Nuclear polarization corrections in the mu-4He+ Lamb shift

Understand

Stimulated by the proton radius conundrum, measurements of the Lamb shift in various light muonic atoms are planned at PSI.

• The aim is to extract the rms charge radius with high precision, limited by the uncertainty in the nuclear polarization corrections.
• We present an ab-initio calculation of the nuclear polarization for mu-4He+ leading to an energy correction in the 2S-2P transitions of $\delta_{pol}=-2.47$ meV $\pm$ 6%.
• We use two different state-of-the-art nuclear Hamiltonians and utilize the Lorentz integral transform with hyperspherical harmonics expansion as few-body methods.