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| CMS-PAS-SUS-20-001 | ||
| Search for physics beyond the standard model in final states with two opposite-charge same-flavor leptons, jets, and missing transverse momentum in pp collisions at 13 TeV | ||
| CMS Collaboration | ||
| July 2020 | ||
| Abstract: A search for phenomena beyond the standard model (BSM) is presented in final states with two opposite-charge same-flavor leptons, jets, and missing transverse momentum. The search is performed in a data sample of pp collisions at $\sqrt{s}= $ 13 TeV, collected by the CMS experiment at the LHC, and corresponding to an integrated luminosity of 137 fb$^{-1}$. Three potential signatures of BSM physics are explored: (i) an excess of events with a lepton pair whose invariant mass is consistent with the Z boson mass; (ii) a kinematic edge in the invariant mass distribution of the lepton pair; (iii) the non-resonant production of two leptons. The observed event yields are consistent with the predicted standard model backgrounds. The results are used to constrain models of BSM physics that result in the production of pairs of gluinos, squarks, sleptons, or charginos and neutralinos. Upper limits at 95% CL are set on the production cross-section of supersymmetric particles. Searching for (i) allows to probe gluino masses up to 1875 GeV, as well as chargino (neutralino) masses up to 750 (800) GeV; searching for (ii) allows to exclude light-flavor (bottom) squark masses up to 1800 (1600) GeV; finally, by searching for (iii) slepton masses up to 650 GeV can also be excluded. | ||
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Links:
CDS record (PDF) ;
CADI line (restricted) ;
These preliminary results are superseded in this paper, JHEP 04 (2021) 123. The superseded preliminary plots can be found here. |
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| Figures | |
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Figure 1:
Diagrams for models of (upper left) direct slepton pair production, (upper right) neutralino/chargino production, and GMSB neutralino pair production with (lower left) ZZ and (lower right) ZH bosons in the final state, where in the latter model the $\tilde{\chi}^0_1$ decays to H or Z with a 50% probability for each of the modes. Such models predict the involved SUSY particles to be produced via EW interaction, with absence or moderate presence of quarks in the final state. |
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Figure 1-a:
Diagrams for models of (upper left) direct slepton pair production, (upper right) neutralino/chargino production, and GMSB neutralino pair production with (lower left) ZZ and (lower right) ZH bosons in the final state, where in the latter model the $\tilde{\chi}^0_1$ decays to H or Z with a 50% probability for each of the modes. Such models predict the involved SUSY particles to be produced via EW interaction, with absence or moderate presence of quarks in the final state. |
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Figure 1-b:
Diagrams for models of (upper left) direct slepton pair production, (upper right) neutralino/chargino production, and GMSB neutralino pair production with (lower left) ZZ and (lower right) ZH bosons in the final state, where in the latter model the $\tilde{\chi}^0_1$ decays to H or Z with a 50% probability for each of the modes. Such models predict the involved SUSY particles to be produced via EW interaction, with absence or moderate presence of quarks in the final state. |
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Figure 1-c:
Diagrams for models of (upper left) direct slepton pair production, (upper right) neutralino/chargino production, and GMSB neutralino pair production with (lower left) ZZ and (lower right) ZH bosons in the final state, where in the latter model the $\tilde{\chi}^0_1$ decays to H or Z with a 50% probability for each of the modes. Such models predict the involved SUSY particles to be produced via EW interaction, with absence or moderate presence of quarks in the final state. |
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Figure 1-d:
Diagrams for models of (upper left) direct slepton pair production, (upper right) neutralino/chargino production, and GMSB neutralino pair production with (lower left) ZZ and (lower right) ZH bosons in the final state, where in the latter model the $\tilde{\chi}^0_1$ decays to H or Z with a 50% probability for each of the modes. Such models predict the involved SUSY particles to be produced via EW interaction, with absence or moderate presence of quarks in the final state. |
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Figure 2:
Diagrams for models of (left) $\tilde{\mathrm{q}}$ and (center) $\tilde{\mathrm{b}}$ pair production. Such models feature a mass edge from the decay of a $\tilde{\chi}^{0}_2$ via an intermediate slepton, ${\tilde{\ell}}$. In the diagram in the center, a pair of b quarks is present in the final state. In these models the $\tilde{\chi}^0_1$ mass is fixed to 100 GeV, while the mass of the slepton is taken to be equidistant from the masses of the two neutralinos. (Right) Diagram for a model of GMSB gluino pair production, where each ${\mathrm{\tilde{g}}}$ decays into a pair of quarks and a neutralino. The neutralino then decays to a Z boson and an LSP. All these models assume strong production of SUSY particles and predict abundance of quarks in the final state. |
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Figure 2-a:
Diagrams for models of (left) $\tilde{\mathrm{q}}$ and (center) $\tilde{\mathrm{b}}$ pair production. Such models feature a mass edge from the decay of a $\tilde{\chi}^{0}_2$ via an intermediate slepton, ${\tilde{\ell}}$. In the diagram in the center, a pair of b quarks is present in the final state. In these models the $\tilde{\chi}^0_1$ mass is fixed to 100 GeV, while the mass of the slepton is taken to be equidistant from the masses of the two neutralinos. (Right) Diagram for a model of GMSB gluino pair production, where each ${\mathrm{\tilde{g}}}$ decays into a pair of quarks and a neutralino. The neutralino then decays to a Z boson and an LSP. All these models assume strong production of SUSY particles and predict abundance of quarks in the final state. |
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Figure 2-b:
Diagrams for models of (left) $\tilde{\mathrm{q}}$ and (center) $\tilde{\mathrm{b}}$ pair production. Such models feature a mass edge from the decay of a $\tilde{\chi}^{0}_2$ via an intermediate slepton, ${\tilde{\ell}}$. In the diagram in the center, a pair of b quarks is present in the final state. In these models the $\tilde{\chi}^0_1$ mass is fixed to 100 GeV, while the mass of the slepton is taken to be equidistant from the masses of the two neutralinos. (Right) Diagram for a model of GMSB gluino pair production, where each ${\mathrm{\tilde{g}}}$ decays into a pair of quarks and a neutralino. The neutralino then decays to a Z boson and an LSP. All these models assume strong production of SUSY particles and predict abundance of quarks in the final state. |
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Figure 2-c:
Diagrams for models of (left) $\tilde{\mathrm{q}}$ and (center) $\tilde{\mathrm{b}}$ pair production. Such models feature a mass edge from the decay of a $\tilde{\chi}^{0}_2$ via an intermediate slepton, ${\tilde{\ell}}$. In the diagram in the center, a pair of b quarks is present in the final state. In these models the $\tilde{\chi}^0_1$ mass is fixed to 100 GeV, while the mass of the slepton is taken to be equidistant from the masses of the two neutralinos. (Right) Diagram for a model of GMSB gluino pair production, where each ${\mathrm{\tilde{g}}}$ decays into a pair of quarks and a neutralino. The neutralino then decays to a Z boson and an LSP. All these models assume strong production of SUSY particles and predict abundance of quarks in the final state. |
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Figure 3:
Distributions for (left) ${m_{\ell \ell}}$, (middle) ${{p_{\mathrm {T}}} ^\text {miss}}$ and (right) $ {p_{\mathrm {T}}} ^{\ell \ell}$ in a ${\mathrm{t} {}\mathrm{\bar{t}}} $-enriched CR in data. The data-driven flavor-symmetric background prediction (gray solid histogram) is compared to data (black marker). Other backgrounds are estimated directly from simulation (green and blue solid histograms). The uncertainty band includes systematic and statistical uncertainties in the prediction. |
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Figure 3-a:
Distributions for (left) ${m_{\ell \ell}}$, (middle) ${{p_{\mathrm {T}}} ^\text {miss}}$ and (right) $ {p_{\mathrm {T}}} ^{\ell \ell}$ in a ${\mathrm{t} {}\mathrm{\bar{t}}} $-enriched CR in data. The data-driven flavor-symmetric background prediction (gray solid histogram) is compared to data (black marker). Other backgrounds are estimated directly from simulation (green and blue solid histograms). The uncertainty band includes systematic and statistical uncertainties in the prediction. |
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Figure 3-b:
Distributions for (left) ${m_{\ell \ell}}$, (middle) ${{p_{\mathrm {T}}} ^\text {miss}}$ and (right) $ {p_{\mathrm {T}}} ^{\ell \ell}$ in a ${\mathrm{t} {}\mathrm{\bar{t}}} $-enriched CR in data. The data-driven flavor-symmetric background prediction (gray solid histogram) is compared to data (black marker). Other backgrounds are estimated directly from simulation (green and blue solid histograms). The uncertainty band includes systematic and statistical uncertainties in the prediction. |
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Figure 3-c:
Distributions for (left) ${m_{\ell \ell}}$, (middle) ${{p_{\mathrm {T}}} ^\text {miss}}$ and (right) $ {p_{\mathrm {T}}} ^{\ell \ell}$ in a ${\mathrm{t} {}\mathrm{\bar{t}}} $-enriched CR in data. The data-driven flavor-symmetric background prediction (gray solid histogram) is compared to data (black marker). Other backgrounds are estimated directly from simulation (green and blue solid histograms). The uncertainty band includes systematic and statistical uncertainties in the prediction. |
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Figure 4:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution observed in data (black markers) is compared to the background prediction (solid histograms) in the on-Z VRs. (Upper) Comparison in the strong on-Z VRs: (left) SRA, (middle) SRB, and (right) SRC. (Lower) Comparison in the EW on-Z VRs: (left) resolved VZ, (middle) boosted VZ, and (right) HZ. The uncertainty band includes systematic and statistical uncertainties in the prediction. |
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Figure 4-a:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution observed in data (black markers) is compared to the background prediction (solid histograms) in the on-Z VRs. (Upper) Comparison in the strong on-Z VRs: (left) SRA, (middle) SRB, and (right) SRC. (Lower) Comparison in the EW on-Z VRs: (left) resolved VZ, (middle) boosted VZ, and (right) HZ. The uncertainty band includes systematic and statistical uncertainties in the prediction. |
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Figure 4-b:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution observed in data (black markers) is compared to the background prediction (solid histograms) in the on-Z VRs. (Upper) Comparison in the strong on-Z VRs: (left) SRA, (middle) SRB, and (right) SRC. (Lower) Comparison in the EW on-Z VRs: (left) resolved VZ, (middle) boosted VZ, and (right) HZ. The uncertainty band includes systematic and statistical uncertainties in the prediction. |
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Figure 4-c:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution observed in data (black markers) is compared to the background prediction (solid histograms) in the on-Z VRs. (Upper) Comparison in the strong on-Z VRs: (left) SRA, (middle) SRB, and (right) SRC. (Lower) Comparison in the EW on-Z VRs: (left) resolved VZ, (middle) boosted VZ, and (right) HZ. The uncertainty band includes systematic and statistical uncertainties in the prediction. |
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Figure 4-d:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution observed in data (black markers) is compared to the background prediction (solid histograms) in the on-Z VRs. (Upper) Comparison in the strong on-Z VRs: (left) SRA, (middle) SRB, and (right) SRC. (Lower) Comparison in the EW on-Z VRs: (left) resolved VZ, (middle) boosted VZ, and (right) HZ. The uncertainty band includes systematic and statistical uncertainties in the prediction. |
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Figure 4-e:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution observed in data (black markers) is compared to the background prediction (solid histograms) in the on-Z VRs. (Upper) Comparison in the strong on-Z VRs: (left) SRA, (middle) SRB, and (right) SRC. (Lower) Comparison in the EW on-Z VRs: (left) resolved VZ, (middle) boosted VZ, and (right) HZ. The uncertainty band includes systematic and statistical uncertainties in the prediction. |
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Figure 4-f:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution observed in data (black markers) is compared to the background prediction (solid histograms) in the on-Z VRs. (Upper) Comparison in the strong on-Z VRs: (left) SRA, (middle) SRB, and (right) SRC. (Lower) Comparison in the EW on-Z VRs: (left) resolved VZ, (middle) boosted VZ, and (right) HZ. The uncertainty band includes systematic and statistical uncertainties in the prediction. |
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Figure 5:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution in data is compared to the SM background prediction in the strong-production on-Z (upper) SRA, (middle) SRB, and (lower) SRC search regions, for (left) the b veto and (right) b tag categories, before the fits to data described in Section 8. The lower panel of each plot shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band in the upper panels shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distributions correspond to the gluino pair production model, with the gluino having a mass of 1600 GeV and $\tilde{\chi}^0_1$ having a mass of 700 GeV. The ${{p_{\mathrm {T}}} ^\text {miss}}$ template prediction in each search region is normalized to the first ${{p_{\mathrm {T}}} ^\text {miss}}$ bin of each distribution in data. |
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Figure 5-a:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution in data is compared to the SM background prediction in the strong-production on-Z (upper) SRA, (middle) SRB, and (lower) SRC search regions, for (left) the b veto and (right) b tag categories, before the fits to data described in Section 8. The lower panel of each plot shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band in the upper panels shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distributions correspond to the gluino pair production model, with the gluino having a mass of 1600 GeV and $\tilde{\chi}^0_1$ having a mass of 700 GeV. The ${{p_{\mathrm {T}}} ^\text {miss}}$ template prediction in each search region is normalized to the first ${{p_{\mathrm {T}}} ^\text {miss}}$ bin of each distribution in data. |
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Figure 5-b:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution in data is compared to the SM background prediction in the strong-production on-Z (upper) SRA, (middle) SRB, and (lower) SRC search regions, for (left) the b veto and (right) b tag categories, before the fits to data described in Section 8. The lower panel of each plot shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band in the upper panels shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distributions correspond to the gluino pair production model, with the gluino having a mass of 1600 GeV and $\tilde{\chi}^0_1$ having a mass of 700 GeV. The ${{p_{\mathrm {T}}} ^\text {miss}}$ template prediction in each search region is normalized to the first ${{p_{\mathrm {T}}} ^\text {miss}}$ bin of each distribution in data. |
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Figure 5-c:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution in data is compared to the SM background prediction in the strong-production on-Z (upper) SRA, (middle) SRB, and (lower) SRC search regions, for (left) the b veto and (right) b tag categories, before the fits to data described in Section 8. The lower panel of each plot shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band in the upper panels shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distributions correspond to the gluino pair production model, with the gluino having a mass of 1600 GeV and $\tilde{\chi}^0_1$ having a mass of 700 GeV. The ${{p_{\mathrm {T}}} ^\text {miss}}$ template prediction in each search region is normalized to the first ${{p_{\mathrm {T}}} ^\text {miss}}$ bin of each distribution in data. |
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Figure 5-d:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution in data is compared to the SM background prediction in the strong-production on-Z (upper) SRA, (middle) SRB, and (lower) SRC search regions, for (left) the b veto and (right) b tag categories, before the fits to data described in Section 8. The lower panel of each plot shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band in the upper panels shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distributions correspond to the gluino pair production model, with the gluino having a mass of 1600 GeV and $\tilde{\chi}^0_1$ having a mass of 700 GeV. The ${{p_{\mathrm {T}}} ^\text {miss}}$ template prediction in each search region is normalized to the first ${{p_{\mathrm {T}}} ^\text {miss}}$ bin of each distribution in data. |
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Figure 5-e:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution in data is compared to the SM background prediction in the strong-production on-Z (upper) SRA, (middle) SRB, and (lower) SRC search regions, for (left) the b veto and (right) b tag categories, before the fits to data described in Section 8. The lower panel of each plot shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band in the upper panels shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distributions correspond to the gluino pair production model, with the gluino having a mass of 1600 GeV and $\tilde{\chi}^0_1$ having a mass of 700 GeV. The ${{p_{\mathrm {T}}} ^\text {miss}}$ template prediction in each search region is normalized to the first ${{p_{\mathrm {T}}} ^\text {miss}}$ bin of each distribution in data. |
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Figure 5-f:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution in data is compared to the SM background prediction in the strong-production on-Z (upper) SRA, (middle) SRB, and (lower) SRC search regions, for (left) the b veto and (right) b tag categories, before the fits to data described in Section 8. The lower panel of each plot shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band in the upper panels shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distributions correspond to the gluino pair production model, with the gluino having a mass of 1600 GeV and $\tilde{\chi}^0_1$ having a mass of 700 GeV. The ${{p_{\mathrm {T}}} ^\text {miss}}$ template prediction in each search region is normalized to the first ${{p_{\mathrm {T}}} ^\text {miss}}$ bin of each distribution in data. |
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Figure 6:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution in data is compared to the SM background prediction in the EW on-Z (upper left) boosted VZ, (upper right) resolved VZ, and (lower) HZ search regions, before the fits to data described in Section 8. The lower panel of each figure shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution for the boosted and resolved VZ search regions correspond to the $\tilde{\chi}^{\pm}_1 / \tilde{\chi}^{0}_2$ production model with a $\tilde{\chi}^{\pm}_1 /\tilde{\chi}^{0}_2$ mass of 400 GeV and $\tilde{\chi}^0_1$ mass of 200 GeV, while for the HZ search region the ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution corresponds to a $\tilde{\chi}^0_1$ pair production model decaying into a Higgs boson, a Z boson and two $\tilde{\mathrm{G}}$, with the $\tilde{\chi}^0_1$ and the $\tilde{\mathrm{G}}$ having a mass of 500 GeV and 1 GeV. The ${{p_{\mathrm {T}}} ^\text {miss}}$ template prediction in each search region is normalized to the first ${{p_{\mathrm {T}}} ^\text {miss}}$ bin of each distribution in data. |
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Figure 6-a:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution in data is compared to the SM background prediction in the EW on-Z (upper left) boosted VZ, (upper right) resolved VZ, and (lower) HZ search regions, before the fits to data described in Section 8. The lower panel of each figure shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution for the boosted and resolved VZ search regions correspond to the $\tilde{\chi}^{\pm}_1 / \tilde{\chi}^{0}_2$ production model with a $\tilde{\chi}^{\pm}_1 /\tilde{\chi}^{0}_2$ mass of 400 GeV and $\tilde{\chi}^0_1$ mass of 200 GeV, while for the HZ search region the ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution corresponds to a $\tilde{\chi}^0_1$ pair production model decaying into a Higgs boson, a Z boson and two $\tilde{\mathrm{G}}$, with the $\tilde{\chi}^0_1$ and the $\tilde{\mathrm{G}}$ having a mass of 500 GeV and 1 GeV. The ${{p_{\mathrm {T}}} ^\text {miss}}$ template prediction in each search region is normalized to the first ${{p_{\mathrm {T}}} ^\text {miss}}$ bin of each distribution in data. |
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Figure 6-b:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution in data is compared to the SM background prediction in the EW on-Z (upper left) boosted VZ, (upper right) resolved VZ, and (lower) HZ search regions, before the fits to data described in Section 8. The lower panel of each figure shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution for the boosted and resolved VZ search regions correspond to the $\tilde{\chi}^{\pm}_1 / \tilde{\chi}^{0}_2$ production model with a $\tilde{\chi}^{\pm}_1 /\tilde{\chi}^{0}_2$ mass of 400 GeV and $\tilde{\chi}^0_1$ mass of 200 GeV, while for the HZ search region the ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution corresponds to a $\tilde{\chi}^0_1$ pair production model decaying into a Higgs boson, a Z boson and two $\tilde{\mathrm{G}}$, with the $\tilde{\chi}^0_1$ and the $\tilde{\mathrm{G}}$ having a mass of 500 GeV and 1 GeV. The ${{p_{\mathrm {T}}} ^\text {miss}}$ template prediction in each search region is normalized to the first ${{p_{\mathrm {T}}} ^\text {miss}}$ bin of each distribution in data. |
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Figure 6-c:
The ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution in data is compared to the SM background prediction in the EW on-Z (upper left) boosted VZ, (upper right) resolved VZ, and (lower) HZ search regions, before the fits to data described in Section 8. The lower panel of each figure shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution for the boosted and resolved VZ search regions correspond to the $\tilde{\chi}^{\pm}_1 / \tilde{\chi}^{0}_2$ production model with a $\tilde{\chi}^{\pm}_1 /\tilde{\chi}^{0}_2$ mass of 400 GeV and $\tilde{\chi}^0_1$ mass of 200 GeV, while for the HZ search region the ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution corresponds to a $\tilde{\chi}^0_1$ pair production model decaying into a Higgs boson, a Z boson and two $\tilde{\mathrm{G}}$, with the $\tilde{\chi}^0_1$ and the $\tilde{\mathrm{G}}$ having a mass of 500 GeV and 1 GeV. The ${{p_{\mathrm {T}}} ^\text {miss}}$ template prediction in each search region is normalized to the first ${{p_{\mathrm {T}}} ^\text {miss}}$ bin of each distribution in data. |
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Figure 7:
Results of the counting experiment in the edge search regions, before the fits to data described in Section 8. In each search region, the number of observed events in data (black markers) is compared to the SM background prediction, for the (left) b veto and (right) b tag categories. The hashed band shows the total uncertainty in the background prediction, including statistical and systematic sources.The signal distribution corresponds to the $\tilde{\mathrm{b}}$ pair production model, with the $\tilde{\mathrm{b}}$ having a mass of 1250 GeV and the $\tilde{\chi}^{0}_2$ a mass of 400 GeV. |
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Figure 7-a:
Results of the counting experiment in the edge search regions, before the fits to data described in Section 8. In each search region, the number of observed events in data (black markers) is compared to the SM background prediction, for the (left) b veto and (right) b tag categories. The hashed band shows the total uncertainty in the background prediction, including statistical and systematic sources.The signal distribution corresponds to the $\tilde{\mathrm{b}}$ pair production model, with the $\tilde{\mathrm{b}}$ having a mass of 1250 GeV and the $\tilde{\chi}^{0}_2$ a mass of 400 GeV. |
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Figure 7-b:
Results of the counting experiment in the edge search regions, before the fits to data described in Section 8. In each search region, the number of observed events in data (black markers) is compared to the SM background prediction, for the (left) b veto and (right) b tag categories. The hashed band shows the total uncertainty in the background prediction, including statistical and systematic sources.The signal distribution corresponds to the $\tilde{\mathrm{b}}$ pair production model, with the $\tilde{\mathrm{b}}$ having a mass of 1250 GeV and the $\tilde{\chi}^{0}_2$ a mass of 400 GeV. |
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Figure 8:
Fit to data of the dilepton mass (${m_{\ell \ell}}$) distributions in the edge fit search regions, under the signal+background hypothesis, projected onto the (left) SF and (right) DF data samples. The fit shape is shown as a solid blue line. The individual fit components are indicated by dashed and dotted lines. The flavor-symmetric background is shown as a black dashed line. The $\mathrm{Z} +\mathrm {X}$ background is displayed as a red dotted line. The extracted signal component is displayed as a purple dash-dotted line. The lower panel in each plot shows the difference between the observed data yield and the fit, divided by the square root of the number of fitted events. |
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Figure 8-a:
Fit to data of the dilepton mass (${m_{\ell \ell}}$) distributions in the edge fit search regions, under the signal+background hypothesis, projected onto the (left) SF and (right) DF data samples. The fit shape is shown as a solid blue line. The individual fit components are indicated by dashed and dotted lines. The flavor-symmetric background is shown as a black dashed line. The $\mathrm{Z} +\mathrm {X}$ background is displayed as a red dotted line. The extracted signal component is displayed as a purple dash-dotted line. The lower panel in each plot shows the difference between the observed data yield and the fit, divided by the square root of the number of fitted events. |
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Figure 8-b:
Fit to data of the dilepton mass (${m_{\ell \ell}}$) distributions in the edge fit search regions, under the signal+background hypothesis, projected onto the (left) SF and (right) DF data samples. The fit shape is shown as a solid blue line. The individual fit components are indicated by dashed and dotted lines. The flavor-symmetric background is shown as a black dashed line. The $\mathrm{Z} +\mathrm {X}$ background is displayed as a red dotted line. The extracted signal component is displayed as a purple dash-dotted line. The lower panel in each plot shows the difference between the observed data yield and the fit, divided by the square root of the number of fitted events. |
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Figure 9:
Distribution of ${{p_{\mathrm {T}}} ^\text {miss}}$ for events in the slepton (left) search regions and (right) control regions obtained by inverting the ${m_{\ell \ell}}$ selection, used to obtain the DY background normalization, for regions (upper) without jets and (lower) with jets. A background-only fit to data in the control region has been performed to determine the DY+jets contribution as described in section 8. The lower panel of each figure shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution corresponds to the direct slepton pair production model, with a slepton mass of 600 GeV and a massless $\tilde{\chi}^0_1$ particle. |
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Figure 9-a:
Distribution of ${{p_{\mathrm {T}}} ^\text {miss}}$ for events in the slepton (left) search regions and (right) control regions obtained by inverting the ${m_{\ell \ell}}$ selection, used to obtain the DY background normalization, for regions (upper) without jets and (lower) with jets. A background-only fit to data in the control region has been performed to determine the DY+jets contribution as described in section 8. The lower panel of each figure shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution corresponds to the direct slepton pair production model, with a slepton mass of 600 GeV and a massless $\tilde{\chi}^0_1$ particle. |
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Figure 9-b:
Distribution of ${{p_{\mathrm {T}}} ^\text {miss}}$ for events in the slepton (left) search regions and (right) control regions obtained by inverting the ${m_{\ell \ell}}$ selection, used to obtain the DY background normalization, for regions (upper) without jets and (lower) with jets. A background-only fit to data in the control region has been performed to determine the DY+jets contribution as described in section 8. The lower panel of each figure shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution corresponds to the direct slepton pair production model, with a slepton mass of 600 GeV and a massless $\tilde{\chi}^0_1$ particle. |
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Figure 9-c:
Distribution of ${{p_{\mathrm {T}}} ^\text {miss}}$ for events in the slepton (left) search regions and (right) control regions obtained by inverting the ${m_{\ell \ell}}$ selection, used to obtain the DY background normalization, for regions (upper) without jets and (lower) with jets. A background-only fit to data in the control region has been performed to determine the DY+jets contribution as described in section 8. The lower panel of each figure shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution corresponds to the direct slepton pair production model, with a slepton mass of 600 GeV and a massless $\tilde{\chi}^0_1$ particle. |
png pdf |
Figure 9-d:
Distribution of ${{p_{\mathrm {T}}} ^\text {miss}}$ for events in the slepton (left) search regions and (right) control regions obtained by inverting the ${m_{\ell \ell}}$ selection, used to obtain the DY background normalization, for regions (upper) without jets and (lower) with jets. A background-only fit to data in the control region has been performed to determine the DY+jets contribution as described in section 8. The lower panel of each figure shows the ratio of observed data to the SM prediction in each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin. The hashed band shows the total uncertainty in the background prediction, including statistical and systematic sources. The signal ${{p_{\mathrm {T}}} ^\text {miss}}$ distribution corresponds to the direct slepton pair production model, with a slepton mass of 600 GeV and a massless $\tilde{\chi}^0_1$ particle. |
png pdf |
Figure 10:
Cross section upper limits and exclusion contours at 95% CL for a SMS of GMSB gluino pair production, as a function of the ${\mathrm{\tilde{g}}}$ and $\tilde{\chi}^0_1$ masses, obtained from the results in the strong on-Z search regions. The area enclosed by the thick black curve represents the observed exclusion region, while the dashed red lines indicate the expected limits and their $ \pm $1 and $ \pm $2 standard deviation (s.d.) ranges. The thin black lines show the effect of the theoretical uncertainties in the signal cross section. |
png pdf |
Figure 11:
Cross section upper limits and exclusion contours at 95% CL for a SMS of $\tilde{\chi}^{\pm}_1 \tilde{\chi}^{0}_2$ production, with final states containing a $\mathrm{W^{\pm}}$ and a Z boson, as a function of the $\tilde{\chi}^{\pm}_1 /\tilde{\chi}^{0}_2$ and $\tilde{\chi}^0_1$ masses, obtained from the results in the EW on-Z search regions. The area enclosed by the thick black curve represents the observed exclusion region, while the dashed red lines indicate the expected limits and their $ \pm $1 and $ \pm $2 standard deviation (s.d.) ranges. The thin black lines show the effect of the theoretical uncertainties in the signal cross section. |
png pdf |
Figure 12:
Production cross section upper limits at 95% CL as a function of the $\tilde{\chi}^0_1$ mass, for a model of EW $\tilde{\chi}^0_1$ pair production, where either (left) both $\tilde{\chi}^0_1$ decay into a Z boson with 100% branching fraction ($\mathcal {B}$), or (right) each $\tilde{\chi}^0_1$ can decay to a Z or a H boson with equal probability. The magenta curve shows the theoretical production cross section with its uncertainty. The solid (dashed) black line represents the observed (median expected) exclusion. The inner green (outer yellow) band indicates the region containing 68 (95)% of the distribution of limits expected under the background-only hypothesis. |
png pdf |
Figure 12-a:
Production cross section upper limits at 95% CL as a function of the $\tilde{\chi}^0_1$ mass, for a model of EW $\tilde{\chi}^0_1$ pair production, where either (left) both $\tilde{\chi}^0_1$ decay into a Z boson with 100% branching fraction ($\mathcal {B}$), or (right) each $\tilde{\chi}^0_1$ can decay to a Z or a H boson with equal probability. The magenta curve shows the theoretical production cross section with its uncertainty. The solid (dashed) black line represents the observed (median expected) exclusion. The inner green (outer yellow) band indicates the region containing 68 (95)% of the distribution of limits expected under the background-only hypothesis. |
png pdf |
Figure 12-b:
Production cross section upper limits at 95% CL as a function of the $\tilde{\chi}^0_1$ mass, for a model of EW $\tilde{\chi}^0_1$ pair production, where either (left) both $\tilde{\chi}^0_1$ decay into a Z boson with 100% branching fraction ($\mathcal {B}$), or (right) each $\tilde{\chi}^0_1$ can decay to a Z or a H boson with equal probability. The magenta curve shows the theoretical production cross section with its uncertainty. The solid (dashed) black line represents the observed (median expected) exclusion. The inner green (outer yellow) band indicates the region containing 68 (95)% of the distribution of limits expected under the background-only hypothesis. |
png pdf |
Figure 13:
Cross section upper limits and exclusion contours at 95% CL for SMSs of (left) bottom and (right) light-flavor squark pair production, where each squark decays into a quark and a $\tilde{\chi}^{0}_2$, and the $\tilde{\chi}^{0}_2$ then decays via an intermediate slepton, forming a kinematic edge in the ${m_{\ell \ell}}$ distribution. The limits are obtained from the results in the edge search regions, and are shown as a function of the (left) $\tilde{\mathrm{b}}$ or (right) $\tilde{\mathrm{q}}$ and $\tilde{\chi}^{0}_2$ masses. The area enclosed by the thick black curve represents the observed exclusion region, while the dashed red lines indicate the expected limits and their $ \pm $1 and $ \pm $2 standard deviation (s.d.) ranges. The thin black lines show the effect of the theoretical uncertainties in the signal cross section. |
png pdf |
Figure 13-a:
Cross section upper limits and exclusion contours at 95% CL for SMSs of (left) bottom and (right) light-flavor squark pair production, where each squark decays into a quark and a $\tilde{\chi}^{0}_2$, and the $\tilde{\chi}^{0}_2$ then decays via an intermediate slepton, forming a kinematic edge in the ${m_{\ell \ell}}$ distribution. The limits are obtained from the results in the edge search regions, and are shown as a function of the (left) $\tilde{\mathrm{b}}$ or (right) $\tilde{\mathrm{q}}$ and $\tilde{\chi}^{0}_2$ masses. The area enclosed by the thick black curve represents the observed exclusion region, while the dashed red lines indicate the expected limits and their $ \pm $1 and $ \pm $2 standard deviation (s.d.) ranges. The thin black lines show the effect of the theoretical uncertainties in the signal cross section. |
png pdf |
Figure 13-b:
Cross section upper limits and exclusion contours at 95% CL for SMSs of (left) bottom and (right) light-flavor squark pair production, where each squark decays into a quark and a $\tilde{\chi}^{0}_2$, and the $\tilde{\chi}^{0}_2$ then decays via an intermediate slepton, forming a kinematic edge in the ${m_{\ell \ell}}$ distribution. The limits are obtained from the results in the edge search regions, and are shown as a function of the (left) $\tilde{\mathrm{b}}$ or (right) $\tilde{\mathrm{q}}$ and $\tilde{\chi}^{0}_2$ masses. The area enclosed by the thick black curve represents the observed exclusion region, while the dashed red lines indicate the expected limits and their $ \pm $1 and $ \pm $2 standard deviation (s.d.) ranges. The thin black lines show the effect of the theoretical uncertainties in the signal cross section. |
png pdf |
Figure 14:
Cross section upper limits and exclusion contours at 95% CL for a SMS of slepton pair production, as a function of the slepton and $\tilde{\chi}^0_1$ masses, obtained from the results in the slepton search regions. The area enclosed by the thick black curve represents the observed exclusion region, while the dashed red lines indicate the expected limits and their $ \pm $1 and $ \pm $2 standard deviation (s.d.) ranges. The thin black lines show the effect of the theoretical uncertainties in the signal cross section. |
| Tables | |
png pdf |
Table 1:
List of SUSY particles involved in the models considered, together with the symbols representing them. |
png pdf |
Table 2:
Summary of search category selections. |
png pdf |
Table 3:
Summary of the ${r_{\mu /\mathrm{e}}}$ parameters obtained by fitting the lepton ${p_{\mathrm {T}}}$ and $\eta $, in a DY-enriched CR for the different data taking years. Only statistical uncertainties are tabulated. |
png pdf |
Table 4:
Summary of the systematic uncertainties in the predicted Z+$\nu$ background yields, together with their typical sizes across the SRs. |
png pdf |
Table 5:
Predicted and observed event yields in the strong-production on-Z search regions, for each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin, as defined in Table 2, before the fits to data described in Section 8. Uncertainties include both statistical and systematic sources. The ${{p_{\mathrm {T}}} ^\text {miss}}$ template prediction in each search region is normalized to the first ${{p_{\mathrm {T}}} ^\text {miss}}$ bin of each distribution in data. |
png pdf |
Table 6:
Predicted and observed event yields in the EW on-Z search regions, for each ${{p_{\mathrm {T}}} ^\text {miss}}$ bin, as defined in Table 2, before the fits to data described in Section 8. Uncertainties include both statistical and systematic sources. The ${{p_{\mathrm {T}}} ^\text {miss}}$ template prediction in each search region is normalized to the first ${{p_{\mathrm {T}}} ^\text {miss}}$ bin of each distribution in data. |
png pdf |
Table 7:
Predicted and observed yields in each bin of the edge search counting experiment, as defined in Table 2, before the fits to data described in Section 8. Uncertainties include statistical and systematic sources. |
png pdf |
Table 8:
Results of the ${m_{\ell \ell}}$ unbinned maximum likelihood fit to data in the edge fit search region, as defined in Table 2. The fitted yields of the $\mathrm{Z} +\mathrm {X}$ and flavor-symmetric background components are tabulated, together with the fitted value of ${R_{\mathrm {SF/DF}}}$. The fitted signal contribution and the corresponding edge position are also shown. The local and global signal significances are expressed in terms of standard deviations (s.d.). The uncertainties include both statistical and systematic sources. |
png pdf |
Table 9:
Predicted and observed event yields in the slepton search regions and control regions. A background-only fit to data in the control region has been performed to determine the DY+jets contribution as described in section 8. Uncertainties include both statistical and systematic sources. |
png pdf |
Table 10:
Summary of the systematic uncertainties in the signal yields, together with their typical sizes across the search regions and the SMSs under consideration. |
| Summary |
| A search is presented for phenomena beyond the standard model in events with two opposite-charge, same-flavor leptons, and missing transverse momentum in the final state. The measurements are performed in a sample of pp collisions at $\sqrt{s}=$ 13 TeV, collected with the CMS detector in 2016--2018, and corresponding to an integrated luminosity of 137 fb$^{-1}$. Search regions are defined in order to be sensitive to a wide range of new physics signatures. The observed data yields are found to be consistent with the SM background predictions, and the results are used to set upper limits on the production cross section of simplified models of supersymmetry. We probe gluino masses up to 1875 GeV, light-flavor (bottom) squark masses up to 1800 (1600) GeV, chargino (neutralino) masses up to 750 (800) GeV, and slepton masses up to 650 GeV, typically extending the reach of previous CMS results by hundreds of GeV. |
| References | ||||
| 1 | G. Bertone, D. Hooper, and J. Silk | Particle dark matter: Evidence, candidates and constraints | PR 405 (2005) 279--390 | hep-ph/0404175 |
| 2 | P. Ramond | Dual theory for free fermions | PRD 3 (1971) 2415 | |
| 3 | \relax Yu. A. Gol'fand and E. P. Likhtman | Extension of the algebra of Poincar$ \'e $ group generators and violation of P invariance | JEPTL 13 (1971)323 | |
| 4 | A. Neveu and J. H. Schwarz | Factorizable dual model of pions | NPB 31 (1971) 86 | |
| 5 | D. V. Volkov and V. P. Akulov | Possible universal neutrino interaction | JEPTL 16 (1972)438 | |
| 6 | J. Wess and B. Zumino | A Lagrangian model invariant under supergauge transformations | PLB 49 (1974) 52 | |
| 7 | J. Wess and B. Zumino | Supergauge transformations in four dimensions | NPB 70 (1974) 39 | |
| 8 | P. Fayet | Supergauge invariant extension of the Higgs mechanism and a model for the electron and its neutrino | NPB 90 (1975) 104 | |
| 9 | H. P. Nilles | Supersymmetry, supergravity and particle physics | Phys. Rep. 110 (1984) 1 | |
| 10 | H. E. Haber and G. L. Kane | The search for supersymmetry: Probing physics beyond the standard model | PR 117 (1985) 75 | |
| 11 | G. R. Farrar and P. Fayet | Phenomenology of the production, decay, and detection of new hadronic states associated with supersymmetry | PLB 76 (1978) 575 | |
| 12 | J. Alwall, P. Schuster, and N. Toro | Simplified Models for a First Characterization of New Physics at the LHC | PRD 79 (2009) 075020 | 0810.3921 |
| 13 | CMS Collaboration | Search for new phenomena in final states with two opposite-charge, same-flavor leptons, jets, and missing transverse momentum in pp collisions at $ \sqrt{s}= $ 13 TeV | JHEP 03 (2018) 076 | CMS-SUS-16-034 1709.08908 |
| 14 | CMS Collaboration | Search for supersymmetric partners of electrons and muons in proton-proton collisions at $ \sqrt{s}= $ 13 TeV | Phys.\ Lett.\ B 790 (2019) 140 | CMS-SUS-17-009 1806.05264 |
| 15 | CMS Collaboration | Search for physics beyond the Standard Model in events with two leptons, jets, and missing transverse momentum in pp collisions at $ \sqrt{s} = $ 8 TeV | JHEP 04 (2015) 124 | CMS-SUS-14-014 1502.06031 |
| 16 | CMS Collaboration | Search for new physics in final states with two opposite-sign, same-flavor leptons, jets, and missing transverse momentum in pp collisions at $ \sqrt{s} = $ 13 TeV | JHEP 12 (2016) 013 | CMS-SUS-15-011 1607.00915 |
| 17 | CMS Collaboration | Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at $ \sqrt{s} = $ 7 TeV | PLB 718 (2013) 815 | CMS-SUS-11-011 1206.3949 |
| 18 | CMS Collaboration | Search for physics beyond the Standard Model in opposite-sign dilepton events in pp collisions at $ \sqrt{s} = $ 7 TeV | JHEP 06 (2011) 26 | CMS-SUS-10-007 1103.1348 |
| 19 | CMS Collaboration | Searches for electroweak production of charginos, neutralinos, and sleptons decaying to leptons and W, Z, and Higgs bosons in pp collisions at 8 TeV | EPJC 74 (2014) 3036 | CMS-SUS-13-006 1405.7570 |
| 20 | CMS Collaboration | Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV | PRD 90 (2014) 092007 | CMS-SUS-14-002 1409.3168 |
| 21 | ATLAS Collaboration | Search for electroweak production of charginos and sleptons decaying into final states with two leptons and missing transverse momentum in $ \sqrt{s}=13 TeV pp $ collisions using the ATLAS detector | Eur.\ Phys.\ J.\ C 80 (2020) 123 | 1908.08215 |
| 22 | ATLAS Collaboration | Search for supersymmetry in events containing a same-flavour opposite-sign dilepton pair, jets, and large missing transverse momentum in $ \sqrt{s} = $ 8 TeV pp collisions with the ATLAS detector | EPJC 75 (2015) 318 | 1503.03290 |
| 23 | ATLAS Collaboration | Search for the electroweak production of supersymmetric particles in $ \sqrt{s} = $ 8 TeV pp collisions with the ATLAS detector | PRD 93 (2016) 052002 | 1509.07152 |
| 24 | ATLAS Collaboration | Search for new phenomena in events containing a same-flavour opposite-sign dilepton pair, jets, and large missing transverse momentum in $ \sqrt{s} = $ 13 TeV pp collisions with the ATLAS detector | EPJC 77 (2017) 144 | 1611.05791 |
| 25 | CMS Collaboration | The CMS experiment at the CERN LHC | JINST 3 (2008) S08004 | CMS-00-001 |
| 26 | CMS Collaboration | The CMS trigger system | JINST 12 (2017) P01020 | CMS-TRG-12-001 1609.02366 |
| 27 | CMS Collaboration | CMS technical design report for the pixel detector upgrade | CERN-LHCC-2012-016, CMS-TDR-011 | |
| 28 | CMS Collaboration | Particle-flow reconstruction and global event description with the CMS detector | JINST 12 (2017) P10003 | CMS-PRF-14-001 1706.04965 |
| 29 | M. Cacciari, G. P. Salam, and G. Soyez | The anti-$ k_t $ jet clustering algorithm | JHEP 04 (2008) 063 | 0802.1189 |
| 30 | M. Cacciari, G. P. Salam, and G. Soyez | FastJet user manual | EPJC 72 (2012) 1896 | 1111.6097 |
| 31 | CMS Collaboration | Performance of the CMS muon detector and muon reconstruction with proton-proton collisions at $ \sqrt{s}= $ 13 TeV | JINST 13 (2018) P06015 | CMS-MUO-16-001 1804.04528 |
| 32 | CMS Collaboration | Performance of electron reconstruction and selection with the CMS detector in proton-proton collisions at $ \sqrt{s} = $ 8 TeV | JINST 10 (2015) P06005 | CMS-EGM-13-001 1502.02701 |
| 33 | CMS Collaboration | Performance of photon reconstruction and identification with the CMS detector in proton-proton collisions at $ \sqrt{s} = $ 8 TeV | JINST 10 (2015) P08010 | CMS-EGM-14-001 1502.02702 |
| 34 | M. Cacciari and G. P. Salam | Dispelling the N$ ^3 $ myth for the $ k_t $ jet-finder | PLB 641 (2006) 57 | hep-ph/0512210 |
| 35 | CMS Collaboration | Determination of jet energy calibration and transverse momentum resolution in CMS | JINST 6 (2011) P11002 | CMS-JME-10-011 1107.4277 |
| 36 | M. Cacciari and G. P. Salam | Pileup subtraction using jet areas | PLB 659 (2008) 119 | 0707.1378 |
| 37 | CMS Collaboration | Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV | JINST 13 (2018) P05011 | CMS-BTV-16-002 1712.07158 |
| 38 | A. J. Larkoski, S. Marzani, G. Soyez, and J. Thaler | Soft Drop | JHEP 05 (2014) 146 | 1402.2657 |
| 39 | J. Thaler and K. Van Tilburg | Identifying Boosted Objects with N-subjettiness | JHEP 03 (2011) 015 | 1011.2268 |
| 40 | CMS Collaboration | Identification of heavy, energetic, hadronically decaying particles using machine-learning techniques | JINST 15 (2020) P06005 | CMS-JME-18-002 2004.08262 |
| 41 | J. Alwall et al. | The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations | JHEP 07 (2014) 079 | 1405.0301 |
| 42 | P. Nason | A new method for combining NLO QCD with shower Monte Carlo algorithms | JHEP 11 (2004) 040 | hep-ph/0409146 |
| 43 | S. Frixione, P. Nason, and C. Oleari | Matching NLO QCD computations with parton shower simulations: the POWHEG method | JHEP 11 (2007) 070 | 0709.2092 |
| 44 | S. Alioli, P. Nason, C. Oleari, and E. Re | NLO single-top production matched with shower in POWHEG: $ s $- and $ t $-channel contributions | JHEP 09 (2009) 111 | 0907.4076 |
| 45 | S. Gieseke, T. Kasprzik, and J. H. Kuhn | Vector-boson pair production and electroweak corrections in HERWIG++ | EPJC 74 (2014) 2988 | 1401.3964 |
| 46 | J. Baglio, L. D. Ninh, and M. M. Weber | Massive gauge boson pair production at the LHC: a next-to-leading order story | PRD 88 (2013) 113005 | 1307.4331 |
| 47 | A. Bierweiler, T. Kasprzik, and J. H. Kuhn | Vector-boson pair production at the LHC to $ \mathcal{O}(\alpha^3) $ accuracy | JHEP 12 (2013) 071 | 1305.5402 |
| 48 | J. M. Campbell and R. Ellis | An Update on vector boson pair production at hadron colliders | PRD 60 (1999) 113006 | hep-ph/9905386 |
| 49 | J. M. Campbell, R. Ellis, and C. Williams | Vector boson pair production at the LHC | JHEP 07 (2011) 018 | 1105.0020 |
| 50 | J. M. Campbell, R. K. Ellis, and W. T. Giele | A Multi-Threaded Version of MCFM | EPJC 75 (2015) 246 | 1503.06182 |
| 51 | F. Caola, K. Melnikov, R. Rontsch, and L. Tancredi | QCD corrections to ZZ production in gluon fusion at the LHC | PRD 92 (2015) 094028 | 1509.06734 |
| 52 | T. Sjostrand et al. | An Introduction to PYTHIA 8.2 | CPC 191 (2015) 159 | 1410.3012 |
| 53 | J. Alwall et al. | Comparative study of various algorithms for the merging of parton showers and matrix elements in hadronic collisions | EPJC 53 (2008) 473 | 0706.2569 |
| 54 | R. Frederix and S. Frixione | Merging meets matching in MC@NLO | JHEP 12 (2012) 061 | 1209.6215 |
| 55 | CMS Collaboration | Event generator tunes obtained from underlying event and multiparton scattering measurements | EPJC 76 (2016) 155 | CMS-GEN-14-001 1512.00815 |
| 56 | CMS Collaboration | Extraction and validation of a new set of CMS PYTHIA8 tunes from underlying-event measurements | EPJC 80 (2020) 4 | CMS-GEN-17-001 1903.12179 |
| 57 | NNPDF Collaboration | Parton distributions for the LHC Run II | JHEP 04 (2015) 040 | 1410.8849 |
| 58 | NNPDF Collaboration | Parton distributions from high-precision collider data | EPJC 77 (2017) 663 | 1706.00428 |
| 59 | GEANT4 Collaboration | GEANT4--a simulation toolkit | NIMA 506 (2003) 250 | |
| 60 | S. Abdullin et al. | The fast simulation of the CMS detector at LHC | J. Phys. Conf. Ser. 331 (2011) 032049 | |
| 61 | A. Giammanco | The fast simulation of the CMS experiment | J. Phys. Conf. Ser. 513 (2014) 022012 | |
| 62 | E. Re | Single-top Wt-channel production matched with parton showers using the POWHEG method | EPJC 71 (2011) 1547 | 1009.2450 |
| 63 | R. Gavin, Y. Li, F. Petriello, and S. Quackenbush | FEWZ 2.0: A code for hadronic Z production at next-to-next-to-leading order | CPC 182 (2011) 2388 | 1011.3540 |
| 64 | R. Gavin, Y. Li, F. Petriello, and S. Quackenbush | W physics at the LHC with FEWZ 2.1 | CPC 184 (2013) 208 | 1201.5896 |
| 65 | M. Czakon and A. Mitov | Top++: a program for the calculation of the top-pair cross-section at hadron colliders | CPC 185 (2014) 2930 | 1112.5675 |
| 66 | W. Beenakker et al. | The Production of charginos / neutralinos and sleptons at hadron colliders | PRL 83 (1999) 3780 | hep-ph/9906298 |
| 67 | G. Bozzi, B. Fuks, and M. Klasen | Threshold resummation for slepton-pair production at hadron colliders | NPB 777 (2007) 157 | |
| 68 | J. Debove, B. Fuks, and M. Klasen | Threshold resummation for gaugino pair production at hadron colliders | NPB 842 (2011) 51 | 1005.2909 |
| 69 | B. Fuks, M. Klasen, D. R. Lamprea, and M. Rothering | Gaugino production in proton-proton collisions at a center-of-mass energy of 8 TeV | JHEP 10 (2012) 081 | 1207.2159 |
| 70 | B. Fuks, M. Klasen, D. R. Lamprea, and M. Rothering | Precision predictions for electroweak superpartner production at hadron colliders with $ \sc $ Resummino | EPJC 73 (2013) 2480 | 1304.0790 |
| 71 | B. Fuks, M. Klasen, D. R. Lamprea, and M. Rothering | Revisiting slepton pair production at the Large Hadron Collider | JHEP 01 (2014) 168 | 1310.2621 |
| 72 | J. Fiaschi and M. Klasen | Neutralino-chargino pair production at NLO+NLL with resummation-improved parton density functions for LHC Run II | PRD 98 (2018), no. 5, 055014 | 1805.11322 |
| 73 | J. Fiaschi and M. Klasen | Slepton pair production at the LHC in NLO+NLL with resummation-improved parton densities | JHEP 03 (2018) 094 | 1801.10357 |
| 74 | W. Beenakker, R. Hopker, M. Spira, and P. M. Zerwas | Squark and gluino production at hadron colliders | NPB 492 (1997) 51 | hep-ph/9610490 |
| 75 | W. Beenakker et al. | Stop production at hadron colliders | NPB 515 (1998) 3 | hep-ph/9710451 |
| 76 | A. Kulesza and L. Motyka | Threshold resummation for squark-antisquark and gluino-pair production at the LHC | PRL 102 (2009) 111802 | 0807.2405 |
| 77 | A. Kulesza and L. Motyka | Soft gluon resummation for the production of gluino-gluino and squark-antisquark pairs at the LHC | PRD 80 (2009) 095004 | 0905.4749 |
| 78 | W. Beenakker et al. | Soft-gluon resummation for squark and gluino hadroproduction | JHEP 12 (2009) 041 | 0909.4418 |
| 79 | W. Beenakker et al. | Supersymmetric top and bottom squark production at hadron colliders | JHEP 08 (2010) 098 | 1006.4771 |
| 80 | W. Beenakker et al. | Squark and gluino hadroproduction | Int. J. Mod. Phys. A 26 (2011) 2637 | 1105.1110 |
| 81 | W. Beenakker et al. | NNLL resummation for squark-antisquark pair production at the LHC | JHEP 01 (2012) 076 | 1110.2446 |
| 82 | W. Beenakker et al. | Towards NNLL resummation: hard matching coefficients for squark and gluino hadroproduction | JHEP 10 (2013) 120 | 1304.6354 |
| 83 | W. Beenakker et al. | NNLL resummation for squark and gluino production at the LHC | JHEP 12 (2014) 023 | 1404.3134 |
| 84 | W. Beenakker et al. | NNLL resummation for stop pair-production at the LHC | JHEP 05 (2016) 153 | 1601.02954 |
| 85 | W. Beenakker et al. | NNLL-fast: predictions for coloured supersymmetric particle production at the LHC with threshold and Coulomb resummation | JHEP 12 (2016) 133 | 1607.07741 |
| 86 | C. G. Lester and D. J. Summers | Measuring masses of semiinvisibly decaying particles pair produced at hadron colliders | PLB 463 (1999) 99 | hep-ph/9906349 |
| 87 | A. Barr, C. Lester, and P. Stephens | A variable for measuring masses at hadron colliders when missing energy is expected; $ M_{T2} $: the truth behind the glamour | JPG 29 (2003) 2343 | hep-ph/0304226 |
| 88 | Particle Data Group, C. Patrignani et al. | Review of Particle Physics | CPC 40 (2016) 100001 | |
| 89 | E. Gross and O. Vitells | Trial factors or the look elsewhere effect in high energy physics | EPJC 70 (2010) 525 | 1005.1891 |
| 90 | T. Junk | Confidence level computation for combining searches with small statistics | NIMA 434 (1999) 435 | hep-ex/9902006 |
| 91 | A. L. Read | Presentation of search results: the $ \rm CL_s $ technique | JPG 28 (2002) 2693 | |
| 92 | G. Cowan, K. Cranmer, E. Gross, and O. Vitells | Asymptotic formulae for likelihood-based tests of new physics | EPJC 71 (2011) 1554 | 1007.1727 |
| 93 | ATLAS and CMS Collaborations | Procedure for the LHC Higgs boson search combination in summer 2011 | CMS-NOTE-2011-005 | |
| 94 | CMS Collaboration | CMS luminosity measurements for the 2016 data-taking period | ||
| 95 | CMS Collaboration | CMS luminosity measurement for the 2017 data-taking period at $ \sqrt{s} = $ 13 TeV | ||
| 96 | CMS Collaboration | CMS luminosity measurement for the 2018 data-taking period at $ \sqrt{s} = $ 13 TeV | ||
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