The transverse polarization of $$\Lambda $$ Λ hyperons in $$e^+e^-\rightarrow \Lambda ^\uparrow h X$$ e + e - → Λ ↑ h X processes within TMD factorization
Abstract We investigate the transverse polarization of the $$\Lambda $$ Λ hyperon in the processes $$e^+e^-\rightarrow \Lambda ^\uparrow \pi ^\pm X$$ e + e - → Λ ↑ π ± X and $$e^+e^-\rightarrow \Lambda ^\uparrow K^\pm X$$ e + e - → Λ ↑ K ± X within the framework of the transverse momentum dependent ...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2021-04-01
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| Series: | European Physical Journal C: Particles and Fields |
| Online Access: | https://doi.org/10.1140/epjc/s10052-021-09064-1 |
| _version_ | 1818328818486607872 |
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| author | Hui Li Xiaoyu Wang Yongliang Yang Zhun Lu |
| author_facet | Hui Li Xiaoyu Wang Yongliang Yang Zhun Lu |
| author_sort | Hui Li |
| collection | DOAJ |
| description | Abstract We investigate the transverse polarization of the $$\Lambda $$ Λ hyperon in the processes $$e^+e^-\rightarrow \Lambda ^\uparrow \pi ^\pm X$$ e + e - → Λ ↑ π ± X and $$e^+e^-\rightarrow \Lambda ^\uparrow K^\pm X$$ e + e - → Λ ↑ K ± X within the framework of the transverse momentum dependent (TMD) factorization. The transverse polarization is contributed by the convolution of the transversely polarizing fragmentation function (PFF) $$D_{1T}^\perp $$ D 1 T ⊥ of the lambda hyperon and the unpolarized fragmentation function $$D_1$$ D 1 of pion/kaon. We adopt the spectator diquark model result for $$D_{1T}^{\perp }$$ D 1 T ⊥ to numerically estimate the transverse polarization in $$e^+e^-\rightarrow \Lambda ^\uparrow h X$$ e + e - → Λ ↑ h X process at the kinematical region of Belle Collaboration. To implement the TMD evolution formalism of the fragmentation functions, we apply two different parametrizations on the nonperturbative Sudakov form factors associated with the fragmentation functions of the $$\Lambda $$ Λ , pion and kaon. It is found that our prediction on the polarization in the $$\Lambda \pi ^+$$ Λ π + production and $${\bar{\Lambda }} \pi ^-$$ Λ ¯ π - is consistent with the recent Belle measurement in size and sign, while the model predictions on the polarizations in $$\Lambda \pi ^-$$ Λ π - and $$\Lambda K^\pm $$ Λ K ± productions show strong disagreement with the Belle data. The reason for the discrepancies is discussed and possible approaches to improve the calculation in the future are also discussed. |
| first_indexed | 2024-12-13T12:38:12Z |
| format | Article |
| id | doaj.art-603812da483441c7af2a15073010f48b |
| institution | Directory Open Access Journal |
| issn | 1434-6044 1434-6052 |
| language | English |
| last_indexed | 2024-12-13T12:38:12Z |
| publishDate | 2021-04-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | European Physical Journal C: Particles and Fields |
| spelling | doaj.art-603812da483441c7af2a15073010f48b2022-12-21T23:45:44ZengSpringerOpenEuropean Physical Journal C: Particles and Fields1434-60441434-60522021-04-0181411110.1140/epjc/s10052-021-09064-1The transverse polarization of $$\Lambda $$ Λ hyperons in $$e^+e^-\rightarrow \Lambda ^\uparrow h X$$ e + e - → Λ ↑ h X processes within TMD factorizationHui Li0Xiaoyu Wang1Yongliang Yang2Zhun Lu3School of Physics, Southeast UniversitySchool of Physics and Microelectronics, Zhengzhou UniversityCollege of Physics, Qingdao UniversitySchool of Physics, Southeast UniversityAbstract We investigate the transverse polarization of the $$\Lambda $$ Λ hyperon in the processes $$e^+e^-\rightarrow \Lambda ^\uparrow \pi ^\pm X$$ e + e - → Λ ↑ π ± X and $$e^+e^-\rightarrow \Lambda ^\uparrow K^\pm X$$ e + e - → Λ ↑ K ± X within the framework of the transverse momentum dependent (TMD) factorization. The transverse polarization is contributed by the convolution of the transversely polarizing fragmentation function (PFF) $$D_{1T}^\perp $$ D 1 T ⊥ of the lambda hyperon and the unpolarized fragmentation function $$D_1$$ D 1 of pion/kaon. We adopt the spectator diquark model result for $$D_{1T}^{\perp }$$ D 1 T ⊥ to numerically estimate the transverse polarization in $$e^+e^-\rightarrow \Lambda ^\uparrow h X$$ e + e - → Λ ↑ h X process at the kinematical region of Belle Collaboration. To implement the TMD evolution formalism of the fragmentation functions, we apply two different parametrizations on the nonperturbative Sudakov form factors associated with the fragmentation functions of the $$\Lambda $$ Λ , pion and kaon. It is found that our prediction on the polarization in the $$\Lambda \pi ^+$$ Λ π + production and $${\bar{\Lambda }} \pi ^-$$ Λ ¯ π - is consistent with the recent Belle measurement in size and sign, while the model predictions on the polarizations in $$\Lambda \pi ^-$$ Λ π - and $$\Lambda K^\pm $$ Λ K ± productions show strong disagreement with the Belle data. The reason for the discrepancies is discussed and possible approaches to improve the calculation in the future are also discussed.https://doi.org/10.1140/epjc/s10052-021-09064-1 |
| spellingShingle | Hui Li Xiaoyu Wang Yongliang Yang Zhun Lu The transverse polarization of $$\Lambda $$ Λ hyperons in $$e^+e^-\rightarrow \Lambda ^\uparrow h X$$ e + e - → Λ ↑ h X processes within TMD factorization European Physical Journal C: Particles and Fields |
| title | The transverse polarization of $$\Lambda $$ Λ hyperons in $$e^+e^-\rightarrow \Lambda ^\uparrow h X$$ e + e - → Λ ↑ h X processes within TMD factorization |
| title_full | The transverse polarization of $$\Lambda $$ Λ hyperons in $$e^+e^-\rightarrow \Lambda ^\uparrow h X$$ e + e - → Λ ↑ h X processes within TMD factorization |
| title_fullStr | The transverse polarization of $$\Lambda $$ Λ hyperons in $$e^+e^-\rightarrow \Lambda ^\uparrow h X$$ e + e - → Λ ↑ h X processes within TMD factorization |
| title_full_unstemmed | The transverse polarization of $$\Lambda $$ Λ hyperons in $$e^+e^-\rightarrow \Lambda ^\uparrow h X$$ e + e - → Λ ↑ h X processes within TMD factorization |
| title_short | The transverse polarization of $$\Lambda $$ Λ hyperons in $$e^+e^-\rightarrow \Lambda ^\uparrow h X$$ e + e - → Λ ↑ h X processes within TMD factorization |
| title_sort | transverse polarization of lambda λ hyperons in e e rightarrow lambda uparrow h x e e λ ↑ h x processes within tmd factorization |
| url | https://doi.org/10.1140/epjc/s10052-021-09064-1 |
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