systematic uncertainties in the background.](Figure_002-a.pdf "fig:"){width="48.00000%"} ![\[fig:srvariables\_tautau\] Distributions in [$\Sigma\mT$]{}() and () for events in the combined 2016 and 2017 data sets passing the baseline selection in the [$\tauh\tauh$]{}final state, along with the corresponding prediction for the SM background and three benchmark models for [$\PSGt_{\mathrm{L}}$]{}pair production with $m({\ensuremath{\PSGt_{\mathrm{L}}}\xspace})=100$, 125, and 200, $m(\PSGczDo)=1\GeV$. The numbers within parentheses in the legend correspond to the masses of the [$\PSGt_{\mathrm{L}}$]{}and in . The last bin includes overflow events in each case. The shaded uncertainty bands represent the combined statistical and systematic uncertainties in the background.](Figure_002-b.pdf "fig:"){width="48.00000%"}

Event selection in the lep-tau final states {#sec:leptausel}
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The baseline event selections for the [$\ell\tauh$]{}analyses require either an electron with $\pt > 26\,(35)$and $\abs{\eta} < 2.1$ or a muon with $\pt > 25\,(28)$and $\abs{\eta}<2.4$ for the 2016 (2017) data, and a candidate with $\pt > 30$and $\abs{\eta} < 2.3$. Electrons, muons, and candidates are required to have $\abs{{\ensuremath{d_{z}}\xspace}} < 0.2\cm$, and electrons and muons are also required to have $\abs{{\ensuremath{d_{xy}}\xspace}} < 0.045\cm$. Electrons and muons have to satisfy ${\ensuremath{I_{\text{rel}}}\xspace}<0.15$ and $<$0.1, respectively. Backgrounds from and [$\PW$+jets]{}are greatly reduced by vetoing events that contain jets with $\pt > 20\GeV$. Events from the [$\PW$+jets]{}background are further reduced by requiring 