Ablikim, M.Achasov, M.N.Adlarson, P.Afedulidis, O.Ai, X.C.Aliberti, R.Çetin, Serkant Ali2024-05-192024-05-1920242470-0010https://doi.org/10.1103/PhysRevD.109.L071104https://hdl.handle.net/20.500.12713/4527Using e+e- collision data collected with the BESIII detector operating at the BEPCII collider, the Born cross sections of e+e-??c+?¯c(2595)-+c.c. and e+e-??c+?¯c(2625)-+c.c. are measured for the first time at center-of-mass energies of s=4918.0 and 4950.9 MeV. Nonzero cross sections are observed very close to the production threshold. The measured Born cross sections of e+e-??c+?¯c(2625)-+c.c. are about 2-3 times greater than those of e+e-??c+?¯c(2595)-+c.c., providing the similar behavior as semileptonic decays of ?b0, but different behavior from that in the hadronic decays of ?b0. The Born cross sections are 15.6±3.1±0.9 pb and 29.4±3.7±2.7 pb for e+e-??c+?¯c(2595)-+c.c., and are 43.4±4.0±4.1 pb and 76.8±6.5±4.2 pb for e+e-??c+?¯c(2625)-+c.c. at s=4918.0 and 4950.9 MeV, respectively. Based on the polar angle distributions of the ?¯c(2625)- and ?c(2625)+, the form-factor ratios |GE|2+3|GM|2/|GC| are determined for e+e-??c+?¯c(2625)-+c.c. for the first time, which are 5.95±4.07±0.15 and 0.94±0.32±0.02 at s=4918.0 and 4950.9 MeV, respectively. All of these first uncertainties are statistical and second systematic. © 2024 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"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. Funded by SCOAP3.eninfo:eu-repo/semantics/openAccessArticle10972-s2.0-8519214460410.1103/PhysRevD.109.L071104Q1