Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Calibration of the photon spectrometer PHOS of the ALICE experiment   The procedure for the energy calibration of the high granularity
electromagnetic calorimeter PHOS of the ALICE experiment is presented. The
methods used to perform the relative gain calibration, to evaluate the
geometrical alignment and the corresponding correction of the absolute energy
scale, to obtain the nonlinearity correction coefficients and finally, to
calculate the time-dependent calibration corrections, are discussed and
illustrated by the PHOS performance in proton-proton (pp) collisions at
$\sqrt{s}$ = 13 TeV. After applying all corrections, the achieved mass
resolutions for $\pi^0$ and $\eta$ mesons for $p_{\rm{T}} > 1.7$ GeV/$c$ are
$\sigma_m^{\pi^0} = 4.56 \pm 0.03$ MeV/$c^2$ and $\sigma_m^{\eta} = 15.3 \pm
1.0$ MeV/$c^2$, respectively.

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The categories of this paper are: astro-ph
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The categories of this paper are: q-alg
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The categories of this paper are: stat
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The categories of this paper are: adap-org
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The categories of this paper are: eess
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The categories of this paper are: math
33
The categories of this paper are: plasm-ph
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The categories of this paper are: hep-th
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The categories of this paper are: econ
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The categories of this paper are: supr-con
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The categories of this paper are: funct-an
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The categories of this paper are: nlin
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The categories of this paper are: mtrl-th
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The categories of this paper are: gr-qc
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The categories of this paper are: nucl-ex
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The categories of this paper are: solv-int