Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fine structure of the isoscalar giant quadrupole resonance in 40Ca due
  to Landau damping?   The fragmentation of the Isoscalar Giant Quadrupole Resonance (ISGQR) in 40Ca
has been investigated in high energy-resolution experiments using proton
inelastic scattering at E_p = 200 MeV. Fine structure is observed in the region
of the ISGQR and its characteristic energy scales are extracted from the
experimental data by means of a wavelet analysis. The experimental scales are
well described by Random Phase Approximation (RPA) and second-RPA calculations
with an effective interaction derived from a realistic nucleon-nucleon
interaction by the Unitary Correlation Operator Method (UCOM). In these results
characteristic scales are already present at the mean-field level pointing to
their origination in Landau damping, in contrast to the findings in heavier
nuclei and also to SRPA calculations for 40Ca based on phenomenological
effective interactions, where fine structure is explained by the coupling to
two-particle two-hole (2p-2h) states.

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The categories of this paper are: hep-th
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The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
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The categories of this paper are: eess
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The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th