Speaker
Description
We evaluate the hadronic vacuum polarization corrections to the Lamb shift and hyperfine splitting of $1S$ and $2S$ energy levels in ordinary and muonic hydrogen as well as ${}^3\mathrm{He}^+$ ions. Despite the smallness of these corrections, their precise knowledge is very important in view of the high experimental precision achieved in measurements of the spectra of both ordinary and muonic atoms and ions. While our results for the Lamb shift are consistent with the literature, the hyperfine splitting contributions significantly differ from the previous evaluations. Our updated evaluation of the hadronic vacuum polarization effects is especially important in view of the upcoming experiments designed to measure the hyperfine splitting of the $1S$ state in muonic hydrogen with a high precision, to be carried out by the CREMA and FAMU collaborations.