High-statistics study of the reaction gamma p -> p 2 pi(0)

作者：Sokhoyan V^*; Gutz E; Crede V; van Pee H; Anisovich A V; Bacelar J C S; Bantes B; Bartholomy O; Bayadilov D; Beck R; Beloglazov Y A; Castelijns R; Dutz H; Elsner D; Ewald R; Frommberger F; Fuchs M; Funke Ch; Gregor R; Gridnev A B; Hillert W; Hoffmeister Ph; Horn I; Jaegle I; Junkersfeld J; Kalinowsky H; Kammer S; Kleber V; Klein Frank; Klein Friedrich; Klempt E; Kotulla M; Krusche B; Lang M; Lohner H; Lopatin I V

来源：European Physical Journal A, 2015, 51(8): 95.

DOI：10.1140/epja/i2015-15095-x

The photoproduction of 2 pi(0) mesons off protons was studied with the Crystal Barrel/TAPS experiment at the electron accelerator ELSA. in Bonn. The energy of photons produced.in a radiator was tagged in the energy range from 600 MeV to 2.5 GeV. Differential and total cross sections and p pi(0)pi(0) Dalitz plots are presented. Part of the data was taken with a diamond radiator producing linearly polarized photons, and beam asymmetries were derived. Properties of nucleon and Delta resonances contributing to the p pi(0)7r final state were determined within the Bonn-Gatchina (BnGa) partial-wave analysis. The data presented here allow us to determine branching ratios of nucleon and Delta resonances for their decays into p pi(0)pi(0) via several intermediate states. Most prominent are decays proceeding via Delta(1232)pi, N(1440)1/2(+)pi, N(1520)3/2(-pi), N(1680)5/2(+)pi, but also p f (500), pf(0) (980), and pf(o)(1270) contribute to the reaction.

• 出版日期2015-8-6