Measurement of the cross-section for Z$^0\rightarrow$ e$^+$e$^-$ production in pp collisions at $\sqrt{s}$ = 7 TeV

A measurement of the cross-section for Z$^0\rightarrow$ e$^+$e$^-$ at $\sqrt{s}$ = 7 TeV is presented using LHCb data recorded in 2011 corresponding to an integrated luminosity of 945 pb$^{-1}$. Within the kinematic acceptance, $p_{\mathrm{T}}$ > 20 GeV and 2 < $\eta$ < 4.5 for the leptons and 60 < $M$ < 120 GeV and 2 < $y$ < 4 for the Z$^0$, the cross-section is measured to be \begin{align} \sigma(Z^0 \to e^+ e^-) = 75.7 \pm 0.5 \mathrm{(stat.)} \pm 2.4 \mathrm{(syst.)} \pm 2.6 \mathrm{(lumi.) pb.} \end{align} The results are compared with previous measurements and with theoretical predictions using QCD at NNLO.