Measurement of Born Cross Sections for e⁺e^- → K⁺Ξ⁰Σ̅^- at √s = 3.51−4.95 GeV and Observation of ψ(3770) → K⁺Ξ⁰Σ̅^-

@misc{collaboration2026measurement,
  title = {{Measurement of Born Cross Sections for $e^+e^- \to K^+Ξ^0\barΣ^-$ at $\sqrts = 3.51-4.95$ GeV and Observation of $ψ(3770) \to K^+Ξ^0\barΣ^-$}},
  author = {BESIII Collaboration and M. Ablikim and M. N. Achasov and P. Adlarson and X. C. Ai and C. S. Akondi and R. Aliberti and A. Amoroso and Q. An and Y. H. An and Y. Bai and O. Bakina and H. R. Bao and X. L. Bao and M. Barbagiovanni and V. Batozskaya and K. Begzsuren and N. Berger and M. Berlowski and M. B. Bertani and D. Bettoni and F. Bianchi and E. Bianco and A. Bortone and I. Boyko and R. A. Briere and A. Brueggemann and D. Cabiati and H. Cai and M. H. Cai and X. Cai and A. Calcaterra and G. F. Cao and N. Cao and S. A. Cetin and X. Y. Chai and J. F. Chang and T. T. Chang and G. R. Che and Y. Z. Che and C. H. Chen and Chao Chen and G. Chen and H. S. Chen and H. Y. Chen and M. L. Chen and S. J. Chen and S. M. Chen and T. Chen and W. Chen and X. R. Chen and X. T. Chen and X. Y. Chen and Y. B. Chen and Y. Q. Chen and Z. K. Chen and J. Cheng and L. N. Cheng and S. K. Choi and X. Chu},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2605.19780},
  eprint = {2605.19780},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2605.19780},
}

TY  - UNPB
TI  - Measurement of Born Cross Sections for e^+e^- → K^+Ξ^0Σ̅^- at √s = 3.51−4.95 GeV and Observation of ψ(3770) → K^+Ξ^0Σ̅^-
AU  - BESIII Collaboration
AU  - M. Ablikim
AU  - M. N. Achasov
AU  - P. Adlarson
AU  - X. C. Ai
AU  - C. S. Akondi
AU  - R. Aliberti
AU  - A. Amoroso
AU  - Q. An
AU  - Y. H. An
AU  - Y. Bai
AU  - O. Bakina
AU  - H. R. Bao
AU  - X. L. Bao
AU  - M. Barbagiovanni
AU  - V. Batozskaya
AU  - K. Begzsuren
AU  - N. Berger
AU  - M. Berlowski
AU  - M. B. Bertani
AU  - D. Bettoni
AU  - F. Bianchi
AU  - E. Bianco
AU  - A. Bortone
AU  - I. Boyko
AU  - R. A. Briere
AU  - A. Brueggemann
AU  - D. Cabiati
AU  - H. Cai
AU  - M. H. Cai
AU  - X. Cai
AU  - A. Calcaterra
AU  - G. F. Cao
AU  - N. Cao
AU  - S. A. Cetin
AU  - X. Y. Chai
AU  - J. F. Chang
AU  - T. T. Chang
AU  - G. R. Che
AU  - Y. Z. Che
AU  - C. H. Chen
AU  - Chao Chen
AU  - G. Chen
AU  - H. S. Chen
AU  - H. Y. Chen
AU  - M. L. Chen
AU  - S. J. Chen
AU  - S. M. Chen
AU  - T. Chen
AU  - W. Chen
AU  - X. R. Chen
AU  - X. T. Chen
AU  - X. Y. Chen
AU  - Y. B. Chen
AU  - Y. Q. Chen
AU  - Z. K. Chen
AU  - J. Cheng
AU  - L. N. Cheng
AU  - S. K. Choi
AU  - X. Chu
PY  - 2026
DA  - 2026/10/29
PB  - arXiv
DO  - 10.48550/arxiv.2605.19780
UR  - https://arxiv.org/abs/2605.19780
AB  - Using 44.55 fb^−1 of e^+e^- collision data collected by the BESIII detector at the BEPCII collider, we report the first measurement of the Born cross sections for the e^+e^- → K^+Ξ^0Σ̅^- reaction at fifty-six center-of-mass energies between 3.51 and 4.95~GeV. A fit to the dressed cross sections reveals the first observation of the ψ(3770) → K^+Ξ^0Σ̅^- process, with a statistical significance of 6.0σ including systematic uncertainties. This result represents the first observation of charmless three-body baryonic decay of a vector charmonium state above the open-charm threshold. No significant signals for other charmonium(-like) states i.e., ψ(4040), ψ(4160), Y(4230), Y(4360), ψ(4415), Y(4500), Y(4660) or Y(4710) are observed, and the upper limits for the product of the branching fraction and the electronic partial width at the 90% confidence level for each assumed charmonium(-like) state are provided. Additionally, the ratios of Born cross sections between this work and the previous measurements of e^+e^- → K^0_SΞ̅^−Σ^- and K^-Ξ̅^+Σ̅^0 are provided, which can be used to validate theoretical predictions related to isospin symmetry.
ER  -