Measurement of cross section for e+e- → Ξ0(Ξ)over-bar0 near threshold

作者：Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ahmed, S.; Albrecht, M.; Aliberti, R.; Amoroso, A.; An, M. R.; An, Q.; Bai, X. H.; Bai, Y.; Bakina, O.; Ferroli, R. Baldini; Balossino, I; Ban, Y.; Begzsuren, K.; Berger, N.; Bertani, M.; Bettoni, D.; Bianchi, F.; Bloms, J.; Bortone, A.; Boyko, I; Briere, R. A.; Cai, H.; Cai, X.; Calcaterra, A.; Cao, G. F.; Cao, N.; Cetin, S. A.; Chai, X. Y.; Chang, J. F.; Chang, W. L.; Chelkov, G.; Chen, D. Y.; Chen, G.; Chen, H. S.; Chen, M. L.; Chen, S. J.

来源：Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics , 2021, 820: 136557.

DOI：10.1016/j.physletb.2021.136557

• Born cross section
• Effective form factor
• Threshold effect

Using e(+)e(-) collision data at ten center-of-mass energies between 2.644 and 3.080 GeV collected with the BESIII detector at BEPCII and corresponding to an integrated luminosity of about 500 pb(-1), we measure the cross sections and effective form factors for the process e(+)e(-) -> Xi(0)(Xi) over bar (0) utilizing a single-tag method. A fit to the cross section of e(+)e(-) -> Xi(0)(Xi) over bar (0) with a pQCD-driven power function is performed, from which no significant resonance or threshold enhancement is observed. In addition, the ratio of cross sections for the processes e(+)e(-) -> Xi(0)(Xi) over bar (0) and Xi(0)(Xi) over bar (0) is calculated using recent BESIII measurement and is found to be compatible with expectation from isospin symmetry.