Measurement of the cross-section for Z->e+e- production in pp collisions at sqrt{s}=7TeV

TL;DR

This paper reports a precise measurement of the Z boson production cross-section in proton-proton collisions at 7 TeV, analyzing electron decay channels within specific kinematic ranges, and compares results with theoretical models and previous experiments.

Contribution

It provides the first detailed measurement of Z->e+e- cross-section at 7 TeV with differential analysis and comparison to QCD predictions.

Findings

Measured cross-section: 76.0 pb with uncertainties

Differential cross-section as a function of Z rapidity

Agreement with theoretical QCD predictions

Abstract

A measurement of the cross-section for pp->Z->e+e- is presented using data at sqrt{s}=7TeV corresponding to an integrated luminosity of 0.94 fb^{-1}. The process is measured within the kinematic acceptance pT>20GeV/c and 2<\eta<4.5 for the daughter electrons and dielectron invariant mass in the range 60--120GeV/c^2. The cross-section is determined to be \sigma(pp->Z->e+e-)=76.0+-0.8+-2.0+-2.6pb where 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.