Using a sample of 158×106 Υ(2S) events collected with the Belle detector, we search for the first time for double-charmonium decays of the P-wave spin-triplet bottomonium states (Υ(2S) →γχ bJ, χ bJ→J/ψJ/ψ, J/ψψ ′, ψ ′ψ ′ for J=0, 1, and 2). No significant χ bJ signal is observed in the double-charmonium mass spectra, and we obtain the following upper limits: B(χ bJ→J/ψJ/ψ)<7.1×10 -5, 2.7×10 -5, 4.5×10 -5, B(χ bJ→ J/ψψ ′)<1.2×10 -4, 1.7×10 -5, 4.9×10 -5, B(χ bJ→ψ ′ψ ′)<3. 1×10 -5, 6.2×10 -5, 1.6×10 -5 for J=0, 1, and 2, respectively, at the 90% confidence level. These limits are significantly lower than the central values (with uncertainties of 50% to 70%) predicted using the light cone formalism but are consistent with calculations using the nonrelativistic QCD (NRQCD) factorization approach.
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|Publication status||Published - 2012 Apr 18|
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)