Precision luminosity measurement at LHC using two-photon production of   mu^+ mu^- pairs
  The application of the two-photon process pp -> pp + mu^+mu^- for the luminosity measurements at LHC with the ATLAS detector is considered. The expected accuracy of the absolute offline luminosity determination is 1 - 2 % for the luminosity range of 10^{33} - 10^{34} cm^-2 s^-1. The preliminary cross section estimates done for LHCb promise the same level of the luminosity measurement accuracy at L = 2 x 10^{32} cm^-2 s^-1. 
A.G. Shamov and V.I. Telnov (Institute of Nuclear Physics,   Novosibirsk)