Hadroproduction of $\Upsilon(nS)$ above $B\bar B$ Thresholds and Implications for $Y_b(10890)$

Abstract

Based on the non-relativistic QCD factorization scheme, we study the hadroproduction of the bottomonium states $\Upsilon(5S)$ and $\Upsilon(6S)$. We argue to search for them in the final states $\Upsilon(1S,2S,3S)\pi^+\pi^-$, which are found to have anomalously large production rates at $\Upsilon(5S)$. The enhanced rates for the dipionic transitions in the $\Upsilon(5S)$-energy region could, besides $\Upsilon(5S)$, be ascribed to $Y_b(10890)$, a state reported by the Belle collaboration, which may be interpreted as a tetraquark. The LHC/Tevatron measurements are capable of making a case in favor of or against the existence of $Y_b(10890)$, as demonstrated here. Dalitz analysis of the $\Upsilon(1S,2S,3S)\pi^+\pi^-$ states from the $\Upsilon(5S)/Y_b(10890)$ decays also impacts directly on the interpretation of the charged bottomonium-like states, $Z_b(10600)$ and $Z_b(10650)$, discovered by Belle in these puzzling decays.