Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hexadecapole fluctuation mechanism for s-wave heavy fermion
  superconductor CeCu2Si2: Interplay between intra- and inter-orbital Cooper
  pairs   In heavy-fermion superconductors, it is widely believed that the
superconducting gap function has sign-reversal due to the strong electron
correlation. However, recently discovered fully-gapped s-wave superconductivity
in CeCu2Si2 has clarified that strong attractive pairing interaction can appear
even in heavy-fermion systems. To understand the origin of attractive force, we
develop the multipole fluctuation theory by focusing on the inter-multipole
many-body interaction called the vertex corrections. By analyzing the periodic
Anderson model for CeCu2Si2, we find that hexadecapole fluctuations mediate
strong attractive pairing interaction. Therefore, fully-gapped s-wave
superconductivity is driven by pure on-site Coulomb repulsion, without
introducing electron-phonon interactions. The present theory of
superconductivity will be useful to understand rich variety of the
superconducting states in heavy fermion systems.

6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin