  A detailed description is reported of the analysis used by the CMS
Collaboration in the search for the standard model Higgs boson in pp collisions
at the LHC, which led to the observation of a new boson. The data sample
corresponds to integrated luminosities up to 5.1 inverse femtobarns at sqrt(s)
= 7 TeV, and up to 5.3 inverse femtobarns at sqrt(s) = 8 TeV. The results for
five Higgs boson decay modes gamma gamma, ZZ, WW, tau tau, and bb, which show a
combined local significance of 5 standard deviations near 125 GeV, are
reviewed. A fit to the invariant mass of the two high resolution channels,
gamma gamma and ZZ to 4 ell, gives a mass estimate of 125.3 +/- 0.4 (stat) +/-
0.5 (syst) GeV. The measurements are interpreted in the context of the standard
model Lagrangian for the scalar Higgs field interacting with fermions and
vector bosons. The measured values of the corresponding couplings are compared
to the standard model predictions. The hypothesis of custodial symmetry is
tested through the measurement of the ratio of the couplings to the W and Z
bosons. All the results are consistent, within their uncertainties, with the
expectations for a standard model Higgs boson.
