| THE PHYSICS OF ELEMENTARY PARTICLES AND FIELDS |
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$e^+ e^- \to \varLambda^+_c \bar{\varLambda}^-_c$ Cross Sections and the $\varLambda_c^+$ Electromagnetic Form Factors within the Extended Vector Meson Dominance Model |
| Cheng Chen1,2*, Bing Yan1,3*, and Ju-Jun Xie1,2,4* |
1Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
2School of Nuclear Sciences and Technology, University of Chinese Academy of Sciences, Beijing 101408, China
3College of Mathematics and Physics, Chengdu University of Technology, Chengdu 610059, China
4Southern Center for Nuclear-Science Theory (SCNT), Institute of Modern Physics, Chinese Academy of Sciences, Huizhou 516000, China
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| Cite this article: |
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Cheng Chen, Bing Yan, and Ju-Jun Xie 2024 Chin. Phys. Lett. 41 021302 |
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Abstract Within the extended vector meson dominance model, we investigate the $e^+ e^- \to \varLambda^+_c \bar{\varLambda}^-_c$ reaction and the electromagnetic form factors of the charmed baryon $\varLambda_c^+$. The model parameters are determined by fitting them to the cross sections of the process $e^+e^-\rightarrow \varLambda_c^+ \bar{\varLambda}_c^-$ and the magnetic form factor $|G_{\scriptscriptstyle{\rm M}}|$ of $\varLambda^+_c$. By considering four charmonium-like states, called $\psi(4500)$, $\psi(4660)$, $\psi(4790)$, and $\psi(4900)$, we can well describe the current data on the $e^+ e^- \to \varLambda^+_c \bar{\varLambda}^-_c$ reaction from the reaction threshold up to $4.96$ GeV. In addition to the total cross sections and $|G_{\scriptscriptstyle{\rm M}}|$, the ratio $|G_{\scriptscriptstyle{\rm E}}/G_{\scriptscriptstyle{\rm M}}|$ and the effective form factor $|G_{\mathrm{eff}}|$ for $\varLambda^+_c$ are also calculated, and found that these calculations are consistent with the experimental data. Within the fitted model parameters, we have also estimated the charge radius of the charmed $\varLambda_c^+$ baryon.
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Received: 29 December 2023
Express Letter
Published: 04 February 2024
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| PACS: |
13.40.Gp
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(Electromagnetic form factors)
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13.40.-f
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(Electromagnetic processes and properties)
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13.60.Rj
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(Baryon production)
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13.66.Bc
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(Hadron production in e?e+ interactions)
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| [1] | Denig A and Salme G 2013 Prog. Part. Nucl. Phys. 68 113 |
| [2] | Pacetti S, Baldini F R, and Tomasi-Gustafsson E 2015 Phys. Rep. 550 1 |
| [3] | Punjabi V, Perdrisat C F, Jones M K, Brash E J, and Carlson C E 2015 Eur. Phys. J. A 51 79 |
| [4] | Aubert B et al. (BaBar) 2007 Phys. Rev. D 76 092006 |
| [5] | Ablikim M et al. (BESIII) 2019 Phys. Rev. Lett. 123 122003 |
| [6] | Ablikim M et al. (BESIII) 2021 Phys. Lett. B 814 136110 |
| [7] | Gong G et al. (Belle) 2023 Phys. Rev. D 107 072008 |
| [8] | Iachello F, Jackson A D, and Lande A 1973 Phys. Lett. B 43 191 |
| [9] | Iachello F and Wan Q 2004 Phys. Rev. C 69 055204 |
| [10] | Bijker R and Iachello F 2004 Phys. Rev. C 69 068201 |
| [11] | Li Z Y and Xie J J 2021 Commun. Theor. Phys. 73 055201 |
| [12] | Yan B, Chen C, and Xie J J 2023 Phys. Rev. D 107 076008 |
| [13] | Yang Y L, Chen D Y, and Lu Z 2019 Phys. Rev. D 100 073007 |
| [14] | Li Z Y, Dai A X, and Xie J J 2022 Chin. Phys. Lett. 39 011201 |
| [15] | Pakhlova G et al. (Belle) 2008 Phys. Rev. Lett. 101 172001 |
| [16] | Ablikim M et al. (BESIII) 2018 Phys. Rev. Lett. 120 132001 |
| [17] | Dai L Y, Haidenbauer J, and Meißner U G 2017 Phys. Rev. D 96 116001 |
| [18] | Cao Q F, Qi H R, Wang Y F, and Zheng H Q 2019 Phys. Rev. D 100 054040 |
| [19] | Wan J Y, Yang Y L, and Lu Z 2021 Eur. Phys. J. Plus 136 949 |
| [20] | Workman R L et al. (Particle Data Group) 2022 Prog. Theor. Exp. Phys. 2022 083C01 |
| [21] | Ablikim M et al. (BESIII) 2023 Phys. Rev. Lett. 131 191901 |
| [22] | Amoroso A et al. 2021 Universe 7 436 |
| [23] | Salnikov S G and Milstein A I 2023 Phys. Rev. D 108 L071505 |
| [24] | Lees J P et al. (BaBar) 2014 Phys. Rev. D 89 111103 |
| [25] | Wang X L et al. (Belle) 2007 Phys. Rev. Lett. 99 142002 |
| [26] | Wang X L et al. (Belle) 2015 Phys. Rev. D 91 112007 |
| [27] | Ablikim M et al. (BESIII) 2021 Phys. Rev. D 104 052012 |
| [28] | Ablikim M et al. (BESIII) 2023 Phys. Rev. Lett. 130 121901 |
| [29] | Ablikim M et al. (BESIII) 2022 Chin. Phys. C 46 111002 |
| [30] | Yuan C Z et al. (Belle) 2008 Phys. Rev. D 77 011105 |
| [31] | Shen C P et al. (Belle) 2014 Phys. Rev. D 89 072015 |
| [32] | Ablikim M et al. (BESIII) 2018 Phys. Rev. D 97 071101 |
| [33] | Ablikim M et al. (BESIII) 2023 Phys. Rev. Lett. 131 211902 |
| [34] | Ablikim M et al. (BESIII) 2023 Phys. Rev. D 107 092005 |
| [35] | Ablikim M et al. (BESIII) 2023 Phys. Rev. Lett. 131 151903 |
| [36] | van Beveren E and Rupp G 2011 Chin. Phys. C 35 319 |
| [37] | van Beveren E and Rupp G 2009 Phys. Rev. D 80 074001 |
| [38] | van Beveren E, Liu X, Coimbra R, and Rupp G 2009 Europhys. Lett. 85 61002 |
| [39] | Sakharov A D 1991 Sov. Phys. Usp. 34 375 |
| [40] | Shi R X, Xiao Y, and Geng L S 2019 Phys. Rev. D 100 054019 |
| [41] | Wang G J, Meng L, Li H S, Liu Z W, and Zhu S L 2018 Phys. Rev. D 98 054026 |
| [42] | Lepage G P and Brodsky S J 1979 Phys. Rev. Lett. 43 545 |
| [43] | Lepage G P and Brodsky S J 1980 Phys. Rev. D 22 2157 |
| [44] | Flatté S M 1976 Phys. Lett. B 63 224 |
| [45] | Dong X K, Guo F K, and Zou B S 2021 Prog. Phys. 41 65 |
| [46] | Song L Q, Song D, Zhu J T, and He J 2022 Phys. Lett. B 835 137586 |
| [47] | Dai A X, Li Z Y, Chang L, and Xie J J 2022 Chin. Phys. C 46 073104 |
| [48] | Yan B, Chen C, Li X, and Xie J J 2023 arXiv:2312.04866 [nucl-th] |
| [49] | Bianconi A and Tomasi-Gustafsson E 2015 Phys. Rev. Lett. 114 232301 |
| [50] | Bianconi A and Tomasi-Gustafsson E 2016 Phys. Rev. C 93 035201 |
| [51] | Tomasi-Gustafsson E, Bianconi A, and Pacetti S 2021 Phys. Rev. C 103 035203 |
| [52] | Yang Q H, Dai L Y, Guo D, Haidenbauer J, Kang X W, and Meißner U G 2023 Sci. Bull. 68 2729 |
| [53] | Lin Y H, Hammer H W, and Meißner U G 2022 Phys. Rev. Lett. 128 052002 |
| [54] | Qian R Q, Liu Z W, Cao X, and Liu X 2023 Phys. Rev. D 107 L091502 |
| [55] | Baldini R, Pacetti S, Zallo A, and Zichichi A 2009 Eur. Phys. J. A 39 315 |
| [56] | Kuraev E A, Tomasi-Gustafsson E, and Dbeyssi A 2012 Phys. Lett. B 712 240 |
| [57] | Jia S, Xiong W T, and Shen C 2023 Chin. Phys. Lett. 40 121301 |
| [58] | Fäldt G and Kupsc A 2017 Phys. Lett. B 772 16 |
| [59] | Ablikim M et al. (BESIII) 2020 Phys. Rev. Lett. 125 052004 |
| [60] | Ablikim M et al. (BESIII) 2022 Phys. Rev. D 105 L011101 |
| [61] | Note that turning to the space-like region, these low-lying excited vector states should also contribute to the $\varLambda^+_c$ elactromagnetic form factors in the $t$-channel exchanges. Such a kind of mechanism is checked in the present work based on the insufficient experimental data of $e^+ e^- \to \varLambda^+_c \bar{\varLambda}^-_c$ reaction in the time-like region, and it is found that the contributions from the low-lying excited vector states could be very small and can be neglected. |
| [62] | Kim J Y and Kim H C 2018 Phys. Rev. D 97 114009 |
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