Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Direct Calculation of the Boundary $S$ Matrix for the Open Heisenberg
  Chain   We calculate the boundary $S$ matrix for the open antiferromagnetic spin
$1/2$ isotropic Heisenberg chain with boundary magnetic fields. Our approach,
which starts from the model's Bethe Ansatz solution, is an extension of the
Korepin-Andrei-Destri method. Our result agrees with the boundary $S$ matrix
for the boundary sine-Gordon model with $\beta^2 \rightarrow 8\pi$ and with
``fixed'' boundary conditions.

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The categories of this paper are: eess
30
The categories of this paper are: q-alg
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The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
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The categories of this paper are: math-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
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The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
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The categories of this paper are: supr-con
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The categories of this paper are: astro-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: atom-ph
34
The categories of this paper are: chem-ph