Tetraquark interpretation of the BELLE data on the anomalous $\Upsilon(1S) \pi^+\pi^-$ and $\Upsilon(2S) \pi^+\pi^-$ production near the $\Upsilon(5S)$ resonance

Understand

We analyze the Belle data [K.

• F.
• Chen {\it et al.} (Belle Collaboration), Phys.\ Rev.\ Lett.\ {\bf 100}, 112001 (2008); I.
• Adachi {\it et al.} (Belle Collaboration), arXiv:0808.2445] on the processes $e^+ e^- \to \Upsilon(1S)\; \pi^+\pi^-, \Upsilon(2S)\; \pi^+\pi^-$ near the peak of the $\Upsilon(5S)$ resonance, which are found to be anomalously large in rates compared to similar dipion transitions between the lower $\Upsilon$ resonances.