The P-wave charmonium annihilation into two photons $$\chi _{c0, c2}\rightarrow \gamma \gamma $$ χ c 0 , c 2 → γ γ with high-order QCD corrections
Abstract In this paper, we present a new analysis on the P-wave charmonium annihilation into two photons up to next-to-next-to-leading order (NNLO) QCD corrections by using the principle of maximum conformality (PMC). The conventional perturbative QCD prediction shows strong scale dependence and dev...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2021-07-01
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| Series: | European Physical Journal C: Particles and Fields |
| Online Access: | https://doi.org/10.1140/epjc/s10052-021-09424-x |
| _version_ | 1818576565692268544 |
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| author | Hua Zhou Qing Yu Xu-Dong Huang Xu-Chang Zheng Xing-Gang Wu |
| author_facet | Hua Zhou Qing Yu Xu-Dong Huang Xu-Chang Zheng Xing-Gang Wu |
| author_sort | Hua Zhou |
| collection | DOAJ |
| description | Abstract In this paper, we present a new analysis on the P-wave charmonium annihilation into two photons up to next-to-next-to-leading order (NNLO) QCD corrections by using the principle of maximum conformality (PMC). The conventional perturbative QCD prediction shows strong scale dependence and deviates largely from the BESIII measurements. After applying the PMC, we obtain a more precise scale-invariant pQCD prediction, which also agrees with the BESIII measurements within errors, i.e. $$R={\Gamma _{\gamma \gamma }(\chi _{c2})} /{\Gamma _{\gamma \gamma }(\chi _{c0})}=0.246\pm 0.013$$ R = Γ γ γ ( χ c 2 ) / Γ γ γ ( χ c 0 ) = 0.246 ± 0.013 , where the error is for $$\Delta \alpha _s(M_\tau )=\pm 0.016$$ Δ α s ( M τ ) = ± 0.016 . By further considering the color-octet contributions, even the central value can be in agreement with the data. This shows the importance of a correct scale-setting approach. We also give a prediction for the ratio involving $$\chi _{b0, b2} \rightarrow \gamma \gamma $$ χ b 0 , b 2 → γ γ , which could be tested in future Belle II experiment. |
| first_indexed | 2024-12-16T06:16:03Z |
| format | Article |
| id | doaj.art-7cdc9d11d12943479e625c8157c630e2 |
| institution | Directory Open Access Journal |
| issn | 1434-6044 1434-6052 |
| language | English |
| last_indexed | 2024-12-16T06:16:03Z |
| publishDate | 2021-07-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | European Physical Journal C: Particles and Fields |
| spelling | doaj.art-7cdc9d11d12943479e625c8157c630e22022-12-21T22:41:15ZengSpringerOpenEuropean Physical Journal C: Particles and Fields1434-60441434-60522021-07-018171610.1140/epjc/s10052-021-09424-xThe P-wave charmonium annihilation into two photons $$\chi _{c0, c2}\rightarrow \gamma \gamma $$ χ c 0 , c 2 → γ γ with high-order QCD correctionsHua Zhou0Qing Yu1Xu-Dong Huang2Xu-Chang Zheng3Xing-Gang Wu4Department of Physics, Chongqing UniversityDepartment of Physics, Chongqing UniversityDepartment of Physics, Chongqing UniversityDepartment of Physics, Chongqing UniversityDepartment of Physics, Chongqing UniversityAbstract In this paper, we present a new analysis on the P-wave charmonium annihilation into two photons up to next-to-next-to-leading order (NNLO) QCD corrections by using the principle of maximum conformality (PMC). The conventional perturbative QCD prediction shows strong scale dependence and deviates largely from the BESIII measurements. After applying the PMC, we obtain a more precise scale-invariant pQCD prediction, which also agrees with the BESIII measurements within errors, i.e. $$R={\Gamma _{\gamma \gamma }(\chi _{c2})} /{\Gamma _{\gamma \gamma }(\chi _{c0})}=0.246\pm 0.013$$ R = Γ γ γ ( χ c 2 ) / Γ γ γ ( χ c 0 ) = 0.246 ± 0.013 , where the error is for $$\Delta \alpha _s(M_\tau )=\pm 0.016$$ Δ α s ( M τ ) = ± 0.016 . By further considering the color-octet contributions, even the central value can be in agreement with the data. This shows the importance of a correct scale-setting approach. We also give a prediction for the ratio involving $$\chi _{b0, b2} \rightarrow \gamma \gamma $$ χ b 0 , b 2 → γ γ , which could be tested in future Belle II experiment.https://doi.org/10.1140/epjc/s10052-021-09424-x |
| spellingShingle | Hua Zhou Qing Yu Xu-Dong Huang Xu-Chang Zheng Xing-Gang Wu The P-wave charmonium annihilation into two photons $$\chi _{c0, c2}\rightarrow \gamma \gamma $$ χ c 0 , c 2 → γ γ with high-order QCD corrections European Physical Journal C: Particles and Fields |
| title | The P-wave charmonium annihilation into two photons $$\chi _{c0, c2}\rightarrow \gamma \gamma $$ χ c 0 , c 2 → γ γ with high-order QCD corrections |
| title_full | The P-wave charmonium annihilation into two photons $$\chi _{c0, c2}\rightarrow \gamma \gamma $$ χ c 0 , c 2 → γ γ with high-order QCD corrections |
| title_fullStr | The P-wave charmonium annihilation into two photons $$\chi _{c0, c2}\rightarrow \gamma \gamma $$ χ c 0 , c 2 → γ γ with high-order QCD corrections |
| title_full_unstemmed | The P-wave charmonium annihilation into two photons $$\chi _{c0, c2}\rightarrow \gamma \gamma $$ χ c 0 , c 2 → γ γ with high-order QCD corrections |
| title_short | The P-wave charmonium annihilation into two photons $$\chi _{c0, c2}\rightarrow \gamma \gamma $$ χ c 0 , c 2 → γ γ with high-order QCD corrections |
| title_sort | p wave charmonium annihilation into two photons chi c0 c2 rightarrow gamma gamma χ c 0 c 2 γ γ with high order qcd corrections |
| url | https://doi.org/10.1140/epjc/s10052-021-09424-x |
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