Measurement of the matrix elements for the decays η' → ηπ<SUP>+</SUP> π<SUP>-</SUP> and η' → ηπ<SUP>0</SUP>π<SUP>0</SUP>


Creative Commons License

Ablikim M., Achasov M. N., Ahmed S., Albrecht M., Amoroso A., An F. F., ...More

PHYSICAL REVIEW D, vol.97, no.1, 2018 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 97 Issue: 1
  • Publication Date: 2018
  • Doi Number: 10.1103/physrevd.97.012003
  • Journal Name: PHYSICAL REVIEW D
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Bursa Uludag University Affiliated: No

Abstract

Based on a sample of 1.31 x 10(9) J/psi events collected with the BESIII detector, the matrix elements for the decays eta' -> eta pi(+) pi(-) and eta' -> eta pi(0)pi(0) are determined using 351,016 eta' -> (eta -> gamma gamma)pi' pi(-) and 56,249 eta' -> (eta -> gamma gamma)pi(0) pi(0) events with background levels less than 1%. Two commonly used representations are used to describe the Dalitz plot density. We find that an assumption of a linear amplitude does not describe the data well. A small deviation of the obtained matrix elements between eta' -> eta pi(+) pi(-) and eta' -> eta pi(0)pi(0) is probably caused by the mass difference between charged and neutral pions or radiative corrections. No cusp structure in eta' -> eta pi(0)pi(0) is observed.