Observation of a structure at 1.84 GeV/<i>c</i><SUP>2</SUP> in the 3(π<SUP>+</SUP>π<SUP>-</SUP>) mass spectrum in J/ψ → γ3(π<SUP>+</SUP> π<SUP>-</SUP>) decays


Creative Commons License

Ablikim M., Achasov M. N., Albayrak O., Ambrose D. J., An F. F., An Q., ...More

PHYSICAL REVIEW D, vol.88, no.9, 2013 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 88 Issue: 9
  • Publication Date: 2013
  • Doi Number: 10.1103/physrevd.88.091502
  • Journal Name: PHYSICAL REVIEW D
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Bursa Uludag University Affiliated: No

Abstract

With a sample of 225.3 x 10(6) J/psi events taken with the BESIII detector, the decay J/psi -> gamma 3(pi(+) pi(-)) is analyzed. A structure at 1.84 GeV/c(2) is observed in the 3(pi(+) pi(-)) invariant mass spectrum with a statistical significance of 7.6 sigma. The mass and width are measured to be M = 1842.2 +/- 4.2(-2.6)(+7.1) MeV/c(2) and Gamma = 83 +/- 14 +/- 11 MeV. The product branching fraction is determined to be B(J/psi -> gamma X(1840) x B(X(1840) -> 3(pi(+)pi(-))) = (2.44 +/- 0.36(-0.74)(+0.60)) x 10(-5). No eta' signals are observed in the 3(pi(+) pi(-)) invariant mass spectrum, and the upper limit of the branching fraction for the decay eta' -> 3(pi(+) pi(-)) is set to be 3.1 x 10(-5) at a 90% confidence level.