Investigation of Bbar B four-quark systems using lattice QCD

We investigate $B \bar B$ systems by computing potentials of two static quarks in the presence of two quarks of finite mass using lattice QCD. By solving the Schr\"odinger equation we check whether these potentials are sufficiently attractive to host bound states. Particular focus is put on the experimentally most promising bottomonium-like tetraquark candidate $Z_b^\pm$ with quantum numbers $I(J^P)=1(1^+)$.