Cross-section measurements for the production of a $Z$ boson in association with high-transverse-momentum jets in $pp$ collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector

The collaboration
CERN-EP-2022-075, 2022.

Abstract (data abstract)
CERN-LHC. Cross-section measurements for the production of a Z boson decaying to a charged lepton pair in association with at least one high-transverse-momentum jet using the e+e- and mu+mu- decay channels in proton-proton collisions at a centre-of-mass energy of 13 TeV with 139 fb$^{-1}$ of data collected with the ATLAS detector. The cross-section measurements correspond to the Z boson decaying to a single charged lepton pair, or $Z\to\ell^+\ell^-$. The final states used are 2 electrons or 2 muons, and jets with transverse momentum greater than 100 GeV. The fiducial region is defined as: - 2 opposite signed leptons with $71 < m_{ll} < 111$ GeV where $m_{ll}$ is the mass of the dilepton system - ptLepton > 25 GeV - |etaLepton| < 2.5 - ptJet > 100 GeV - |yJet| < 2.5 - Overlap Removal: Remove jets within $\Delta R(j,l)$ < 0.2, followed by removal of leptons within $\Delta R(j,l)$ < 0.4 of remaining jets. Jets used in this overlap procedure have p$_{\mathrm{T}}$ greater than 30 GeV instead of the fiducial selection of p$_{\mathrm{T}}$ greater than 100 GeV. The High-p$_{\mathrm{T}}$ region is defined as having the leading jet p$_{\mathrm{T}}$ greater than 500 GeV. The Collinear region is defined as a subset of the High-p$_{\mathrm{T}}$ region, where the minimum $\Delta R(Z,j)$ < 1.4. The Back-to-back region is defined as a subset of the High-p$_{\mathrm{T}}$ region, where the minimum $\Delta R(Z,j)$ > 2.0. The High-S$_{\mathrm{T}}$ region is defined as S$_{\mathrm{T}}$ > 600 GeV. Correction scale factors are given to translate the cross sections from Born-level leptons to dressed-level leptons used in this analysis. Correction scale factors are also given to translate the cross sections obtained with an overlap removal procedure done only with jets of p$_{\mathrm{T}}$ greater than 100 GeV to the overlap removal used in this analysis. Non-pertubative corrections are found to be consistent with zero when the leading jet p$_{\mathrm{T}}$ exceeds 100 GeV and are not needed to match the fiducial selection of these measurements. Differential cross sections and their uncertainties are also given in the case where the EW Zjj processes are treated as signal and not subtracted as background.