First results on nucleon resonance photocouplings from the γp → π+πp reaction

CLAS Collaboration

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We report the first experimental measurements of the nine 1-fold differential cross sections for the γp→π+πp reaction, obtained with the CLAS detector at Jefferson Laboratory. The measurements cover the invariant mass range of the final state hadrons from 1.6 GeV <W< 2.0 GeV. For the first time the photocouplings of all prominent nucleon resonances in this mass range have been extracted from this exclusive channel. Photoproduction of two charged pions is of particular importance for the evaluation of the photocouplings for the Δ(1620)1/2, Δ(1700)3/2, N(1720)3/2+, and Δ(1905)5/2+ resonances, which have dominant decays into the ππN final states rather than the more extensively studied single meson decay channels.

Original languageEnglish
Pages (from-to)371-379
Number of pages9
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Early online date12 Oct 2018
Publication statusPublished - 10 Jan 2019

Bibliographical note

©2018 The Author


  • Baryon state
  • Resonance photocouplings
  • Two pion photoproduction

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