We study the ultraviolet asymptotics in affine Toda theories. These models
are considered as perturbed non-affine Toda theories. We calculate the
reflection amplitudes, which relate different exponential fields with the same
quantum numbers. Using these amplitudes we derive the quantization condition
for the vacuum wave function, describing zero-mode dynamics, and calculate the
UV asymptotics of the effective central charge. These asymptotics are in a good
agreement with thermodynamic Bethe ansatz results.Comment: 20 pages, 2 ps figures, LaTeX 2e. We added the last section,
"Concluding Remarks", in which the new result for the one point function <
\exp a\cdot\phi > in ADE affine Toda theories is given explicitly. Version to
appear in Nucl. Phys.
