Consistency of parity-violating pion-nucleon couplings extracted from measurements in 18F and 133Cs

The recent measurement of the nuclear anapole moment of 133Cs has been interpreted to yield a value of the weak pion-nucleon coupling Hπ1 which contradicts the upper limit from the 18F experiments. We argue that because of the sensitivity of the anapole moment to Hρ0 in the odd proton nucleus 133Cs, there is a combination of weak meson-nucleon couplings which satisfies both experiments and which is (barely) in agreement with theory. In addition, the anapole moment measurement in 205Tl gives a constraint which is inconsistent with the value from 133Cs, calling into question the theory of nuclear anapole moments. We argue that measurements of directional asymmetry in rvec n+p→d+γ and in the photodisintegration of the deuteron by circularly polarized photons, combined with results from pp scattering, would determine Hπ1 and several other weak meson-nucleon couplings in a model-independent way. copyright 1998 The American Physical Society