Branched conjugated diene copolymer, rubber composition and pneumatic tire

A rubber composition, comprising:

• a branched conjugated diene copolymer as a rubber component, in which a half width at half maximum of a viscoelasticity tan δ is 40 or less, where the half width at half maximum=(Higher temperature at half height of tan δ peak)−(Tanδ peak temperature),
• wherein the branched conjugated diene copolymer is composed of monomer components comprising a branched conjugated diene compound represented by a general formula (1):
• wherein R1 represents an aliphatic hydrocarbon group having 6 to 11 carbon atoms, and an aromatic vinyl compound represented by a general formula (2):
• wherein R2 represents an aromatic hydrocarbon group having 6 to 10 carbon atoms, and R5 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms,
• wherein a copolymerization ratio (m) of the aromatic vinyl compound (2) is 45% by mass or more,
• wherein the branched conjugated diene copolymer has glass transition temperature of −25° C. or more.