Branching ratio of the electromagnetic decay of the Sigma(+)(1385)

作者：Keller D^*; Hicks K; Adhikari K P; Adikaram D; Amaryan M J; Anghinolfi M; Baghdasaryan H; Ball J; Battaglieri M; Bedlinskiy I; Biselli A S; Bookwalter C; Boiarinov S; Branford D; Briscoe W J; Brooks W K; Burkert V D; Carman D S; Celentano A; Chandavar S; Cole P L; Contalbrigo M; Crede V; D' Angelo A; Daniel A; Dashyan N; De Vita R; De Sanctis E; Djalali C; Doughty D; Dupre R; El Alaoui A; El Fassi L; Elouadrhiri L

来源：Physical Review D - Particles, Fields, Gravitation and Cosmology, 2012, 85(5): 052004.

DOI：10.1103/PhysRevD.85.052004

The CLAS detector was used to obtain the first ever measurement of the electromagnetic decay of the Sigma*(+)(1385) from the reaction gamma p -%26gt; 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)-%26gt;Sigma(+)gamma/Sigma(+)(1385)-%26gt;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)-%26gt;Sigma(+)gamma and Sigma*(0)(1385)-%26gt;Lambda gamma partial widths that agree with the experimental measurements.

• 出版日期2012-3-19
• 单位中国地震局