Heavy-quark spin-symmetry partners of Zb(10610) and Zb(10650) molecules

V Baru,A A Filin,A V Nefediev,C Hanhart,E Epelbaum

doi:10.1051/epjconf/201921808005

Abstract

Heavy-quark spin-symmetry (HQSS) partners of the isovector bottomonium like states Zb(10610) and Zb(10650) are predicted within the molecular picture. Treating both Zb’s as shallow bound states, we solve the system of coupled-channel integral equations for the contact plus one-pion exchange (OPE) potentials to predict the location of the partner states with the quantum numbers J++ (J = 0,1,2). In particular, we predict the existence of a narrow tensor 2++ state residing a few MeV below the B∗ B¯∗ threshold. It is emphasised that the tensor part of the OPE potential in combination with HQSS breaking due to the nonvanishing B∗ -B mass splitting has a significant impact on the location of this partner state.

Highlights

Heavy-quark spin-symmetry (HQSS) partners of the isovector bottomoniumlike states Zb(10610) and Zb(10650) are predicted within the molecular picture
The experimental discovery and further studies by the Belle collaboration of the bottomonium-like JPC = 1+− resonances Zb(10610) and Zb(10650) [1,2,3] revealed very peculiar properties of these states
Heavy-quark spin-symmetry (HQSS) partners of the isovector bottomoniumlike states Zb(10610) and Zb(10650) are predicted within the molecular picture. Treating both Zb’s as shallow bound states, we solve the system of coupled-channel integral equations for the contact plus one-pion exchange (OPE) potentials to predict the location of the partner states with the quantum numbers J++ (J = 0, 1, 2)