Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the distances between entangled pseudoscalar mesons states   Entangled states of pseudoscalar mesons represent a very interesting tool for
studying foundations of quantum mechanics, e.g. for testing Bell inequalities.
Recently, they also emerged as a test bench for quantum information protocols.
On the other hand, from a quantum information point of view, the
characterization of the distance between two quantum states is a topic of the
utmost importance. In this letter, with the purpose of providing a useful tool
for further investigations, we address the problem of which distance allows a
better discrimination between density matrices appearing in pseudoscalar
phenomenology.

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The categories of this paper are: cs
3
The categories of this paper are: physics
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
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The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph
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The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
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The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg