Abstract: | Using a sample of $(448.1pm2.9) imes10^6$ $psi(3686)$ events collected
with the BESIII detector, we perform the first partial wave analysis of
$psi(3686)
ightarrow K^+K^-eta$. In addition to the well established states,
$phi(1020)$, $phi(1680)$ and $K_3^*(1780)$, contributions from $X(1750)$,
$
ho(2150)$, $
ho_3(2250)$ and $K^*_2(1980)$ are also observed. The $X(1750)$
state is determined to be a $1^{--}$ resonance. The simultaneous observation of
the $phi(1680)$ and $X(1750)$ indicates that the $X(1750)$, with previous
observations in photoproduction, is distinct from the $phi(1680)$. The masses,
widths, branching fractions of $psi(3686)
ightarrow K^+K^-eta$ and the
intermediate resonances are also measured. |