在e+ e − → K + K − π 0 π 0中觀測到共振結構
A partial-wave analysis is performed for the process e+ e − → K + K − π 0 π 0 at the center-of-mass energies ranging from 2.000 to 2.644 GeV. The data samples of e+ e − collisions, collected by the BESIII detector at the BEPCII collider with a total integrated luminosity of 300 pb−1, are analyzed. The total Born crosssections for the process e + e − → K + K− π 0 π 0, as well as the Born cross sections for the subprocesses e + e −→ϕ π 0π 0, K+(1460)K−, K1+(1400)K−, K1+(1270)K−, and K*+(892)K*−(892), are measured versus the center-of-mass energy. The corresponding results for e+ e − → K + K − π 0 π 0 and ϕ π0 π 0 are consistent with those of BABAR with better precision. By analyzing the cross sections for the four subprocesses, K+(1460)K−, K1+(1400)K−, K1+(1270)K−, and K*+(892)K*−(892), a structure with mass M=(2126.5±16.8±12.4) MeV/c2 and width Γ=(106.9±32.1±28.1) MeV is observed with an overall statistical significance of 6.3σ, although with very limited significance in the subprocesses e+e−→K1+(1270)K− and K*+(892)K*−(892). The resonant parameters of the observed structure suggest it can be identified with the ϕ(2170), thus the results provide valuable input to the internal nature of the ϕ(2170).
Observation of a Resonant Structure in e + e − → K + K− π 0 π 0
M. Ablikim et al. (BESIII Collaboration)
Phys.Rev. Lett. 124, 112001 (2020)
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.124.112001