Measurement of the hybrid content of heavy quarkonia using lattice nonrelativistic QCD

Using lowest-order lattice nonrelativistic QCD to create heavy meson propagators and applying the spin-dependent interaction, c_B(-g/2m_q)σ^→-B^→, at varying intermediate time slices, we compute the off-diagonal matrix element of the Hamiltonian for the quarkonium-hybrid two-state system. Thus far, we have results for one set of quenched lattices with an interpolation in quark mass to match the bottomonium spectrum. After diagonalization of the two-state Hamiltonian, we find the ground state of the Y to show a 0.0035(1)c_B² (with c_B²∼1.5-3.1) probability admixture of hybrid, |bb̄g〉.