Lepton angular distributions of fixed-target Drell-Yan experiments in perturbative QCD and a geometric approach
| Autor: | Chang, Wen-Chen, McClellan, Randall Evan, Peng, Jen-Chieh, Teryaev, Oleg |
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| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | Phys. Rev. D 99, 014032 (2019) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.99.014032 |
| Popis: | The lepton angular distributions of the Drell-Yan process in fixed-target experiments are investigated by NLO and NNLO perturbative QCD. We present the calculated angular parameters $\lambda$, $\mu$, $\nu$ and the degree of violation of the Lam-Tung relation, $1-\lambda-2\nu$, for the NA10, E615 and E866 experiments. Predictions for the ongoing COMPASS and SeaQuest experiments are also presented. The transverse momentum ($q_T$) distributions of $\lambda$ and $\nu$ show a clear dependence on the dimuon mass ($Q$) while those of $\mu$ have a strong rapidity ($x_F$) dependence. Furthermore, $\lambda$ and $\nu$ are found to scale with $q_T/Q$. These salient features could be qualitatively understood by a geometric approach where the lepton angular distribution parameters are expressed in terms of the polar and azimuthal angles of the "natural axis" in the dilepton rest frame. Comment: published version, two-column format, 10 pages, 14 figures |
| Databáze: | arXiv |
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