Generalized Radiative Corrections for Hadronic Targets

Abstract

After the pionnering work of Schwinger in the ’40s for potential scattering, the most elaborate and widely used radiative correction procedure for electro-magnetic scattering on hadronic targets remains that given in the ’60s by Y. S. Tsai¹⁾ for structureless spin zero bosons. However, with the enhanced accuracy of new experimental data — the error is currently down to 1–2% on electron scattering cross sections -, and the improvements in theoretical models and computing power, some of the approximations acceptable then may be questioned today. The error on the computed radiative correction due to these approximations is difficult to estimate because “[Publications] present only the result and very few intermediary steps of the calculation” as Källén and Sabry remarked sadly 35 years ago²⁾, let alone unstated approximations, overlooked divergences and ad hoc compensations “guessed on intuitive physical grounds”. Moreover, when the target is scattered into several components, a procedure to radiatively correct coincidence experiments is still wanting.