Biomedical subjects

P G Blunden

Publications and source records attributed to P G Blunden.

2 recordsLinked to original sources

PubMed2005

Delta resonance contribution to two-photon exchange in electron-proton scattering.

We calculate the effects on the elastic electron-proton scattering cross section of the two-photon exchange contribution with an intermediate Delta resonance. The Delta two-photon exchange contribution is found to be smaller in magnitude than the previously evaluated nucleon contribution, with an opposite sign at backward scattering angles. The sum of the nucleon and Delta two-photon exchange corrections has an angular dependence compatible with both the polarization-transfer and the Rosenbluth methods of measuring the nucleon electromagnetic form factors.

Journal Article↗

PubMed2003

Two-photon exchange and elastic electron-proton scattering.

Two-photon exchange contributions to elastic electron-proton scattering cross sections are evaluated in a simple hadronic model including the finite size of the proton. The corrections are found to be small in magnitude, but with a strong angular dependence at fixed Q2. This is significant for the Rosenbluth technique for determining the ratio of the electric and magnetic form factors of the proton at high Q2, and partly reconciles the apparent discrepancy with the results of the polarization transfer technique.

Journal Article↗