Electromagnetic corrections in hadronic processes
The European Physical Journal C, 32 (1):
97--114 (Dec 22, 2003)DOI: 10.1140/epjc/s2003-01383-1
Abstract
In quantum field theory, the splitting of the Hamiltonian into a strong and
an electromagnetic part cannot be performed in a unique manner. We propose a
convention for disentangling these two effects: one matches the parameters of
two theories -- with and without electromagnetic interactions -- at a given
scale mu\_1, referred to as the matching scale. This procedure enables one to
analyze the separation of strong and electromagnetic contributions in a
transparent manner. We illustrate the method -- in the framework of the loop
expansion -- in a Yukawa model, as well as in the linear sigma model, where we
also investigate the corresponding low-energy effective theory.