Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin alignment of leading K*(892)^0 mesons in hadronic Z^0 decays   Helicity density matrix elements for inclusive K*(892)^0 mesons from hadronic
Z^0 decays have been measured over the full range of K^*0 momentum using data
taken with the OPAL experiment at LEP. A preference for occupation of the
helicity zero state is observed at all scaled momentum x_p values above 0.3,
with the matrix element rho_00 rising to 0.66 +/- 0.11 for x_p > 0.7. The
values of the real part of the off-diagonal element rho_1-1 are negative at
large x_p, with a weighted average value of -0.09 +/- 0.03 for x_p > 0.3, in
agreement with new theoretical predictions based on Standard Model parameters
and coherent fragmentation of the qq(bar) system from the Z^0 decay. All other
helicity density matrix elements measured are consistent with zero over the
entire x_p range. The K^*0 fragmentation function has also been measured and
the total rate determined to be 0.74 +/- 0.02 +/- 0.02 K*(892)^0 mesons per
hadronic Z^0 decay.

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The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
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The categories of this paper are: math-ph
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The categories of this paper are: hep-th
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The categories of this paper are: quant-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: cs
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The categories of this paper are: funct-an
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The categories of this paper are: q-fin
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The categories of this paper are: comp-gas
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The categories of this paper are: q-alg
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The categories of this paper are: ao-sci
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The categories of this paper are: supr-con
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The categories of this paper are: stat
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The categories of this paper are: econ