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arXiv · 2310.19328

Towards higher-order calculations of quarkonia production with $k_T$-factorization: $P$-wave charmonia

S. P. Baranov·A. V. Lipatov·A. A. Prokhorov·X. Chen
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Abstract

Inclusive $P$-wave charmonia production in hadronic collisions at high energies is discussed in the framework of non-relativistic QCD and $k_T$-factorization formalism. We present two consistent approches to merge the usual leading order $k_T$-factorization calculations with tree-level next-to-leading order off-shell amplitudes. Using these prescriptions, we extracted long-distance matrix elements for $χ_c$ mesons from a combined fit to available Tevatron and LHC data. In contrast to previous (leading order) calculations, our fits do not contradict equal color singlet wave functions of $χ_{c1}$ and $χ_{c2}$ states. The extracted values of long-distance matrix elements are employed to analyse the $χ_c$ polarization data reported recently by the CMS Collaboration. Our predictions are in a reasonably good agreement with the Tevatron and LHC measurements within the theoretical and experimental uncertainties.

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S. P. Baranov, A. V. Lipatov, A. A. Prokhorov, X. Chen. 2023-10-30. Towards higher-order calculations of quarkonia production with $k_T$-factorization: $P$-wave charmonia. https://arxiv.org/abs/2310.19328

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