EPJ Web of Conferences (Dec 2012)

ABC Effect and Resonance Structure in the Double-Pionic Fusion to 3He

  • Pricking A.,
  • Doroshkevich E.,
  • Clement H.,
  • Bashkanov M.,
  • Perez del Rio E.,
  • Skorodko T.,
  • Wagner G. J.

DOI
https://doi.org/10.1051/epjconf/20123709029
Journal volume & issue
Vol. 37
p. 09029

Abstract

Read online

Historically the double-pionic fusion to 3He is the reaction, where the ABC effect (low-mass enhancement of the ππ-invariant mass spectrum) was observed for the first time more than 50 years ago. Meanwhile exclusive and kinematically complete high-statistics measurements with WASA at COSY revealed a strict correlation between the ABC effect and a narrow resonance structure with I(JP) = 0(3+) in the total cross section of the most basic double-pionic fusion, the pn → dπ0π0 reaction. In order to investigate the situation in the double-pionic fusion to 3He the energy dependence of the ABC effect in the fusion to 3He has been measured by fixed energy measurements of the type pd →3Heππ as well as by quasifree and coherent measurements of the type dd →3He n ππ.