Measurement of e+ e- ---> pi+ pi- J/psi cross-section via initial state radiation at Belle

Collaboration
Jul, 2007
11 pages
Published in:
  • Phys.Rev.Lett. 99 (2007) 182004
e-Print:
Report number:
  • BELLE-PREPRINT-2007-31,
  • KEK-PREPRINT-2007-23
Experiments:

Citations per year

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Abstract: (arXiv)
The cross section for e^+e^- to pi^+pi^-J/psi between 3.8 and 5.5 GeV/c^2 is measured using a 548 fb^{-1} data sample collected on or near the Upsilon(4S) resonance with the Belle detector at KEKB. A peak near 4.25 GeV/c^2, corresponding to the so called Y(4260), is observed. In addition, there is another cluster of events at around 4.05 GeV/c^2. A fit using two interfering Breit-Wigner shapes describes the data better than one that uses only the Y(4260), especially for the lower mass side of the 4.25 GeV enhancement.
Note:
  • 11 pages, 5 figures, 2 tables/ version to appear in PRL
  • 14.40.Gx
  • 13.66.Bc
  • 13.25.Gv
  • electron-positron interactions
  • hadron electroproduction
  • pion production
  • psi mesons
  • Upsilon meson resonances
  • electron positron: colliding beams
  • electron positron: annihilation