Four-lepton production in proton-proton collisions, pp to (Z/gamma*)(Z/gamma*) to l+l-l'+l'-, where l, l' = e or mu, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 2.6 inverse femtobarns. The ZZ production cross section, sigma(pp to ZZ) = 14.6 +1.9/-1.8 (stat) +0.5/-0.3 (syst) +/- 0.2 (theo) +/- 0.4 (lumi) pb, is measured for events with two opposite-sign, same-flavor lepton pairs produced in the mass region 60 < m[l+l-], m[l'+l'-] < 120 GeV. The Z boson branching fraction to four leptons is measured to be B(Z to l+l-l'+l'-) = 4.9 +0.8/-0.7 (stat) +0.3/-0.2 (syst) +0.2/-0.1 (theo) +/- 0.1 (lumi) x E-6 for the four-lepton invariant mass in the range 80 < m[l+l-l'+l'-] < 100 GeV and dilepton mass m[l+l-] > 4 GeV for all opposite-sign, same-flavor lepton pairs. The results are in agreement with standard model predictions.
The (P P to Z Z to l+l-l'+l'-) fiducial cross section. The first systematic uncertainty is detector systematics, the second is luminosity uncertainty. The theoretical prediction is POWHEG generated at NLO plus the gluon-gluon initial state contribution from MCFM, using NNPDF3.0 PDFs and scales mu_F = mu_R = 0.5m[l+l-l'+l'-].
The (P P to Z to l+l-l'+l'-) fiducial cross section. The first systematic uncertainty is detector systematics, the second is luminosity uncertainty. The theoretical prediction is POWHEG generated at NLO using NNPDF3.0 PDFs and scales mu_F = mu_R = m[l+l-l'+l'-].
The total (P P to Z) cross section times the (Z to l+l-l'+l'-) branching ratio. The first systematic uncertainty is detector systematics, the second is theoretical uncertainty, and the third is luminosity uncertainty.
The cross section of top quark-antiquark pair production in proton-proton collisions at sqrt(s) = 13 TeV is measured by the CMS experiment at the LHC, using data corresponding to an integrated luminosity of 2.2 inverse femtobarns. The measurement is performed by analyzing events in which the final state includes one electron, one muon, and two or more jets, at least one of which is identified as originating from hadronization of a b quark. The measured cross section is 815 +/- 9 (stat) +/- 38 (syst) +/- 19 (lumi) pb, in agreement with the expectation from the standard model.
Summary of the individual contributions to the uncertainty in the $\sigma_{t\bar{t}}$ measurement.
Measurement of the $t\bar{t}$ production cross-section in $pp$ collisions at $\sqrt{s} = 13$ TeV.
Number of dilepton events obtained after applying the full selection. The results are given for the individual sources of background, $t\bar{t}$ signal with a top quark mass of 172.5 GeV and $\sigma_{t\bar{t}}$ = 832 +/- 46 pb, and data. The uncertainties correspond to statistical and systematic components.
The differential cross section for inclusive particle production as a function of energy in proton-proton collisions at a center-of-mass energy of 13 TeV is measured in the very forward region of the CMS detector. The measurement is based on data collected with the CMS apparatus at the LHC, and corresponds to an integrated luminosity of 0.35 inverse microbarns. The energy is measured in the CASTOR calorimeter, which covers the pseudorapidity region -6.6 < eta < -5.2. The results are given as a function of the total energy deposited in CASTOR, as well as of its electromagnetic and hadronic components. The spectra are sensitive to the modeling of multiparton interactions in pp collisions, and provide new constraints for hadronic interaction models used in collider and in high energy cosmic ray physics.
Differential cross section as a function of the electromagnetic energy in the region −6.6 < eta < −5.2 for events with xi>10−6.
Differential cross section as a function of the total energy in the region −6.6 < eta < −5.2 for events with xi>10−6.
Differential cross section as a function of the hadronic energy in the region −6.6 < eta < −5.2 for events with xi>10−6.
The WZ production cross section in proton-proton collisions at sqrt(s) = 13 TeV is measured with the CMS experiment at the LHC using a data sample corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in the leptonic decay modes WZ to l nu l' l', where l, l'= e, mu. The measured cross section for the range 60 < m[l'l'] < 120 GeV is sigma(pp to WZ) = 39.9 +/- 3.2 (stat) +2.9/-3.1 (syst) +/- 0.4 (theo) +/- 1.3 (lumi) pb, consistent with the standard model prediction.
The fiducial pp to WZ to lnul'l' cross section. The first systematic uncertainty is detector systematics and the second is luminosity uncertainty. The theoretical prediction is calculated with MCFM at NLO with NNPDF3.0 PDFs, with dynamic renormalization and factorization scales set to muR = muF = m[WZ]. The uncertainty is obtained by varying the factorization and renormalization scales independently up and down by a factor of two with the condition that 0.5 < muR/muF < 2.
The total pp to WZ cross section. The first systematic uncertainty is detector systematics and the second is luminosity uncertainty. The first theoretical prediction is calculated with MCFM at NLO with NNPDF3.0 PDFs, with dynamic renormalization and factorization scales set to muR = muF = m[WZ]. The second theoretical prediction is calculated with MATRIX at NNLO with fixed QCD scales set to muR = muF = 1/2 (m[Z] + m[W]) and with NNPDF3.0 PDFs. The uncertainty is obtained by varying the factorization and renormalization scales independently up and down by a factor of two with the condition that 0.5 < muR/muF < 2.
The top quark pair production cross section is measured for the first time in proton-proton collisions at sqrt(s) = 13 TeV by the CMS experiment at the CERN LHC, using data corresponding to an integrated luminosity of 43 inverse picobarns. The measurement is performed by analyzing events with at least one electron and one muon of opposite charge, and at least two jets. The measured cross section is 746 +/- 58 (stat) +/- 53 (syst) +/- 36 (lumi) pb, in agreement with the expectation from the standard model.
The first measurement of the $t\bar{t}$ production cross-section in $pp$ collisions at $\sqrt{s} = 13$ TeV.
A measurement of the double-differential inclusive jet cross section as a function of jet transverse momentum pT and absolute jet rapidity |y| is presented. The analysis is based on proton-proton collisions collected by the CMS experiment at the LHC at a centre-of-mass energy of 13 TeV. The data samples correspond to integrated luminosities of 71 and 44 inverse picobarns for |y| < 3 and 3.2 < |y| < 4.7, respectively. Jets are reconstructed with the anti-kt clustering algorithm for two jet sizes, R, of 0.7 and 0.4, in a phase space region covering jet pT up to 2 TeV and jet rapidity up to |y| = 4.7. Predictions of perturbative quantum chromodynamics at next-to-leading order precision, complemented with electroweak and nonperturbative corrections, are used to compute the absolute scale and the shape of the inclusive jet cross section. The cross section difference in R, when going to a smaller jet size of 0.4, is best described by Monte Carlo event generators with next-to-leading order predictions matched to parton showering, hadronisation, and multiparton interactions. In the phase space accessible with the new data, this measurement provides a first indication that jet physics is as well understood at sqrt(s) = 13 TeV as at smaller centre-of-mass energies.
Inclusive Jet Cross Section for |rapidity| < 0.5 as a function of the jet transverse momentum. Jets are clustered with the anti-kt algorithm ( R = 0.7). The (sys) error is the total systematic error, including the luminosity uncertainty of 2.7%.
Inclusive Jet Cross Section for |rapidity| 0.5 TO 1.0 as a function of the jet transverse momentum. Jets are clustered with the anti-kt algorithm ( R = 0.7). The (sys) error is the total systematic error, including the luminosity uncertainty of 2.7%.
Inclusive Jet Cross Section for |rapidity| 1.0 TO 1.5 as a function of the jet transverse momentum. Jets are clustered with the anti-kt algorithm ( R = 0.7). The (sys) error is the total systematic error, including the luminosity uncertainty of 2.7%.
Differential and double-differential cross sections for the production of top quark pairs in proton-proton collisions at 13 TeV are measured as a function of jet multiplicity and of kinematic variables of the top quarks and the top quark-antiquark system. This analysis is based on data collected by the CMS experiment at the LHC corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurements are performed in the lepton+jets decay channels with a single muon or electron in the final state. The differential cross sections are presented at particle level, within a phase space close to the experimental acceptance, and at parton level in the full phase space. The results are compared to several standard model predictions.
Absolute cross section at particle level.
Covariance matrix of absolute cross section at particle level.
Absolute cross section at particle level.
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 phenomena is performed in final states containing one or more jets and an imbalance in transverse momentum in pp collisions at a centre-of-mass energy of 13 TeV. The analysed data sample, recorded with the CMS detector at the CERN LHC, corresponds to an integrated luminosity of 2.3 inverse femtobarns. Several kinematic variables are employed to suppress the dominant background, multijet production, as well as to discriminate between other standard model and new physics processes. The search provides sensitivity to a broad range of new-physics models that yield a stable weakly interacting massive particle. The number of observed candidate events is found to agree with the expected contributions from standard model processes, and the result is interpreted in the mass parameter space of fourteen simplified supersymmetric models that assume the pair production of gluinos or squarks and a range of decay modes. For models that assume gluino pair production, masses up to 1575 and 975 GeV are excluded for gluinos and neutralinos, respectively. For models involving the pair production of top squarks and compressed mass spectra, top squark masses up to 400 GeV are excluded.
Summary of the lower bounds of the first and final bins in $H_{\mathrm{T}}$ in [GeV] (the latter in parentheses) as a function of $n_{\text{jet}}$ and $n_{\text{b}}$.
Systematic uncertainties (in percent) in the transfer ($\mathcal{T}$) factors used in the method to estimate the SM backgrounds with genuine $\vec{p}_t^{miss}$ in the signal region. The quoted ranges provide representative values of the observed variations as a function of $n_{\mathrm{jet}}$ and $H_{\mathrm{T}}$.
A summary of the simplified SUSY models used to interpret the results of this search. All on-shell SUSY particles in the decay are stated.
A search for physics beyond the standard model in the final state with two same-flavour leptons (electrons or muons) and two quarks produced in proton-proton collisions at sqrt(s) = 13 TeV is presented. The data were recorded by the CMS experiment at the CERN LHC and correspond to an integrated luminosity of 2.3 inverse femtobarns. The observed data are in good agreement with the standard model background prediction. The results of the measurement are interpreted in the framework of a recently proposed model in which a heavy Majorana neutrino, N(l), stems from a composite-fermion scenario. Exclusion limits are set for the first time on the mass of the heavy composite Majorana neutrino, m[N(l)], and the compositeness scale Lambda. For the case m[N(l)] = Lambda, the existence of N(e) (N(mu)) is excluded for masses up to 4.60 (4.70) TeV at 95% confidence level.
Invariant mass distribution of two electrons and one large-radius jet. The events are selected accordingly to the signal region slection in the electron channel described in the paper.
Invariant mass distribution of two muons and one large-radius jet. The events are selected accordingly to the signal region slection in the muon channel described in the paper.
95% CL upper limits on the product of the production cross section $\sigma(pp\to N_e)$ and the branching ratio $B(N_e \to e q \bar{q}^{\prime})$ in electron channel, compared with theoretical predictions for HCMN model calculated with CalcHEP.
A search is performed for anomalous interactions of the recently discovered Higgs boson using matrix element techniques with the information from its decay to four leptons and from associated Higgs boson production with two quark jets in either vector boson fusion or associated production with a vector boson. The data were recorded by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 38.6 inverse femtobarns. These data are combined with the data collected at center-of-mass energies of 7 and 8 TeV, corresponding to integrated luminosities of 5.1 and 19.7 inverse femtobarns, respectively. All observations are consistent with the expectations for the standard model Higgs boson.
Observed and expected likelihood scans $f_{a3}\cos\phi_{a3}$. See Section 2 of the paper for more details.
Observed and expected likelihood scans $f_{a2}\cos\phi_{a2}$. See Section 2 of the paper for more details.
Observed and expected likelihood scans $f_{\Lambda1}\cos\phi_{\Lambda1}$. See Section 2 of the paper for more details.
A search for charged Higgs bosons produced via vector boson fusion and decaying into W and Z bosons using proton-proton collisions at sqrt(s) = 13 TeV is presented. The data sample corresponds to an integrated luminosity of 15.2 inverse femtobarns collected with the CMS detector in 2015 and 2016. The event selection requires three leptons (electrons or muons), two jets with large pseudorapidity separation and high dijet mass, and missing transverse momentum. The observation agrees with the standard model prediction. Limits on the vector boson fusion production cross section times branching fraction for new charged physical states are reported as a function of mass from 200 to 2000 GeV and interpreted in the context of Higgs triplet models.
Expected and observed exclusion limits at 95% confidence level as a function of $m(H^{\pm})$ for $\sigma_\mathrm{VBF}(H^{\pm}) \, \mathcal{B}(H^{\pm}\to W^{\pm}Z)$ for 15.2 $\mathrm{fb}^{-1}$ of proton-proton collisions at 13 TeV collected in 2015 and 2016.
A measurement is presented of the associated production of a single top quark and a Z boson. The study uses data from proton-proton collisions at $\sqrt{s} =$ 13 TeV recorded by the CMS experiment, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. Using final states with three leptons (electrons or muons), the tZq production cross section is measured to be $\sigma$(pp$\to$tZq$\to$Wb$\ell^+\ell^-$q) = $123 ^{+33}_{-31}$ (stat) $^{+29}_{-23}$ (syst) fb, where $\ell$ stands for electrons, muons, or $\tau$ leptons, with observed and expected significances of 3.7 and 3.1 standard deviations, respectively.
The measured cross section, with statistical and systematic uncertainties. The observed significance. The expected significance
Searches for invisible decays of the Higgs boson are presented. The data collected with the CMS detector at the LHC correspond to integrated luminosities of 5.1, 19.7, and 2.3 inverse femtobarns at centre-of-mass energies of 7, 8, and 13 TeV, respectively. The search channels target Higgs boson production via gluon fusion, vector boson fusion, and in association with a vector boson. Upper limits are placed on the branching fraction of the Higgs boson decay to invisible particles, as a function of the assumed production cross sections. The combination of all channels, assuming standard model production, yields an observed (expected) upper limit on the invisible branching fraction of 0.24 (0.23) at the 95% confidence level. The results are also interpreted in the context of Higgs-portal dark matter models.
Observed and expected 95% CL limits on $\sigma\mathcal{B}(H\rightarrow inv)/\sigma(SM)$ for individual combinations of categories targeting qqH, VH, and ggH production, and the full combination assuming a Higgs boson with a mass of 125 GeV.
Profile likelihood ratio as a function of $\mathcal{B}(H\rightarrow inv)$ assuming SM production cross sections of a Higgs boson with a mass of 125 GeV. The solid curves represent the observations in data and the dashed curves represent the expected result assuming no invisible decays of the Higgs boson. The observed and expected likelihood scans for the partial combinations of the qqH tagged, VH tagged, and ggH tagged analyses, and the full combination.
Profile likelihood ratio as a function of $\mathcal{B}(H\rightarrow inv)$ assuming SM production cross sections of a Higgs boson with a mass of 125 GeV. The solid curves represent the observations in data and the dashed curves represent the expected result assuming no invisible decays of the Higgs boson. The observed and expected likelihood scans for the partial combinations of the 7+8 and 13 TeV analyses, and the full combination.
Searches for resonant and nonresonant pair-produced Higgs bosons (HH) decaying respectively into ll nu nu, through either W or Z bosons, and bbbar are presented. The analyses are based on a sample of proton-proton collisions at sqrt(s) = 13 TeV, collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9 inverse femtobarns. Data and predictions from the standard model are in agreement within uncertainties. For the standard model HH hypothesis, the data exclude at 95% confidence level a product of the production cross section and branching fraction larger than 72 fb, corresponding to 79 times the prediction, consistent with expectations. Constraints are placed on different scenarios considering anomalous couplings, which could affect the rate and kinematics of HH production. Upper limits at 95% confidence level are set on the production cross section of narrow-width spin-0 and spin-2 particles decaying to Higgs boson pairs, the latter produced with minimal gravity-like coupling.
The dijet pT distributions in data and simulated events after requiring two leptons, two b-tagged jets, and 12 < m_ll < mZ − 15 GeV, for e+e- events. The various signal hypotheses displayed have been scaled to a cross section of 5 pb for display purposes.
The dijet pT distributions in data and simulated events after requiring two leptons, two b-tagged jets, and 12 < m_ll < mZ − 15 GeV, for e+mu- and e-mu+ events. The various signal hypotheses displayed have been scaled to a cross section of 5 pb for display purposes.
The dijet pT distributions in data and simulated events after requiring two leptons, two b-tagged jets, and 12 < m_ll < mZ − 15 GeV, for mu+mu- events. The various signal hypotheses displayed have been scaled to a cross section of 5 pb for display purposes.
A search for new physics is presented in final states with two oppositely charged leptons (electrons or muons), jets identified as originating from b quarks, and missing transverse momentum ($p_\mathrm{T}^\text{miss}$). The search uses proton-proton collision data at $\sqrt{s}=$ 13 TeV amounting to 35.9 fb$^{-1}$ of integrated luminosity collected using the CMS detector in 2016. Hypothetical signal events are efficiently separated from the dominant $\mathrm{t}\overline{\mathrm{t}}$ background with requirements on $p_\mathrm{T}^\text{miss}$ and transverse mass variables. No significant deviation is observed from the expected background. Exclusion limits are set in the context of simplified supersymmetric models with pair-produced top squarks. For top squarks, decaying exclusively to a top quark and a neutralino, exclusion limits are placed at 95% confidence level on the mass of the lightest top squark up to 800 GeV and on the lightest neutralino up to 360 GeV. These results, combined with searches in the single-lepton and all-jet final states, raise the exclusion limits up to 1050 GeV for the lightest top squark and up to 500 GeV for the lightest neutralino. For top squarks undergoing a cascade decay through charginos and sleptons, the mass limits reach up to 1300 GeV for top squarks and up to 800 GeV for the lightest neutralino. The results are also interpreted in a simplified model with a dark matter (DM) particle coupled to the top quark through a scalar or pseudoscalar mediator. For light DM, mediator masses up to 100 (50) GeV are excluded for scalar (pseudoscalar) mediators. The result for the scalar mediator achieves some of the most stringent limits to date in this model.
Figure 2 (left). Distribution of $M_{T2}(ll)$ in simulation after preselection and requiring $M_{T2}(ll) > 100$ GeV.
Figure 2 (center). Distribution of $M_{T2}(blbl)$ in simulation after preselection and requiring $M_{T2}(ll) > 100$ GeV.
Figure 2 (right). Distribution of $p_{T}^{miss}$ in simulation after preselection and requiring $M_{T2}(ll) > 100$ GeV.
This paper presents a measurement of the underlying event activity in proton-proton collisions at a center-of-mass energy of 13 TeV, performed using inclusive Z boson production events collected with the CMS experiment at the LHC. The analyzed data correspond to an integrated luminosity of 2.1 fb$^{-1}$. The underlying event activity is quantified in terms of the charged particle multiplicity, as well as of the scalar sum of the charged particles' transverse momenta in different topological regions defined with respect to the Z boson direction. The distributions are unfolded to the stable particle level and compared with predictions from various Monte Carlo event generators, as well as with similar CDF and CMS measurements at center-of-mass energies of 1.96 and 7 TeV respectively.
Unfolded distributions of particle density in Z events, as a function of $p_{T}^{\mu\mu}$ in the towards ($\Delta\phi< 60^{\circ}$) region. Error bars represent the statistical and systematic uncertainties added in quadrature.
Unfolded distributions of particle density in Z events, as a function of $p_{T}^{\mu\mu}$ in the transverse ($60^{\circ} <\Delta\phi< 120^{\circ}$) region. Error bars represent the statistical and systematic uncertainties added in quadrature.
Unfolded distributions of particle density in Z events, as a function of $p_{T}^{\mu\mu}$ in the away ($\Delta\phi> 120^{\circ}$) region. Error bars represent the statistical and systematic uncertainties added in quadrature.
Results are reported from a search for physics beyond the standard model in proton-proton collisions at a center-of-mass energy of $\sqrt{s} = $ 13 TeV. The search uses a signature of a single lepton, large jet and bottom quark jet multiplicities, and high sum of large-radius jet masses, without any requirement on the missing transverse momentum in an event. The data sample corresponds to an integrated luminosity of 35.9 fb$^{-1}$ recorded by the CMS experiment at the LHC. No significant excess beyond the prediction from standard model processes is observed. The results are interpreted in terms of upper limits on the production cross section for $R$-parity violating supersymmetric extensions of the standard model using a benchmark model of gluino pair production, in which each gluino decays promptly via $ {\mathrm{\widetilde{g}}} \rightarrow \mathrm{t} \mathrm{b} \mathrm{s} $. Gluinos with a mass below 1610 GeV are excluded at 95% confidence level.
Figure 8. Observed cross section upper limits at 95% CL for a model of gluino pair production with gluino->tbs compared to the gluino pair production cross section.
Figure 8. Expected limits at 95% CL and their ±1 sigma variations for a model of gluino pair production with gluino->tbs compared to the gluino pair production cross section.
Figure 8. Expected limits at 95% CL and their ±2 sigma variations for a model of gluino pair production with gluino->tbs compared to the gluino pair production cross section.
The first observation of electroweak production of same-sign W boson pairs in proton-proton collisions is reported. The data sample corresponds to an integrated luminosity of 35.9 fb$^{-1}$ collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. Events are selected by requiring exactly two leptons (electrons or muons) of the same charge, moderate missing transverse momentum, and two jets with a large rapidity separation and a large dijet mass. The observed significance of the signal is 5.5 standard deviations, where a significance of 5.7 standard deviations is expected based on the standard model. The ratio of measured event yields to that expected from the standard model at leading-order is 0.90 $\pm$ 0.22. A cross section measurement in a fiducial region is reported. Bounds are given on the structure of quartic vector boson interactions in the framework of dimension-eight effective field theory operators and on the production of doubly charged Higgs bosons.
The measured W+W+ EWK fiducual cross section.
Data and estimated signal and background yields after the selection in the two dimensional dijet-dilepton mass distributions. This is used for the standard model measurements.
Data and estimated signal and background yields after the selection in the one dimensional dilepton mass distribution. This is used for the evaluation of the anomalous coupling limits.
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.
Properties of the Higgs boson are measured in the H to ZZ to 4l (l= e, mu) decay channel. A data sample of proton-proton collisions at sqrt(s) = 13 TeV, collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 35.9 inverse femtobarns is used. The signal strength modifier mu, defined as the ratio of the observed Higgs boson rate in the H to ZZ to 4l decay channel to the standard model expectation, is measured to be mu = 1.05 +0.19/-0.17 at m[H ]= 125.09 GeV, the combined ATLAS and CMS measurement of the Higgs boson mass. The signal strength modifiers for the individual Higgs boson production modes are also measured. The cross section in the fiducial phase space defined by the requirements on lepton kinematics and event topology is measured to be 2.92 +0.48/-0.44 (stat) +0.28/-0.24 (syst) fb, which is compatible with the standard model prediction of 2.76 +/- 0.14 fb. Differential cross sections are reported as a function of the transverse momentum of the Higgs boson, the number of associated jets, and the transverse momentum of the leading associated jet. The Higgs boson mass is measured to be m[H] = 125.26 +/- 0.21 GeV and the width is constrained using on-shell production to be Gamma[H] < 1.10 GeV, at 95% confidence level.
Integrated Fiducial Higgs cross section. The first uncertainty is the combined statistical uncertainty, the second is the combined systematic uncertainty. As described in the publication, the fiducial volume for 7 and 8 TeV is different than for 13 TeV.
Higgs fiducial cross section in bins of pT for the 4 leptons. The first uncertainty is statistical, the second is systematic uncertainties. The numbers in this HEP data entry are not divided by the bin width, and therefore the units are in fb.
Higgs fiducial cross section in bins of Jet Multiplicity The first uncertainty is statistical, the second is systematic uncertainty.
A measurement of the differential cross sections for a W boson produced in association with jets in the muon decay channel is presented. The measurement is based on 13 TeV proton-proton collision data corresponding to an integrated luminosity of 2.2 inverse femtobarns, recorded by the CMS detector at the LHC. The cross sections are reported as functions of jet multiplicity, jet transverse momentum pT, jet rapidity, the scalar pT sum of the jets, and angular correlations between the muon and the jet for different jet multiplicities. The measured cross sections are in agreement with predictions that include multileg leading-order (LO) and next-to-LO matrix element calculations interfaced with parton showers, as well as a next-to-next-to-LO calculation for the W boson and one jet production.
The cross section measurement as a function of the exclusive jet multiplicity, for jet multiplicities of up to 6.
The cross section measurement as a function of the inclusive jet multiplicity, for jet multiplicities of up to 6.
The differential cross section measurement as a function of the transverse momentum of the first leading jet.
Four-lepton production in proton-proton collisions, $\mathrm{pp}\to (\mathrm{Z}/ \gamma^*)(\mathrm{Z}/\gamma^*) \to 4\ell$, where $\ell = \mathrm{e}$ or $\mu$, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 35.9 fb$^{-1}$. The ZZ production cross section, $\sigma(\mathrm{pp} \to \mathrm{Z}\mathrm{Z}) = 17.2 \pm 0.5\text{ (stat) }\pm 0.7\text{ (syst) }\pm 0.4(\mathrm{theo}) \pm 0.4\text{ (lumi)}$ pb, measured using events with two opposite-sign, same-flavor lepton pairs produced in the mass region $60 < m_{\ell^+\ell^-} < $120 GeV, is consistent with standard model predictions. Differential cross sections are measured and are well described by the theoretical predictions. The Z boson branching fraction to four leptons is measured to be $\mathcal{B}(\mathrm{Z}\to 4\ell) = 4.8 \pm 0.2\text{ (stat) }\pm 0.2\text{ (syst) } \pm 0.1\text{ (theo) }\pm 0.1\text{ (lumi) }\times 10^{-6}$ for events with a four-lepton invariant mass in the range 80 $ < m_{4\ell} < $ 100 GeV and a dilepton mass $m_{\ell\ell} > $4 GeV for all opposite-sign, same-flavor lepton pairs. The results agree with standard model predictions. The invariant mass distribution of the four-lepton system is used to set limits on anomalous ZZZ and ZZ$\gamma$ couplings at 95% confidence level: $-0.0012 < f_4^\mathrm{Z} < 0.0010$, $-0.0010 < f_5^\mathrm{Z} < 0.0013$, $-0.0012 < f_4^{\gamma} < 0.0013$, $-0.0012 < f_5^{\gamma} < 0.0013$.
The measured total ZZ cross section using 2016 data. The first systematic uncertainty is the combined systematic uncertainty excluding luminosity and theortical sources, the second is theoretical uncertianty on the extrapolation from the selected region to the total phase space, the third is the luminosity uncertianty
The measured total ZZ cross section using 2015 and 2016. The first systematic uncertainty is the combined systematic uncertainty excluding luminosity and theortical sources, the second is theoretical uncertianty on the extrapolation from the selected region to the total phase space, the third is the luminosity uncertianty
The measured fiducial ZZ cross sections. The first systematic uncertainty is the combined systematic uncertainty excluding luminosity, the second is the luminosity uncertianty
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 top squark pair production in pp collisions at sqrt(s) = 13 TeV is performed using events with a single isolated electron or muon, jets, and a large transverse momentum imbalance. The results are based on data collected in 2016 with the CMS detector at the LHC, corresponding to an integrated luminosity of 35.9 inverse femtobarns. No significant excess of events is observed above the expectation from standard model processes. Exclusion limits are set in the context of supersymmetric models of pair production of top squarks that decay either to a top quark and a neutralino or to a bottom quark and a chargino. Depending on the details of the model, we exclude top squarks with masses as high as 1120 GeV. Detailed information is also provided to facilitate theoretical interpretations in other scenarios of physics beyond the standard model.
Result of the background estimates and data yields corresponding to 35.9 $\text{fb}^\text{$-$1}$ for the 27 signal regions.
Result of the background estimates and data yields corresponding to 35.9 $\text{fb}^\text{$-$1}$ for the 4 signal regions dedicated to compressed spectra.
The observed exclusion limits at 95% CL assuming 100% branching fraction for direct top squark pair production with decay $\widetilde{t}\widetilde{t} \rightarrow t \widetilde{\chi_1^0} t \widetilde{\chi_1^0}$.
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