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

V. Sokhoyan*, E. Gutz, V. Crede, H. van Pee, A. V. Anisovich, J. C. S. Bacelar, B. Bantes, O. Bartholomy, D. Bayadilov, R. Beck, Y. A. Beloglazov, R. Castelijns, H. Dutz, D. Elsner, R. Ewald, F. Frommberger, M. Fuchs, Ch. Funke, R. Gregor, A. B. GridnevW. Hillert, Ph. Hoffmeister, I. Horn, I. Jaegle, J. Junkersfeld, H. Kalinowsky, S. Kammer, V. Kleber, Frank Klein, Friedrich Klein, E. Klempt, M. Kotulla, B. Krusche, M. Lang, H. Löhner, I. V. Lopatin, S. Lugert, T. Mertens, J. G. Messchendorp, V. Metag, B. Metsch, M. Nanova, V. A. Nikonov, D. Novinsky, R. Novotny, M. Ostrick, L. Pant, M. Pfeiffer, D. Piontek, S. Shende, CBELSA-TAPS Collaboration

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

31 Citations (Scopus)

Abstract

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.

Original languageEnglish
Article number95
Number of pages29
JournalEuropean Physical Journal A
Volume51
Issue number8
DOIs
Publication statusPublished - 6-Aug-2015

Keywords

  • DOUBLE-PION-PHOTOPRODUCTION
  • DOUBLE PI(0) PHOTOPRODUCTION
  • RELATIVIZED QUARK-MODEL
  • PARTIAL-WAVE ANALYSIS
  • BARYON RESONANCES
  • BUBBLE-CHAMBER
  • HIGH-ENERGY
  • PROTON
  • THRESHOLD
  • REGION

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