Peking Univ, Sch Phys, Beijing 100871, Peoples R China; Chinese Acad Sci, Inst Theoret Phys, Beijing 100080, Peoples R China
英文摘要:
It is shown that the four-particle amplitude of superstring theory at two loops obtained in [1, 2] is equivalent to the previously obtained results in [3]-[5]. Here the Z(2) symmetry in hyperelliptic Riemann surface plays an important role in the proof.
