The BESIII collaboration has presented the most precise measurements of the e+e-→ Ds*+Ds*- cross sections at center-of-mass energies from threshold to 4.95 GeV. The result has been published in Physical Review Letters on October 13th, 2023. [Phys. Rev. Lett.131.151903].
The vector-charmonium-like states exhibit properties without matching the conventional cˉc mesons and provide a crucial opportunity to study exotic configurations of quarks and gluons. The vector-charmonium-like state, ψ(4230), has been discovered in e+e- annihilations into charmonium and light hadrons, while results from final states of charmed mesons are scarce. Interestingly, the mass of the ψ(4230) state lies just at the production threshold of the Ds*+Ds*- pair.
With the world’s largest e+e- scan data sample between 4.226 and 4.95 GeV accumulated by BESIII, the Born cross sections of e+e-→ Ds*+Ds*- are measured precisely. Two enhancements in the ECM dependent cross sections are observed around 4.2 and 4.45 GeV. The fitted mass and width for the first resonance are (4186.8±8.7±30) MeV/c2 and (55±15±53) MeV, respectively. The fitted mass and width for the second resonance are (4414.6±3.4±6.1) MeV/c2 and (122.5±7.5±8.1) MeV, respectively. An additional third BW amplitude describes the energy-dependent cross sections around 4.79 GeV better than just using two BW functions, with statistical significance greater than 5.9σ, however, more data points in the vicinity are needed for further clarification.