Experiment E949 at Brookhaven National Laboratory studied the rare decay K+ -> pi(+)nu(nu) over bar and other processes with an exposure of 1.77 x 10(12) K+'s. The data were analyzed using a blind analysis technique yielding one candidate event with an estimated background of 0.30 +/- 0.03 events. Combining this result with the observation of two candidate events by the predecessor experiment E787 gave the branching ratio B(K+ -> pi(+)nu (nu) = 1.47(-0.89)(+1.30) x 10(-10), consistent with the standard model prediction of (0.74 +/- 0.20) x 10(-10). This is a more detailed report of results previously published [V. V. Anisimovsky et al., Phys. Rev. Lett. 93, 031801 (2004)].
