Observation of ${\rm Y}(4S)\to {\eta }^{\prime }{\rm Y}(1S)$

Abstract

We report the first observation of the hadronic transition ${\rm Y}(4S)\to {\eta }^{\prime }{\rm Y}(1S)$, using 496 fb${}^{-1}$ data collected at the ${\rm Y}(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. We reconstruct the ${\eta }^{\prime }$ meson through its decays to ${\rho }^0\gamma$ and to ${\pi }^{+}{\pi }^{-}\eta$, with $\eta \to \gamma \gamma$. We measure: $\mathcal{B}({\rm Y}(4S)\to {\eta }^{\prime }{\rm Y}(1S))=(3.43\pm 0.88(stat.)\pm 0.21(syst.))\times 10^{-5}$, with a significance of 5.7$\sigma$.

arXiv comment6 pages, 4 figures. Submitted to PRL

References in corpus (14)

• Heavy quarkonium: progress, puzzles, and opportunities
• QCD and strongly coupled gauge theories: challenges and perspectives
• Charmonium Decays of $Y(4260), psi(4160), and psi(4040)
• Electron Identification in Belle
• Spectroscopy at B-factories Using Hard Photon Emission
• QCD Multipole Expansion and Hadronic Transitions in Heavy Quarkonium Systems
• Precision Study of ${\eta }^{\prime }\to \gamma {\pi }^{+}{\pi }^{-}$ Decay Dynamics
• Study of hadronic transitions between Y states and observation of Y(4S)-> eta Y(1S) decay
• First observation of the hadronic transition ${\rm Y}(4S)\to \eta h_b(1P)$ and new measurement of the $h_b(1P)$ and ${\eta }_b(1S)$ parameters
• Measurement of ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}{e}^{+}{e}^{-}$ and ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}{\mu }^{+}{\mu }^{-}$
• Observation of $e^{+}{e}^{-}\to {\eta }^{\prime }J/\psi$ at center-of-mass energies between 4.189 and 4.600 GeV
• Study of $\eta$ and dipion transitions in ${\rm Y}(4S)$ decays to lower bottomonia
• Hadronic transitions from Upsilon(4S) as a probe of four-quark admixture
• Inclusive study of bottomonium production in association with an $\eta$ meson in $e^{+}{e}^{-}$ annihilations near ${\rm Y}(5S)$

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