Speaker
Prof.
Vladimir Vereshagin
(St.-Petersburg State University)
Description
I discuss the renormalization of the one-loop 2-leg functions in
multi-component effective scalar theory. It is shown that only a part of
numerous contributions that appear in the general expression for 2-leg
graph can be considered as the true self energy function. This part is
completely fixed by two conventional requirements -- correctness of the
pole position and the wave function normalization. This part is the only
one which should be taken into account in the conventional process of
simming Dyson's chain that results in explicit expression for the full
propagator in S-matrix graphs. The other parts provide well defined finite
corrections for the graphs with the number of legs n>2.
It is also shown that there is no need in attracting the prescriptions
for the higher derivatives of the 2-leg function on the mass shell: the
requirements of finiteness and diagonability turn out quite sufficient.
Author
Prof.
Vladimir Vereshagin
(St.-Petersburg State University)
