1209.4667 (Gerald A. Miller)

Proton Polarizability Contribution: Muonic Hydrogen Lamb Shift and
Elastic Scattering    [PDF]

Gerald A. Miller

The uncertainty in the computed contribution to the Lamb shift in muonic hydrogen, DeltaE(subt) arising from proton polarizability effects entering in the two-photon exchange diagram at large virtual photon momenta is shown to be large enough to account for the proton radius puzzle. This is because the integral that determines DeltaE(subt) contains a logarithmic divergence. We evaluate this integral using a chosen form factor and also by using the dimensional regularization procedure which makes explicit the need for a low energy constant. The consequences of this new contribution to two photon exchange are approximately independent of the method of calculation and should be observable in a planned low energy lepton-proton scattering experiment planned to run at PSI.

View original: http://arxiv.org/abs/1209.4667