Observation of ${\chi }_{cJ}(J=0,1,2)\to p\bar{p}\eta \eta$

Using $(2712.4\pm 14.3)\times {10}^6$ $\psi (3686)$ events collected by the BESIII detector operating at the BEPCII storage ring, the decays ${\chi }_{cJ}(J=0,1,2)\to p\bar{p}\eta \eta$ are observed for the first time through the radiative transition $\psi (3686)\to \gamma {\chi }_{cJ}$. The statistical significances for ${\chi }_{cJ}$ signals are all larger than 5$\sigma$. The branching fractions of ${\chi }_{c0,1,2}\to p\bar{p}\eta \eta$ are determined to be $(5.75\pm 0.59\pm 0.42)\times {10}^{-5}$, $(1.40\pm 0.33\pm 0.17)\times {10}^{-5}$, and $(2.64\pm 0.40\pm 0.27)\times {10}^{-5}$, respectively, where the first uncertainties are statistical and the second systematic. No evident resonant structures are found in the $p\bar{p}$ and $p\eta \mathrm{/}\bar{p}\eta$ systems.