Branching Ratio of the Electromagnetic Decay of the Σ+(1385)

The CLAS detector was used to obtain the first ever measurement of the electromagnetic decay of the Sigma*(+)(1385) from the reaction gamma p -> K-0 Sigma*(+)(1385). A real photon beam with a maximum energy of 3.8 GeV was incident on a liquid-hydrogen target, resulting in the photoproduction of the kaon and Sigma* hyperon. Kinematic fitting was used to separate the reaction channel from the background processes. The fitting algorithm exploited a new method to kinematically fit neutrons in the CLAS detector, leading to the measured decay widths ratio Sigma(+)(1385)->Sigma(+)gamma/Sigma(+)(1385)->Sigma(+)pi(0)=11.95 +/-.2.21(stat)(-1.21)(+0.53)(sys)%and a deduced partial width of 250.0 +/- 56.9(stat)(-41.2)(+34.3)(sys) keV. AU-spin symmetry test using the SU(3) flavor-multiplet representation yields predictions for the Sigma*(+)(1385)->Sigma(+)gamma and Sigma*(0)(1385)->Lambda gamma partial widths that agree with the experimental measurements.