Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Propagation of a $K$-body force into $A$-body space   The calculation of the spreading width of a compound nuclear reaction caused
by a symmetry breaking $K$-body force acting in an $A$-body system ($K << A$,
usually $K=2$) involves the determination of the local average square matrix
element in $A$-body space. This problem is reduced to finding the global mean
square matrix element $v^2$ in $K$-body space. The result is a compact formula
for the spreading width which contains $v^2$ as an input. Our method is based
on the dilute gas approximation for excitons close to the Fermi edge. The
relative strength of the contributions of operators with different exciton rank
as well as the connection between the energy dependence of the spreading width
and the body rank of the underlying interaction are established.

8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph