Spin analysis of theχbstates

Abstract

Angular correlations in the cascade reaction $e^{+}$ $e^{\mathrm{-}}$→Υ(2S)→γ${\chi }_b$, ${\chi }_b$→γΥ, Υ→${\mu }^{+}$ ${\mu }^{\mathrm{-}}$ or Υ→$e^{+}$ $e^{\mathrm{-}}$, have been used for the first time to investigate the spins of the ${\chi }_b$ states. The results support the ${\chi }_b$ spins predicted by the potential models of heavy quarkonia.