We locate resonances inη-light nucleus elastic scattering using the time delay method. We solve few-body equations within the finite rank approximation in order to calculate the t-matrices and hence the time delay for theη-³He andη-⁴He systems. We find a resonance very close to the threshold inη-³He elastic scattering, at about 0.5 MeV above threshold with a width of ∼2 MeV. The calculations also hint at the presence of sub-threshold states in both the cases

We briefly review the so-called `proton puzzle’, i.e., the disagreement of the newly extracted value of the proton charge radius $r_p$ from muonic hydrogen spectroscopy with other extractions, its possible significance and related problems. After describing the conventional theory to extract the proton radius from atomic spectroscopy we focus on a novel consistent approach based on the Breit equation. With this new tool, we confirm that the radius has indeed become smaller compared to the value extracted from scattering experiments, but the existence of different theoretical approaches casts some doubt on the accuracy of the new value. Precision measurements in atomic physics do provide the opportunity to extract light nuclear radii but the accuracy is limited by the methods of incorporating the nuclear structure effects.