THE IMPULSE APPROXIMATION AND EXPERIMENT
The results of the calculations are compared with
the experimental data in Figs. 1- 14.
A calculation in which the coefficients in the potential were evaluated
in terms of the amplitudes for free xN scattering, taken at the
energy determined by the initial particle, is shown by the dashed curves
(in the impulse approximation). It is evident from Figs. 2,
7, 9, and
10 that in this case the results of the
calculations for p A and pA scattering
agree with the conclusions of other authors discussed above, i.e., for
p +,- 12C scattering it is possible
to obtain satisfactory agreement with experiment at pion energies above
100 MeV for the total cross sections s tot
and the reaction cross sections the reaction cross sections s
r (Figs. 7a and 7b), and above
70 MeV for the elastic-scattering differential distributions (Figs. 9
and 10).
For p 12C and p4He
interactions, the calculated results are close to the experimental data
in the region of energies above 300 MeV (see Figs. 2a,
2b, and 4). It is found that for the
total cross section s tot, of the
pd interaction (Fig. 2d) over the
entire interval of energies the theoretical cross sections are larger than
the experimental ones. This excess becomes smaller with increasing energy.
An analogous picture (Figs. 2a - 2c) is
seen for p12C and p4He interactions
in the interval 100-300 MeV. In the range of energies below 70- 100 MeV
for p12C and p4He interactions, a different
picture is observed (see Figs. la - 1c):
the calculated total cross sections s tot
are smaller than the experimental ones, and the reaction cross sections
s r are close to experiment. An analysis
has shown that this situation occurs because the calculation underestimates
the elastic-scattering cross sections [mainly as a result of a substantial
underestimation of small- angle scattering (see Figs.
3 and 5) ]. In contrast to pA
and p A interactions, the calculated results
for scattering of K+ on d and 12C in
the impulse approximation are found to be very close to the experimental
data (see Figs. 11-14
and Refs. 40 and 41). This may indicate that
the mechanism of the K+ A interaction is simpler than
that of the p-nucleus and p -nucleus
interactions.
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