Ablikim, M.Achasov, M. N.Adlarson, P.Ai, X. C.Aliberti, R.Amoroso, A.Çetin, Serkant Ali2024-05-192024-05-1920230031-90071079-7114https://doi.org10.1103/PhysRevLett.131.191901https://hdl.handle.net/20.500.12713/5871We study the process e(+)e(-) -> Lambda(+)(c) (Lambda) over bar (-)(c) at twelve center-of-mass energies from 4.6119 to 4.9509 GeV using data samples collected by the BESIII detector at the BEPCII collider. The Born cross sections and effective form factors (vertical bar G(eff)vertical bar) are determined with unprecedented precision after combining the single and double-tag methods based on the decay process Lambda(+)(c) -> pK(-)pi(+). Flat cross sections around 4.63 GeV are obtained and no indication of the resonant structure Yo4630THORN, as reported by Belle, is found. In addition, no oscillatory behavior is discerned in the vertical bar G(eff)vertical bar energy dependence of Lambda(+)(c), in contrast to what is seen for the proton and neutron cases. Analyzing the cross section together with the polar-angle distribution of the. thornc baryon at each energy point, the moduli of electric and magnetic form factors (vertical bar G(E)vertical bar and vertical bar G(M)vertical bar) are extracted and separated. For the first time, the energy dependence of the form factor ratio vertical bar G(E)vertical bar/vertical bar G(M)vertical bar is observed, which can be well described by an oscillatory function.eninfo:eu-repo/semantics/openAccessE(+)E(-)P(P)Over-BarArticle1311938000396WOS:0011733529000032-s2.0-85177799416N/A10.1103/PhysRevLett.131.191901Q1