highlights

JHEP10(2021)097 computed [23,24,25,26], and studies have been dedicated to the NLO QCD corrections to the loop-induced gluon-gluon channel [27,28,29,30]
We present the numerical results of our computation
We consider the INC setup and NLO EW accuracy. These results provide both a validation of the calculation and a first assessment of how the polarization structure of ZZ production is modified by EW corrections

Summary

Introduction

JHEP10(2021) computed [23,24,25,26], and studies have been dedicated to the NLO QCD corrections to the loop-induced gluon-gluon channel [27,28,29,30]. For the process pp → ZZ → e+e−μ+μ−, the possibility to fully reconstruct the final state allows to access observables that are sensitive to the polarization of Z bosons. This can be done in the Higgs-resonance region [52,53,54], where the polarization of the weak bosons may give hints of new-physics effects in the coupling of the Higgs to longitudinallyor transversely-polarized bosons. The separation of polarized signals at the amplitude level has been extended to NLO QCD [79, 80] and to NNLO QCD [81] for diboson production in the fully-leptonic channel.

Objectives

Results

Conclusion