Complete three-loop QCD corrections to leptonic width of vector quarkonium
| Autor: | Feng, Feng, Jia, Yu, Mo, Zhewen, Pan, Jichen, Sang, Wen-Long, Zhang, Jia-Yue |
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| Rok vydání: | 2022 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Within the nonrelativistic QCD (NRQCD) factorization framework, we compute the order-$\alpha_s^3$ perturbative corrections to the leptonic decay of the $\Upsilon$ and $J/\psi$ with high numerical accuracy, at the lowest order in velocity expansion. We confirm the existing three-loop results in literature. Furthermore, we explicitly consider the complex-valued light-by-light (singlet) contributions. We for the first time also consider the finite charm quark mass effect for $\Upsilon$ leptonic decay, and obtain a new piece of 3-loop contribution to the anomalous dimension related to the composite NRQCD bilinear of vector current that arises from the nonzero charm quark mass. Based on the complete three-loop NRQCD short-distance coefficients, we also present a comprehensive phenomenological analysis for $\Upsilon(J/\psi)$ leptonic width. Comment: 16 pages, 7 figures |
| Databáze: | arXiv |
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