This week Thibault Damour and I put out two papers on potential violations of the equivalence principle due to light scalars. These are:
a short paper with the main results designed to be easier to read, and
I think that these will be useful for the field. Maybe the most unusual aspect is that they took 7.5 years to complete. On my sabbatical to the IHES, Thibault was discussing the EP and noted that the main unknown was in the effects of nuclear binding. This lead to my work on the quark mass dependence of nuclear binding, and our other collaborative work on limits on the variation of quark masses. So it has been a fruitful effort, but it sure did take longer than it needed to.