Observation of $\psi \left(3686\right)\to p\overline{p}\varphi $

Using a data sample of $4.48×{10}^{8}$ $\psi \left(3686\right)$ events collected with the BESIII detector, we present a first observation of $\psi \left(3686\right)\to p\overline{p}\varphi $, and we measure its branching fraction to be $\left[6.06±0.38\left(\mathrm{stat}\right)±\phantom{\rule{0ex}{0ex}}0.48\left(\mathrm{syst}\right)\right]×{10}^{-6}$. In contrast to the earlier discovery of a threshold enhancement in the $p\overline{p}$-mass spectrum of the channel $J/\psi \to \gamma p\overline{p}$, denoted as $X\left(p\overline{p}\right)$, we do not find a similar enhancement in $\psi \left(3686\right)\to p\overline{p}\varphi $. An upper limit of $1.82×{10}^{-7}$ at the 90% confidence level on the branching fraction of $\psi \left(3686\right)\to X\left(p\overline{p}\right)\varphi \to p\overline{p}\varphi $ is obtained.