Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Parity and Charge Conjugation Symmetries and S Matrix of the XXZ Chain   We formulate the notion of parity for the periodic XXZ spin chain within the
Quantum Inverse Scattering Method. We also propose an expression for the
eigenvalues of the charge conjugation operator. We use these discrete
symmetries to help classify low-lying S^z=0 states in the critical regime, and
we give a direct computation of the S matrix.

22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc