Measurement of the cross sections for e+e- ???+?- at center-of-mass energies between 2.00 and 3.08 GeV

Using data samples collected at center-of-mass energies between 2.000 and 3.080 GeV with the BESIII detector operating at the BEPCII collider, a partial-wave analysis is performed on the process e+e-???+?-. In addition to the dominant e+e-??? component, the e+e-?a2(1320)? process is also sizable, contributing up to 24% of the total reaction. The measured cross sections of the process e+e-???+?- are systematically higher than those of BABAR by more than 3? at center-of-mass energies between 2.000 and 2.300 GeV. In the cross section line shape for e+e-?a2(1320)?, a resonant structure is observed with a significance of 5.5?, with M=(2044±31±4) MeV/c2, ?=(163±69±24) MeV, and BR·?e+e-R=(34.6±17.1±6.0) eV or (137.1±73.3±2.1) eV. In the cross section line shape for e+e-???, an evidence of a dip structure around 2180 MeV/c2 is observed with statistical significance of 3.0?. © 2023 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.