Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Signature of clustering in quantum many body systems probed by the giant
  dipole resonance   The present experimental study illustrates how large deformations attained by
nuclei due to cluster formation are perceived through the giant dipole
resonance (GDR) strength function. The high energy GDR $\gamma$-rays have been
measured from $^{32}$S at different angular momenta ($J$) but similar
temperatures in the reactions $^{4}$He(E$_{lab}$=45MeV) + $^{28}$Si and
$^{20}$Ne(E$_{lab}$=145MeV) + $^{12}$C. The experimental data at lower J
($\sim$ 10$\hbar$) suggests a normal deformation, similar to the ground state
value, showing no potential signature of clustering. However, it is found that
the GDR lineshape is fragmented into two prominent peaks at high J ($\sim$
20$\hbar$) providing a direct measurement of the large deformation developed in
the nucleus. The observed lineshape is also completely different from the ones
seen for Jacobi shape transition at high $J$ pointing towards the formation of
cluster structure in super-deformed states of $^{32}$S at such high spin. Thus,
the GDR can be regarded as a unique tool to study cluster formation at high
excitation energies and angular momenta.

21
The categories of this paper are: adap-org
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex