  The top-quark mass is measured in proton-proton collisions at sqrt(s) = 7 TeV
using a data sample corresponding to an integrated luminosity of 5.0 inverse
femtobarns collected by the CMS experiment at the LHC. The measurement is
performed in the dilepton decay channel t t-bar to ell+ nu[ell] b, ell-
anti-nu[ell] b-bar, where ell=e,mu. Candidate top-quark decays are selected by
requiring two leptons, at least two jets, and imbalance in transverse momentum.
The mass is reconstructed with an analytical matrix weighting technique using
distributions derived from simulated samples. Using a maximum-likelihood fit,
the top-quark mass is determined to be 172.5 +/- 0.4 (stat) +/- 1.5 (syst) GeV.
