Open Access

Production and Decay Dynamics of the Charmed Baryon $Λ_{c}^{+}$ in $e^{+} e^{-}$ Annihilations near Threshold

M. Ablikim ¹, M. N. Achasov ^4,b, P. Adlarson ⁷⁷, X. C. Ai ⁸², R. Aliberti ³⁶, A. Amoroso ^76a,76c, Q. An^73,59,†, Y. Bai ⁵⁸, O. Bakina ³⁷ et al. (BESIII Collaboration)

O. Bakina ³⁷, Y. Ban ^47,g, H.-R. Bao ⁶⁵, V. Batozskaya ^1,45, K. Begzsuren³³, N. Berger ³⁶, M. Berlowski ⁴⁵, M. Bertani ^29a, D. Bettoni ^30a, F. Bianchi ^76a,76c, E. Bianco^76a,76c, A. Bortone ^76a,76c, I. Boyko ³⁷, R. A. Briere ⁵, A. Brueggemann ⁷⁰, H. Cai ⁷⁸, M. H. Cai ^39,j,k, X. Cai ^1,59, A. Calcaterra ^29a, G. F. Cao ^1,65, N. Cao ^1,65, S. A. Cetin ^63a, X. Y. Chai ^47,g, J. F. Chang ^1,59, G. R. Che ⁴⁴, Y. Z. Che ^1,59,65, C. H. Chen ⁹, Chao Chen ⁵⁶, G. Chen ¹, H. S. Chen ^1,65, H. Y. Chen ²¹, M. L. Chen ^1,59,65, S. J. Chen ⁴³, S. L. Chen ⁴⁶, S. M. Chen ⁶², T. Chen ^1,65, X. R. Chen ^32,65, X. T. Chen ^1,65, X. Y. Chen ^12,f, Y. B. Chen ^1,59, Y. Q. Chen ³⁵, Y. Q. Chen¹⁶, Z. Chen ²⁵, Z. J. Chen ^26,h, Z. K. Chen ⁶⁰, S. K. Choi ¹⁰, X. Chu ^12,f, G. Cibinetto ^30a, F. Cossio ^76c, J. Cottee-Meldrum ⁶⁴, J. J. Cui ⁵¹, H. L. Dai ^1,59, J. P. Dai ⁸⁰, A. Dbeyssi¹⁹, R. E. de Boer ³, D. Dedovich ³⁷, C. Q. Deng ⁷⁴, Z. Y. Deng ¹, A. Denig ³⁶, I. Denysenko ³⁷, M. Destefanis ^76a,76c, F. De Mori ^76a,76c, B. Ding ^68,1, X. X. Ding ^47,g, Y. Ding ⁴¹, Y. Ding ³⁵, Y. X. Ding ³¹, J. Dong ^1,59, L. Y. Dong ^1,65, M. Y. Dong ^1,59,65, X. Dong ⁷⁸, M. C. Du ¹, S. X. Du ⁸², S. X. Du ^12,f, Y. Y. Duan ⁵⁶, P. Egorov ^37,a, G. F. Fan ⁴³, J. J. Fan ²⁰, Y. H. Fan ⁴⁶, J. Fang ^1,59, J. Fang ⁶⁰, S. S. Fang ^1,65, W. X. Fang ¹, Y. Q. Fang ^1,59, R. Farinelli ^30a, L. Fava ^76b,76c, F. Feldbauer ³, G. Felici ^29a, C. Q. Feng ^73,59, J. H. Feng ¹⁶, L. Feng ^39,j,k, Q. X. Feng ^39,j,k, Y. T. Feng ^73,59, M. Fritsch ³, C. D. Fu ¹, J. L. Fu ⁶⁵, Y. W. Fu ^1,65, H. Gao ⁶⁵, X. B. Gao ⁴², Y. Gao ^73,59, Y. N. Gao ^47,g, Y. N. Gao ²⁰, Y. Y. Gao ³¹, S. Garbolino ^76c, I. Garzia ^30a,30b, L. Ge ⁵⁸, P. T. Ge ²⁰, Z. W. Ge ⁴³, C. Geng ⁶⁰, E. M. Gersabeck ⁶⁹, A. Gilman ⁷¹, K. Goetzen ¹³, J. D. Gong ³⁵, L. Gong ⁴¹, W. X. Gong ^1,59, W. Gradl ³⁶, S. Gramigna ^30a,30b, M. Greco ^76a,76c, M. H. Gu ^1,59, Y. T. Gu ¹⁵, C. Y. Guan ^1,65, A. Q. Guo ³², L. B. Guo ⁴², M. J. Guo ⁵¹, R. P. Guo ⁵⁰, Y. P. Guo ^12,f, A. Guskov ^37,a, J. Gutierrez ²⁸, K. L. Han ⁶⁵, T. T. Han ¹, F. Hanisch ³, K. D. Hao ^73,59, X. Q. Hao ²⁰, F. A. Harris ⁶⁷, K. K. He ⁵⁶, K. L. He ^1,65, F. H. Heinsius ³, C. H. Heinz ³⁶, Y. K. Heng ^1,59,65, C. Herold ⁶¹, P. C. Hong ³⁵, G. Y. Hou ^1,65, X. T. Hou ^1,65, Y. R. Hou ⁶⁵, Z. L. Hou ¹, H. M. Hu ^1,65, J. F. Hu ^57,i, Q. P. Hu ^73,59, S. L. Hu ^12,f, T. Hu ^1,59,65, Y. Hu ¹, Z. M. Hu ⁶⁰, G. S. Huang ^73,59, K. X. Huang ⁶⁰, L. Q. Huang ^32,65, P. Huang ⁴³, X. T. Huang ⁵¹, Y. P. Huang ¹, Y. S. Huang ⁶⁰, T. Hussain ⁷⁵, N. Hüsken ³⁶, N. in der Wiesche ⁷⁰, J. Jackson ²⁸, Q. Ji ¹, Q. P. Ji ²⁰, W. Ji ^1,65, X. B. Ji ^1,65, X. L. Ji ^1,59, Y. Y. Ji ⁵¹, Z. K. Jia ^73,59, D. Jiang ^1,65, H. B. Jiang ⁷⁸, P. C. Jiang ^47,g, S. J. Jiang ⁹, T. J. Jiang ¹⁷, X. S. Jiang ^1,59,65, Y. Jiang ⁶⁵, J. B. Jiao ⁵¹, J. K. Jiao ³⁵, Z. Jiao ²⁴, S. Jin ⁴³, Y. Jin ⁶⁸, M. Q. Jing ^1,65, X. M. Jing ⁶⁵, T. Johansson ⁷⁷, S. Kabana ³⁴, N. Kalantar-Nayestanaki ⁶⁶, X. L. Kang ⁹, X. S. Kang ⁴¹, M. Kavatsyuk ⁶⁶, B. C. Ke ⁸², V. Khachatryan ²⁸, A. Khoukaz ⁷⁰, R. Kiuchi¹, O. B. Kolcu ^63a, B. Kopf ³, M. Kuessner ³, X. Kui ^1,65, N. Kumar ²⁷, A. Kupsc ^45,77, W. Kühn ³⁸, Q. Lan ⁷⁴, W. N. Lan ²⁰, T. T. Lei ^73,59, M. Lellmann ³⁶, T. Lenz ³⁶, C. Li ⁴⁸, C. Li ⁴⁴, C. H. Li ⁴⁰, C. K. Li ²¹, D. M. Li ⁸², F. Li ^1,59, G. Li ¹, H. B. Li ^1,65, H. J. Li ²⁰, H. N. Li ^57,i, Hui Li ⁴⁴, J. R. Li ⁶², J. S. Li ⁶⁰, K. Li ¹, K. L. Li ²⁰, K. L. Li^39,j,k, L. J. Li ^1,65, Lei Li ⁴⁹, M. H. Li ⁴⁴, M. R. Li ^1,65, P. L. Li ⁶⁵, P. R. Li ^39,j,k, Q. M. Li ^1,65, Q. X. Li ⁵¹, R. Li ^18,32, S. X. Li ¹², T. Li ⁵¹, T. Y. Li ⁴⁴, W. D. Li ^1,65, W. G. Li ^1,†, X. Li ^1,65, X. H. Li ^73,59, X. L. Li ⁵¹, X. Y. Li ^1,8, X. Z. Li ⁶⁰, Y. Li ²⁰, Y. G. Li ^47,g, Y. P. Li ³⁵, Z. J. Li ⁶⁰, Z. Y. Li ⁸⁰, H. Liang ^73,59, Y. F. Liang ⁵⁵, Y. T. Liang ^32,65, G. R. Liao ¹⁴, L. B. Liao ⁶⁰, M. H. Liao ⁶⁰, Y. P. Liao ^1,65, J. Libby ²⁷, A. Limphirat ⁶¹, C. C. Lin ⁵⁶, D. X. Lin ^32,65, L. Q. Lin ⁴⁰, T. Lin ¹, B. J. Liu ¹, B. X. Liu ⁷⁸, C. Liu ³⁵, C. X. Liu ¹, F. Liu ¹, F. H. Liu ⁵⁴, Feng Liu ⁶, G. M. Liu ^57,i, H. Liu ^39,j,k, H. B. Liu ¹⁵, H. H. Liu ¹, H. M. Liu ^1,65, Huihui Liu ²², J. B. Liu ^73,59, J. J. Liu ²¹, K. Liu ^39,j,k, K. Liu ⁷⁴, K. Y. Liu ⁴¹, Ke Liu ²³, L. C. Liu ⁴⁴, Lu Liu ⁴⁴, M. H. Liu ^12,f, P. L. Liu ¹, Q. Liu ⁶⁵, S. B. Liu ^73,59, T. Liu ^12,f, W. K. Liu ⁴⁴, W. M. Liu ^73,59, W. T. Liu ⁴⁰, X. Liu ^39,j,k, X. Liu ⁴⁰, X. K. Liu ^39,j,k, X. L. Liu ^12,f, X. Y. Liu ⁷⁸, Y. Liu ^39,j,k, Y. Liu ⁸², Yuan Liu⁸², Y. B. Liu ⁴⁴, Z. A. Liu ^1,59,65, Z. D. Liu ⁹, Z. Q. Liu ⁵¹, X. C. Lou ^1,59,65, F. X. Lu ⁶⁰, H. J. Lu ²⁴, J. G. Lu ^1,59, X. L. Lu ¹⁶, Y. Lu ⁷, Y. H. Lu ^1,65, Y. P. Lu ^1,59, Z. H. Lu ^1,65, C. L. Luo ⁴², J. R. Luo ⁶⁰, J. S. Luo ^1,65, M. X. Luo⁸¹, T. Luo ^12,f, X. L. Luo ^1,59, Z. Y. Lv ²³, X. R. Lyu ^65,o, Y. F. Lyu ⁴⁴, Y. H. Lyu ⁸², F. C. Ma ⁴¹, H. L. Ma ¹, J. L. Ma ^1,65, L. L. Ma ⁵¹, L. R. Ma ⁶⁸, Q. M. Ma ¹, R. Q. Ma ^1,65, R. Y. Ma ²⁰, T. Ma ^73,59, X. T. Ma ^1,65, X. Y. Ma ^1,59, Y. M. Ma ³², F. E. Maas ¹⁹, I. MacKay ⁷¹, M. Maggiora ^76a,76c, S. Malde ⁷¹, Q. A. Malik ⁷⁵, H. X. Mao ^39,j,k, Y. J. Mao ^47,g, Z. P. Mao ¹, S. Marcello ^76a,76c, A. Marshall ⁶⁴, F. M. Melendi ^30a,30b, Y. H. Meng ⁶⁵, Z. X. Meng ⁶⁸, G. Mezzadri ^30a, H. Miao ^1,65, T. J. Min ⁴³, R. E. Mitchell ²⁸, X. H. Mo ^1,59,65, B. Moses ²⁸, N. Yu. Muchnoi ^4,b, J. Muskalla ³⁶, Y. Nefedov ³⁷, F. Nerling ^19,d, L. S. Nie ²¹, I. B. Nikolaev^4,b, Z. Ning ^1,59, S. Nisar^11,l, Q. L. Niu ^39,j,k, W. D. Niu ^12,f, C. Normand ⁶⁴, S. L. Olsen ^10,65, Q. Ouyang ^1,59,65, S. Pacetti ^29b,29c, X. Pan ⁵⁶, Y. Pan ⁵⁸, A. Pathak ¹⁰, Y. P. Pei ^73,59, M. Pelizaeus ³, H. P. Peng ^73,59, X. J. Peng ^39,j,k, Y. Y. Peng ^39,j,k, K. Peters ^13,d, K. Petridis ⁶⁴, J. L. Ping ⁴², R. G. Ping ^1,65, S. Plura ³⁶, V. Prasad ³⁵, F. Z. Qi ¹, H. R. Qi ⁶², M. Qi ⁴³, S. Qian ^1,59, W. B. Qian ⁶⁵, C. F. Qiao ⁶⁵, J. H. Qiao ²⁰, J. J. Qin ⁷⁴, J. L. Qin ⁵⁶, L. Q. Qin ¹⁴, L. Y. Qin ^73,59, P. B. Qin ⁷⁴, X. P. Qin ^12,f, X. S. Qin ⁵¹, Z. H. Qin ^1,59, J. F. Qiu ¹, Z. H. Qu ⁷⁴, J. Rademacker ⁶⁴, C. F. Redmer ³⁶, A. Rivetti ^76c, M. Rolo ^76c, G. Rong ^1,65, S. S. Rong ^1,65, F. Rosini ^29b,29c, Ch. Rosner ¹⁹, M. Q. Ruan ^1,59, N. Salone ⁴⁵, A. Sarantsev ^37,c, Y. Schelhaas ³⁶, K. Schoenning ⁷⁷, M. Scodeggio ^30a, K. Y. Shan ^12,f, W. Shan ²⁵, X. Y. Shan ^73,59, Z. J. Shang ^39,j,k, J. F. Shangguan ¹⁷, L. G. Shao ^1,65, M. Shao ^73,59, C. P. Shen ^12,f, H. F. Shen ^1,8, W. H. Shen ⁶⁵, X. Y. Shen ^1,65, B. A. Shi ⁶⁵, H. Shi ^73,59, J. L. Shi ^12,f, J. Y. Shi ¹, S. Y. Shi ⁷⁴, X. Shi ^1,59, H. L. Song ^73,59, J. J. Song ²⁰, T. Z. Song ⁶⁰, W. M. Song ³⁵, Y. J. Song ^12,f, Y. X. Song ^47,g,m, S. Sosio ^76a,76c, S. Spataro ^76a,76c, F. Stieler ³⁶, S. S. Su⁴¹, Y. J. Su ⁶⁵, G. B. Sun ⁷⁸, G. X. Sun ¹, H. Sun ⁶⁵, H. K. Sun ¹, J. F. Sun ²⁰, K. Sun ⁶², L. Sun ⁷⁸, S. S. Sun ^1,65, T. Sun ^52,e, Y. C. Sun ⁷⁸, Y. H. Sun ³¹, Y. J. Sun ^73,59, Y. Z. Sun ¹, Z. Q. Sun ^1,65, Z. T. Sun ⁵¹, C. J. Tang⁵⁵, G. Y. Tang ¹, J. Tang ⁶⁰, J. J. Tang ^73,59, L. F. Tang ⁴⁰, Y. A. Tang ⁷⁸, L. Y. Tao ⁷⁴, M. Tat ⁷¹, J. X. Teng ^73,59, J. Y. Tian ^73,59, W. H. Tian ⁶⁰, Y. Tian ³², Z. F. Tian ⁷⁸, I. Uman ^63b, B. Wang ¹, B. Wang ⁶⁰, Bo Wang ^73,59, C. Wang ^39,j,k, C. Wang ²⁰, Cong Wang ²³, D. Y. Wang ^47,g, H. J. Wang ^39,j,k, J. J. Wang ⁷⁸, K. Wang ^1,59, L. L. Wang ¹, L. W. Wang ³⁵, M. Wang ⁵¹, M. Wang ^73,59, N. Y. Wang ⁶⁵, S. Wang ^12,f, T. Wang ^12,f, T. J. Wang ⁴⁴, W. Wang ⁶⁰, Wei Wang⁷⁴, W. P. Wang ^36,73,59,n, X. Wang ^47,g, X. F. Wang ^39,j,k, X. J. Wang ⁴⁰, X. L. Wang ^12,f, X. N. Wang ^1,65, Y. Wang⁶², Y. D. Wang ⁴⁶, Y. F. Wang ^1,8,65, Y. H. Wang ^39,j,k, Y. J. Wang ^73,59, Y. L. Wang ²⁰, Y. N. Wang ⁷⁸, Y. Q. Wang ¹, Yaqian Wang ¹⁸, Yi Wang ⁶², Yuan Wang ^18,32, Z. Wang ^1,59, Z. L. Wang ⁷⁴, Z. L. Wang², Z. Q. Wang ^12,f, Z. Y. Wang ^1,65, D. H. Wei ¹⁴, H. R. Wei ⁴⁴, F. Weidner ⁷⁰, S. P. Wen ¹, Y. R. Wen ⁴⁰, U. Wiedner ³, G. Wilkinson ⁷¹, M. Wolke⁷⁷, C. Wu ⁴⁰, J. F. Wu ^1,8, L. H. Wu ¹, L. J. Wu ^1,65, L. J. Wu²⁰, Lianjie Wu ²⁰, S. G. Wu ^1,65, S. M. Wu ⁶⁵, X. Wu ^12,f, X. H. Wu ³⁵, Y. J. Wu ³², Z. Wu ^1,59, L. Xia ^73,59, X. M. Xian ⁴⁰, B. H. Xiang ^1,65, D. Xiao ^39,j,k, G. Y. Xiao ⁴³, H. Xiao ⁷⁴, Y. L. Xiao ^12,f, Z. J. Xiao ⁴², C. Xie ⁴³, K. J. Xie ^1,65, X. H. Xie ^47,g, Y. Xie ⁵¹, Y. G. Xie ^1,59, Y. H. Xie ⁶, Z. P. Xie ^73,59, T. Y. Xing ^1,65, C. F. Xu^1,65, C. J. Xu ⁶⁰, G. F. Xu ¹, H. Y. Xu ^68,2, H. Y. Xu², M. Xu ^73,59, Q. J. Xu ¹⁷, Q. N. Xu ³¹, T. D. Xu ⁷⁴, W. Xu ¹, W. L. Xu ⁶⁸, X. P. Xu ⁵⁶, Y. Xu ⁴¹, Y. Xu^12,f, Y. C. Xu ⁷⁹, Z. S. Xu ⁶⁵, F. Yan ^12,f, H. Y. Yan ⁴⁰, L. Yan ^12,f, W. B. Yan ^73,59, W. C. Yan ⁸², W. H. Yan ⁶, W. P. Yan ²⁰, X. Q. Yan ^1,65, H. J. Yang ^52,e, H. L. Yang ³⁵, H. X. Yang ¹, J. H. Yang ⁴³, R. J. Yang ²⁰, T. Yang ¹, Y. Yang ^12,f, Y. F. Yang ⁴⁴, Y. H. Yang ⁴³, Y. Q. Yang ⁹, Y. X. Yang ^1,65, Y. Z. Yang ²⁰, M. Ye ^1,59, M. H. Ye ^8,†, Z. J. Ye ^57,i, Junhao Yin ⁴⁴, Z. Y. You ⁶⁰, B. X. Yu ^1,59,65, C. X. Yu ⁴⁴, G. Yu ¹³, J. S. Yu ^26,h, L. Q. Yu ^12,f, M. C. Yu ⁴¹, T. Yu ⁷⁴, X. D. Yu ^47,g, Y. C. Yu ⁸², C. Z. Yuan ^1,65, H. Yuan ^1,65, J. Yuan ³⁵, J. Yuan ⁴⁶, L. Yuan ², S. C. Yuan ^1,65, X. Q. Yuan ¹, Y. Yuan ^1,65, Z. Y. Yuan ⁶⁰, C. X. Yue ⁴⁰, Ying Yue ²⁰, A. A. Zafar ⁷⁵, S. H. Zeng ⁶⁴, X. Zeng ^12,f, Y. Zeng^26,h, Yujie Zeng⁶⁰, Y. J. Zeng ^1,65, X. Y. Zhai ³⁵, Y. H. Zhan ⁶⁰, Shunan Zhang⁷¹, A. Q. Zhang ^1,65, B. L. Zhang ^1,65, B. X. Zhang ¹, D. H. Zhang ⁴⁴, G. Y. Zhang ²⁰, G. Y. Zhang ^1,65, H. Zhang ^73,59, H. Zhang ⁸², H. C. Zhang ^1,59,65, H. H. Zhang ⁶⁰, H. Q. Zhang ^1,59,65, H. R. Zhang ^73,59, H. Y. Zhang ^1,59, Jin Zhang⁸², J. Zhang ⁶⁰, J. J. Zhang ⁵³, J. L. Zhang ²¹, J. Q. Zhang ⁴², J. S. Zhang ^12,f, J. W. Zhang ^1,59,65, J. X. Zhang ^39,j,k, J. Y. Zhang ¹, J. Z. Zhang ^1,65, Jianyu Zhang ⁶⁵, L. M. Zhang ⁶², Lei Zhang ⁴³, N. Zhang ⁸², P. Zhang ^1,8, Q. Zhang ²⁰, Q. Y. Zhang ³⁵, R. Y. Zhang ^39,j,k, S. H. Zhang ^1,65, Shulei Zhang ^26,h, X. M. Zhang ¹, X. Y. Zhang ⁴¹, X. Y. Zhang⁵¹, Y. Zhang ¹, Y. Zhang ⁷⁴, Y. T. Zhang ⁸², Y. H. Zhang ^1,59, Y. M. Zhang ⁴⁰, Y. P. Zhang ^73,59, Z. D. Zhang ¹, Z. H. Zhang ¹, Z. L. Zhang ³⁵, Z. L. Zhang ⁵⁶, Z. X. Zhang ²⁰, Z. Y. Zhang ⁷⁸, Z. Y. Zhang ⁴⁴, Z. Z. Zhang ⁴⁶, Zh. Zh. Zhang ²⁰, G. Zhao ¹, J. Y. Zhao ^1,65, J. Z. Zhao ^1,59, L. Zhao ¹, L. Zhao ^73,59, M. G. Zhao ⁴⁴, N. Zhao ⁸⁰, R. P. Zhao ⁶⁵, S. J. Zhao ⁸², Y. B. Zhao ^1,59, Y. L. Zhao ⁵⁶, Y. X. Zhao ^32,65, Z. G. Zhao ^73,59, A. Zhemchugov ^37,a, B. Zheng ⁷⁴, B. M. Zheng ³⁵, J. P. Zheng ^1,59, W. J. Zheng ^1,65, X. R. Zheng ²⁰, Y. H. Zheng ^65,o, B. Zhong ⁴², C. Zhong ²⁰, H. Zhou ^36,51,n, J. Q. Zhou ³⁵, J. Y. Zhou ³⁵, S. Zhou ⁶, X. Zhou ⁷⁸, X. K. Zhou ⁶, X. R. Zhou ^73,59, X. Y. Zhou ⁴⁰, Y. X. Zhou ⁷⁹, Y. Z. Zhou ^12,f, A. N. Zhu ⁶⁵, J. Zhu ⁴⁴, K. Zhu ¹, K. J. Zhu ^1,59,65, K. S. Zhu ^12,f, L. Zhu ³⁵, L. X. Zhu ⁶⁵, S. H. Zhu ⁷², T. J. Zhu ^12,f, W. D. Zhu ⁴², W. D. Zhu^12,f, W. J. Zhu ¹, W. Z. Zhu ²⁰, Y. C. Zhu ^73,59, Z. A. Zhu ^1,65, X. Y. Zhuang ⁴⁴, J. H. Zou ¹, and J. Zu ^73,59 (BESIII Collaboration)

¹Institute of High Energy Physics, Beijing 100049, People’s Republic of China
²Beihang University, Beijing 100191, People’s Republic of China
³Bochum Ruhr-University, D-44780 Bochum, Germany
⁴Budker Institute of Nuclear Physics SB RAS (BINP), Novosibirsk 630090, Russia
⁵Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
⁶Central China Normal University, Wuhan 430079, People’s Republic of China
⁷Central South University, Changsha 410083, People’s Republic of China
⁸China Center of Advanced Science and Technology, Beijing 100190, People’s Republic of China
⁹China University of Geosciences, Wuhan 430074, People’s Republic of China
¹⁰Chung-Ang University, Seoul, 06974, Republic of Korea
¹¹COMSATS University Islamabad, Lahore Campus, Defence Road, Off Raiwind Road, 54000 Lahore, Pakistan
¹²Fudan University, Shanghai 200433, People’s Republic of China
¹³GSI Helmholtzcentre for Heavy Ion Research GmbH, D-64291 Darmstadt, Germany
¹⁴Guangxi Normal University, Guilin 541004, People’s Republic of China
¹⁵Guangxi University, Nanning 530004, People’s Republic of China
¹⁶Guangxi University of Science and Technology, Liuzhou 545006, People’s Republic of China
¹⁷Hangzhou Normal University, Hangzhou 310036, People’s Republic of China
¹⁸Hebei University, Baoding 071002, People’s Republic of China
¹⁹Helmholtz Institute Mainz, Staudinger Weg 18, D-55099 Mainz, Germany
²⁰Henan Normal University, Xinxiang 453007, People’s Republic of China
²¹Henan University, Kaifeng 475004, People’s Republic of China
²²Henan University of Science and Technology, Luoyang 471003, People’s Republic of China
²³Henan University of Technology, Zhengzhou 450001, People’s Republic of China
²⁴Huangshan College, Huangshan 245000, People’s Republic of China
²⁵Hunan Normal University, Changsha 410081, People’s Republic of China
²⁶Hunan University, Changsha 410082, People’s Republic of China
²⁷Indian Institute of Technology Madras, Chennai 600036, India
²⁸Indiana University, Bloomington, Indiana 47405, USA
^29aINFN Laboratori Nazionali di Frascati, I-00044, Frascati, Italy
^29bINFN Sezione di Perugia, I-06100, Perugia, Italy
^29cUniversity of Perugia, I-06100, Perugia, Italy
^30aINFN Sezione di Ferrara, I-44122, Ferrara, Italy
^30bUniversity of Ferrara, I-44122, Ferrara, Italy
³¹Inner Mongolia University, Hohhot 010021, People’s Republic of China
³²Institute of Modern Physics, Lanzhou 730000, People’s Republic of China
³³Institute of Physics and Technology, Mongolian Academy of Sciences, Peace Avenue 54B, Ulaanbaatar 13330, Mongolia
³⁴Instituto de Alta Investigación, Universidad de Tarapacá, Casilla 7D, Arica 1000000, Chile
³⁵Jilin University, Changchun 130012, People’s Republic of China
³⁶Johannes Gutenberg University of Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz, Germany
³⁷Joint Institute for Nuclear Research, 141980 Dubna, Moscow region, Russia
³⁸Justus-Liebig-Universitaet Giessen, II. Physikalisches Institut, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
³⁹Lanzhou University, Lanzhou 730000, People’s Republic of China
⁴⁰Liaoning Normal University, Dalian 116029, People’s Republic of China
⁴¹Liaoning University, Shenyang 110036, People’s Republic of China
⁴²Nanjing Normal University, Nanjing 210023, People’s Republic of China
⁴³Nanjing University, Nanjing 210093, People’s Republic of China
⁴⁴Nankai University, Tianjin 300071, People’s Republic of China
⁴⁵National Centre for Nuclear Research, Warsaw 02-093, Poland
⁴⁶North China Electric Power University, Beijing 102206, People’s Republic of China
⁴⁷Peking University, Beijing 100871, People’s Republic of China
⁴⁸Qufu Normal University, Qufu 273165, People’s Republic of China
⁴⁹Renmin University of China, Beijing 100872, People’s Republic of China
⁵⁰Shandong Normal University, Jinan 250014, People’s Republic of China
⁵¹Shandong University, Jinan 250100, People’s Republic of China
⁵²Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
⁵³Shanxi Normal University, Linfen 041004, People’s Republic of China
⁵⁴Shanxi University, Taiyuan 030006, People’s Republic of China
⁵⁵Sichuan University, Chengdu 610064, People’s Republic of China
⁵⁶Soochow University, Suzhou 215006, People’s Republic of China
⁵⁷South China Normal University, Guangzhou 510006, People’s Republic of China
⁵⁸Southeast University, Nanjing 211100, People’s Republic of China
⁵⁹State Key Laboratory of Particle Detection and Electronics, Beijing 100049, Hefei 230026, People’s Republic of China
⁶⁰Sun Yat-Sen University, Guangzhou 510275, People’s Republic of China
⁶¹Suranaree University of Technology, University Avenue 111, Nakhon Ratchasima 30000, Thailand
⁶²Tsinghua University, Beijing 100084, People’s Republic of China
^63aTurkish Accelerator Center Particle Factory Group, Istinye University, 34010, Istanbul, Turkey
^63bTurkish Accelerator Center Particle Factory Group, Near East University, Nicosia, North Cyprus, 99138, Mersin 10, Turkey
⁶⁴University of Bristol, H H Wills Physics Laboratory, Tyndall Avenue, Bristol, BS8 1TL, United Kingdom
⁶⁵University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
⁶⁶University of Groningen, NL-9747 AA Groningen, The Netherlands
⁶⁷University of Hawaii, Honolulu, Hawaii 96822, USA
⁶⁸University of Jinan, Jinan 250022, People’s Republic of China
⁶⁹University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
⁷⁰University of Muenster, Wilhelm-Klemm-Strasse 9, 48149 Muenster, Germany
⁷¹University of Oxford, Keble Road, Oxford OX13RH, United Kingdom
⁷²University of Science and Technology Liaoning, Anshan 114051, People’s Republic of China
⁷³University of Science and Technology of China, Hefei 230026, People’s Republic of China
⁷⁴University of South China, Hengyang 421001, People’s Republic of China
⁷⁵University of the Punjab, Lahore-54590, Pakistan
^76aUniversity of Turin, I-10125, Turin, Italy
^76bUniversity of Eastern Piedmont, I-15121, Alessandria, Italy
^76cINFN, I-10125, Turin, Italy
⁷⁷Uppsala University, Box 516, SE-75120 Uppsala, Sweden
⁷⁸Wuhan University, Wuhan 430072, People’s Republic of China
⁷⁹Yantai University, Yantai 264005, People’s Republic of China
⁸⁰Yunnan University, Kunming 650500, People’s Republic of China
⁸¹Zhejiang University, Hangzhou 310027, People’s Republic of China
⁸²Zhengzhou University, Zhengzhou 450001, People’s Republic of China

^*Full author list given at the end of the paper.
^†Deceased.
^aAlso at the Moscow Institute of Physics and Technology, Moscow 141700, Russia.
^bAlso at the Novosibirsk State University, Novosibirsk, 630090, Russia.
^cAlso at the NRC “Kurchatov Institute,” PNPI, 188300, Gatchina, Russia.
^dAlso at Goethe University Frankfurt, 60323 Frankfurt am Main, Germany.
^eAlso at Key Laboratory for Particle Physics, Astrophysics and Cosmology, Ministry of Education; Shanghai Key Laboratory for Particle Physics and Cosmology; Institute of Nuclear and Particle Physics, Shanghai 200240, People’s Republic of China.
^fAlso at Key Laboratory of Nuclear Physics and Ion-beam Application (MOE) and Institute of Modern Physics, Fudan University, Shanghai 200443, People’s Republic of China.
^gAlso at State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, People’s Republic of China.
^hAlso at School of Physics and Electronics, Hunan University, Changsha 410082, China.
ⁱAlso at Guangdong Provincial Key Laboratory of Nuclear Science, Institute of Quantum Matter, South China Normal University, Guangzhou 510006, China.
^jAlso at MOE Frontiers Science Center for Rare Isotopes, Lanzhou University, Lanzhou 730000, People’s Republic of China.
^kAlso at Lanzhou Center for Theoretical Physics, Lanzhou University, Lanzhou 730000, People’s Republic of China.
^lAlso at the Department of Mathematical Sciences, IBA, Karachi 75270, Pakistan.
^mAlso at Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
ⁿAlso at Helmholtz Institute Mainz, Staudinger Weg 18, D-55099 Mainz, Germany.
^oAlso at Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China.

PDF

Phys. Rev. X 16, 031058 – Published 4 September, 2026

DOI: https://doi.org/10.1103/5v2c-55m1

Abstract

The study of the charmed baryons is crucial for investigating the strong and weak interactions in the standard model and for gaining insights into the internal structure of baryons. In an $e^{+} e^{-}$ experiment, the lightest charmed baryon, $Λ_{c}^{+}$ , can be produced in pairs through the single-photon annihilation process. This process can be described by two complex electromagnetic form factors. The presence of a nonzero relative phase between these form factors gives rise to a transverse polarization of the charmed baryon and provides additional constraints on the dynamic parameters in the decays. In this article, we present the first observation of the transverse polarization of $Λ_{c}^{+}$ in the reaction $e^{+} e^{-} \to Λ_{c}^{+} {\bar{Λ}}_{c}^{-}$ , based on $6.4 {fb}^{- 1}$ of $e^{+} e^{-}$ annihilation data collected at center-of-mass energies between 4600 MeV and 4951 MeV with the BESIII detector. The decay asymmetry parameters in the decays $Λ_{c}^{+} \to p K_{S}^{0}$ , $Λ π^{+}$ , $Σ^{0} π^{+}$ , and $Σ^{+} π^{0}$ are simultaneously extracted from the joint angular distributions. By independently extracting the above parameters for the process and its $C P$ -conjugate counterpart, we derive both the strong and weak phase differences between different partial waves and test several $C P$ observables. The obtained results fully demonstrate the feasibility of exploiting transverse polarization at electron-positron colliders to search for $C P$ -violating effects, opening up a new avenue for exploring $C P$ violation in the charmed baryon sector.

Physics Subject Headings (PhySH)

Popular Summary

Protons and neutrons are the fundamental constituents of nuclei and the most familiar baryons, each made of three quarks. Charmed baryons, which contain a charm quark, remain far less well understood. Because the charm quark is much heavier than the quarks inside protons and neutrons, charmed baryons offer a distinctive way to test how the strong force binds quarks together. Using the BESIII detector, we studied the lightest charmed baryon, the $Λ_{c}$ , and its antimatter partner at 13 collision energies. We found that their spin orientations are not completely random: They exhibit a measurable polarization perpendicular to the production plane of the $Λ_{c} {\bar{Λ}}_{c}$ pairs. This polarization reaches about 18% at its largest value and varies with collision energy. These results provide the most finely resolved measurement to date of the electromagnetic phase for any baryon and establish a route for searches for matter-antimatter differences in charmed-baryon decays.

Article Text

References (102)

G. S. Abrams et al., Observation of charmed baryon production in $e^{+} e^{-}$ annihilation, Phys. Rev. Lett. 44, 10 (1980).
K. Schönning, V. Batozskaya, P. Adlarson, and X. Zhou, Production and decay of polarized hyperon-antihyperon pairs, Chin. Phys. C 47, 052002 (2023).
G. Huang and R. B. Ferroli (BESIII Collaboration), Probing the internal structure of baryons, Natl. Sci. Rev. 8, nwab187 (2021).
S. Pacetti, R. Baldini Ferroli, and E. Tomasi-Gustafsson, Proton electromagnetic form factors: Basic notions, present achievements and future perspectives, Phys. Rep. 550–551, 1 (2015).
V. Punjabi, C. F. Perdrisat, M. K. Jones, E. J. Brash, and C. E. Carlson, The structure of the nucleon: Elastic electromagnetic form factors, Eur. Phys. J. A 51, 79 (2015).
H. Atac, M. Constantinou, Z. E. Meziani, M. Paolone, and N. Sparveris, Measurement of the neutron charge radius and the role of its constituents, Nat. Commun. 12, 1759 (2021).
M. Ablikim et al. (BESIII Collaboration), Determination of the $Σ^{+}$ timelike electromagnetic form factors, Phys. Rev. Lett. 132, 081904 (2024).
M. Ablikim et al. (BESIII Collaboration), Unraveling the structure of $Λ$ hyperons with polarized $Λ \bar{Λ}$ pairs, Phys. Rev. Lett. 135, 191902 (2025).
A. Mangoni, S. Pacetti, and E. Tomasi-Gustafsson, The first exploration of the physical Riemann surfaces of the ratio $G_{E}^{Λ} / G_{M}^{Λ}$ , Phys. Rev. D 104, 116016 (2021).
H. Chen and R.-G. Ping, $Λ_{c}^{+}$ transverse polarization and decay asymmetry parameters, Phys. Rev. D 99, 114027 (2019).
M. Ablikim et al. (BESIII Collaboration), Polarization and entanglement in baryon-antibaryon pair production in electron-positron annihilation, Nat. Phys. 15, 631 (2019).
M. Ablikim et al. (BESIII Collaboration), Complete measurement of the $Λ$ electromagnetic form factors, Phys. Rev. Lett. 123, 122003 (2019).
M. Ablikim et al. (BESIII Collaboration), Precise measurements of decay parameters and $C P$ asymmetry with entangled $Λ - \bar{Λ}$ pairs pairs, Phys. Rev. Lett. 129, 131801 (2022).
M. Ablikim et al. (BESIII Collaboration), Measurement of $Λ$ transverse polarization in $e^{+} e^{-}$ collisions at $\sqrt{s} = 3.68 - 3.71 GeV$ , J. High Energy Phys. 10 (2023) 081; 12 (2023) 80.
M. Ablikim et al. (BESIII Collaboration), Extracting the femtometer structure of strange baryons using the vacuum polarization effect, Nat. Commun. 15, 8812 (2024).
M. Ablikim et al. (BESIII Collaboration), Strong and weak $C P$ tests in sequential decays of polarized $Σ^{0}$ hyperons, Phys. Rev. Lett. 133, 101902 (2024).
M. Ablikim et al. (BESIII Collaboration), Probing $C P$ symmetry and weak phases with entangled double-strange baryons, Nature (London) 606, 64 (2022).
M. Ablikim et al. (BESIII Collaboration), Observation of $Ξ^{-}$ hyperon transverse polarization in $ψ (3686) \to Ξ^{-} {\bar{Ξ}}^{+}$ , Phys. Rev. D 106, L091101 (2022).
M. Ablikim et al. (BESIII Collaboration), Tests of $C P$ symmetry in entangled $Ξ^{0} - {\bar{Ξ}}^{0}$ pairs, Phys. Rev. D 108, L031106 (2023).
T. D. Lee and C.-N. Yang, General partial wave analysis of the decay of a hyperon of spin $1 / 2$ , Phys. Rev. 108, 1645 (1957).
M. Ablikim et al. (BESIII Collaboration), Measurements of weak decay asymmetries of $Λ_{c}^{+} \to p K_{S}^{0}$ , $Λ π^{+}$ , $Σ^{+} π^{0}$ , and $Σ^{0} π^{+}$ , Phys. Rev. D 100, 072004 (2019).
H.-J. Wang, P.-R. Li, X.-R. Lyu, J. Tandean, and H.-B. Li, Remarks on strong phase shifts in weak nonleptonic baryon decays, Sci. Bull. 70, 1189 (2025).
P. Avery et al. (CLEO Collaboration), Measurement of the $Λ_{c}^{+}$ decay asymmetry parameter, Phys. Rev. Lett. 65, 2842 (1990).
J. G. Korner and M. Kramer, Exclusive nonleptonic charm baryon decays, Z. Phys. C 55, 659 (1992).
M. A. Ivanov, J. G. Korner, V. E. Lyubovitskij, and A. G. Rusetsky, Exclusive nonleptonic decays of bottom and charm baryons in a relativistic three quark model: Evaluation of nonfactorizing diagrams, Phys. Rev. D 57, 5632 (1998).
Q. P. Xu and A. N. Kamal, Cabibbo favored nonleptonic decays of charmed baryons, Phys. Rev. D 46, 270 (1992).
H.-Y. Cheng and B. Tseng, Nonleptonic weak decays of charmed baryons, Phys. Rev. D 46, 1042 (1992); 55, 1697(E) (1997).
H.-Y. Cheng and B. Tseng, Cabibbo allowed nonleptonic weak decays of charmed baryons, Phys. Rev. D 48, 4188 (1993).
P. Zenczykowski, Nonleptonic charmed baryon decays: Symmetry properties of parity violating amplitudes, Phys. Rev. D 50, 5787 (1994).
P. Zenczykowski, Quark and pole models of nonleptonic decays of charmed baryons, Phys. Rev. D 50, 402 (1994).
A. Datta, Nonleptonic two-body decays of charmed and $Λ_{b}$ baryons, arXiv:hep-ph/9504428.
K. K. Sharma and R. C. Verma, A Study of weak mesonic decays of $Λ_{c}$ and $Ξ_{c}$ baryons on the basis of HQET results, Eur. Phys. J. C 7, 217 (1999).
L. K. Li et al. (Belle Collaboration), Search for $C P$ violation and measurement of branching fractions and decay asymmetry parameters for $Λ_{c}^{+} \to Λ h^{+}$ and $Λ_{c}^{+} \to Σ^{0} h^{+} (h = K, π)$ , Sci. Bull. 68, 583 (2023).
S. X. Li et al. (Belle Collaboration), Measurements of branching fractions of $Λ_{c}^{+} \to Σ^{+} η$ and $Λ_{c}^{+} \to Σ^{+} η^{'}$ and asymmetry parameters of $Λ_{c}^{+} \to Σ^{+} π^{0}$ , $Λ_{c}^{+} \to Σ^{+} η$ , and $Λ_{c}^{+} \to Σ^{+} η^{'}$ , Phys. Rev. D 107, 032003 (2023).
M. Ablikim et al. (BESIII Collaboration), First measurement of the decay asymmetry in the pure $W$ -boson-exchange decay $Λ_{c}^{+} \to Ξ^{0} K^{+}$ , Phys. Rev. Lett. 132, 031801 (2024).
C. Yang, X.-G. He, and C.-W. Liu, Charmed baryon decays: ${SU (3)}_{F}$ breaking and $C P$ violation, J. High Energy Phys. 09 (2025) 193.
C.-Q. Geng, X.-G. He, X.-N. Jin, C.-W. Liu, and C. Yang, Complete determination of $S U (3)_{F}$ amplitudes and strong phase in $Λ_{c}^{+} \to Ξ^{0} K^{+}$ , Phys. Rev. D 109, L071302 (2024).
H. Zhong, F. Xu, and H.-Y. Cheng, Topological diagrams and hadronic weak decays of charmed baryons, arXiv:2401.15926.
H. Zhong, F. Xu, and H.-Y. Cheng, Analysis of hadronic weak decays of charmed baryons in the topological diagrammatic approach, Phys. Rev. D 109, 114027 (2024).
C. Q. Geng, C.-W. Liu, and T.-H. Tsai, Asymmetries of anti-triplet charmed baryon decays, Phys. Lett. B 794, 19 (2019).
J. Zou, F. Xu, G. Meng, and H.-Y. Cheng, Two-body hadronic weak decays of antitriplet charmed baryons, Phys. Rev. D 101, 014011 (2020).
H. Zhong, F. Xu, Q. Wen, and Y. Gu, Weak decays of antitriplet charmed baryons from the perspective of flavor symmetry, J. High Energy Phys. 02 (2023) 235.
C.-W. Liu, Nonleptonic two-body weak decays of charmed baryons, Phys. Rev. D 109, 033004 (2024).
H.-Y. Cheng, F. Xu, and H. Zhong, Hadronic weak decays of charmed baryons in the topological diagrammatic approach: An update, Phys. Rev. D 111, 034011 (2025).
H. Albrecht et al. (ARGUS Collaboration), A measurement of asymmetry in the decay $Λ_{c}^{+} \to Λ π^{+}$ , Phys. Lett. B 274, 239 (1992).
M. Bishai et al. (CLEO Collaboration), Measurement of the decay asymmetry parameters in $Λ_{c}^{+} \to Λ π^{+}$ and $Λ_{c}^{+} \to Σ^{+} π^{0}$ , Phys. Lett. B 350, 256 (1995).
J. M. Link et al. (FOCUS Collaboration), Study of the decay asymmetry parameter and $C P$ violation parameter in the $Λ_{c}^{+} \to Λ π^{+}$ decay, Phys. Lett. B 634, 165 (2006).
R. Aaij et al. (LHCb Collaboration), Measurement of $Λ_{b}^{0}$ , $Λ_{c}^{+}$ , and $Λ$ decay parameters using $Λ_{b}^{0} \to Λ_{c}^{+} h^{-}$ decays, Phys. Rev. Lett. 133, 261804 (2024).
S. Navas et al. (Particle Data Group), Review of particle physics, Phys. Rev. D 110, 030001 (2024).
A. Alavi-Harati et al. (KTeV Collaboration), Observation of direct $C P$ violation in $K_{S, L} \to π π$ decays, Phys. Rev. Lett. 83, 22 (1999).
V. Fanti et al. (NA48 Collaboration), A new measurement of direct $C P$ violation in two pion decays of the neutral kaon, Phys. Lett. B 465, 335 (1999).
R. Aaij et al. (LHCb Collaboration), Observation of $C P$ violation in charm decays, Phys. Rev. Lett. 122, 211803 (2019).
B. Aubert et al. (BABAR Collaboration), Observation of direct $C P$ violation in $B^{0} \to K^{+} π^{-}$ decays, Phys. Rev. Lett. 93, 131801 (2004).
Y. Chao et al. (Belle Collaboration), Evidence for direct $C P$ violation in $B^{0} \to K^{+} π^{-}$ decays, Phys. Rev. Lett. 93, 191802 (2004).
R. Aaij et al. (LHCb Collaboration), Observation of charge-parity symmetry breaking in baryon decays, Nature (London) 643, 1223 (2025).
R. Aaij et al. (LHCb Collaboration), Measurement of matter-antimatter differences in beauty baryon decays, Nat. Phys. 13, 391 (2017).
R. Aaij et al. (LHCb Collaboration), Study of $Λ_{b}^{0}$ and $Ξ_{b}^{0}$ decays to $Λ h^{+} {h^{'}}^{-}$ and evidence for $C P$ violation in $Λ_{b}^{0} \to Λ K^{+} K^{-}$ decays, Phys. Rev. Lett. 134, 101802 (2025).
M. Ablikim et al. (BESIII Collaboration), Precision studies and searches for $C P$ asymmetries in the inclusive decay $Λ_{c}^{+} \to Λ X$ , arXiv:2602.24089.
M. Ablikim et al. (BESIII Collaboration), Investigation of the $Δ I = 1 / 2$ rule and test of $C P$ symmetry through the measurement of decay asymmetry parameters in $Ξ^{-}$ decays, Phys. Rev. Lett. 132, 101801 (2024).
M. Ablikim et al. (BESIII Collaboration), Design and construction of the BESIII detector, Nucl. Instrum. Methods Phys. Res., Sect. A 614, 345 (2010).
C. Yu et al., BEPCII performance and beam dynamics studies on luminosity, in 7th International Particle Accelerator Conference (JACoW Publishing, Geneva, Switzerland, 2016), p. TUYA01, 10.18429/JACoW-IPAC2016-TUYA01.
M. Ablikim et al. (BESIII Collaboration), Future physics programme of BESIII, Chin. Phys. C 44, 040001 (2020).
J. Lu, Y. Xiao, and X. Ji, Online monitoring of the center-of-mass energy from real data at BESIII, Radiat. Detect. Technol. Methods 4, 337 (2020).
J.-W. Zhang et al., Suppression of top-up injection backgrounds with offline event filter in the BESIII experiment, Radiat. Detect. Technol. Methods 6, 289 (2022).
Y.-X. Guo et al., The study of time calibration for upgraded end cap TOF of BESIII, Radiat. Detect. Technol. Methods 1, 15 (2017).
X. Li et al., Study of MRPC technology for BESIII endcap-tof upgrade, Radiat. Detect. Technol. Methods 1, 13 (2017).
C. Cao, P et al., Design and construction of the new BESIII endcap time-of-flight system with MRPC technology, Nucl. Instrum. Methods Phys. Res., Sect. A 953, 163053 (2020).
M. Ablikim et al. (BESIII Collaboration), Measurement of integrated luminosities at BESIII for data samples at center-of-mass energies between 4.0 and 4.6 GeV, Chin. Phys. C 46, 113002 (2022).
M. Ablikim et al. (BESIII Collaboration), Luminosities and energies of $e^{+} e^{-}$ collision data taken between 4.61 GeV and 4.95 GeV at BESIII, Chin. Phys. C 46, 113003 (2022).
S. Agostinelli et al. (GEANT4 Collaboration), GEANT4–a simulation toolkit, Nucl. Instrum. Methods Phys. Res., Sect. A 506, 250 (2003).
S. Jadach, B. F. L. Ward, and Z. Was, Coherent exclusive exponentiation for precision Monte Carlo calculations, Phys. Rev. D 63, 113009 (2001).
S. Jadach, B. F. L. Ward, and Z. Was, The precision Monte Carlo event generator $K K$ for two fermion final states in $e^{+} e^{-}$ collisions, Comput. Phys. Commun. 130, 260 (2000).
D. J. Lange, The EvtGen particle decay simulation package, Nucl. Instrum. Methods Phys. Res., Sect. A 462, 152 (2001).
R.-G. Ping, Event generators at BESIII, Chin. Phys. C 32, 599 (2008).
J. C. Chen, G. S. Huang, X. R. Qi, D. H. Zhang, and Y. S. Zhu, Event generator for $J / ψ$ and $ψ (2 S)$ decay, Phys. Rev. D 62, 034003 (2000).
R.-L. Yang, R.-G. Ping, and H. Chen, Tuning and validation of the Lundcharm model with $J / ψ$ decays, Chin. Phys. Lett. 31, 061301 (2014).
E. Barberio, B. van Eijk, and Z. Was, PHOTOS: A universal Monte Carlo for QED radiative corrections in decays, Comput. Phys. Commun. 66, 115 (1991).
M. Ablikim et al. (BESIII Collaboration), Precision measurement of the $e^{+} e^{-} \to Λ_{c}^{+} {\bar{Λ}}_{c}^{-}$ cross section near threshold, Phys. Rev. Lett. 120, 132001 (2018).
M. Ablikim et al. (BESIII Collaboration), Observations of the Cabibbo-suppressed decays $Λ_{c}^{+} \to n π^{+} π^{0}$ , $n π^{+} π^{-} π^{+}$ and the Cabibbo-favored decay $Λ_{c}^{+} \to n K^{-} π^{+} π^{+}$ , Chin. Phys. C 47, 023001 (2023).
R. Aaij et al. (LHCb Collaboration), Evidence for a new structure in the $J / ψ p$ and $J / ψ \bar{p}$ systems in $B_{s}^{0} \to J / ψ p \bar{p}$ decays, Phys. Rev. Lett. 128, 062001 (2022).
R. Aaij et al. (LHCb Collaboration), Observation of a $J / ψ Λ$ resonance consistent with a strange pentaquark candidate in $B^{-} \to J / ψ Λ \bar{p}$ decays, Phys. Rev. Lett. 131, 031901 (2023).
H. Albrecht et al. (ARGUS Collaboration), Search for hadronic $b \to u$ decays, Phys. Lett. B 241, 278 (1990).
E. Perotti, G. Fäldt, A. Kupsc, S. Leupold, and J. J. Song, Polarization observables in $e^{+} e^{-}$ annihilation to a baryon-antibaryon pair, Phys. Rev. D 99, 056008 (2019).
R. Aaij et al. (LHCb Collaboration), $Λ_{c}^{+}$ polarimetry using the dominant hadronic mode, J. High Energy Phys. 07 (2023) 228.
R. Aaij et al. (LHCb Collaboration), Amplitude analysis of the $Λ_{c}^{+} \to p K^{-} π^{+}$ decay and $Λ_{c}^{+}$ baryon polarization measurement in semileptonic beauty hadron decays, Phys. Rev. D 108, 012023 (2023).
M. Ablikim et al. (BESIII Collaboration), Partial wave analysis of the charmed baryon hadronic decay $Λ_{c}^{+} Λ π^{+} π^{0}$ , J. High Energy Phys. 12 (2022) 033.
C. Langenbruch, Parameter uncertainties in weighted unbinned maximum likelihood fits, Eur. Phys. J. C 82, 393 (2022).
F. James and M. Roos, Minuit: A system for function minimization and analysis of the parameter errors and correlations, Comput. Phys. Commun. 10, 343 (1975).
M. Ablikim et al. (BESIII Collaboration), Measurement of absolute branching fraction of the inclusive decay $Λ_{c}^{+} \to Λ + X$ , Phys. Rev. Lett. 121, 062003 (2018).
N. Salone, P. Adlarson, V. Batozskaya, A. Kupsc, S. Leupold, and J. Tandean, Study of $C P$ violation in hyperon decays at super-charm-tau factories with a polarized electron beam, Phys. Rev. D 105, 116022 (2022).
C. Chen, B. Yan, and J.-J. Xie, Cross sections and the electromagnetic form factors within the extended vector meson dominance model, Chin. Phys. Lett. 41, 021302 (2024).
J. Wan, Y. Yang, and Z. Lu, The electromagnetic form factors of $Λ_{c}$ hyperon in the vector meson dominance model, Eur. Phys. J. Plus 136, 949 (2021).
M. Ablikim et al. (BESIII Collaboration), Measurement of energy-dependent pair-production cross section and electromagnetic form factors of a charmed baryon, Phys. Rev. Lett. 131, 191901 (2023).
Z.-Y. Li, A.-X. Dai, and J.-J. Xie, Electromagnetic form factors of $Λ$ hyperon in the vector meson dominance model and a possible explanation of the near-threshold enhancement of the reaction, Chin. Phys. Lett. 39, 011201 (2022).
C. Chen, B. Yan, and J.-J. Xie, The electromagnetic form factors and spin polarization of $Λ_{c}^{+}$ in the process $e^{+} e^{-} \to Λ_{c}^{+} {\bar{Λ}}_{c}^{-}$ , Chin. Phys. C 49, 023102 (2025).
Y. Yang, D.-Y. Chen, and Z. Lu, Electromagnetic form factors of $Λ$ hyperon in the vector meson dominance model, Phys. Rev. D 100, 073007 (2019).
G. Pakhlova et al. (Belle Collaboration), Observation of a near-threshold enhancement in the $e^{+} e^{-} \to Λ_{c}^{+} {\bar{Λ}}_{c}^{-}$ cross section using initial-state radiation, Phys. Rev. Lett. 101, 172001 (2008).
P.-R. Li, X.-R. Lyu, and Y. Zheng, Experimental overview on the charmed baryon decays, Chin. Phys. C 50, 022002 (2026).
C.-P. Jia, H.-Y. Jiang, J.-P. Wang, and F.-S. Yu, Final-state rescattering mechanism of charmed baryon decays, J. High Energy Phys. 11 (2024) 072.
X.-G. He and C.-W. Liu, Large $C P$ violation in charmed baryon decays, Sci. Bull. 70, 2598 (2025).
H.-J. Wang, C. Wang, H. Sun, P.-R. Li, X.-R. Lyu, and R.-G. Ping, Prospects for $P$ and $C P$ violation in $Λ_{c}^{+}$ decays with a polarized beam at the Super Tau-Charm Facility, Phys. Rev. D 112, 112002 (2025).
https://cstr.cn/31109.02.BEPC

Phys. Rev. X 16, 031058– Published 4 September, 2026

Vol. 16, Iss. 3 — July - September 2026

Received 18 August 2025
Revised 19 November 2025
Accepted 8 July 2026

DOI: https://doi.org/10.1103/5v2c-55m1

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

Published by the American Physical Society

Physical Review X

Reuse & Permissions

Export citation

Export citation

Production and Decay Dynamics of the Charmed Baryon $Λ_{c}^{+}$ in $e^{+} e^{-}$ Annihilations near Threshold

Abstract

Physics Subject Headings (PhySH)

Popular Summary

Article Text

References (102)

Outline

Information

Filter

Filter

Article Lookup

Enter a citation

Production and Decay Dynamics of the Charmed Baryon Λc+ in e+e− Annihilations near Threshold

Abstract

Physics Subject Headings (PhySH)

Popular Summary

Article Text

References (102)

Production and Decay Dynamics of the Charmed Baryon $Λ_{c}^{+}$ in $e^{+} e^{-}$ Annihilations near Threshold