Renormalization factor of four fermi operators with clover fermion and Iwasaki gauge action

Renormalization factors of four-quark operators are perturbatively calculated for the improved Wilson fermion with clover term and the Iwasaki gauge action. A main application shall be the $K\to\pi\pi$ decay amplitude and the calculation is restricted to the parity odd operator, for which the operators are multiplicatively renormalizable without mixing with wrong operators that have different chiral structures.