We present results of an exclusive measurement of the first-excited state of the Sigma hyperon, Sigma(1385)(+), produced in p + p -> Sigma(+) + K+ + n at 3.5 GeV beam energy. The extracted data allow the detailed study of the invariant mass distribution of the Sigma(1385)(+). The mass distribution is well described by a relativistic Breit-Wigner function with a maximum at m(0) = 1383.2 +/- 0.9 MeV/c(2) and a width of 40.2 +/- 2.1 MeV/c(2). The exclusive production cross section comes out to be 22.27 +/- 0.89 +/- 1.56(-2.10)(+3.07) mu b. Angular distributions of the Sigma(1385)(+) in different reference frames are found to be compatible with the hypothesis that 33% of Sigma(1385)(+) result from the decay of an intermediate broad Delta(++) excitation at about 2000 MeV/c(2).
