Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Neutron width statistics using a realistic description of the neutron
  channel   A basic prediction of the statistical model of compound nucleus reactions is
that the partial widths for decay into any open channel channel fluctuate
according to the Porter-Thomas distribution (PTD). A recent experiment on $s$-
and $p$-wave neutron scattering from platinum isotopes found that the
experimental $s$-wave partial neutron width distributions deviated
substantially from the PTD. Several explanations for this finding have been
proposed within the statistical model, but none has resolved this issue. Here,
we review the application of a realistic resonance-reaction model to $s$-wave
neutron scattering from $^{194}$Pt. Our main conclusion is that the PTD
provides an excellent description of the partial neutron width distribution,
provided that the secular energy dependence of the average neutron width is
correctly described. Within a realistic range of model parameters, there can be
a near-threshold bound or virtual state of the neutron channel that changes
this secular dependence from the usual $\sqrt{E}$ dependence, as proposed by
Weidenm\"uller [1]. In this case, the use of the $\sqrt{E}$ dependence to
analyze the data will lead to apparent deviations from the PTD. We discuss the
limited parameter range where such a near threshold state can have a
significant effect.

6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an