Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: General Constraints on Spin Observables, Applications to Antiproton
  Proton to Antilambda Lambda and to Polarized Quark Distributions   We review the density matrix formalism and the positivity conditions for
general multiple spin asymmetries, taking as an example the case antiproton +
proton -> antiLambda + Lambda, in which one, two or three spins are analyzed.
Some aspects related to quantum information and entangled states are discussed.
Some positivity domains for pairs and triplets of spin parameters are
displayed, together with the experimental points. The case of inclusive
reaction is also treated, taking as an example the spin- and transverse
momentum- dependent quark distributions.

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The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs