Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Is friction responsible for the reduction of fusion rates far below the
  Coulomb barrier?   The fusion of two interacting heavy ions traditionally has been interpreted
in terms of the penetration of the projectile into the target. Observed rates
well below the Coulomb barrier are considerably lower than estimates obtained
from penetration factors. One approach in the analysis of the data invokes
coupling to non-elastic channels in the scattering as the source of the
depletion. Another is to analyze those data in terms of tunneling in
semi-classical models, with the observed depletion being taken as evidence of a
``friction'' under the barrier. A complementary approach is to consider such
tunneling in terms of a fully quantal model. We investigate tunneling with both
one-dimensional and three-dimensional models in a fully quantal approach to
investigate possible sources for such a friction. We find that the observed
phenomenon may not be explained by friction. However, we find that under
certain conditions tunneling may be enhanced or diminished by up to 50%, which
finds analogy with observation, without the invocation of a friction under the
barrier.

30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an