Theta-Induced Electric Dipole Moment of the Neutron via QCD Sum Rules

Abstract

Using the QCD sum rule approach, we calculate the electric dipole moment of the neutron induced by a vacuum theta--angle to approximately 40-50% precision, d_n = 2.4 x 10^{-16} \theta e.cm. Combined with the new experimental bound, this translates into the limit |\theta|< 3 x 10^{-10}.

Comments: 4 pages, RevTeX: v2: typos corrected; v3: missing overall factor of two reinstated