Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pygmy dipole resonance in 208Pb   Scattering of protons of several hundred MeV is a promising new spectroscopic
tool for the study of electric dipole strength in nuclei. A case study of 208Pb
shows that at very forward angles J^pi = 1- states are strongly populated via
Coulomb excitation. A separation from nuclear excitation of other modes is
achieved by a multipole decomposition analysis of the experimental cross
sections based on theoretical angular distributions calculated within the
quasiparticle-phonon model. The B(E1) transition strength distribution is
extracted for excitation energies up to 9 MeV, i.e., in the region of the
so-called pygmy dipole resonance (PDR). The Coulomb-nuclear interference shows
sensitivity to the underlying structure of the E1 transitions, which allows for
the first time an experimental extraction of the electromagnetic transition
strength and the energy centroid of the PDR.

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The categories of this paper are: dg-ga
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an