Nucleon Deformation and Atomic Spectroscopy

Recent ineleastic electron-proton scattering experiments have led to rather accurate values for the N → ∆ transition quadrupole moment Q N →∆. The experimental results imply a prolate (cigar-shaped) intrinsic deformation of the nucleon. The nonsphericity of the proton's charge distribution might be seen in the spectrum of atomic hydrogen. The possibilities and limitations for determining the geometric shape of the nucleon in an atomic physics experiment are discussed.