Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Universality of three-body systems in 2D: parametrization of the bound
  states energies   Universal properties of mass-imbalanced three-body systems in 2D are studied
using zero-range interactions in momentum space. The dependence of the
three-particle binding energy on the parameters (masses and two-body energies)
is highly non-trivial even in the simplest case of two identical particles and
a distinct one. This dependence is parametrized for ground and excited states
in terms of {\itshape supercircles} functions in the most general case of three
distinguishable particles.

5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con