The complete study on polarization of $\Upsilon(nS)$ hadroproduction at QCD next-to-leading order
| Autor: | Feng, Yu, Gong, Bin, Chang, Chao-Hsi, Wang, Jian-Xiong |
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| Rok vydání: | 2020 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/1674-1137/abc682 |
| Popis: | Applying the nonrelativistic quantum chromodynamics factorization formalism to the $\Upsilon(1S,2S,3S)$ hadroproduction, a complete analysis on the polarization parameters $\lambda_{\theta}$, $\lambda_{\theta\phi}$, $\lambda_{\phi}$ for the production are presented at QCD next-to-leading order. With the long-distance matrix elements extracted from experimental data for the production rate and polarization parameter $\lambda_{\theta}$ of $\Upsilon$ hadroproduction, our results provide a good description for the measured parameters $\lambda_{\theta\phi}$ and $\lambda_{\phi}$ in both the helicity and the Collins-Soper frames. In our calculations the frame invariant parameter $\tilde{\lambda}$ is consistent in the two frames. Finally, it is pointed out that there are discrepancies for $\tilde{\lambda}$ between available experimental data and corresponding theoretical predictions. Comment: 9 pages, 8 figures |
| Databáze: | arXiv |
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