Precision measurement of forward Z boson production in proton-proton collisions at √s = 13 TeV

A precision measurement of the Z boson production cross-section at 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 p_T> 20 GeV/c for both muons and dimuon invariant mass 60 < M_μμ< 120 GeV/c². The integrated cross-section is determined to beσ(Z→μ+μ−)=196.4±0.2±1.6±3.9pb, 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. [Figure not available: see fulltext.]