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| CMS-SUS-19-010 ; CERN-EP-2021-022 | ||
| Search for top squark production in fully-hadronic final states in proton-proton collisions at $\sqrt{s} = $ 13 TeV | ||
| CMS Collaboration | ||
| 1 March 2021 | ||
| Phys. Rev. D 104 (2021) 052001 | ||
| Abstract: A search for production of the supersymmetric partners of the top quark, top squarks, is presented. The search is based on proton-proton collision events containing multiple jets, no leptons, and large transverse momentum imbalance. The data were collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV, and correspond to an integrated luminosity of 137 fb$^{-1}$. The targeted signal production scenarios are direct and gluino-mediated top squark production, including scenarios in which the top squark and neutralino masses are nearly degenerate. The search utilizes novel algorithms based on deep neural networks that identify hadronically decaying top quarks and W bosons, which are expected in many of the targeted signal models. No statistically significant excess of events is observed relative to the expectation from the standard model, and limits on the top squark production cross section are obtained in the context of simplified supersymmetric models for various production and decay modes. Exclusion limits as high as 1310 GeV are established at the 95% confidence level on the mass of the top squark for direct top squark production models, and as high as 2260 GeV on the mass of the gluino for gluino-mediated top squark production models. These results represent a significant improvement over the results of previous searches for supersymmetry by CMS in the same final state. | ||
| Links: e-print arXiv:2103.01290 [hep-ex] (PDF) ; CDS record ; inSPIRE record ; HepData record ; CADI line (restricted) ; | ||
| Figures & Tables | Summary | Additional Figures & Tables | References | CMS Publications |
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Additional information on efficiencies needed for reinterpretation of
these results are available here Additional technical material for CMS speakers can be found here |
| Figures | |
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Figure 1:
Diagrams for the direct top squark production scenarios considered in this study: the T2tt (upper left), T2bW (upper middle), T2tb (upper right), T2ttC (lower left), T2bWC (lower middle), and T2cc (lower right) simplified models. |
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Figure 1-a:
Diagram for the direct top squark production in the T2tt simplified model. |
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Figure 1-b:
Diagram for the direct top squark production in the T2bW simplified model. |
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Figure 1-c:
Diagram for the direct top squark production in the T2tb simplified model. |
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Figure 1-d:
Diagram for the direct top squark production in the T2ttC simplified model. |
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Figure 1-e:
Diagram for the direct top squark production in the T2bWC simplified model. |
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Figure 1-f:
Diagram for the direct top squark production in the T2cc simplified model. |
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Figure 2:
Diagrams for the direct gluino production scenarios considered in this study: the T1tttt (left), T1ttbb (middle), and T5ttcc (right) simplified models. |
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Figure 2-a:
Diagram for the direct gluino production in the T1tttt simplified model. |
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Figure 2-b:
Diagram for the direct gluino production in the T1ttbb simplified model. |
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Figure 2-c:
Diagram for the direct gluino production in the T5ttcc simplified model. |
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Figure 3:
Top quark and W boson tagging efficiencies are shown as a function of the generator-level top quark ${p_{\mathrm {T}}}$ and the generator-level W boson ${p_{\mathrm {T}}}$, respectively, for the merged tagging algorithm and resolved tagging algorithm described in Section 5.2. The left plot shows the efficiencies as calculated in a sample of simulated ${\mathrm{t} {}\mathrm{\bar{t}}}$ events in which one top quark decays leptonically, while the other decays hadronically. The right plot shows the W boson tagging efficiency when calculated in a sample of simulated WW events. In addition to the individual algorithms shown as orange squares (boosted top quarks), green inverted triangles (resolved top quarks), and red triangles (boosted W bosons), the total top quark tagging efficiency (blue dots) is also shown. |
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Figure 3-a:
Top quark tagging efficiencies are shown as a function of the generator-level top quark ${p_{\mathrm {T}}}$ for the merged tagging algorithm and resolved tagging algorithm described in Section 5.2. The plot shows the efficiencies as calculated in a sample of simulated ${\mathrm{t} {}\mathrm{\bar{t}}}$ events in which one top quark decays leptonically, while the other decays hadronically. In addition to the individual algorithms shown as orange squares (boosted top quarks) and green inverted triangles (resolved top quarks), the total top quark tagging efficiency (blue dots) is also shown. |
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Figure 3-b:
Boosted W boson tagging efficiency shown as a function of the generator-level W boson ${p_{\mathrm {T}}}$ for the merged tagging algorithm described in Section 5.2. The plot shows the tagging efficiency (red triangles) when calculated in a sample of simulated WW events. |
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Figure 4:
Comparison between data and simulation in the high ${\Delta m}$ portion of the $\ell$+jets control region, as a function of ${{p_{\mathrm {T}}} ^\text {miss}}$ (upper left), $N_{\mathrm{t}}$ (upper right), $N_{\mathrm{W}}$ (lower left), and $N_{\text{res}}$ (lower right) after scaling the simulation to match the total yield in data. The hatched region indicates the total shape uncertainty in the simulation. The lower panels display the ratios between the observed data and the simulation. |
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Figure 4-a:
Comparison between data and simulation in the high ${\Delta m}$ portion of the $\ell$+jets control region, as a function of ${{p_{\mathrm {T}}} ^\text {miss}}$ after scaling the simulation to match the total yield in data. The hatched region indicates the total shape uncertainty in the simulation. The lower panel displays the ratios between the observed data and the simulation. |
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Figure 4-b:
Comparison between data and simulation in the high ${\Delta m}$ portion of the $\ell$+jets control region, as a function of $N_{\mathrm{t}}$ after scaling the simulation to match the total yield in data. The hatched region indicates the total shape uncertainty in the simulation. The lower panel displays the ratios between the observed data and the simulation. |
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Figure 4-c:
Comparison between data and simulation in the high ${\Delta m}$ portion of the $\ell$+jets control region, as a function of $N_{\mathrm{W}}$ after scaling the simulation to match the total yield in data. The hatched region indicates the total shape uncertainty in the simulation. The lower panel displays the ratios between the observed data and the simulation. |
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Figure 4-d:
Comparison between data and simulation in the high ${\Delta m}$ portion of the $\ell$+jets control region, as a function of $N_{\text{res}}$ after scaling the simulation to match the total yield in data. The hatched region indicates the total shape uncertainty in the simulation. The lower panel displays the ratios between the observed data and the simulation. |
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Figure 5:
The observed numbers of events and the SM background predictions for the low ${\Delta m}$ validation bins (left) and for the high ${\Delta m}$ validation bins (right). The hatched region indicates the total uncertainty in the background predictions. The lower panels display the ratios between the data and the SM predictions. |
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Figure 5-a:
The observed numbers of events and the SM background predictions for the low ${\Delta m}$ validation bins. The hatched region indicates the total uncertainty in the background predictions. The lower panel displays the ratios between the data and the SM predictions. |
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Figure 5-b:
The observed numbers of events and the SM background predictions for the high ${\Delta m}$ validation bins. The hatched region indicates the total uncertainty in the background predictions. The lower panel displays the ratios between the data and the SM predictions. |
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Figure 6:
Observed event yields in data (black points) and predicted SM background (filled histograms) for the low ${\Delta m}$ search bins 0-52 (upper), and for the high ${\Delta m}$ search bins 53-104 (lower). The bracketed numbers in the lower plot represent the respective ${N_{\mathrm{t}}}$, ${N_{\mathrm{W}}}$, and ${N_{\text {res}}}$ requirements used in that region. The signal models are denoted in the legend with the masses in GeV of the SUSY particles in parentheses: $({m_{\tilde{\mathrm{t}}}}, {m_{\tilde{\chi}^0_1}})$ or $({m_{{\mathrm{\widetilde{g}}}}}, {m_{\tilde{\chi}^0_1}})$ for the T2 or T1 signal models, respectively. For both plots, the lower panel shows the ratio of the data to the total background prediction. The hatched bands correspond to the total uncertainty in the background prediction. The (unstacked) distributions for two example signal models are also shown in both plots. |
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Figure 6-a:
Observed event yields in data (black points) and predicted SM background (filled histograms) for the low ${\Delta m}$ search bins 0-52. The signal T2 models are denoted in the legend with the masses in GeV of the SUSY particles in parentheses, $({m_{\tilde{\mathrm{t}}}}, {m_{\tilde{\chi}^0_1}})$. The lower panel shows the ratio of the data to the total background prediction. The hatched band corresponds to the total uncertainty in the background prediction. The (unstacked) distributions for two example signal models are also shown. |
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Figure 6-b:
Observed event yields in data (black points) and predicted SM background (filled histograms) for the high ${\Delta m}$ search bins 53-104. The bracketed numbers represent the respective ${N_{\mathrm{t}}}$, ${N_{\mathrm{W}}}$, and ${N_{\text {res}}}$ requirements used in that region. The signal models are denoted in the legend with the masses in GeV of the SUSY particles in parentheses, $({m_{\tilde{\mathrm{t}}}}, {m_{\tilde{\chi}^0_1}})$ or $({m_{{\mathrm{\widetilde{g}}}}}, {m_{\tilde{\chi}^0_1}})$, for the T2 or T1 signal models. The lower panel shows the ratio of the data to the total background prediction. The hatched band corresponds to the total uncertainty in the background prediction. The (unstacked) distributions for two example signal models are also shown. |
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Figure 7:
Observed event yields in data (black points) and predicted SM background (filled histograms) for the high ${\Delta m}$ search bins 105-152 with ${{N_{\mathrm{b}}} = 2}$ (upper), and for the high ${\Delta m}$ search bins 153-182 with ${{N_{\mathrm{b}}} \geq 3}$ (lower). The bracketed numbers in each plot represent the respective ${N_{\mathrm{t}}}$, ${N_{\mathrm{W}}}$, and ${N_{\text {res}}}$ requirements used in that region. The signal models are denoted in the legend with the masses in GeV of the SUSY particles in parentheses: $({m_{\tilde{\mathrm{t}}}}, {m_{\tilde{\chi}^0_1}})$ or $({m_{{\mathrm{\widetilde{g}}}}}, {m_{\tilde{\chi}^0_1}})$ for the T2 or T1 signal models, respectively. For both plots, the lower panel shows the ratio of the data to the total background prediction. The hatched bands correspond to the total uncertainty in the background prediction. The (unstacked) distributions for two example signal models are also shown in both plots. |
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Figure 7-a:
Observed event yields in data (black points) and predicted SM background (filled histograms) for the high ${\Delta m}$ search bins 105-152 with ${{N_{\mathrm{b}}} = 2}$. The bracketed numbers represent the respective ${N_{\mathrm{t}}}$, ${N_{\mathrm{W}}}$, and ${N_{\text {res}}}$ requirements used in that region. The signal models are denoted in the legend with the masses in GeV of the SUSY particles in parentheses: $({m_{\tilde{\mathrm{t}}}}, {m_{\tilde{\chi}^0_1}})$ or $({m_{{\mathrm{\widetilde{g}}}}}, {m_{\tilde{\chi}^0_1}})$ for the T2 or T1 signal models, respectively. The lower panel shows the ratio of the data to the total background prediction. The hatched band corresponds to the total uncertainty in the background prediction. The (unstacked) distributions for two example signal models are also shown. |
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Figure 7-b:
Observed event yields in data (black points) and predicted SM background (filled histograms) for the high ${\Delta m}$ search bins 153-182 with ${{N_{\mathrm{b}}} \geq 3}$. The bracketed numbers represent the respective ${N_{\mathrm{t}}}$, ${N_{\mathrm{W}}}$, and ${N_{\text {res}}}$ requirements used in that region. The signal models are denoted in the legend with the masses in GeV of the SUSY particles in parentheses: $({m_{\tilde{\mathrm{t}}}}, {m_{\tilde{\chi}^0_1}})$ or $({m_{{\mathrm{\widetilde{g}}}}}, {m_{\tilde{\chi}^0_1}})$ for the T2 or T1 signal models, respectively. The lower panel shows the ratio of the data to the total background prediction. The hatched band corresponds to the total uncertainty in the background prediction. The (unstacked) distributions for two example signal models are also shown. |
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Figure 8:
The 95% CL upper limit on the production cross section of the T2tt (upper left), T2bW (upper right), and T2tb (lower) simplified models as a function of the top squark and LSP masses. The solid black curves represent the observed exclusion contour with respect to approximate NNLO+NNLL signal cross sections and the change in this contour due to variation of these cross sections within their theoretical uncertainties ($\sigma _{\text {theory}}$) [64,65,66,67,68,69,70,71,72,73,74]. The dashed red curves indicate the mean expected exclusion contour and the region containing 68 and 95% ($\pm$1 and 2$\sigma _{\text {experiment}}$) of the distribution of expected exclusion limits under the background-only hypothesis. For T2tt, no interpretation is provided for signal models for which ${| {m_{\tilde{\mathrm{t}}}} - {m_{\tilde{\chi}^0_1}} - {m_{\mathrm{t}}} |} < $ 25 GeV and ${m_{\tilde{\mathrm{t}}}} < $ 275 GeV as described in the text. |
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Figure 8-a:
The 95% CL upper limit on the production cross section of the T2tt simplified model as a function of the top squark and LSP masses. The solid black curves represent the observed exclusion contour with respect to approximate NNLO+NNLL signal cross sections and the change in this contour due to variation of these cross sections within their theoretical uncertainties ($\sigma _{\text {theory}}$). The dashed red curves indicate the mean expected exclusion contour and the region containing 68 and 95% ($\pm$1 and 2$\sigma _{\text {experiment}}$) of the distribution of expected exclusion limits under the background-only hypothesis. For this model, no interpretation is provided for signal models for which ${| {m_{\tilde{\mathrm{t}}}} - {m_{\tilde{\chi}^0_1}} - {m_{\mathrm{t}}} |} < $ 25 GeV and ${m_{\tilde{\mathrm{t}}}} < $ 275 GeV as described in the text. |
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Figure 8-b:
The 95% CL upper limit on the production cross section of the T2bW simplified model as a function of the top squark and LSP masses. The solid black curves represent the observed exclusion contour with respect to approximate NNLO+NNLL signal cross sections and the change in this contour due to variation of these cross sections within their theoretical uncertainties ($\sigma _{\text {theory}}$). The dashed red curves indicate the mean expected exclusion contour and the region containing 68 and 95% ($\pm$1 and 2$\sigma _{\text {experiment}}$) of the distribution of expected exclusion limits under the background-only hypothesis. |
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Figure 8-c:
The 95% CL upper limit on the production cross section of the T2tb simplified model as a function of the top squark and LSP masses. The solid black curves represent the observed exclusion contour with respect to approximate NNLO+NNLL signal cross sections and the change in this contour due to variation of these cross sections within their theoretical uncertainties ($\sigma _{\text {theory}}$). The dashed red curves indicate the mean expected exclusion contour and the region containing 68 and 95% ($\pm$1 and 2$\sigma _{\text {experiment}}$) of the distribution of expected exclusion limits under the background-only hypothesis. |
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Figure 9:
The 95% CL upper limit on the production cross section of the T2ttC (upper left), T2bWC (upper right), and T2cc (lower) simplified models as a function of the top squark mass and the difference between the top squark and LSP masses. The solid black curves represent the observed exclusion contour with respect to approximate NNLO+NNLL signal cross sections and the change in this contour due to variation of these cross sections within their theoretical uncertainties ($\sigma _{\text {theory}}$) [64,65,66,67,68,69,70,71,72,73,74]. The dashed red curves indicate the mean expected exclusion contour and the region containing 68% ($\pm$1$\sigma _{\text {experiment}}$) of the distribution of expected exclusion limits under the background-only hypothesis. |
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Figure 9-a:
The 95% CL upper limit on the production cross section of the T2ttC simplified model as a function of the top squark mass and the difference between the top squark and LSP masses. The solid black curves represent the observed exclusion contour with respect to approximate NNLO+NNLL signal cross sections and the change in this contour due to variation of these cross sections within their theoretical uncertainties ($\sigma _{\text {theory}}$). The dashed red curves indicate the mean expected exclusion contour and the region containing 68% ($\pm$1$\sigma _{\text {experiment}}$) of the distribution of expected exclusion limits under the background-only hypothesis. |
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Figure 9-b:
The 95% CL upper limit on the production cross section of the T2bWC simplified model as a function of the top squark mass and the difference between the top squark and LSP masses. The solid black curves represent the observed exclusion contour with respect to approximate NNLO+NNLL signal cross sections and the change in this contour due to variation of these cross sections within their theoretical uncertainties ($\sigma _{\text {theory}}$). The dashed red curves indicate the mean expected exclusion contour and the region containing 68% ($\pm$1$\sigma _{\text {experiment}}$) of the distribution of expected exclusion limits under the background-only hypothesis. |
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Figure 9-c:
The 95% CL upper limit on the production cross section of the T2cc simplified model as a function of the top squark mass and the difference between the top squark and LSP masses. The solid black curves represent the observed exclusion contour with respect to approximate NNLO+NNLL signal cross sections and the change in this contour due to variation of these cross sections within their theoretical uncertainties ($\sigma _{\text {theory}}$). The dashed red curves indicate the mean expected exclusion contour and the region containing 68% ($\pm$1$\sigma _{\text {experiment}}$) of the distribution of expected exclusion limits under the background-only hypothesis. |
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Figure 10:
The 95% CL upper limit on the production cross section of the T1tttt (left) and T1ttbb (right) simplified models as a function of the gluino and LSP masses. The solid black curves represent the observed exclusion contour with respect to approximate NNLO+NNLL signal cross sections and the change in this contour due to variation of these cross sections within their theoretical uncertainties ($\sigma _{\text {theory}}$) [64,65,66,67,68,69,70,71,72,73,74]. The dashed red curves indicate the mean expected exclusion contour and the region containing 68 and 95% ($\pm$1 and 2$\sigma _{\text {experiment}}$) of the distribution of expected exclusion limits under the background-only hypothesis. |
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Figure 10-a:
The 95% CL upper limit on the production cross section of the T1tttt simplified model as a function of the gluino and LSP masses. The solid black curves represent the observed exclusion contour with respect to approximate NNLO+NNLL signal cross sections and the change in this contour due to variation of these cross sections within their theoretical uncertainties ($\sigma _{\text {theory}}$). The dashed red curves indicate the mean expected exclusion contour and the region containing 68 and 95% ($\pm$1 and 2$\sigma _{\text {experiment}}$) of the distribution of expected exclusion limits under the background-only hypothesis. |
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Figure 10-b:
The 95% CL upper limit on the production cross section of the T1ttbb simplified model as a function of the gluino and LSP masses. The solid black curves represent the observed exclusion contour with respect to approximate NNLO+NNLL signal cross sections and the change in this contour due to variation of these cross sections within their theoretical uncertainties ($\sigma _{\text {theory}}$). The dashed red curves indicate the mean expected exclusion contour and the region containing 68 and 95% ($\pm$1 and 2$\sigma _{\text {experiment}}$) of the distribution of expected exclusion limits under the background-only hypothesis. |
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Figure 11:
The 95% CL upper limit on the production cross section of the T5ttcc simplified model as a function of the gluino and LSP masses. The solid black curves represent the observed exclusion contour with respect to approximate NNLO+NNLL signal cross sections and the change in this contour due to variation of these cross sections within their theoretical uncertainties ($\sigma _{\text {theory}}$) [64,65,66,67,68,69,70,71,72,73,74]. The dashed red curves indicate the mean expected exclusion contour and the region containing 68% and 95% ($\pm$1 and 2$\sigma _{\text {experiment}}$) of the distribution of expected exclusion limits under the background-only hypothesis. The expected and observed upper limits do not take into account contributions from direct top squark pair production; however, its effect is small for $ {m_{\tilde{\chi}^0_1}} > $ 600 GeV, which corresponds to the phase space beyond the exclusions based on direct top squark pair production. The excluded regions based on direct top squark pair production from this search and earlier searches by the ATLAS [27] and CMS [37,40,42] experiments, as well as by the LEP experiments [129,130,131,132] are indicated by the hatched areas. |
| Tables | |
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Table 1:
Summary of the preselection requirements (baseline selection) imposed on the reconstructed physics objects for this search, as well as the low ${\Delta m}$ and high ${\Delta m}$ baseline selections. Here $R$ is the distance parameter of the anti-$ {k_{\mathrm {T}}}$ algorithm. Electron and muon candidates as well as ${\tau _\mathrm {h}}$ candidates and isolated tracks are as defined in Section 5. The $i$-th highest- ${p_{\mathrm {T}}}$ jet is denoted by ${\mathrm {j}_{i}}$. |
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Table 2:
Summary of the 53 search bins that mainly target low ${\Delta m}$ signal models. For these search bins, events are required to pass the low ${\Delta m}$ region selection discussed in Section 6.1. Within each row of this table, the bins are ordered by increasing ${{p_{\mathrm {T}}} ^\text {miss}}$ requirements. A dash (--) indicates that no requirements are made. |
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Table 3:
Summary of the 130 search bins that mainly target high ${\Delta m}$ signal models. For these search bins, events are required to pass the high ${\Delta m}$ region selection discussed in Section 6.2. Within each row of this table, the bins are ordered by increasing ${{p_{\mathrm {T}}} ^\text {miss}}$ requirements. |
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Table 4:
Summary of the 19 validation bins for low ${\Delta m}$. Bins 0 to 14 use the normal low ${\Delta m}$ region selection with lower ${{p_{\mathrm {T}}} ^\text {miss}}$ requirements than any of the low ${\Delta m}$ search bins. Bins 15-18 use a similar selection, but additionally require medium ${\Delta \phi}$, as discussed in Section 6.3. A dash (--) indicates that no requirements are made. |
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Table 5:
Summary of the 24 validation bins for high ${\Delta m}$. These search bins are orthogonal to the high ${\Delta m}$ search region because of the ${\Delta \phi}$ requirements discussed in Section 6.3. |
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Table A1:
Observed number of events and SM background predictions in search bins 0-27. |
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Table A2:
Observed number of events and SM background predictions in search bins 28-52. |
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Table A3:
Observed number of events and SM background predictions in search bins 53-80. |
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Table A4:
Observed number of events and SM background predictions in search bins 81-107. |
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Table A5:
Observed number of events and SM background predictions in search bins 108-136. |
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Table A6:
Observed number of events and SM background predictions in search bins 137-161. |
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Table A7:
Observed number of events and SM background predictions in search bins 162-182. |
| Summary |
|
Results are presented from a search for direct and gluino-mediated top squark production in proton-proton collisions at a center-of-mass energy of 13 TeV. The analysis includes deep neural network based tagging algorithms for top quarks and W bosons both at low and high transverse momentum. The search is based on events with at least two jets and large imbalance in transverse momentum ${p_{\mathrm{T}}^{\text{miss}}}$. The data set corresponds to an integrated luminosity of 137 fb$^{-1}$ collected with the CMS detector at the LHC in 2016-2018. A set of 183 search bins is defined based on several kinematic variables and the number of reconstructed top quarks, bottom quarks, and W bosons. No statistically significant excess of events is observed with respect to the expectation from the standard model. Upper limits at the 95% confidence level are established on the cross section for several simplified models of direct and gluino-mediated top squark pair production as a function of the masses of the supersymmetric particles. Using the predicted cross sections, which are calculated with approximate next-to-next-to-leading order plus next-to-next-to-leading logarithmic accuracy, lower limits at the 95% confidence level are established on the top squark, lightest supersymmetric particle (LSP), and gluino masses. In the case of the direct top squark production models, top squark masses are excluded below a limit ranging from 1150 to 1310 GeV in the region of parameter space where the mass difference between the top squark and the LSP is larger than the W boson mass, depending on the top squark decay scenario. In the region of parameter space where the mass difference between the top squark and the LSP is smaller than the mass of the W boson, top squark masses are excluded below a limit ranging from 630 to 740 GeV, depending on the top squark decay scenario. In the case of the gluino-mediated top squark production models, gluino masses are excluded below a limit ranging from 2150 to 2260 GeV, depending on the signal model. These results significantly extend the mass exclusions of the previous top squark searches in the fully-hadronic final state from CMS [40,41] by about 100-300 GeV, benefiting not only from the larger data set, but also from improved analysis methods. For models of direct top squark production, the results obtained in this analysis are the most stringent constraints to date, regardless of the final state. |
| Additional Figures | |
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Additional Figure 1:
The misidentification rate for the DeepResolved top quark tagger is shown as a function of the ${p_{\mathrm {T}}}$ of the top quark candidate with the highest ${p_{\mathrm {T}}}$. A top quark candidate is defined as a trijet combination which satisfies the preselection requirements on the trijet mass (100 to 250 GeV), the maximum angle (no jet is farther than 3.1 from the trijet centroid in $\Delta R$), and the ${p_{\mathrm {T}}}$ of each of the three jets ($ {p_{\mathrm {T}}} > $ 40, 30, and 20 GeV, respectively). Top quark candidates must also survive the cross-cleaning process, which removes overlaps with tagged AK8 jets and other trijet candidates with lower NN discriminator scores. The misidentification rate is calculated in a simulated sample of QCD multijet events with $ {H_{\mathrm {T}}} > $ 300 GeV and is defined as the fraction of the candidates which have an NN discriminator score greater than 0.92. |
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Additional Figure 2:
The observed significance of any excess in the data above the expected backgrounds, interpreted in the context of the SMS squark models for T2tt as a function of the top squark and LSP masses. |
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Additional Figure 3:
The observed significance of any excess in the data above the expected backgrounds, interpreted in the context of the SMS squark models for T2bW as a function of the top squark and LSP masses. |
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Additional Figure 4:
The observed significance of any excess in the data above the expected backgrounds, interpreted in the context of the SMS squark models for T2tb as a function of the top squark and LSP masses. |
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Additional Figure 5:
The observed significance of any excess in the data above the expected backgrounds, interpreted in the context of the SMS squark models for T2ttC as a function of the top squark mass and the difference between the top squark and LSP masses. |
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Additional Figure 6:
The observed significance of any excess in the data above the expected backgrounds, interpreted in the context of the SMS squark models for T2bWC as a function of the top squark mass and the difference between the top squark and LSP masses. |
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Additional Figure 7:
The observed significance of any excess in the data above the expected backgrounds, interpreted in the context of the SMS squark models for T2cc as a function of the top squark mass and the difference between the top squark and LSP masses. |
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Additional Figure 8:
The observed significance of any excess in the data above the expected backgrounds, interpreted in the context of the SMS squark models for T1tttt as a function of the gluino and LSP masses. |
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Additional Figure 9:
The observed significance of any excess in the data above the expected backgrounds, interpreted in the context of the SMS squark models for T1ttbb as a function of the gluino and LSP masses. |
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Additional Figure 10:
The observed significance of any excess in the data above the expected backgrounds, interpreted in the context of the SMS squark models for T5ttcc as a function of the gluino and LSP masses. Excluded regions based on direct top squark pair production from this search and earlier searches by the ATLAS, CMS, and LEP experiments are indicated by the hatched areas. |
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Additional Figure 11:
The efficiency times acceptance of the SMS squark models for T2tt as a function of the top squark and LSP masses in the union of the 53 low ${\Delta m}$ search regions (left) and the 130 high ${\Delta m}$ search regions (right). |
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Additional Figure 11-a:
The efficiency times acceptance of the SMS squark models for T2tt as a function of the top squark and LSP masses in the union of the 53 low ${\Delta m}$ search regions. |
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Additional Figure 11-b:
The efficiency times acceptance of the SMS squark models for T2tt as a function of the top squark and LSP masses in the union of the 130 high ${\Delta m}$ search regions. |
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Additional Figure 12:
The efficiency times acceptance of the SMS squark models for T2bW as a function of the top squark and LSP masses in the union of the 53 low ${\Delta m}$ search regions (left) and the 130 high ${\Delta m}$ search regions (right). |
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Additional Figure 12-a:
The efficiency times acceptance of the SMS squark models for T2bW as a function of the top squark and LSP masses in the union of the 53 low ${\Delta m}$ search regions. |
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Additional Figure 12-b:
The efficiency times acceptance of the SMS squark models for T2bW as a function of the top squark and LSP masses in the union of the 130 high ${\Delta m}$ search regions. |
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Additional Figure 13:
The efficiency times acceptance of the SMS squark models for T2tb as a function of the top squark and LSP masses in the union of the 53 low ${\Delta m}$ search regions (left) and the 130 high ${\Delta m}$ search regions (right). |
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Additional Figure 13-a:
The efficiency times acceptance of the SMS squark models for T2tb as a function of the top squark and LSP masses in the union of the 53 low ${\Delta m}$ search regions. |
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Additional Figure 13-b:
The efficiency times acceptance of the SMS squark models for T2tb as a function of the top squark and LSP masses in the union of the 130 high ${\Delta m}$ search regions. |
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Additional Figure 14:
The efficiency times acceptance of the SMS squark models for T2ttC as a function of the top squark and the difference between the top squark and LSP masses in the union of the 53 low ${\Delta m}$ search regions (left) and the 130 high ${\Delta m}$ search regions (right). |
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Additional Figure 14-a:
The efficiency times acceptance of the SMS squark models for T2ttC as a function of the top squark and the difference between the top squark and LSP masses in the union of the 53 low ${\Delta m}$ search regions. |
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Additional Figure 14-b:
The efficiency times acceptance of the SMS squark models for T2ttC as a function of the top squark and the difference between the top squark and LSP masses in the union of the 130 high ${\Delta m}$ search regions. |
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Additional Figure 15:
The efficiency times acceptance of the SMS squark models for T2bWC as a function of the top squark and the difference between the top squark and LSP masses in the union of the 53 low ${\Delta m}$ search regions (left) and the 130 high ${\Delta m}$ search regions (right). |
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Additional Figure 15-a:
The efficiency times acceptance of the SMS squark models for T2bWC as a function of the top squark and the difference between the top squark and LSP masses in the union of the 53 low ${\Delta m}$ search regions. |
png pdf |
Additional Figure 15-b:
The efficiency times acceptance of the SMS squark models for T2bWC as a function of the top squark and the difference between the top squark and LSP masses in the union of the 130 high ${\Delta m}$ search regions. |
png pdf |
Additional Figure 16:
The efficiency times acceptance of the SMS squark models for T2cc as a function of the top squark and the difference between the top squark and LSP masses in the union of the 53 low ${\Delta m}$ search regions (left) and the 130 high ${\Delta m}$ search regions (right). |
png pdf |
Additional Figure 16-a:
The efficiency times acceptance of the SMS squark models for T2cc as a function of the top squark and the difference between the top squark and LSP masses in the union of the 53 low ${\Delta m}$ search regions. |
png pdf |
Additional Figure 16-b:
The efficiency times acceptance of the SMS squark models for T2cc as a function of the top squark and the difference between the top squark and LSP masses in the union of the 130 high ${\Delta m}$ search regions. |
png pdf |
Additional Figure 17:
The efficiency times acceptance of the SMS gluino models for T1tttt as a function of the gluino and LSP masses in the union of the 53 low ${\Delta m}$ search regions (left) and the 130 high ${\Delta m}$ search regions (right). |
png pdf |
Additional Figure 17-a:
The efficiency times acceptance of the SMS gluino models for T1tttt as a function of the gluino and LSP masses in the union of the 53 low ${\Delta m}$ search regions. |
png pdf |
Additional Figure 17-b:
The efficiency times acceptance of the SMS gluino models for T1tttt as a function of the gluino and LSP masses in the union of the 130 high ${\Delta m}$ search regions. |
png pdf |
Additional Figure 18:
The efficiency times acceptance of the SMS gluino models for T1ttbb as a function of the gluino and LSP masses in the union of the 53 low ${\Delta m}$ search regions (left) and the 130 high ${\Delta m}$ search regions (right). |
png pdf |
Additional Figure 18-a:
The efficiency times acceptance of the SMS gluino models for T1ttbb as a function of the gluino and LSP masses in the union of the 53 low ${\Delta m}$ search regions. |
png pdf |
Additional Figure 18-b:
The efficiency times acceptance of the SMS gluino models for T1ttbb as a function of the gluino and LSP masses in the union of the 130 high ${\Delta m}$ search regions. |
png pdf |
Additional Figure 19:
The efficiency times acceptance of the SMS gluino models for T5ttcc as a function of the gluino and LSP masses in the union of the 53 low ${\Delta m}$ search regions (left) and the 130 high ${\Delta m}$ search regions (right). |
png pdf |
Additional Figure 19-a:
The efficiency times acceptance of the SMS gluino models for T5ttcc as a function of the gluino and LSP masses in the union of the 53 low ${\Delta m}$ search regions. |
png pdf |
Additional Figure 19-b:
The efficiency times acceptance of the SMS gluino models for T5ttcc as a function of the gluino and LSP masses in the union of the 130 high ${\Delta m}$ search regions. |
png pdf |
Additional Figure 20:
The expected and observed limits for T2ttC signal as a function of the top squark and LSP masses. |
png pdf |
Additional Figure 21:
The expected and observed limits for T2bWC signal as a function of the top squark and LSP masses. |
png pdf |
Additional Figure 22:
The expected and observed limits for T2cc signal as a function of the top squark and LSP masses. |
png pdf |
Additional Figure 23:
The expected and observed limits for all of the signals for direct top squark production as a function of the top squark and LSP masses. |
| Additional Tables | |
png pdf |
Additional Table 1:
The expected number of direct top squark production signal events that satisfy each selection requirement in turn. The percentages shown are the efficiency with respect to the previous line in most cases; the start of the low ${\Delta m}$ and high ${\Delta m}$ sections are with respect to the end of the general baseline. |
png pdf |
Additional Table 2:
The expected number of gluino-mediated top squark production signal events that satisfy each selection requirement in turn. All object and event weights are applied. Percentages shown are the efficiency with respect to the previous line in most cases; the start of the low ${\Delta m}$ and high ${\Delta m}$ sections are with respect to the end of the general baseline. |
png pdf |
Additional Table 3:
Summary of the 10 disjoint super search regions in the low ${\Delta m}$ category. |
png pdf |
Additional Table 4:
Summary of the 15 disjoint super search regions in the high ${\Delta m}$ category. The selection requirements $ {{\Delta \phi} (\text {j}_{\text {1,2,3,4}}, {{p_{\mathrm {T}}} ^\text {miss}})} > 0.5$ and zero leptons are common to all high ${\Delta m}$ regions. A dash ({\text {--}}) indicates that no requirements are made. |
png pdf |
Additional Table 5:
Predicted event yields in super search regions 0-9 for a selection of direct top squark production signals. |
png pdf |
Additional Table 6:
Predicted event yields in super search regions 10-24 for a selection of direct top squark production signals. |
png pdf |
Additional Table 7:
Predicted event yields in super search regions 0-9 for a selection of gluino-mediated production signals. |
png pdf |
Additional Table 8:
Predicted event yields in super search regions 10-24 for a selection of gluino-mediated production signals. |
png pdf |
Additional Table 9:
Prediction for bins 0-9 |
png pdf |
Additional Table 10:
Prediction for bins 10-24 |
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| 129 | ALEPH Collaboration | Search for scalar quarks in $ e^{+} e^{-} $ collisions at $ \sqrt{s} $ up to 209 GeV | PLB 537 (2002) 5 | hep-ex/0204036 |
| 130 | DELPHI Collaboration | Searches for supersymmetric particles in $ e^{+} e^{-} $ collisions up to 208 GeV and interpretation of the results within the MSSM | EPJC 31 (2003) 421 | hep-ex/0311019 |
| 131 | L3 Collaboration | Search for scalar leptons and scalar quarks at LEP | PLB 580 (2004) 37 | hep-ex/0310007 |
| 132 | OPAL Collaboration | Search for scalar top and scalar bottom quarks at LEP | PLB 545 (2002) 272 | hep-ex/0209026 |
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Compact Muon Solenoid LHC, CERN |
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