Results are presented from a search for physics beyond the standard model in proton-proton collisions at $\sqrt{s} =$ 13 TeV in channels with two Higgs bosons, each decaying via the process H $\to$$\mathrm{b\bar{b}}$, and large missing transverse momentum. The search uses a data sample corresponding to an integrated luminosity of 137 fb$^{-1}$ collected by the CMS experiment at the CERN LHC. The search is motivated by models of supersymmetry that predict the production of neutralinos, the neutral partners of the electroweak gauge and Higgs bosons. The observed event yields in the signal regions are found to be consistent with the standard model background expectations. The results are interpreted using simplified models of supersymmetry. For the electroweak production of nearly mass-degenerate higgsinos, each of whose decay chains yields a neutralino ($\tilde{\chi}^0_1$) that in turn decays to a massless goldstino and a Higgs boson, $\tilde{\chi}^0_1$ masses in the range 175 to 1025 GeV are excluded at 95% confidence level. For the strong production of gluino pairs decaying via a slightly lighter $\tilde{\chi}^0_2$ to H and a light $\tilde{\chi}^0_1$, gluino masses below 2330 GeV are excluded.
Predicted background and observed yields vs bin index
Cross section 95% CL upper limit vs m($\widetilde{\chi}^0_1$) for SMS model TChiHH-G.
Theory cross sections vs m($\widetilde{\chi}^0_1$) for SMS model TChiHH-G.
A search for long-lived particles decaying in the outer regions of the CMS silicon tracker or in the calorimeters is presented. The search is based on a data sample of proton-proton collisions at $\sqrt{s}$ = 13 TeV recorded with the CMS detector at the LHC in 2016-2018, corresponding to an integrated luminosity of 138 fb$^{-1}$. A novel technique, using trackless and out-of-time jet information combined in a deep neural network discriminator, is employed to identify decays of long-lived particles. The results are interpreted in a simplified model of chargino-neutralino production, where the neutralino is the next-to-lightest supersymmetric particle, is long-lived, and decays to a gravitino and either a Higgs or Z boson. This search is most sensitive to neutralino proper decay lengths of approximately 0.5 m, for which masses up to 1.18 TeV are excluded at 95% confidence level. The current search is the best result to date in the mass range from the kinematic limit imposed by the Higgs mass up to 1.8 TeV.
Summary of combined statistical and systematic uncertainties, the size of their effect, and whether it applies to the signal or background yield predictions. Ranges for signal systematic uncertainties reflect their impact on different signal parameter space points.
Summary of combined statistical and systematic uncertainties, the size of their effect, and whether it applies to the signal or background yield predictions. Ranges for signal systematic uncertainties reflect their impact on different signal parameter space points.
Feynman diagrams of the effective neutralino pair production in the GMSB simplified model in which the two neutralinos decay into two gravitinos ($\tilde{G}$) and two $Z$ bosons (left), a $Z$ and a Higgs boson ($H$) (center), or two Higgs bosons (right).
A data sample of events from proton-proton collisions with at least two jets, and two isolated same-sign or three or more charged leptons, is studied in a search for signatures of new physics phenomena. The data correspond to an integrated luminosity of 137 fb$^{-1}$ at a center-of-mass energy of 13 TeV, collected in 2016-2018 by the CMS experiment at the LHC. The search is performed using a total of 168 signal regions defined using several kinematic variables. The properties of the events are found to be consistent with the expectations from standard model processes. Exclusion limits at 95% confidence level are set on cross sections for the pair production of gluinos or squarks for various decay scenarios in the context of supersymmetric models conserving or violating R parity. The observed lower mass limits are as large as 2.1 TeV for gluinos and 0.9 TeV for top and bottom squarks. To facilitate reinterpretations, model-independent limits are provided in a set of simplified signal regions.
Exclusion regions at 95% CL in the $m_{\tilde{\chi}_1^0}$ versus $m_{\tilde{g}}$ plane for the T1tttt (upper left) and T5ttbbWW (upper right) models, with off-shell third-generation squarks, and the T5tttt (lower left) and T5ttcc (lower right) models, with on-shell third-generation squarks. For the T5ttbbWW model, $m_{\tilde{\chi}_1^\pm} = m_{\tilde{\chi}_1^0} + 5 GeV$, for the T5tttt model, $m_{\tilde{t}} - m_{\tilde{\chi}_1^0} = m_t$, and for the T5ttcc model, $m_{\tilde{t}} - m_{\tilde{\chi}_1^0} = 20 GeV$ and the decay proceeds through $\tilde{t} \to c \tilde{\chi}_1^0$. The right-hand side color scale indicates the excluded cross section values for a given point in the SUSY particle mass plane. The solid black curves represent the observed exclusion limits assuming the approximate-NNLO+NNLL cross sections (thick line), or their variations of $\pm 1$ standard deviations (s.d.) (thin lines). The dashed red curves show the expected limits with the corresponding $\pm 1$ s.d. and $\pm 2$ s.d. uncertainties. Excluded regions are to the left and below the limit curves.
Exclusion regions at 95% CL in the $m_{\tilde{\chi}_1^0}$ versus $m_{\tilde{g}}$ plane for the T1tttt (upper left) and T5ttbbWW (upper right) models, with off-shell third-generation squarks, and the T5tttt (lower left) and T5ttcc (lower right) models, with on-shell third-generation squarks. For the T5ttbbWW model, $m_{\tilde{\chi}_1^\pm} = m_{\tilde{\chi}_1^0} + 5 GeV$, for the T5tttt model, $m_{\tilde{t}} - m_{\tilde{\chi}_1^0} = m_t$, and for the T5ttcc model, $m_{\tilde{t}} - m_{\tilde{\chi}_1^0} = 20 GeV$ and the decay proceeds through $\tilde{t} \to c \tilde{\chi}_1^0$. The right-hand side color scale indicates the excluded cross section values for a given point in the SUSY particle mass plane. The solid black curves represent the observed exclusion limits assuming the approximate-NNLO+NNLL cross sections (thick line), or their variations of $\pm 1$ standard deviations (s.d.) (thin lines). The dashed red curves show the expected limits with the corresponding $\pm 1$ s.d. and $\pm 2$ s.d. uncertainties. Excluded regions are to the left and below the limit curves.
Exclusion regions at 95% CL in the $m_{\tilde{\chi}_1^0}$ versus $m_{\tilde{g}}$ plane for the T1tttt (upper left) and T5ttbbWW (upper right) models, with off-shell third-generation squarks, and the T5tttt (lower left) and T5ttcc (lower right) models, with on-shell third-generation squarks. For the T5ttbbWW model, $m_{\tilde{\chi}_1^\pm} = m_{\tilde{\chi}_1^0} + 5 GeV$, for the T5tttt model, $m_{\tilde{t}} - m_{\tilde{\chi}_1^0} = m_t$, and for the T5ttcc model, $m_{\tilde{t}} - m_{\tilde{\chi}_1^0} = 20 GeV$ and the decay proceeds through $\tilde{t} \to c \tilde{\chi}_1^0$. The right-hand side color scale indicates the excluded cross section values for a given point in the SUSY particle mass plane. The solid black curves represent the observed exclusion limits assuming the approximate-NNLO+NNLL cross sections (thick line), or their variations of $\pm 1$ standard deviations (s.d.) (thin lines). The dashed red curves show the expected limits with the corresponding $\pm 1$ s.d. and $\pm 2$ s.d. uncertainties. Excluded regions are to the left and below the limit curves.
A search for supersymmetry is presented based on events with at least one photon, jets, and large missing transverse momentum produced in proton-proton collisions at a center-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 35.9 fb$^{-1}$ and were recorded at the LHC with the CMS detector in 2016. The analysis characterizes signal-like events by categorizing the data into various signal regions based on the number of jets, the number of b-tagged jets, and the missing transverse momentum. No significant excess of events is observed with respect to the expectations from standard model processes. Limits are placed on the gluino and top squark pair production cross sections using several simplified models of supersymmetric particle production with gauge-mediated supersymmetry breaking. Depending on the model and the mass of the next-to-lightest supersymmetric particle, the production of gluinos with masses as large as 2120 GeV and the production of top squarks with masses as large as 1230 GeV are excluded at 95% confidence level.
Values of the predicted SM background events from various sources and observed events in each of the 25 signal regions.
Observed $95\%$ CL upper limit on the production cross section of gluinos in T5qqqqHG model.
Expected $95\%$ CL upper limit on the production cross section of gluinos in T5qqqqHG model.
A search for physics beyond the standard model in final states with at least one photon, large transverse momentum imbalance, and large total transverse event activity is presented. Such topologies can be produced in gauge-mediated supersymmetry models in which pair-produced gluinos or squarks decay to photons and gravitinos via short-lived neutralinos. The data sample corresponds to an integrated luminosity of 35.9 inverse femtobarns of proton-proton collisions at sqrt(s) = 13 TeV recorded by the CMS experiment at the LHC in 2016. No significant excess of events above the expected standard model background is observed. The data are interpreted in simplified models of gluino and squark pair production, in which gluinos or squarks decay via neutralinos to photons. Gluino masses of up to 1.50-2.00 TeV and squark masses up to 1.30-1.65 TeV are excluded at 95% confidence level, depending on the neutralino mass and branching fraction.
Observed data compared to the background prediction. The expectation for the T5Wg signal scenario with a gluino mass of 1600 GeV and a gaugino mass of 100 GeV and the T6gg signal scenario with a squark mass of 1750 GeV and a neutralino mass of 1650 GeV are shown. The last three bins of the low-H_T^gamma selection are displayed, corresponding to three of the search regions The rightmost bin includes all events with ptmiss > 600GeV.
Observed data compared to the background prediction. The expectation for the T5Wg signal scenario with a gluino mass of 1600 GeV and a gaugino mass of 100 GeV and the T6gg signal scenario with a squark mass of 1750 GeV and a neutralino mass of 1650 GeV are shown. The last three bins of the high-H_T^gamma selection are displayed, corresponding to three of the search regions The rightmost bin includes all events with ptmiss > 600GeV.
Exclusion limits on the SUSY cross section at 95% CL for the T6gg model.
A search for supersymmetry in events with two or three low-momentum leptons and missing transverse momentum is performed. The search uses proton-proton collisions at $\sqrt{s} =$ 13 TeV collected in the three-year period 2016-2018 by the CMS experiment at the LHC and corresponding to an integrated luminosity of up to 137 fb$^{-1}$. The data are found to be in agreement with expectations from standard model processes. The results are interpreted in terms of electroweakino and top squark pair production with a small mass difference between the produced supersymmetric particles and the lightest neutralino. For the electroweakino interpretation, two simplified models are used, a wino-bino model and a higgsino model. Exclusion limits at 95% confidence level are set on $\widetilde{\chi}^0_2 / \widetilde{\chi}^\pm_1$ masses up to 275 GeV for a mass difference of 10 GeV in the wino-bino case, and up to 205 (150) GeV for a mass difference of 7.5 (3) GeV in the higgsino case. The results for the higgsino are further interpreted using a phenomenological minimal supersymmetric standard model, excluding the higgsino mass parameter $\mu$ up to 180 GeV with the bino mass parameter $M_1$ at 800 GeV. In the top squark interpretation, exclusion limits are set at top squark masses up to 540 GeV for four-body top squark decays and up to 480 GeV for chargino-mediated decays with a mass difference of 30 GeV.
The post-fit distribution of the $M(\ell\ell)$ variable is shown for the low-MET bin for the DY CR. Uncertainties include both the statistical and systematic components.
The post-fit distribution of the $M(\ell\ell)$ variable is shown for the high-MET bin for the DY CR. Uncertainties include both the statistical and systematic components.
The post-fit distribution of the $M(\ell\ell)$ variable is shown for the low-MET bin for the $\text{t}\bar{\text{t}}$ CR. Uncertainties include both the statistical and systematic components.
A search for supersymmetry is presented based on multijet events with large missing transverse momentum produced in proton-proton collisions at a center-of-mass energy of sqrt(s) = 13 TeV. The data, corresponding to an integrated luminosity of 35.9 inverse femtobarns, were collected with the CMS detector at the CERN LHC in 2016. The analysis utilizes four-dimensional exclusive search regions defined in terms of the number of jets, the number of tagged bottom quark jets, the scalar sum of jet transverse momenta, and the magnitude of the vector sum of jet transverse momenta. No evidence for a significant excess of events is observed relative to the expectation from the standard model. Limits on the cross sections for the pair production of gluinos and squarks are derived in the context of simplified models. Assuming the lightest supersymmetric particle to be a weakly interacting neutralino, 95% confidence level lower limits on the gluino mass as large as 1800 to 1960 GeV are derived, and on the squark mass as large as 960 to 1390 GeV, depending on the production and decay scenario.
Observed number of events and pre-fit background predictions in the $N_{jet}=2$ search bins.
Observed number of events and pre-fit background predictions in the $3\leq N_{jet}\leq4$ search bins.
Observed number of events and pre-fit background predictions in the $5\leq N_{jet}\leq6$ search bins.
Results are reported from a search for supersymmetric particles in proton-proton collisions in the final state with a single, high transverse momentum lepton; multiple jets, including at least one b-tagged jet; and large missing transverse momentum. The data sample corresponds to an integrated luminosity of 2.3 inverse femtobarns at sqrt(s) = 13 TeV, recorded by the CMS experiment at the LHC. The search focuses on processes leading to high jet multiplicities, such as gluino pair production with gluinos to t t-bar neutralino[1]. The quantity M[J], defined as the sum of the masses of the large-radius jets in the event, is used in conjunction with other kinematic variables to provide discrimination between signal and background and as a key part of the background estimation method. The observed event yields in the signal regions in data are consistent with those expected for standard model backgrounds, estimated from control regions in data. Exclusion limits are obtained for a simplified model corresponding to gluino pair production with three-body decays into top quarks and neutralinos. Gluinos with a mass below 1600 GeV are excluded at a 95% confidence level for scenarios with low neutralino[1] mass, and neutralinos with a mass below 800 GeV are excluded for a gluino mass of about 1300 GeV. For models with two-body gluino decays producing on-shell top squarks, the excluded region is only weakly sensitive to the top squark mass.
Event yields obtained from simulated event samples, as the event selection criteria are applied. The category Other includes Drell-Yan, $t\bar{t}H(\rightarrow b\bar{b})$, $t\bar{t}t\bar{t}$, $WZ$, and $WW$. The yields for $t\bar{t}$ events in fully hadronic final states are included in the QCD multijet category. The category $t\bar{t}{\rm V}$ includes $t\bar{t}W$, $t\bar{t}Z$, and $t\bar{t}\gamma$. The benchmark signal models, T1tttt(NC) and T1tttt(C), are described in Section 3. The event selection requirements listed above the horizontal line in the middle of the table are defined as the baseline selection. The background estimates before the $H_{T}$ requirement are not specified because some of the simulated event samples do not extend to the low $H_{T}$ region. Given the size of the MC samples described in Section 3, rows with zero yield have statistical uncertainties of at most 0.16 events, and below 0.05 events in most cases.
Observed and predicted event yields for the signal regions (R4) and background regions (R1--R3) in data (2.3 $\textrm{fb}^{-1}$) in 200<MET<400 GeV region. Expected yields for the two SUSY T1tttt benchmark scenarios are also given. The results from two types of fits are reported: the predictive fit (PF) and the version of the global fit (GF) performed under the assumption of the null hypothesis ($r=0$). The predictive fit uses the observed yields in regions R1, R2, and R3 only and is effectively just a propagation of uncertainties. The global fit uses all four regions. The values of $\kappa$ obtained from the simulation fit are also listed. The first uncertainty in $\kappa$ is statistical, while the second corresponds to the total systematic uncertainty.
Observed and predicted event yields for the signal regions (R4) and background regions (R1--R3) in data (2.3 $\textrm{fb}^{-1}$) in MET>400 GeV region. Expected yields for the two SUSY T1tttt benchmark scenarios are also given. The results from two types of fits are reported: the predictive fit (PF) and the version of the global fit (GF) performed under the assumption of the null hypothesis ($r=0$). The predictive fit uses the observed yields in regions R1, R2, and R3 only and is effectively just a propagation of uncertainties. The global fit uses all four regions. The values of $\kappa$ obtained from the simulation fit are also listed. The first uncertainty in $\kappa$ is statistical, while the second corresponds to the total systematic uncertainty.
A search for new physics in events with two highly Lorentz-boosted Z bosons and large missing transverse momentum is presented. The analyzed proton-proton collision data, corresponding to an integrated luminosity of 137 fb$^{-1}$, were recorded at $\sqrt{s} =$ 13 TeV by the CMS experiment at the CERN LHC. The search utilizes the substructure of jets with large radius to identify quark pairs from Z boson decays. Backgrounds from standard model processes are suppressed by requirements on the jet mass and the missing transverse momentum. No significant excess in the event yield is observed beyond the number of background events expected from the standard model. For a simplified supersymmetric model in which the Z bosons arise from the decay of gluinos, an exclusion limit of 1920 GeV on the gluino mass is set at 95% confidence level. This is the first search for beyond-standard-model production of pairs of boosted Z bosons plus large missing transverse momentum.
Cross section upper limit vs m(GLUINO) for SMS model T5ZZ.
Cross section upper limit vs m(GLUINO) for SMS model T5ZZ.
Cross section upper limit vs m(GLUINO) for SMS model T5ZZ.
Results are reported from a search for supersymmetric particles in the final state with multiple jets and large missing transverse momentum. The search uses a sample of proton-proton collisions at $\sqrt{s} =$ 13 TeV collected with the CMS detector in 2016-2018, corresponding to an integrated luminosity of 137 fb$^{-1}$, representing essentially the full LHC Run 2 data sample. The analysis is performed in a four-dimensional search region defined in terms of the number of jets, the number of tagged bottom quark jets, the scalar sum of jet transverse momenta, and the magnitude of the vector sum of jet transverse momenta. No significant excess in the event yield is observed relative to the expected background contributions from standard model processes. Limits on the pair production of gluinos and squarks are obtained in the framework of simplified models for supersymmetric particle production and decay processes. Assuming the lightest supersymmetric particle to be a neutralino, lower limits on the gluino mass as large as 2000 to 2310 GeV are obtained at 95% confidence level, while lower limits on the squark mass as large as 1190 to 1630 GeV are obtained, depending on the production scenario.
Observed yields and pre-fit background predictions for Njets 2-3.
Observed yields and pre-fit background predictions for Njets 4-5.
Observed yields and pre-fit background predictions for Njets 6-7.
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