  Measurements of the differential and double-differential Drell-Yan cross
sections are presented using an integrated luminosity of 4.5 (4.8) inverse
femtobarns in the dimuon (dielectron) channel of proton-proton collision data
recorded with the CMS detector at the LHC at sqrt(s) = 7 TeV. The measured
inclusive cross section in the Z-peak region (60-120 GeV) is sigma(ell ell) =
986.4 +/- 0.6 (stat.) +/- 5.9 (exp. syst.) +/- 21.7 (th. syst.) +/- 21.7 (lum.)
pb for the combination of the dimuon and dielectron channels. Differential
cross sections d[sigma]/d[m] for the dimuon, dielectron, and combined channels
are measured in the mass range 15 to 1500 GeV and corrected to the full phase
space. Results are also presented for the measurement of the
double-differential cross section d2[sigma]/d[m]d[abs(y)] in the dimuon channel
over the mass range 20 to 1500 GeV and absolute dimuon rapidity from 0 to 2.4.
These measurements are compared to the predictions of perturbative QCD
calculations at next-to-leading and next-to-next-to-leading orders using
various sets of parton distribution functions.
