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

A partial-wave analysis is performed for the process e^{+}e^{-}-->K^{+}K^{-}pi^{0}pi^{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 cross sections for the process e^{+}e^{-}-->K^{+}K^{-}pi^{0}pi^{0}, as well as the Born cross sections for the subprocesses e^{+}e^{-}-->varphipi^{0}pi^{0}, 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^{-}pi^{0}pi^{0} and varphipi^{0}pi^{0} 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/c^{2} and width Gamma=(106.9+/-32.1+/-28.1) MeV is observed with an overall statistical significance of 6.3sigma, 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 varphi(2170), thus the results provide valuable input to the internal nature of the varphi(2170).