Abstract
A precision measurement of the Z boson production cross-section at \( \sqrt{\mathrm{s}} \) = 13 TeV in the forward region is presented, using pp collision data collected by the LHCb detector, corresponding to an integrated luminosity of 5.1 fb−1. The production cross-section is measured using Z → μ+μ− events within the fiducial region defined as pseudorapidity 2.0 < η < 4.5 and transverse momentum pT > 20 GeV/c for both muons and dimuon invariant mass 60 < Mμμ < 120 GeV/c2. The integrated cross-section is determined to be
where the first uncertainty is statistical, the second is systematic, and the third is due to the luminosity determination. The measured results are in agreement with theoretical predictions within uncertainties.

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