Comment on "A phenomenological ${\pi }^{-}p$ scattering length from pionic hydrogen''

Abstract

This short technical note addresses a number of issues regarding the estimates of the 2004 paper by Ericson, Loiseau, and Wycech for the corrections ${\delta }_{ϵ}$ and ${\delta }_{\Gamma }$, which aim at the removal of the effects of electromagnetic origin from the measurements of the strong-interaction shift ${ϵ}_{1s}$ and of the total decay width ${\Gamma }_{1s}$ of the ground state in pionic hydrogen.

Comments: Nine pages. Minor changes to the first version; correction of Ref. [6]