Abstract
In the framework of effective quantum field theory we address the definition
of physical quantities characterizing unstable particles. With the aid of a
one-loop calculation, we study this issue in terms of the charge and the
magnetic moment of a spin-1/2 resonance. By appealing to the invariance of
physical observables under field redefinitions we demonstrate that physical
properties of unstable particles should be extracted from the residues at
complex (double) poles of the corresponding S-matrix.
Users
Please
log in to take part in the discussion (add own reviews or comments).