Figure 4

Ratio of data over theoretical calculations for the Z-boson production cross section measured by the ALICE, LHCb [18], ATLAS [16] and CMS [17] experiments. The LHCb points have been shifted by +0.02 units of rapidity for better visibility. The ATLAS cross sections are measured in a slightly smaller invariant mass range ($66 < m_{ll} < 116$ GeV/$c^2$) compared to the other experiments ($60 < m_{ll} < 120$ GeV/$c^2$). The luminosity uncertainties of 2.7% for ATLAS and 3.5% for CMS are not shown. The pQCD calculations are obtained with the CT10 PDF set and with the EPS09NLO parameterisation of the nuclear modifications.