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Measurement of the $\mathrm{t\bar{t}}\mathrm{b\bar{b}}$ production cross section in the all-jet final state in pp collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Lett.B 803 (2020) 135285, 2020.
Inspire Record 1753720 DOI 10.17182/hepdata.91630

A measurement of the production cross section of top quark pairs in association with two b jets ($\mathrm{t\bar{t}}\mathrm{b\bar{b}}$) is presented using data collected in proton-proton collisions at $\sqrt{s} =$ 13 TeV by the CMS detector at the LHC corresponding to an integrated luminosity of 35.9 fb$^{-1}$. The cross section is measured in the all-jet decay channel of the top quark pair by selecting events containing at least eight jets, of which at least two are identified as originating from the hadronization of b quarks. A combination of multivariate analysis techniques is used to reduce the large background from multijet events not containing a top quark pair, and to help discriminate between jets originating from top quark decays and other additional jets. The cross section is determined for the total phase space to be 5.5 $\pm$ 0.3 (stat)${}^{+1.6}_{-1.3}$ (syst) pb and also measured for two fiducial $\mathrm{t\bar{t}}\mathrm{b\bar{b}}$ definitions. The measured cross sections are found to be larger than theoretical predictions by a factor of 1.5-2.4, corresponding to 1-2 standard deviations.

2 data tables

The measured cross sections. The first uncertainty is statistical, the second uncertianty is the systematic.

The measured cross sections. The first uncertainty is statistical, the second uncertianty is the systematic.


Searches for physics beyond the standard model with the $M_\mathrm{T2}$ variable in hadronic final states with and without disappearing tracks in proton-proton collisions at $\sqrt{s}=$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Eur.Phys.J.C 80 (2020) 3, 2020.
Inspire Record 1753215 DOI 10.17182/hepdata.90834

Two related searches for phenomena beyond the standard model (BSM) are performed using events with hadronic jets and significant transverse momentum imbalance. The results are based on a sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment at the LHC in 2016-2018 and corresponding to an integrated luminosity of 137 fb$^{-1}$. The first search is inclusive, based on signal regions defined by the hadronic energy in the event, the jet multiplicity, the number of jets identified as originating from bottom quarks, and the value of the kinematic variable $M_\mathrm{T2}$ for events with at least two jets. For events with exactly one jet, the transverse momentum of the jet is used instead. The second search looks in addition for disappearing tracks produced by BSM long-lived charged particles that decay within the volume of the tracking detector. No excess event yield is observed above the predicted standard model background. This is used to constrain a range of BSM models that predict the following: the pair production of gluinos and squarks in the context of supersymmetry models conserving $R$-parity, with or without intermediate long-lived charginos produced in the decay chain; the resonant production of a colored scalar state decaying to a massive Dirac fermion and a quark; or the pair production of scalar and vector leptoquarks each decaying to a neutrino and a top, bottom, or light-flavor quark. In most of the cases, the results obtained are the most stringent constraints to date.

52 data tables

Definitions of super signal regions, along with predictions, observed data, and the observed 95% CL upper limits on the number of signal events contributing to each region ($N_{95}^\mathrm{max}$). The limits are given under assumptions of 0% and 15% for the uncertainty on the signal acceptance. All selection criteria as in the full analysis are applied. For regions with $N_\mathrm{j}=1$, $H_\mathrm{T}\equiv p_\mathrm{T}^\mathrm{jet}$.

Exclusion limits at 95% CL for direct gluino pair production, where the gluinos decay to light-flavor quarks ($\tilde{g}\to q\bar{q}\tilde{\chi}_1^0$). Signal cross sections are calculated at approximately NNLO+NNLL order in $\alpha_S$, assuming unity branching fraction to $q\bar{q}\tilde{\chi}_1^0$.

Exclusion limits at 95% CL for direct gluino pair production, where the gluinos decay to light-flavor quarks and either a $\tilde{\chi}_2^0$ that decays to $Z\tilde{\chi}_1^0$ (1/3 of the time), or a $\tilde{\chi}_1^\pm$ that decays to $W^\pm\tilde{\chi}_1^0$ (2/3 of the time). Signal cross sections are calculated at approximately NNLO+NNLL order in $\alpha_S$, assuming unity branching fraction to $q_i\bar{q}_j V\tilde{\chi}_1^0$.

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Search for light pseudoscalar boson pairs produced from decays of the 125 GeV Higgs boson in final states with two muons and two nearby tracks in pp collisions at $\sqrt{s}=$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Lett.B 800 (2020) 135087, 2020.
Inspire Record 1744267 DOI 10.17182/hepdata.90694

A search is presented for pairs of light pseudoscalar bosons, in the mass range from 4 to 15 GeV, produced from decays of the 125 GeV Higgs boson. The decay modes considered are final states that arise when one of the pseudoscalars decays to a pair of tau leptons, and the other one either into a pair of tau leptons or muons. The search is based on proton-proton collisions collected by the CMS experiment in 2016 at a center-of-mass energy of 13 TeV that correspond to an integrated luminosity of 35.9 fb${-1}$. The 2$\mu$2$\tau$ and 4$\tau$ channels are used in combination to constrain the product of the Higgs boson production cross section and the branching fraction into 4$\tau$ final state, $\sigma\mathcal{B}$, exploiting the linear dependence of the fermionic coupling strength of pseudoscalar bosons on the fermion mass. No significant excess is observed beyond the expectation from the standard model. The observed and expected upper limits at 95% confidence level on $\sigma\mathcal{B}$, relative to the standard model Higgs boson production cross section, are set respectively between 0.022 and 0.23 and between 0.027 and 0.19 in the mass range probed by the analysis.

1 data table

Expected and observed 95% CL upper limits on (sigma(pp->h)/sigma(pp->hSM)) * B(h -> aa -> tautautautau) as a function of m(a) obtained from the 13 TeV data, where h(SM) is the Higgs boson of the standard model, h is the observed particle with mass of 125 GeV, and (a) denotes a light Higgs-like state.


Measurement of the differential Drell-Yan cross section in proton-proton collisions at $ \sqrt{\mathrm{s}} $ = 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 12 (2019) 059, 2019.
Inspire Record 1711625 DOI 10.17182/hepdata.88043

Measurements of the differential cross section for the Drell-Yan process, based on proton-proton collision data at a centre-of-mass energy of 13 TeV, collected by the CMS experiment, are presented. The data correspond to an integrated luminosity of 2.8 (2.3) fb$^{-1}$ in the dimuon (dielectron) channel. The total and fiducial cross section measurements are presented as a function of dilepton invariant mass in the range 15 to 3000 GeV, and compared with the perturbative predictions of the standard model. The measured differential cross sections are in good agreement with the theoretical calculations.

10 data tables

Summary of the systematic uncertainties (%) for the $ d\sigma / d{m}$ (pb/GeV) measurement in the dimuon channel. The column labelled "Total" corresponds to the quadratic sum of all the experimental sources, except for that Acceptance+PDF.

Summary of the systematic uncertainties (%) for the $ d\sigma / d{m}$ (pb/GeV) measurement in the dielectron channel. The column labelled "Total" corresponds to the quadratic sum of all the experimental sources, except for that Acceptance+PDF.

Summary of the measured values of $ d\sigma / d{m}$ (pb/GeV) in the dimuon channel with the statistical ($\delta_{\text{stat}}$), experimental ($\delta_{\text{exp}}$) and theoretical ($\delta_{\text{theo}}$) uncertainties, respectively. Here, $\delta_{\text{tot}}$ is the quadratic sum of the three components.

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Search for an exotic decay of the Higgs boson to a pair of light pseudoscalars in the final state with two muons and two b quarks in pp collisions at 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Lett.B 795 (2019) 398-423, 2019.
Inspire Record 1709317 DOI 10.17182/hepdata.91235

A search for exotic decays of the Higgs boson to a pair of light pseudoscalar particles a$_1$ is performed under the hypothesis that one of the pseudoscalars decays to a pair of opposite sign muons and the other decays to b$\overline{\mathrm{b}}$. Such signatures are predicted in a number of extensions of the standard model (SM), including next-to-minimal supersymmetry and two-Higgs-doublet models with an additional scalar singlet. The results are based on a data set of proton-proton collisions corresponding to an integrated luminosity of 35.9 fb$^{-1}$, accumulated with the CMS experiment at the CERN LHC in 2016 at a centre-of-mass energy of 13 TeV. No statistically significant excess is observed with respect to the SM backgrounds in the search region for pseudoscalar masses from 20 GeV to half of the Higgs boson mass. Upper limits at 95% confidence level are set on the product of the production cross section and branching fraction, $\sigma_{\mathrm{h}}\mathcal{B}$(h $\to$ a$_1$ a$_1$ $\to$ $\mu^+\mu^-\mathrm{b}\bar{\mathrm{b}}$), ranging from 5 to 33 fb, depending on the pseudoscalar mass. Corresponding limits on the branching fraction, assuming the SM prediction for $\sigma_{\mathrm{h}}$, are (1$-$7)$\times$ 10$^{-4}$.

2 data tables

Observed and expected upper limits at 95% CL on the product of the Higgs boson production cross section and B(h->aa->mumubb)

Observed and expected upper limits at 95% CL on the branching fraction of (h->aa->mumubb)


Search for leptoquarks coupled to third-generation quarks in proton-proton collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett. 121 (2018) 241802, 2018.
Inspire Record 1694381 DOI 10.17182/hepdata.85765

Three of the most significant measured deviations from standard model predictions, the enhanced decay rate for B $\to$ D$^{(*)}\tau\nu$, hints of lepton universality violation in B $\to$ K$^{(*)}\ell\ell$ decays, and the anomalous magnetic moment of the muon, can be explained by the existence of leptoquarks (LQs) with large couplings to third-generation quarks and masses at the TeV scale. The existence of these states can be probed at the LHC in high energy proton-proton collisions. A novel search is presented for pair production of LQs coupled to a top quark and a muon using data at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb$^{-1}$, recorded by the CMS experiment. No deviation from the standard model prediction has been observed and scalar LQs decaying exclusively into t$\mu$ are excluded up to masses of 1420 GeV. The results of this search are combined with those from previous searches for LQ decays into t$\tau$ and b$\nu$, which excluded scalar LQs below masses of 900 and 1080 GeV. Vector LQs are excluded up to masses of 1190 GeV for all possible combinations of branching fractions to t$\mu$, t$\tau$ and b$\nu$. With this analysis, all relevant couplings of LQs with an electric charge of -1/3 to third-generation quarks are probed for the first time.

6 data tables

Distributions for $M_{LQ}^{rec}$ (category A) after applying the full selection. All backgrounds are normalized according to the post-fit nuisance parameters based on the corresponding SM cross sections.

Distributions for $S_{T}$ (category B) after applying the full selection and estimating the $t\overline{t}$ and DY+jets background contributions from data in category B. All backgrounds are normalized according to the post-fit nuisance parameters based on the corresponding SM cross sections.

Observed upper limits on the production cross section for pair production of LQs decaying into a top quark and a muon or a $\tau$ lepton at 95% CL in the $M_{LQ} - B(LQ \rightarrow t\mu)$ plane.

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Observation of Higgs boson decay to bottom quarks

The CMS collaboration Sirunyan, A. M. ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett. 121 (2018) 121801, 2018.
Inspire Record 1691854 DOI 10.17182/hepdata.86132

The observation of the standard model (SM) Higgs boson decay to a pair of bottom quarks is presented. The main contribution to this result is from processes in which Higgs bosons are produced in association with a W or Z boson (VH), and are searched for in final states including 0, 1, or 2 charged leptons and two identified bottom quark jets. The results from the measurement of these processes in a data sample recorded by the CMS experiment in 2017, comprising 41.3 fb$^{-1}$ of proton-proton collisions at $\sqrt{s} =$ 13 TeV, are described. When combined with previous VH measurements using data collected at $\sqrt{s}=$ 7, 8, and 13 TeV, an excess of events is observed at $m_\mathrm{H} =$ 125.09 GeV with a significance of 4.8 standard deviations, where the expectation for the SM Higgs boson is 4.9. The corresponding measured signal strength is 1.01 $\pm$ 0.22. The combination of this result with searches by the CMS experiment for H $\to\mathrm{b\overline{b}}$ in other production processes yields an observed (expected) significance of 5.6 (5.5) standard deviations and a signal strength of 1.04 $\pm$ 0.20.

2 data tables

Expected and observed significances, in number of standard deviations, and observed signal strengths for the VH production process with H-->b bbar. Results are shown separately for 2017 data, combined Run 2 (2016 and 2017 data), and for the combination of the Run 1 and Run 2 data. For the 2017 analysis, results are shown separately for the individual mu value for each channel from a combined simultaneous fit to all channels. All results are obtained for mH=125.09 GeV. Data are from Table 2 and 2016 added from Figure 1b.

Best-fit value of the H-->b bbar signal strength with its 1 sigma systematic (red) and total (blue) uncertainties for the five individual production modes considered, as well as the overall combined result. The vertical dashed line indicates the standard model expectation. All results are extracted from a single fit combining all input analyses, with mH = 125.09 GeV. Data from Figure 3.


Measurement of differential cross sections for inclusive isolated-photon and photon+jets production in proton-proton collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Eur.Phys.J.C 79 (2019) 20, 2019.
Inspire Record 1680459 DOI 10.17182/hepdata.89456

Measurements of inclusive isolated-photon and photon+jet production in proton-proton collisions at $\sqrt{s} =$ 13 TeV are presented. The analysis uses data collected by the CMS experiment in 2015, corresponding to an integrated luminosity of 2.26 fb$^{-1}$. The cross section for inclusive isolated photon production is measured as a function of the photon transverse energy in a fiducial region. The cross section for photon+jet production is measured as a function of the photon transverse energy in the same fiducial region with identical photon requirements and with the highest transverse momentum jet. All measurements are in agreement with predictions from next-to-leading-order perturbative QCD.

2 data tables

Double differential cross sections for isolated-photon production in photon rapidity bins. The cross section values are presented per photon transverse energy and rapidity unit.

Tripple differential cross sections for photon+jet production in photon and jet rapidity bins. The cross section values are presented per photon transverse energy, photon rapidity, and jet rapidity unit.


Search for beyond the standard model Higgs bosons decaying into a $\mathrm{b\overline{b}}$ pair in pp collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 08 (2018) 113, 2018.
Inspire Record 1675818 DOI 10.17182/hepdata.86133

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.

3 data tables

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.


Search for an exotic decay of the Higgs boson to a pair of light pseudoscalars in the final state with two b quarks and two $\tau$ leptons in proton-proton collisions at $\sqrt{s}=$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Lett.B 785 (2018) 462, 2018.
Inspire Record 1674926 DOI 10.17182/hepdata.86228

A search for an exotic decay of the Higgs boson to a pair of light pseudoscalar bosons is performed for the first time in the final state with two b quarks and two $\tau$ leptons. The search is motivated in the context of models of physics beyond the standard model (SM), such as two Higgs doublet models extended with a complex scalar singlet (2HDM+S), which include the next-to-minimal supersymmetric SM (NMSSM). The results are based on a data set of proton-proton collisions corresponding to an integrated luminosity of 35.9 fb$^{-1}$, accumulated by the CMS experiment at the LHC in 2016 at a center-of-mass energy of 13 TeV. Masses of the pseudoscalar boson between 15 and 60 GeV are probed, and no excess of events above the SM expectation is observed. Upper limits between 3 and 12% are set on the branching fraction $\mathcal{B}$(h $\to$ aa $\to$ 2$\tau$2b) assuming the SM production of the Higgs boson. Upper limits are also set on the branching fraction of the Higgs boson to two light pseudoscalar bosons in different 2HDM+S scenarios. Assuming the SM production cross section for the Higgs boson, the upper limit on this quantity is as low as 20% for a mass of the pseudoscalar of 40 GeV in the NMSSM.

1 data table

Expected and observed 95% CL upper limits on (sigma(pp->h)/sigma(pp->hSM)) * B(h -> aa -> bbtautau) as a function of m(a), where h(SM) is the Higgs boson of the standard model, h is the observed particle with mass of 125 GeV, and a denotes a light Higgs-like state, as obtained from the 13 TeV data.