A search is presented for the production of a Higgs boson in association with a single top quark, based on data collected in 2016 by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV, which corresponds to an integrated luminosity of 35.9 fb$^{-1}$. The production cross section for this process is highly sensitive to the absolute values of the top quark Yukawa coupling, $y_t$, the Higgs boson coupling to vector bosons, $g_\mathrm{HVV}$, and, uniquely, to their relative sign. Analyses using multilepton signatures, targeting H $\to$ WW, H $\to$ $\tau\tau$, and H $\to$ ZZ decay modes, and signatures with a single lepton and a $\mathrm{b\overline{b}}$ pair, targeting the H $\to$ $\mathrm{b\overline{b}}$ decay, are combined with a reinterpretation of a measurement in the H $\to$ $\gamma\gamma$ channel to constrain $y_\mathrm{t}$. For a standard model-like value of $g_\mathrm{HVV}$, the data favor positive values of $y_\mathrm{t}$ and exclude values of $y_\mathrm{t}$ below about $-$0.9 $y_\mathrm{t}^\mathrm{SM}$.
Expected and observed 95% CL upper limits on the tH production cross section times $H \to WW/ZZ/\tau\tau/b\bar{b}/\gamma\gamma$ branching fraction for a scenario of inverted couplings ($\kappa_t=-1.0$ and $\kappa_V=1.0$, top rows), vanishing top quark Yukawa coupling ($\kappa_t=0.0$ and $\kappa_V=1.0$, middle rows), and for an SM-like signal ($\kappa_t=1.0$ and $\kappa_V=1.0$, bottom rows), in pb. The Higgs to vector boson couplings is considered to be SM-like. The expected limit is calculated on a background-only data set, i.e., without tH contribution, but including a coupling dependent contribution from the ttH production. The ttH normalization is kept fixed in the fit, while the tH cross section is allowed to float. Limits can be compared to the expected product of tH cross sections and branching fractions of 0.83, 0.28, and 0.077 pb for the inverted top quark Yukawa coupling, the vanishing top-Yukawa and the SM-like scenario.
Observed and expected 95% CL upper limit on the tH cross section times combined $HH \to WW/ZZ/\tau\tau/b\bar{b}/\gamma\gamma$ branching fraction for different values of the top-Yukawa coupling modifier, assuming SM-like Higgs to vector boson couplings. The expected limit is calculated on a background-only data set, i.e., without tH contribution, but including a coupling dependent contribution from the ttH production. The ttH normalization is kept fixed in the fit, while the tH cross section is allowed to float.
A search is presented for baryon number violating interactions in top quark production and decay. The analysis uses data from proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the CMS detector at the LHC with an integrated luminosity of 138 fb$^{-1}$. Candidate events are selected by requiring two oppositely-charged leptons (electrons or muons) and exactly one jet identified as originating from a bottom quark. Multivariate discriminants are used to separate the signal from the background. No significant deviation from the standard model prediction is observed. Upper limits are placed on the strength of baryon number violating couplings. For the first time the production of single top quarks via baryon number violating interactions is studied. This allows the search to set the most stringent constraints to date on the branching fraction of the top quark decay to a lepton, an up-type quark (u or c), and a down-type quark (d, s, or b). The results improve the previous bounds by three to six orders of magnitude based on the fermion flavor combination of the baryon number violating interactions.
The observed upper limits on the branching fractions of the top quark BNV decays are shown with circle and triangle shapes for electron and muon couplings, respectively. The observed limits corresponding to the $C_t$ and $C_s$ coefficients are shown with filled and open markers, respectively. The yellow light (green dark) bands indicate the range within plus or minus one (two) standard deviations bands around the expected limits.
A search for Higgs bosons that decay into a bottom quark-antiquark pair and are accompanied by at least one additional bottom quark is performed with the CMS detector. The data analyzed were recorded in proton-proton collisions at a centre-of-mass energy of $\sqrt{s} =$ 13 TeV at the LHC, corresponding to an integrated luminosity of 35.7 fb$^{-1}$. The final state considered in this analysis is particularly sensitive to signatures of a Higgs sector beyond the standard model, as predicted in the generic class of two Higgs doublet models (2HDMs). No signal above the standard model background expectation is observed. Stringent upper limits on the cross section times branching fraction are set for Higgs bosons with masses up to 1300 GeV. The results are interpreted within several MSSM and 2HDM scenarios.
Expected and observed 95% CL upper limits on sigma(pp->b+H(MSSM)+X) * B(H(MSSM) -> bb) in pb as a function of m(H(MSSM)), where H(MSSM) denotes a heavy Higgs-like state like the H and A bosons of MSSM and 2HDM, as obtained from the 13 TeV data.
Expected and observed 95% CL upper limits on tan(beta) as a function of m(A) in the mhmodp benchmark scenario for a higgsino mass parameter of mu=+200 GeV. Since theoretical predictions are not reliable for tan(beta)>60, entries for which tan(beta) would exceed this value are indicated by N/A.
Expected and observed 95% CL upper limits on tan(beta) as a function of m(A) in the hMSSM benchmark scenario. Since theoretical predictions are not reliable for tan(beta)>60, entries for which tan(beta) would exceed this value are indicated by N/A.
A search for the central exclusive production of top quark-antiquark pairs ($\mathrm{t\bar{t}}$) is performed for the first time using proton-tagged events in proton-proton collisions at the LHC at a centre-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 29.4 fb$^{-1}$. The $\mathrm{t\bar{t}}$ decay products are reconstructed using the central CMS detector, while forward protons are measured in the CMS-TOTEM precision proton spectrometer. An observed (expected) upper bound on the production cross section of 0.59 (1.14) pb is set at 95% confidence level, for collisions of protons with fractional momentum losses between 2 and 20%.
Expected and observed 95% confidence level (CL) upper limits for the cross section of $\mathrm{pp} \rightarrow \mathrm{p t \bar{t} p}$, for the dilepton and $\ell+$jets channels separately and combined. The green and yellow bands show the 68 and 95% intervals, respectively, for the expected upper limit.
A search for charged Higgs bosons (H$^\pm$) decaying into a top and a bottom quark in the all-jet final states is presented. The analysis uses LHC proton-proton collision data recorded with the CMS detector in 2016 at $\sqrt{s} =$ 13 TeV, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. No significant excess is observed above the expected background. Model-independent upper limits at 95% confidence level are set on the product of the H$^\pm$ production cross section and branching fraction in two scenarios. For production in association with a top quark, limits of 21.3 to 0.007 pb are obtained for H$^\pm$ masses in the range of 0.2 to 3 TeV. Combining this with data from a search in leptonic final states results in improved limits of 9.25 to 0.005 pb. The complementary $s$-channel production of an H$^\pm$ is investigated in the mass range of 0.8 to 3 TeV and the corresponding upper limits are 4.5 to 0.023 pb. These results are interpreted using different minimal supersymmetric extensions of the standard model.
The 95% CL upper limit on the production cross section for the Charged Higgs boson decaying into a top-bottom pair.
The 95% CL upper limit on the production cross section for the Charged Higgs boson decaying into a top-bottom pair for s-channel production in the boosted regime.
The 95% CL upper limit on the production cross section for the Charged Higgs boson decaying into a top-bottom pair for the associated production (fully hadronic).
A search is presented for charged Higgs bosons in the H$^{\pm}$ $\to$ $\tau^{\pm}\nu_\tau$ decay mode in the hadronic final state and in final states with an electron or muon. The search is based on proton-proton collision data recorded by the CMS experiment in 2016 at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. The results agree with the background expectation from the standard model. Upper limits at 95% confidence level are set on the production cross section times branching fraction to $\tau^{\pm}\nu_\tau$ for an H$^{\pm}$ in the mass range of 80 GeV to 3 TeV, including the region near the top quark mass. The observed limit ranges from 6 pb at 80 GeV to 5 fb at 3 TeV. The limits are interpreted in the context of the minimal supersymmetric standard model $m_\mathrm{h}^\mathrm{mod-}$ scenario.
The 95% CL upper limit on the production cross section for the Charged Higgs boson decaying into a tau-nu pair.
The 95% CL upper limit on the branching fraction of the top to a Charged Higgs boson decaying into a tau-nu pair.
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 search for charged Higgs bosons produced in vector boson fusion processes and decaying into vector bosons, using proton-proton collisions at $\sqrt{s} =$ 13 TeV at the LHC, is reported. The data sample corresponds to an integrated luminosity of 137 fb$^{-1}$ collected with the CMS detector. Events are selected by requiring two or three electrons or muons, moderate missing transverse momentum, and two jets with a large rapidity separation and a large dijet mass. No excess of events with respect to the standard model background predictions is observed. Model independent upper limits at 95% confidence level are reported on the product of the cross section and branching fraction for vector boson fusion production of charged Higgs bosons as a function of mass, from 200 to 3000 GeV. The results are interpreted in the context of the Georgi-Machacek model.
Summary of the impact of the systematic uncertainties on the extracted signal strength; for the case of a background-only simulated data set, i.e., assuming no contributions from the $\mathrm{H}^{\pm}$ and $\mathrm{H}^{\pm\pm}$ processes, and including a charged Higgs boson signal for values of $s_{\mathrm{H}}=1.0$ and $m_{\mathrm{H}_{5}}=500$ GeV in the GM model.
Expected signal and background yields from various SM processes and observed data events in all regions used in the analysis. The expected background yields are shown with their normalizations from the simultaneous fit for the background-only hypothesis, i.e., assuming no contributions from the $\mathrm{H}^{\pm}$ and $\mathrm{H}^{\pm\pm}$ processes. The expected signal yields are shown for $s_{\mathrm{H}}=1.0$ in the GM model. The combination of the statistical and systematic uncertainties is shown.
Distributions for signal, backgrounds, and data for the bins used in the simultaneous fit. The bins 1--32 (4$\times$8) show the events in the WW SR ($m_{\mathrm{jj}} \times m_{\mathrm{T}}$), the bins 33--46 (2$\times$7) show the events in the WZ SR ($m_{\mathrm{jj}} \times m_{\mathrm{T}}$), the 4 bins 47--50 show the events in the nonprompt lepton CR ($m_{\mathrm{jj}}$), the 4 bins 51--54 show the events in the tZq CR ($m_{\mathrm{jj}}$), and the 4 bins 55--58 show the events in the ZZ CR ($m_{\mathrm{jj}}$). The predicted yields are shown with their best fit normalizations from the simultaneous fit for the background-only hypothesis, i.e., assuming no contributions from the $\mathrm{H}^{\pm}$ and $\mathrm{H}^{\pm\pm}$ processes. Vertical bars on data points represent the statistical uncertainty in the data. The histograms for tVx backgrounds include the contributions from ttV and tZq processes. The histograms for other backgrounds include the contributions from double parton scattering, VVV, and from oppositely charged dilepton final states from tt, tW, $\mathrm{W}^{+}\mathrm{W}^{-}$, and Drell--Yan processes. The overflow is included in the last bin in each corresponding region. The lower panels show the ratio of the number of events observed in data to that of the total SM prediction. The hatched gray bands represent the uncertainties in the predicted yields. The solid lines show the signal predictions for values of $s_{\mathrm{H}}=1.0$ and $m_{\mathrm{H}_{5}}=500$ GeV in the GM model.
A search is performed for charged-lepton flavor violating processes in top quark (t) production and decay. The data were collected by the CMS experiment from proton-proton collisions at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 138 fb$^{-1}$. The selected events are required to contain one opposite-sign electron-muon pair, a third charged lepton (electron or muon), and at least one jet of which no more than one is associated with a bottom quark. Boosted decision trees are used to distinguish signal from background, exploiting differences in the kinematics of the final states particles. The data are consistent with the standard model expectation. Upper limits at 95% confidence level are placed in the context of effective field theory on the Wilson coefficients, which range between 0.024-0.424 TeV$^{-2}$ depending on the flavor of the associated light quark and the Lorentz structure of the interaction. These limits are converted to upper limits on branching fractions involving up (charm) quarks, t$\to$e$\mu$u (t$\to$e$\mu$c), of 0.032 (0.498)$\times$10$^{-6}$, 0.022 (0.369)$\times$10$^{-6}$, and 0.012 (0.216)$\times$10$^{-6}$ for tensor-like, vector-like, and scalar-like interactions, respectively.
The expected and observed upper limits on CLFV Wilson coefficients. The Limits on the Wilson coefficients are extracted from the upper limits on the cross sections.
The expected and observed upper limits on top quark CLFV branching fractions. The Limits on the top quark CLFV branching fractions are extracted from the upper limits on the Wilson coefficients.
Results are presented from a search for charged-lepton flavor violating (CLFV) interactions in top quark production and decay in pp collisions at a center-of-mass energy of 13 TeV. The events are required to contain one oppositely charged electron-muon pair in the final state, along with at least one jet identified as originating from a bottom quark. The data correspond to an integrated luminosity of 138 fb$^{-1}$, collected by the CMS experiment at the LHC. This analysis includes both the production (q $\to$ e$\mu$t) and decay (t $\to$ e$\mu$q) modes of the top quark through CLFV interactions, with q referring to a u or c quark. These interactions are parametrized using an effective field theory approach. With no significant excess over the standard model expectation, the results are interpreted in terms of vector-, scalar-, and tensor-like CLFV four-fermion effective interactions. Finally, observed exclusion limits are set at 95% confidence levels on the respective branching fractions of a top quark to an e$\mu$ pair and an up (charm) quark of 0.13 $\times$ 10$^{-6}$ (1.31 $\times$ 10$^{-6}$), 0.07 $\times$ 10$^{-6}$ (0.89 $\times$ 10$^{-6}$), and 0.25 $\times$ 10$^{-6}$ (2.59 $\times$ 10$^{-6}$) for vector, scalar, and tensor CLFV interactions, respectively.
The expected and observed upper limits on the signal cross sections.
The expected and observed upper limits on CLFV Wilson coefficients. The Limits on the Wilson coefficients are extracted from the upper limits on the cross sections. Since the cross sections are quadratic functions of the Wilson coefficients, the limits lie on an ellipse given by the coordinate intersections.
The expected and observed upper limits on top quark CLFV branching fractions. The Limits on the top quark CLFV branching fractions are extracted from the upper limits on the Wilson coefficients.
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