Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Centrality and pseudorapidity dependence of the charged-particle
  multiplicity density in Xe-Xe collisions at $\sqrt{s_{\rm NN}}$ = 5.44 TeV   In this Letter, the ALICE Collaboration presents the first measurements of
the charged-particle multiplicity density, $\rm{d}N_{\rm{ch}}/\rm{d}\eta$, and
total charged-particle multiplicity, $N_{\rm{ch}}^{\rm{tot}}$, in Xe-Xe
collisions at a centre-of-mass energy per nucleon--nucleon pair of
$\sqrt{s_{\rm NN}}$ = 5.44 TeV. The measurements are performed as a function of
collision centrality over a wide pseudorapidity range of $-3.5 < \eta < 5$. The
values of $\rm{d}N_{\rm{ch}}/\rm{d}\eta$ at mid-rapidity and
$N_{\rm{ch}}^{\rm{tot}}$ for central collisions, normalised to the number of
nucleons participating in the collision ($N_{\rm{part}}$) as a function of
$\sqrt{s_{\rm NN}}$, follow the trends established in previous heavy-ion
measurements. The same quantities are also found to increase as a function of
$N_{\rm{part}}$, and up to the 5% most central collisions the trends are the
same as the ones observed in Pb-Pb at a similar energy. For more central
collisions, the Xe-Xe scaled multiplicities exceed those in Pb-Pb for a similar
$N_{\rm{part}}$. The results are compared to phenomenological models and
theoretical calculations based on different mechanisms for particle production
in nuclear collisions. All considered models describe the data reasonably well
within 15%.

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The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph
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The categories of this paper are: solv-int
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The categories of this paper are: econ
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The categories of this paper are: quant-ph
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The categories of this paper are: math-ph
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The categories of this paper are: supr-con
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The categories of this paper are: patt-sol
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The categories of this paper are: acc-phys
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The categories of this paper are: cond-mat
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The categories of this paper are: chem-ph
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The categories of this paper are: q-alg
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The categories of this paper are: adap-org
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-lat
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The categories of this paper are: q-bio