Neutron electric dipole moment from electric and chromoelectric dipole moments of quarks

Using QCD sum rules, we calculate the electric dipole moment of the neutron d_n induced by all CP violating operators up to dimension five. We find that the chromoelectric dipole moments of quarks d~_i, including that of the strange quark, provide significant contributions comparable in magnitude to those induced by the quark electric dipole moments d_i. When the theta term is removed via the Peccei-Quinn symmetry, the strange quark contribution is also suppressed and d_n=(1+/-0.5)\{0.55e(d~_d+0.5d~_u)+0.7(d_d-0.25d_u)\}.