Observation of a Resonant Structure in e+e−→K+K−π0π0

A partial-wave analysis is performed for the process e+e−→K+K−π0π0 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 cross sections for the process e+e−→K+K−π0π0, as well as the Born cross sections for the subprocesses e+e−→ϕπ0π0, K+(1460)K−, K+1(1400)K−, K+1(1270)K−, and K*+(892)K*−(892), are measured versus the center-of-mass energy. The corresponding results for e+e−→K+K−π0π0 and ϕπ0π0 are consistent with those of BABAR with better precision. By analyzing the cross sections for the four subprocesses, K+(1460)K−, K+1(1400)K−, K+1(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−→K+1(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).