Evidence of Two Resonant Structures in <i>e</i><SUP>+</SUP><i>e</i><SUP>-</SUP>→π<SUP>+</SUP> π<SUP>-</SUP> <i>h<sub>c</sub></i>


Creative Commons License

Ablikim M., Achasov M. N., Ahmed S., Ai X. C., Albayrak O., Albrecht M., ...Daha Fazla

PHYSICAL REVIEW LETTERS, cilt.118, sa.9, 2017 (SCI-Expanded) identifier identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 118 Sayı: 9
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1103/physrevlett.118.092002
  • Dergi Adı: PHYSICAL REVIEW LETTERS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Bursa Uludağ Üniversitesi Adresli: Hayır

Özet

The cross sections of e(+)e(-) -> pi(+) pi(-) hc at center-of-mass energies from 3.896 to 4.600 GeVare measured using data samples collected with the BESIII detector operating at the Beijing Electron Positron Collider. The cross sections are found to be of the same order of magnitude as those of e(+)e(-) -> pi(+) pi(-) J/psi and e(+)e(-) -> pi(+) pi(-) psi (2S), but the line shape is inconsistent with the Y states observed in the latter two modes. Two structures are observed in the e(+)e(-) -> pi(+) pi(-) hc cross sections around 4.22 and 4.39 GeV/c(2), which we call Y(4220)and Y(4390), respectively. A fit with a coherent sum of two Breit-Wigner functions results in a mass of (4218.4(- 4.5)(vertical bar 5.5) +/- 0.9) MeV/ c(2) and a width of (66.0(- 8.3)(vertical bar 12.3) +/- 0.4) MeV for the Y(4220), and a mass of (4391.5(- 6.8)(+6.3) +/- 1.0) MeV/c(2) and a width of (139.5(- 20.6)(+16.2) +/- 0.6) MeV for the Y(4390), where the first uncertainties are statistical and the second ones systematic. The statistical significance of Y(4220) and Y(4390) is 10 sigma over one structure assumption.