Phenomenological reexamination of two-photon-exchange corrections to the proton recoil-polarization ratio μpGE/GM utilizing electron-proton elastic scattering experimental data

In this work, we have phenomenologically reexamined the ϵ dependence of the proton's recoil-polarization ratio R=μpGE/GM for possible two-photon-exchange (TPE) corrections beyond the one-photon-exchange (OPE) or Born approximation. High-precision Rosenbluth measurements of σR(ϵ,Q2) taken at Q2=2.64, 3.20, and 4.10GeV2 were used to extract the TPE coefficients needed to provide an estimate of the size of the TPE corrections to the ratio R, and construct the two TPE Y(M,E)(ϵ,Q2) amplitudes. Our results suggest that the ratio R shows very small (negligible) enhancement with ϵ, less than 0.40% in magnitude, with values consistent with the OPE prediction for the Q2 range studied. We also compare our results to previous phenomenological extractions and several theoretical calculations.