The ratio of data to the sum of the SM backgrounds. The uncertainties of simulated data are only the statistical unvertainty in the simulation predictions.

Distribution of $p_{T}^{miss}$ after the preselection from 2017 data (black points) and simulation (colored lines). The simulated distribution of two signal points are represented by colored lines, while not being stacked on the background distributions: $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ = (500, 490) and (500, 420) GeV. The last bin includes the overflow events.

The ratio of data to the sum of the SM backgrounds. The uncertainties of simulated data are only the statistical unvertainty in the simulation predictions.

Distribution of $p_{T}^{miss}$ after the preselection from 2018 data (black points) and simulation (colored lines). The simulated distribution of two signal points are represented by colored lines, while not being stacked on the background distributions: $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ = (500, 490) and (500, 420) GeV. The last bin includes the overflow events.

The ratio of data to the sum of the SM backgrounds. The uncertainties of simulated data are only the statistical unvertainty in the simulation predictions.

Distribution of $N_{Jet}$ after the preselection from 2017 data (black points) and simulation (colored lines). The simulated distribution of two signal points are represented by colored lines, while not being stacked on the background distributions: $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ = (500, 490) and (500, 420) GeV. The last bin includes the overflow events.

The ratio of data to the sum of the SM backgrounds. The uncertainties of simulated data are only the statistical unvertainty in the simulation predictions.

Distribution of $N_{Jet}$ after the preselection from 2018 data (black points) and simulation (colored lines). The simulated distribution of two signal points are represented by colored lines, while not being stacked on the background distributions: $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ = (500, 490) and (500, 420) GeV. The last bin includes the overflow events.

The ratio of data to the sum of the SM backgrounds. The uncertainties of simulated data are only the statistical unvertainty in the simulation predictions.

Simulated distribution of $p_{T}(l)$ after the preselection. The total background distribution and the signal distributions are all normalized to unit area. The signal distributions are given for a top squark mass of 300 GeV and $\Delta {m}=10$, 30,50, and 80 GeV.

Simulated distribution of $p_{T}(l)$ after the preselection. The total background distribution and the signal distributions are all normalized to unit area. The signal distributions are shown for four different $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ values, all corresponding to the same $\Delta {m} = 30$ GeV.

Simulated distribution of $p_{T}^{miss}$ after the preselection. The total background distribution and the signal distributions are all normalized to unit area. The signal distributions are given for a top squark mass of 300 GeV and $\Delta {m}=10$, 30,50, and 80 GeV.

Simulated distribution of $p_{T}^{miss}$ after the preselection. The total background distribution and the signal distributions are all normalized to unit area. The signal distributions are shown for four different $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ values, all corresponding to the same $\Delta {m} = 30$ GeV.

Simulated distribution of $N_{Jet}$ after the preselection. The total background distribution and the signal distributions are all normalized to unit area. The signal distributions are given for a top squark mass of 300 GeV and $\Delta {m}=10$, 30,50, and 80 GeV.

Simulated distribution of $N_{Jet}$ after the preselection. The total background distribution and the signal distributions are all normalized to unit area. The signal distributions are shown for four different $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ values, all corresponding to the same $\Delta {m} = 30$ GeV.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 10$ GeV for 2017 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 20$ GeV for 2017 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 30$ GeV for 2017 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 40$ GeV for 2017 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 50$ GeV for 2017 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 60$ GeV for 2017 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 70$ GeV for 2017 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 80$ GeV for 2017 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 10$ GeV for 2018 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 20$ GeV for 2018 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 30$ GeV for 2018 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 40$ GeV for 2018 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 50$ GeV for 2018 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 60$ GeV for 2018 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 70$ GeV for 2018 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

BDT output distributions from data (black points) and simulation (colored lines) after the preselection for $\Delta {m} = 80$ GeV for 2018 data. The last bin corresponds to the SR. A representative $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ signal point is also presented, while not added to the SM background.

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

Distribution of $p_{T}(l)$ for $\Delta {m} = 10$ in the VR where $200 < p_{T}^{miss} < 280$ GeV from 2017 data (black points) and simulation (colored lines). The predicted signal distribution is shown for $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ = (475, 465).

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

Distribution of $p_{T}(l)$ for $\Delta {m} = 10$ in the VR where $200 < p_{T}^{miss} < 280$ GeV from 2018 data (black points) and simulation (colored lines). The predicted signal distribution is shown for $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ = (475, 465).

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

Distribution of BDT for $\Delta {m} = 10$ in the VR where $200 < p_{T}^{miss} < 280$ GeV from 2017 data (black points) and simulation (colored lines). The predicted signal distribution is shown for $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ = (475, 465).

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

Distribution of BDT for $\Delta {m} = 10$ in the VR where $200 < p_{T}^{miss} < 280$ GeV from 2018 data (black points) and simulation (colored lines). The predicted signal distribution is shown for $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ = (475, 465).

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

Distribution of $p_{T}^{miss}$ for $\Delta {m} = 60$ in the VR where $p_{T}(l) > 30$ GeV from 2017 data (black points) and simulation (colored lines). The predicted signal distribution is shown for $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ = (576, 516).

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

Distribution of $p_{T}^{miss}$ for $\Delta {m} = 60$ in the VR where $p_{T}(l) > 30$ GeV from 2018 data (black points) and simulation (colored lines). The predicted signal distribution is shown for $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ = (576, 516).

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

Distribution of BDT for $\Delta {m} = 60$ in the VR where $p_{T}(l) > 30$ GeV from 2017 data (black points) and simulation (colored lines). The predicted signal distribution is shown for $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ = (576, 516).

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

Distribution of BDT for $\Delta {m} = 60$ in the VR where $p_{T}(l) > 30$ GeV from 2018 data (black points) and simulation (colored lines). The predicted signal distribution is shown for $(m(\mathrm{\widetilde{t}}_{1}),m(\widetilde{\chi}^{0}_{1}))$ = (576, 516).

The ratio of data to the sum of the SM backgrounds. Only the statistical uncertainty in the data and the simulated background are represented.

Data yield and prediction of the total background and its composition in the eight SRs as defined in for the 2017 analysis. The predictions of W + jets, ttbar, and nonprompt lepton processes are based on data, while those of rare backgrounds are based on simulation. The predictions and their associated uncertainties are pre-fit. The uncertainties are the quadratic sum of the statistical and systematic uncertainties for background processes predicted from data, and the uncertainties on the cross section for the backgrounds predicted from simulation. The yields for two signal points, with $\Delta {m} = 10$ GeV and $\Delta {m} = 80$ GeV, are also shown. The bins corresponding to different $\Delta {m}$ trainings are not statistically independent.

The ratio of the number of observed events over the predicted total background per SR.

Data yield and prediction of the total background and its composition in the eight SRs as defined in for the 2018 analysis. The predictions of W + jets, ttbar, and nonprompt lepton processes are based on data, while those of rare backgrounds are based on simulation. The predictions and their associated uncertainties are pre-fit. The uncertainties are the quadratic sum of the statistical and systematic uncertainties for background processes predicted from data, and the uncertainties on the cross section for the backgrounds predicted from simulation. The yields for two signal points, with $\Delta {m} = 10$ GeV and $\Delta {m} = 80$ GeV, are also shown. The bins corresponding to different $\Delta {m}$ trainings are not statistically independent.

The ratio of the number of observed events over the predicted total background per SR.

Exclusion limit at 95% CL for the four-body decay of the top squark as a function of $m(\mathrm{\widetilde{t}}_{1})$ and $\Delta {m}$, for the combined data of the years 2016, 2017, and 2018. The lines represent the observed limits. These limits are derived using the expected top squark pair production cross section. The green line represents the central values, and the other lines the variations due to the theoretical or experimental uncertainties.

Exclusion limit at 95% CL for the four-body decay of the top squark as a function of $m(\mathrm{\widetilde{t}}_{1})$ and $\Delta {m}$, for the combined data of the years 2016, 2017, and 2018. The lines represent the expected limits. These limits are derived using the expected top squark pair production cross section. The green line represents the central values, and the other lines the variations due to the theoretical or experimental uncertainties.

Exclusion limit at 95% CL for the four-body decay of the top squark as a function of $m(\mathrm{\widetilde{t}}_{1})$ and $\Delta {m}$, for the combined data of the years 2016, 2017, and 2018.