VI Reunião de Trabalho Física Nuclear.pdf - Sociedade Brasileira ...

A way of simplifying the analysis of data such as the
one above is through the construction of a component in the
optical potential that represents the feed-back of the.inelastic.
2 4 channel into the elastic channel. This may easily be done.
through Feshbach's theory of the optical potential, which gives,
in the particular case of two channels, the following form of the
polarization potential
1+1
V 1:0. 0LA
(.7 = V (V: )1 a jP)VZo C i.1)
OL
where V02 (r) is the coupling potential and G 2
the 2 4 -channel Coulomb-modified Green's function.
V pol
(r,r') is
When expanded in partial waves, the radial part of
would necessarily be angular momentum dependent and non-
local. However a locally-equivalent potential may be obtained
approximately through the identification
5V (7r il * ay') dr' V di c 04'
P
Ckr)
Pitt it (16)
where yk,r) represents the radial wave function in the
elastic channel. At sub-barrier energies, O t (k,r) may be
approximated by the regular Coulomb wave function F i lk,r)
which makes possible the construction of V pol (r) . The resulting
expression for vpo1 (r) may be written as 13) , ignoring the
energy loss involved in the excitation process,
V if 6020r3.er—li. I -SI
10-=...i.rif
160. x1 e t Li (.14) z -f -1-46-14-;i*A.`1 *24- (1. 7)
(1÷0-1. 664. a` ri i" y/3
4
(15)_
As a result of the assumption that the energy loss is
123