Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Potential NRQCD for unequal masses and the $B_c$ spectrum at NNNLO   We determine the $1/m$ and $1/m^2$ spin-independent heavy quarkonium
potentials in the unequal mass case with $\mathcal O(\alpha^3)$ and $\mathcal
O(\alpha^2)$ accuracy, respectively. We discuss in detail different methods to
calculate the potentials, and show the equivalence among them. In particular we
obtain, for the first time, the manifestly gauge invariant $1/m$ and $1/m^2$
potentials in terms of Wilson loops with next-to-leading order (NLO) precision.
As an application of our results we derive the theoretical expression for the
$B_c$ spectrum in the weak-coupling limit through
next-to-next-to-next-to-leading order (N$^3$LO).

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The categories of this paper are: hep-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: econ
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The categories of this paper are: comp-gas
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The categories of this paper are: quant-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: alg-geom
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The categories of this paper are: physics
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The categories of this paper are: supr-con
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The categories of this paper are: cond-mat
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-bio
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The categories of this paper are: nucl-th
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The categories of this paper are: gr-qc
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The categories of this paper are: q-alg