Z Boson Production and Properties at LHC

The study of the Z Boson at the ATLAS experiment provides several interesting aspects already in the starting phase of the LHC. The measurements of cross section and transverse momentum spectrum (ptZ) of the Z boson at ATLAS provide additional tests of the standard model and may be sensitive to exotic physics processes. Z boson production is also a common background process for many other physics analyses and must be understood very well. The achievable precision of the overall cross section (pp ->Z/gamma->Mu+Mu-)measurement with first collisions of LHC recorded by ATLAS detector is discussed. The differential cross-section measurement dsigma/dptZ and its constraints on the PDFs of the proton at high energies has been studied. Special emphasis is placed on methods for calibration and determination of resolutions and efficiencies of the ATLAS detector based on the decay of Z-Bosons into two muons.