Measurement of the cross-section for Z -> e(+)e(-) production in pp collisions at root s=7 TeV

A measurement of the cross-section for pp -> Z -> e(+)e(-) is presented using data at root s = 7 TeV corresponding to an integrated luminosity of 0.94 fb(-1). The process is measured within the kinematic acceptance p(T) > 20 GeV/c and 2 < eta < 4.5 for the daughter electrons and dielectron invariant mass in the range 60-120 GeV/c(2). The cross-section is determined to besigma(pp -> Z -> e(+)e(-)) = 76.0 +/- 0.8 +/- 2.0 +/- 2.6 pbwhere the first uncertainty is statistical, the second is systematic and the third is the uncertainty in the luminosity. The measurement is performed as a function of Z rapidity and as a function of an angular variable which is closely related to the Z transverse momentum. The results are compared with previous LHCb measurements and with theoretical predictions from QCD.