A search for a heavy resonance decaying to a top quark and a W boson in the fully hadronic final state is presented. The analysis is performed using data from proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 137 fb$^{-1}$ recorded by the CMS experiment at the LHC. The search is focused on heavy resonances, where the decay products of each top quark or W boson are expected to be reconstructed as a single, large-radius jet with a distinct substructure. The production of an excited bottom quark, b*, is used as a benchmark when setting limits on the cross section for a heavy resonance decaying to a top quark and a W boson. The hypotheses of b* quarks with left-handed, right-handed, and vector-like chiralities are excluded at 95% confidence level for masses below 2.6, 2.8, and 3.1 TeV, respectively. These are the most stringent limits on the b* quark mass to date, extending the previous best limits by almost a factor of two.
Upper limits on the product of the cross section and branching fraction at 95% CL for a left-handed b* quark as a function of b* quark mass.
Upper limits on the product of the cross section and branching fraction at 95% CL for a right-handed b* quark as a function of b* quark mass.
Upper limits on the product of the cross section and branching fraction at 95% CL for a vector-like b* quark as a function of b* quark mass.
A search is performed for W' bosons decaying to a top and a bottom quark in the all-hadronic final state, in proton-proton collisions at a center-of-mass energy of 13 TeV. The analyzed data were collected by the CMS experiment between 2016 and 2018 and correspond to an integrated luminosity of 137 fb$^{-1}$. Deep neural network algorithms are used to identify the jet initiated by the bottom quark and the jet containing the decay products of the top quark when the W boson from the top quark decays hadronically. No excess above the estimated standard model background is observed. Upper limits on the production cross sections of W' bosons decaying to a top and a bottom quark are set. Both left- and right-handed W' bosons with masses below 3.4 TeV are excluded at 95% confidence level, and the most stringent limits to date on W' bosons decaying to a top and a bottom quark in the all-hadronic final state are obtained.
The reconstructed m$_{tb}$ distributions in data and expected background in signal region for the data taking period of 2016. Yield in each bin is divided by the corresponding bin width.
The reconstructed m$_{tb}$ distributions in data and expected background in validation region for the data taking period of 2016. Yield in each bin is divided by the corresponding bin width.
The reconstructed m$_{tb}$ distributions in data and expected background in signal region for the data taking period of 2017. Yield in each bin is divided by the corresponding bin width.
Production cross sections of the Higgs boson are measured in the H $\to$ ZZ $\to$ $4\ell$ ($\ell$ $=$ e, $\mu$) decay channel. A data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS detector at the LHC and corresponding to an integrated luminosity of 137 fb$^{-1}$ is used. The signal strength modifier $\mu$, defined as the ratio of the Higgs boson production rate in the $4\ell$ channel to the standard model (SM) expectation, is measured to be $\mu$ $=$ 0.94 $\pm$ 0.07 (stat) ${}^{+0.09}_{-0.08}$ (syst) at a fixed value of $m_H$ = 125.38 GeV. The signal strength modifiers for the individual Higgs boson production modes are also reported. The inclusive fiducial cross section for the H $\to$ $4\ell$ process is measured to be 2.84 $^{+0.23}_{-0.22}$ (stat) ${}^{+0.26}_{-0.21}$ (syst) fb, which is compatible with the SM prediction of 2.84 $\pm$ 0.15 fb for the same fiducial region. Differential cross sections as a function of the transverse momentum and rapidity of the Higgs boson, the number of associated jets, and the transverse momentum of the leading associated jet are measured. A new set of cross section measurements in mutually exclusive categories targeted to identify production mechanisms and kinematical features of the events is presented. The results are in agreement with the SM predictions.
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.
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.
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.
Differential cross sections for the Drell-Yan process, including Z boson production, using the dimuon decay channel are measured in proton-lead (pPb) collisions at a nucleon-nucleon centre-of-mass energy of 8.16 TeV. A data sample recorded with the CMS detector at the LHC is used, corresponding to an integrated luminosity of 173 nb$^{-1}$. The differential cross section as a function of the dimuon mass is measured in the range 15-600 GeV, for the first time in proton-nucleus collisions. It is also reported as a function of dimuon rapidity over the mass ranges 15-60 GeV and 60-120 GeV, and ratios for the p-going over the Pb-going beam directions are built. In both mass ranges, the differential cross sections as functions of the dimuon transverse momentum $p_\mathrm{T}$ and of a geometric variable $\phi^*$ are measured, where $\phi^*$ highly correlates with $p_\mathrm{T}$ but is determined with higher precision. In the Z mass region, the rapidity dependence of the data indicate a modification of the distribution of partons within a lead nucleus as compared to the proton case. The data are more precise than predictions based upon current models of parton distributions.
Differential fiducial cross section (without the acceptance correction) for the DY process measured in the muon channel, as a function of dimuon invariant mass. The quoted error is the quadratic sum of the statistical and systematic uncertainties. The global normalisation uncertainty of 3.5% is listed separately.
Differential fiducial cross section (without the acceptance correction) for the DY process measured in the muon channel, as a function of rapidity in the centre-of-mass frame for $15<m_{\mu\mu}<60$ GeV. The quoted error is the quadratic sum of the statistical and systematic uncertainties. The global normalisation uncertainty of 3.5% is listed separately.
Differential fiducial cross section (without the acceptance correction) for the DY process measured in the muon channel, as a function of rapidity in the centre-of-mass frame for $60<m_{\mu\mu}<120$ GeV. The quoted error is the quadratic sum of the statistical and systematic uncertainties. The global normalisation uncertainty of 3.5% is listed separately.
A search is presented for a heavy vector resonance decaying into a Z boson and the standard model Higgs boson, where the Z boson is identified through its leptonic decays to electrons, muons, or neutrinos, and the Higgs boson is identified through its hadronic decays. The search is performed in a Lorentz-boosted regime and is based on data collected from 2016 to 2018 at the CERN LHC, corresponding to an integrated luminosity of 137 fb$^{-1}$. Upper limits are derived on the production of a narrow heavy resonance Z', and a mass below 3.5 and 3.7 TeV is excluded at 95% confidence level in models where the heavy vector boson couples exclusively to fermions and to bosons, respectively. These are the most stringent limits placed on the Heavy Vector Triplet Z' model to date. If the heavy vector boson couples exclusively to standard model bosons, upper limits on the product of the cross section and branching fraction are set between 23 and 0.3 fb for a Z' mass between 0.8 and 4.6 TeV, respectively. This is the first limit set on a heavy vector boson coupling exclusively to standard model bosons in its production and decay.
The product of signal acceptance and efficiency in the 0l categories for the signal produced via qqbar annihilation.
The product of signal acceptance and efficiency in the 2l categories for the signal produced via qqbar annihilation.
The product of signal acceptance and efficiency in the 0l categories for the signal produced via vector boson fusion.
Many new physics models, including versions of supersymmetry characterized by $R$-parity violation (RPV), compressed mass spectra, long decay chains, or additional hidden sectors, predict the production of events with top quarks, low missing transverse momentum, and many additional quarks or gluons. The results of a search for new physics in events with two top quarks and additional jets are reported. The search is performed using events with at least seven jets and exactly one electron or muon. No requirement on missing transverse momentum is imposed. The study is based on a sample of proton-proton collisions at $\sqrt{s} =$ 13 TeV corresponding to 137 fb$^{-1}$ of integrated luminosity collected with the CMS detector at the LHC in 2016-2018. The data are used to determine best fit values and upper limits on the cross section for pair production of top squarks in scenarios of RPV and stealth supersymmetry. Top squark masses up to 670 (870) GeV are excluded at 95% confidence level for the RPV (stealth) scenario, and the maximum observed local signal significance is 2.8 standard deviations for the RPV scenario with top squark mass of 400 GeV.
Fitted background prediction and observed data counts for 2016 as functions of $N_{\text{jets}}$ in each of the four $S_{\textrm{NN}}$ bins. The signal distributions normalized to the predicted cross section for the RPV model with $m_{\tilde{t}}$ = 450 GeV and the stealth SYY model with $m_{\tilde{t}}$ = 850 GeV are shown for comparison.
Fitted background prediction and observed data counts for 2017 as functions of $N_{\text{jets}}$ in each of the four $S_{\textrm{NN}}$ bins. The signal distributions normalized to the predicted cross section for the RPV model with $m_{\tilde{t}}$ = 450 GeV and the stealth SYY model with $m_{\tilde{t}}$ = 850 GeV are shown for comparison.
Fitted background prediction and observed data counts for 2018A as functions of $N_{\text{jets}}$ in each of the four $S_{\textrm{NN}}$ bins. The signal distributions normalized to the predicted cross section for the RPV model with $m_{\tilde{t}}$ = 450 GeV and the stealth SYY model with $m_{\tilde{t}}$ = 850 GeV are shown for comparison.
A fiducial cross section for W$\gamma$ production in proton-proton collisions is measured at a center-of-mass energy of 13 TeV in 137 fb$^{-1}$ of data collected using the CMS detector at the LHC. The W $\to$ e$\nu$ and $\mu\nu$ decay modes are used in a maximum-likelihood fit to the lepton-photon invariant mass distribution to extract the combined cross section. The measured cross section is compared with theoretical expectations at next-to-leading order in quantum chromodynamics. In addition, 95% confidence level intervals are reported for anomalous triple-gauge couplings within the framework of effective field theory.
The measured Wgamma fiducial cross section and corresponding theoretical predictions from MadGraph5_aMC@NLO and POWHEG. The MadGraph5_aMC@NLO prediction includes 0 and 1 jets in the matrix element at NLO in QCD. The POWHEG prediction uses the C-NLO method described in https://arxiv.org/abs/1408.5766. The cross section is measured in a fiducial region defined with isolated prompt photons and isolated prompt dressed leptons (electrons and muons). A lepton or photon is considered isolated if the pt sum of all stable particles within Delta R = 0.4, divided by the pt of the lepton or photon, is less than 0.5. A lepton is considered prompt if it originates from the hard process or from the decay of a tau lepton that originates from the hard process; a photon is considered prompt if it originates from the hard process or an FSR or ISR process involving a particle that originates from the hard process. A lepton is dressed by adding to its four-momentum the four-momenta of all photons within DeltaR = 0.1; this procedure is intended to restore the lepton to its pre-FSR state. The fiducial region kinematic requirements are: photon and lepton |eta|<2.5 and pt > 25 GeV, and DeltaR(lepton,photon) > 0.5.
Data and SM expected event yields corresponding to photon pt distribution used to extract aTGC limits.
95% CL limits on effective field theory parameters in Wgamma events. No unitarity regularisation scheme is applied. All parameters are fixed to their SM values except the one that is fitted.
Measurements of the total and differential fiducial cross sections for the Z boson decaying into two neutrinos are presented at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV. The data were collected by the CMS detector in 2016 and correspond to an integrated luminosity of 35.9 fb$^{-1}$. In these measurements, events are selected containing an imbalance in transverse momentum and one or more energetic jets. The fiducial differential cross section is measured as a function of the Z boson transverse momentum. The results are combined with a previous measurement of charged-lepton decays of the Z boson.
The measured and predicted inclusive fiducial cross sections in fb. The experimental measurement includes both statistical and systematics uncertainties. The theoretical prediction includes both the QCD scale and PDF uncertainties.
The measured and predicted inclusive fiducial cross sections in fb. The experimental measurement includes both statistical and systematics uncertainties. The theoretical prediction includes both the QCD scale and PDF uncertainties.
Experimental uncertainties affecting transfer factors in the analysis that is used to estimate the W background in the signal region (SR). The number of W boson events are denoted as $W_{SR}$ for the SR and in analogy as $W_{\mu\nu}$ ($W_{e\nu}$) for the single-muon (single-electron) control region (CR).
The production of Z boson pairs in proton-proton (pp) collisions, pp $\to$ (Z/$\gamma^*$)(Z/$\gamma^*$) $\to$ 2$\ell$ 2$\ell'$, where $\ell,\ell'$ = e or $\mu$, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the CERN LHC. The data sample corresponds to an integrated luminosity of 137 fb$^{-1}$, collected during 2016-2018. The ZZ production cross section, $\sigma_{\text{tot}}$ (pp $\to$ ZZ) = 17.2 $\pm$ 0.3 (stat) $\pm$ 0.5 (syst) $\pm$ 0.4 (theo) $\pm$ 0.3 (lumi) pb, measured for events with two pairs of opposite-sign, same-flavor leptons produced in the mass region 60 $\lt$ $m_{\ell^+\ell^-}$ $\lt $ 120 GeV is consistent with standard model predictions. Differential cross sections are also measured and agree with theoretical predictions. The invariant mass distribution of the four-lepton system is used to set limits on anomalous ZZZ and ZZ$\gamma$ couplings.
Differential cross sections normalized to the fiducial cross section for the combined 4e, 2e2µ, and 4µ decay channels as a function of pT for all leptons in the event
Differential cross sections normalized to the fiducial cross section for the combined 4e, 2e2µ, and 4µ decay channels as a function of pT for all Z bosons in the event
Differential cross sections normalized to the fiducial cross section for the combined 4e, 2e2µ, and 4µ decay channels as a function of pT of the ZZ system
A measurement of the W$^+$W$^-$ boson pair production cross section in proton-proton collisions at $\sqrt{s} =$ 13 TeV is presented. The data used in this study are collected with the CMS detector at the CERN LHC and correspond to an integrated luminosity of 35.9 fb$^{-1}$. The W$^+$W$^-$ candidate events are selected by requiring two oppositely charged leptons (electrons or muons). Two methods for reducing background contributions are employed. In the first one, a sequence of requirements on kinematic quantities is applied allowing a measurement of the total production cross section: 117.6 $\pm$ 6.8 pb, which agrees well with the theoretical prediction. Fiducial cross sections are also reported for events with zero or one jet, and the change in the zero-jet fiducial cross section with the jet transverse momentum threshold is measured. Normalized differential cross sections are reported within the fiducial region. A second method for suppressing background contributions employs two random forest classifiers. The analysis based on this method includes a measurement of the total production cross section and also a measurement of the normalized jet multiplicity distribution in W$^+$W$^-$ events. Finally, a dilepton invariant mass distribution is used to probe for physics beyond the standard model in the context of an effective field theory, and constraints on the presence of dimension-6 operators are derived.
Summary of cross sections obtained in the sequential cut analysis. The uncertainty listed is the total uncertainty obtained from the fit to the yields. Same flavor, SF, and different flavor, DF, cross sections are given.
Summary of cross sections obtained in the sequential cut analysis. The uncertainty listed is the total uncertainty obtained from the fit to the yields. Same flavor, SF, and different flavor, DF, cross sections are given.
Measured fraction of events after unfolding for $N_J = 0, 1, \geq 2$ jets. The first uncertainty is statistical and the second combines systematic uncertainties from the response matrix and from the background subtraction.
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