Possibility of Exotic States in the Upsilon system

Feb, 2008
5 pages
e-Print:
Report number:
  • TAUP-2869-07,
  • WIS-03-08-FEB-DPP,
  • ANL-HEP-PR-08-7

Citations per year

2008201220162020202401234567
Abstract: (arXiv)
Recent data from Belle show unusually large partial widths Upsilon(5S) --> Upsilon(1S) pi^+pi^- and \Upsilon(5S) --> \Upsilon(2S) pi^+ pi^-. The Z(4430) narrow resonance also reported by Belle in psi' pi^+ spectrum has the properties expected of a (cbar c u dbar) charged isovector tetraquark T^{+-}_cc The analogous state T^{+-} in the bottom sector might mediate anomalously large cascade decays in the Upsilon system, Upsilon(mS) --> T^{+-}_bb pi^{-+} --> Upsilon(nS) pi^+ \pi^-, with a tetraquark-pion intermediate state. We suggest looking for the (bbar b u dbar) tetraquark in these decays as peaks in the invariant mass of Upsilon(1S) pi or Upsilon(2S) pi systems. The (bbar b u sbar) tetraquark can appear in the observed decays Upsilon(5S) --> Upsilon(1S) K^+ K^- as a peak in the invariant mass of Upsilon(1S) K system. We review the model showing that these tetraquarks are below the two heavy meson threshold, but respectively above the Upsilon pi pi and Upsilon K Kbar thresholds.
  • hadron spectroscopy
  • upsilon mesons: hadronic decay
  • upsilon mesons: cascade decay
  • upsilon mesons: width
  • new particle: Z(4430)
  • meson: exotic
  • tetraquark
  • charm
  • bottom
  • numerical calculations