Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Chaotic scattering of a quantum particle weakly coupled to a very
  complicated background   Effect of a complicated many-body environment is analyzed on the chaotic
motion of a quantum particle in a mesoscopic ballistic structure. The dephasing
and absorption phenomena are treated on the same footing in the framework of a
model which is free of the ambiguities inherent to earlier models. The
single-particle doorway resonance states excited via an external channel are
damped not only because of the escape onto such channels but also due to
ulterior population of long-lived background states, the resulting internal
damping being uniquely characterized by the spreading width. On the other hand,
the formation of the fine-structure resonances strongly enhances the delay time
fluctuations thus broadening the delay time distribution.

19
The categories of this paper are: eess
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ