Search for new bottomonium-like state in Belle ϒ(5S) data

Using data samples collected with the Belle detector at the ϒ(5S) resonance,the e⁺e^－→π⁺π^－ϒ (nS) and π⁺π^－h_b (mP) (n=1，2，3，m=1，2) processes were investigated. Two charged bottomonium-like states Z_b(10610) and Z_b(10650) were observed in the π^±ϒ(nS) and π^±h_b (mP) invariant mass distributions. Since they decay into bottomonium states and are charged, they must have at least four quarks in their composition. Very recently, e⁺e^－→π⁺π^－π⁰ γ ϒ (1S) was also studied, and a search for the X(3872)-like state, X_b , was performed in the bottom sector.