Novel method to reliably determine the QCD coupling from R uds measurements and its effects to muon g − 2 and α M Z 2 $$ \alpha \left({M}_Z^2\right) $$ within the tau-charm energy region
Abstract We present a novel method for precisely determining the QCD running coupling from R uds measurements in electron-positron annihilation. When calculating the fixed-order perturbative QCD (pQCD) approximant of R uds, its effective coupling constant α s Q ∗ 2 $$ {\alpha}_s\left({Q}_{\ast}^2\ri...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2023-07-01
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| Series: | Journal of High Energy Physics |
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| Online Access: | https://doi.org/10.1007/JHEP07(2023)109 |
| _version_ | 1797647508288045056 |
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| author | Jian-Ming Shen Bing-Hai Qin Jiang Yan Sheng-Quan Wang Xing-Gang Wu |
| author_facet | Jian-Ming Shen Bing-Hai Qin Jiang Yan Sheng-Quan Wang Xing-Gang Wu |
| author_sort | Jian-Ming Shen |
| collection | DOAJ |
| description | Abstract We present a novel method for precisely determining the QCD running coupling from R uds measurements in electron-positron annihilation. When calculating the fixed-order perturbative QCD (pQCD) approximant of R uds, its effective coupling constant α s Q ∗ 2 $$ {\alpha}_s\left({Q}_{\ast}^2\right) $$ is determined by using the principle of maximum conformality, a systematic scale-setting method for gauge theories, whose resultant pQCD series satisfies all the requirements of renormalization group. Contribution due to the uncalculated higher-order (UHO) terms is estimated by using the Bayesian analysis. Using R uds data measured by the KEDR detector at 22 centre-of-mass energies between 1.84 GeV and 3.72 GeV, we obtain α s M Z 2 $$ {\alpha}_s\left({M}_Z^2\right) $$ = 0.1227 − 0.0132 + 0.0117 exp . ± 0.0016 the . $$ {0.1227}_{-0.0132}^{+0.0117}\left(\exp .\right)\pm 0.0016\left(\textrm{the}.\right) $$ , where the theoretical uncertainty (the.) is negligible compared to the experimental one (exp.). Numerical analyses confirm that the new method for calculating R uds removes conventional renormalization scale ambiguity, and the residual scale dependence due to the UHO-terms will also be highly suppressed due to a more convergent pQCD series. This leads to a significant stabilization of the perturbative series, and a significant reduction of theoretical uncertainty. It thus provides a reliable theoretical basis for precise determination of the QCD running coupling from R uds measurements at future Tau-Charm Facility. It can also be applied for the precise determination of the hadronic contributions to muon g − 2 and QED coupling α M Z 2 $$ \alpha \left({M}_Z^2\right) $$ within the tau-charm energy range. |
| first_indexed | 2024-03-11T15:18:33Z |
| format | Article |
| id | doaj.art-cad25b6690df42279a398c893ccf9c64 |
| institution | Directory Open Access Journal |
| issn | 1029-8479 |
| language | English |
| last_indexed | 2024-03-11T15:18:33Z |
| publishDate | 2023-07-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Journal of High Energy Physics |
| spelling | doaj.art-cad25b6690df42279a398c893ccf9c642023-10-29T12:06:35ZengSpringerOpenJournal of High Energy Physics1029-84792023-07-012023712210.1007/JHEP07(2023)109Novel method to reliably determine the QCD coupling from R uds measurements and its effects to muon g − 2 and α M Z 2 $$ \alpha \left({M}_Z^2\right) $$ within the tau-charm energy regionJian-Ming Shen0Bing-Hai Qin1Jiang Yan2Sheng-Quan Wang3Xing-Gang Wu4School of Physics and Electronics, Hunan Provincial Key Laboratory of High-Energy Scale Physics and Applications, Hunan UniversitySchool of Physics and Electronics, Hunan Provincial Key Laboratory of High-Energy Scale Physics and Applications, Hunan UniversityDepartment of Physics, Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing UniversityDepartment of Physics, Guizhou Minzu UniversityDepartment of Physics, Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing UniversityAbstract We present a novel method for precisely determining the QCD running coupling from R uds measurements in electron-positron annihilation. When calculating the fixed-order perturbative QCD (pQCD) approximant of R uds, its effective coupling constant α s Q ∗ 2 $$ {\alpha}_s\left({Q}_{\ast}^2\right) $$ is determined by using the principle of maximum conformality, a systematic scale-setting method for gauge theories, whose resultant pQCD series satisfies all the requirements of renormalization group. Contribution due to the uncalculated higher-order (UHO) terms is estimated by using the Bayesian analysis. Using R uds data measured by the KEDR detector at 22 centre-of-mass energies between 1.84 GeV and 3.72 GeV, we obtain α s M Z 2 $$ {\alpha}_s\left({M}_Z^2\right) $$ = 0.1227 − 0.0132 + 0.0117 exp . ± 0.0016 the . $$ {0.1227}_{-0.0132}^{+0.0117}\left(\exp .\right)\pm 0.0016\left(\textrm{the}.\right) $$ , where the theoretical uncertainty (the.) is negligible compared to the experimental one (exp.). Numerical analyses confirm that the new method for calculating R uds removes conventional renormalization scale ambiguity, and the residual scale dependence due to the UHO-terms will also be highly suppressed due to a more convergent pQCD series. This leads to a significant stabilization of the perturbative series, and a significant reduction of theoretical uncertainty. It thus provides a reliable theoretical basis for precise determination of the QCD running coupling from R uds measurements at future Tau-Charm Facility. It can also be applied for the precise determination of the hadronic contributions to muon g − 2 and QED coupling α M Z 2 $$ \alpha \left({M}_Z^2\right) $$ within the tau-charm energy range.https://doi.org/10.1007/JHEP07(2023)109Specific QCD PhenomenologyThe Strong CouplingHigher-Order Perturbative Calculations |
| spellingShingle | Jian-Ming Shen Bing-Hai Qin Jiang Yan Sheng-Quan Wang Xing-Gang Wu Novel method to reliably determine the QCD coupling from R uds measurements and its effects to muon g − 2 and α M Z 2 $$ \alpha \left({M}_Z^2\right) $$ within the tau-charm energy region Journal of High Energy Physics Specific QCD Phenomenology The Strong Coupling Higher-Order Perturbative Calculations |
| title | Novel method to reliably determine the QCD coupling from R uds measurements and its effects to muon g − 2 and α M Z 2 $$ \alpha \left({M}_Z^2\right) $$ within the tau-charm energy region |
| title_full | Novel method to reliably determine the QCD coupling from R uds measurements and its effects to muon g − 2 and α M Z 2 $$ \alpha \left({M}_Z^2\right) $$ within the tau-charm energy region |
| title_fullStr | Novel method to reliably determine the QCD coupling from R uds measurements and its effects to muon g − 2 and α M Z 2 $$ \alpha \left({M}_Z^2\right) $$ within the tau-charm energy region |
| title_full_unstemmed | Novel method to reliably determine the QCD coupling from R uds measurements and its effects to muon g − 2 and α M Z 2 $$ \alpha \left({M}_Z^2\right) $$ within the tau-charm energy region |
| title_short | Novel method to reliably determine the QCD coupling from R uds measurements and its effects to muon g − 2 and α M Z 2 $$ \alpha \left({M}_Z^2\right) $$ within the tau-charm energy region |
| title_sort | novel method to reliably determine the qcd coupling from r uds measurements and its effects to muon g 2 and α m z 2 alpha left m z 2 right within the tau charm energy region |
| topic | Specific QCD Phenomenology The Strong Coupling Higher-Order Perturbative Calculations |
| url | https://doi.org/10.1007/JHEP07(2023)109 |
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