Radiative transitions from Upsilon(5S) to molecular bottomonium

Abstract

The heavy quark spin symmetry implies that in addition to the recently observed Z(10610) and Z(10650) molecular resonances with $I^G=1^+$ there should exist two or four molecular bottomonium-like states with $I^G=1^-$. Properties of these G-odd states are considered, including their production in the radiative transitions from Upsilon(5S), by applying the same symmetry to the Upsilon(5S) resonance and the transition amplitudes. The considered radiative processes can provide a realistic option for observing the yet hypothetical states.