Parity violating elastic electron scattering from 27Al and the Qweak measurement

I calculate the parity violating asymmetry A_{pv} for elastic electron scattering from 27Al in order to compare with the Qweak experiment "background" 27Al measurement. I find that Coulomb distortions, and the quadrupole form factor, reduce A_{pv} near the diffraction minimum. The Qweak data can be used to confirm the neutron radius of 27Al, if nuclear structure uncertainties are indeed small, as I suggest, and one can estimate inelastic and impurity contributions. This could provide an important check of the measurement, analysis, and theory.