Evidence of ${\rm Y}(1S)\to J/\psi +{\chi }_{c1}$ and search for double-charmonium production in ${\rm Y}(1S)$ and ${\rm Y}(2S)$ decays

Abstract

Using data samples of $102\times 10^6$ ${\rm Y}(1S)$ and $158\times 10^6$ ${\rm Y}(2S)$ events collected with the Belle detector, a first experimental search has been made for double-charmonium production in the exclusive decays ${\rm Y}(1S,2S)\to J/\psi ({\psi }^{\prime })+X$, where $X={\eta }_c$, ${\chi }_{cJ}(J=0,1,2)$, ${\eta }_c(2S)$, $X(3940)$, and $X(4160)$. No significant signal is observed in the spectra of the mass recoiling against the reconstructed $J/\psi$ or ${\psi }^{\prime }$ except for the evidence of ${\chi }_{c1}$ production with a significance of $4.6\sigma$ for ${\rm Y}(1S)\to J/\psi +{\chi }_{c1}$. The measured branching fraction $\BR(Υ(1S)\rightarrow J/ψ+χ_{c1})$ is $(3.90\pm 1.21(stat.)\pm 0.23(syst.))\times 10^{-6}$. The $90\%$ confidence level upper limits on the branching fractions of the other modes having a significance of less than $3\sigma$ are determined. These results are consistent with theoretical calculations using the nonrelativistic QCD factorization approach.

12 pages, 4 figures, 1 table. The fit range was extended to include X(4160) signal according to referee's suggestions. Other results unchanged. Paper was accepted for publication as a regular article in Physical Review D

References in corpus (14)

• PYTHIA 6.4 Physics and Manual
• Big-Bang Nucleosynthesis
• Heavy quarkonium: progress, puzzles, and opportunities
• Search for new charmonium states in the processes e+ e- --> J/psi D(*) D(*) at sqrt{s} ~ 10.6 GeV
• Improved determination of color-singlet nonrelativistic QCD matrix elements for S-wave charmonium
• Relativistic corrections to $J/\psi$ exclusive and inclusive double charm production at B factories
• Resummation of Relativistic Corrections to e+ e- -> J/psi+eta_c
• Measurement of the e+e- -> J/psi ccbar cross section at \sqrt{s} ~10.6 GeV
• $O({\alpha }_s{v}^2)$ correction to $e^{+}{e}^{-}\to J/\psi +{\eta }_c$ at $B$ factories
• Exclusive $et{a}_b$ decay to double $J/\psi$ at next-to-leading order in $alph{a}_s$
• Which hadronic decay modes are good for ${\eta }_b$ searching: double $J/\psi$ or something else?
• Exclusive Double Charmonium Production from ${\rm Y}$ Decay
• Pseudoscalar Quarkonium Exclusive Decays to Vector Meson Pair
• Search for double charmonium decays of the P-wave spin-triplet bottomonium states

Cited by in corpus (2)

• Systematics of fully heavy tetraquarks
• Experimental review of the ${\rm Y}(1S,2S,3S)$ physics at $e^{+}{e}^{-}$ colliders and the LHC