Version 2
Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at $\sqrt{s} = $ 13 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
JHEP 11 (2021) 153, 2021.
Inspire Record 1894408 DOI 10.17182/hepdata.106115

A search is presented for new particles produced at the LHC in proton-proton collisions at $\sqrt{s} =$ 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb$^{-1}$, collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb$^{-1}$, collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.

110 data tables

Differential signal yields for various signal hypotheses.

Differential signal yields for various signal hypotheses.

Differential signal yields for various signal hypotheses.

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Version 2
Search for long-lived particles decaying in the CMS endcap muon detectors in proton-proton collisions at $\sqrt{s} = $ 13 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
Phys.Rev.Lett. 127 (2021) 261804, 2021.
Inspire Record 1883075 DOI 10.17182/hepdata.104408

A search for long-lived particles (LLPs) produced in decays of standard model (SM) Higgs bosons is presented. The data sample consists of 137 fb$^{-1}$ of proton-proton collisions at $\sqrt{s} =$ 13 TeV, recorded at the LHC in 2016-2018. A novel technique is employed to reconstruct decays of LLPs in the endcap muon detectors. The search is sensitive to a broad range of LLP decay modes and to masses as low as a few GeV. No excess of events above the SM background is observed. The most stringent limits to date on the branching fraction of the Higgs boson to LLPs subsequently decaying to quarks and $\tau^+\tau^-$ are found for proper decay lengths greater than 6, 20, and 40 m, for LLP masses of 7, 15, and 40 GeV, respectively.

29 data tables

The 95% CL observed and expected limits on the branching fraction B(H $\rightarrow$ SS) for 7 GeV mass and $ S \rightarrow d\bar{d}$ decay mode.

The 95% CL observed and expected limits on the branching fraction B(H $\rightarrow$ SS) for 7 GeV mass and $ S \rightarrow d\bar{d}$ decay mode.

The 95% CL observed and expected limits on the branching fraction B(H $\rightarrow$ SS) for 15 GeV mass and $ S \rightarrow d\bar{d}$ decay mode.

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Search for a heavy vector resonance decaying to a Z boson and a Higgs boson 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 81 (2021) 688, 2021.
Inspire Record 1846987 DOI 10.17182/hepdata.101374

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.

21 data tables

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.

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Version 2
Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at $\sqrt{s}=13~\mathrm{TeV}$

The CMS collaboration
CMS-PAS-EXO-20-004, 2021.
Inspire Record 1869138 DOI 10.17182/hepdata.106059

A search is presented for new particles produced in proton-proton collisions at $\sqrt{s}=13~\mathrm{TeV}$ at the LHC, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of $101~\mathrm{fb}^{-1}$, collected in 2017$-$2018 with the CMS detector. Separate categories are defined for events with narrow jets from initial-state radiation and with large-radius jets consistent with a hadronic decay of a W or a Z boson. Novel machine learning techniques are used to identify hadronic W and Z boson decays. The analysis is combined with an earlier search based on a data sample corresponding to an integrated luminosity of $36~\mathrm{fb}^{-1}$, collected in 2016. No significant excess of events is observed with respect to the standard model background expectation, as determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on gravitons in models with large extra dimensions. Several of the new limits are the most restrictive to date.

55 data tables

Differential signal yields for various signal hypotheses.

Differential signal yields for various signal hypotheses.

Differential signal yields for various signal hypotheses.

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Search for the rare decay of the W boson into a pion and a photon in proton-proton collisions at $\sqrt{s} = $ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Lett.B 819 (2021) 136409, 2021.
Inspire Record 1829749 DOI 10.17182/hepdata.100165

A search is performed for the rare decay W$^\pm\to\pi^\pm\gamma$ in proton-proton collisions at $\sqrt{s} =$ 13 TeV. Data corresponding to an on W integrated luminosity of 137 fb$^{-1}$ were collected during 2016 to 2018 with the CMS detector. This analysis exploits a novel search strategy based on W boson production in top quark pair events. An inclusive search for the W$^\pm\to\pi^\pm\gamma$ decay is not optimal at the LHC because of the high trigger thresholds. Instead, a trigger selection is exploited in which the W boson originating from one of the top quarks is used to tag the event in a leptonic decay. The W boson emerging from the other top quark is used to search for the W$^\pm\to\pi^\pm\gamma$ signature. Such decays are characterized by an isolated track pointing to a large energy deposit, and by an isolated photon of large transverse momentum. The presence of b quark jets reduces the background from the hadronization of light-flavor quarks and gluons. The W$^\pm\to\pi^\pm\gamma$ decay is not observed. An upper exclusion limit is set to this branching fraction, corresponding to 1.50 $\times$ 10$^{-5}$ at 95% confidence level, whereas the expected upper limit exclusion limit is 0.85 $^{+0.52}_{-0.29}$ $\times$ 10$^{-5}$.

2 data tables

The product of signal efficiency and acceptance per year and per lepton channel (muon or electron).

Expected and observed upper exclusion limits on the branching fraction of the decay of a W boson into a pion and a photon, using 2016 to 2018 data.


Search for physics beyond the standard model in multilepton final states in proton-proton collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 03 (2020) 051, 2020.
Inspire Record 1764474 DOI 10.17182/hepdata.91969

A search for physics beyond the standard model in events with at least three charged leptons (electrons or muons) is presented. The data sample corresponds to an integrated luminosity of 137 fb$^{-1}$ of proton-proton collisions at $\sqrt{s} =$ 13 TeV, collected with the CMS detector at the LHC in 2016-2018. The two targeted signal processes are pair production of type-III seesaw heavy fermions and production of a light scalar or pseudoscalar boson in association with a pair of top quarks. The heavy fermions may be manifested as an excess of events with large values of leptonic transverse momenta or missing transverse momentum. The light scalars or pseudoscalars may create a localized excess in the dilepton mass spectra. The results exclude heavy fermions of the type-III seesaw model for masses below 880 GeV at 95% confidence level in the scenario of equal branching fractions to each lepton flavor. This is the most restrictive limit on the flavor-democratic scenario of the type-III seesaw model to date. Assuming a Yukawa coupling of unit strength to top quarks, branching fractions of new scalar (pseudoscalar) bosons to dielectrons or dimuons above 0.004 (0.03) and 0.04 (0.03) are excluded at 95% confidence level for masses in the range 15-75 and 108-340 GeV, respectively. These are the first limits in these channels on an extension of the standard model with scalar or pseudoscalar particles.

58 data tables

The $M_{T}$ distribution in the WZ-enriched region. The last bin contains the overflow events.

The $L_{T}$ distribution in the ttZ-enriched region. The last bin contains the overflow events.

The $S_{T}$ distribution in the ZZ-enriched region. The last bin contains the overflow events.

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Version 2
Search for long-lived particles using nonprompt jets and missing transverse momentum with proton-proton collisions at $\sqrt{s}=$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Lett.B 797 (2019) 134876, 2019.
Inspire Record 1740108 DOI 10.17182/hepdata.90583

A search for long-lived particles decaying to displaced, nonprompt jets and missing transverse momentum is presented. The data sample corresponds to an integrated luminosity of 137 fb$^{-1}$ of proton-proton collisions at a center-of-mass energy of 13 TeV collected by the CMS experiment at the CERN LHC in 2016-2018. Candidate signal events containing nonprompt jets are identified using the timing capabilities of the CMS electromagnetic calorimeter. The results of the search are consistent with the background prediction and are interpreted using a gauge-mediated supersymmetry breaking reference model with a gluino next-to-lightest supersymmetric particle. In this model, gluino masses up to 2100, 2500, and 1900 GeV are excluded at 95% confidence level for proper decay lengths of 0.3, 1, and 100 m, respectively. These are the best limits to date for such massive gluinos with proper decay lengths greater than $\sim$0.5 m.

56 data tables

Summary of the estimated number of background events.

Summary of the estimated number of background events.

The timing distribution of the backgrounds predicted to contribute to the signal region, compared to those for a representative signal model. The time is defined by the jet in the event with the largest $t_{\mathrm{jet}}$ passing the relevant selection. The distributions for the major backgrounds are taken from control regions and normalized to the predictions. The observed data is shown by the black points.

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Search for a low-mass $\tau^-\tau^+$ resonance in association with a bottom quark in proton-proton collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 05 (2019) 210, 2019.
Inspire Record 1726509 DOI 10.17182/hepdata.88348

A general search is presented for a low-mass $\tau^-\tau^+$ resonance produced in association with a bottom quark. The search is based on proton-proton collision data at a center-of-mass energy of 13 TeV collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. The data are consistent with the standard model expectation. Upper limits at 95% confidence level on the cross section times branching fraction are determined for two signal models: a light pseudoscalar Higgs boson decaying to a pair of $\tau$ leptons produced in association with bottom quarks, and a low-mass boson X decaying to a $\tau$-lepton pair that is produced in the decay of a bottom-like quark B such that B $\to$ bX. Masses between 25 and 70 GeV are probed for the light pseudoscalar boson with upper limits ranging from 250 to 44 pb. Upper limits from 20 to 0.3 pb are set on B masses between 170 and 450 GeV for X boson masses between 20 and 70 GeV.

18 data tables

The product of acceptance, efficiency, and branching fraction of $\mathrm{b}\overline{\mathrm{b}}\mathrm{A}$ production with $\mathrm{A} \rightarrow \tau\tau$ in the $\mathrm{e}\tau_\mathrm{h}$ and $\mu\tau_\mathrm{h}$ channels of the 1 b tag event category, as a function of the pseudoscalar mass. The selections are as described in the paper. The uncertainty refers to the statistical uncertainty only.

Observed $m_{\tau\tau}$ distribution in the $\mathrm{e}\tau_\mathrm{h}$ channel of the 1 b tag category, compared to the expected SM background contributions. The signal distributions for $\mathrm{b}\overline{\mathrm{b}}\mathrm{A}$ production with pseudoscalar mass 40 and 60 GeV are overlaid to illustrate the sensitivity. They are normalized to the cross section times branching fraction of 800 pb. The uncertainty band represents the sum in quadrature of statistical and systematic uncertainties obtained from the fit. The lower panel shows the ratio between the observed and expected events in each bin.

Observed $m_{\tau\tau}$ distribution in the $\mu\tau_\mathrm{h}$ channel of the 1 b tag category, compared to the expected SM background contributions. The signal distributions for $\mathrm{b}\overline{\mathrm{b}}\mathrm{A}$ production with pseudoscalar mass 40 and 60 GeV are overlaid to illustrate the sensitivity. They are normalized to the cross section times branching fraction of 800 pb. The uncertainty band represents the sum in quadrature of statistical and systematic uncertainties obtained from the fit. The lower panel shows the ratio between the observed and expected events in each bin.

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Search for new particles decaying to a jet and an emerging jet

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 02 (2019) 179, 2019.
Inspire Record 1700173 DOI 10.17182/hepdata.88380

A search is performed for events consistent with the pair production of a new heavy particle that acts as a mediator between a dark sector and normal matter, and that decays to a light quark and a new fermion called a dark quark. The search is based on data corresponding to an integrated luminosity of 16.1 fb$^{-1}$ from proton-proton collisions at $\sqrt{s} =$ 13 TeV collected by the CMS experiment at the LHC in 2016. The dark quark is charged only under a new quantum-chromodynamics-like force, and forms an "emerging jet" via a parton shower, containing long-lived dark hadrons that give rise to displaced vertices when decaying to standard model hadrons. The data are consistent with the expectation from standard model processes. Limits are set at 95% confidence level excluding dark pion decay lengths between 5 and 225 mm for dark mediators with masses between 400 and 1250 GeV. Decay lengths smaller than 5 mm and greater than 225 mm are also excluded in the lower part of this mass range. The dependence of the limit on the dark pion mass is weak for masses between 1 and 10 GeV. This analysis is the first dedicated search for the pair production of a new particle that decays to a jet and an emerging jet.

10 data tables

Distributions of $\langle IP_{\mathrm{2D}}\rangle$ for background (black) and for signals with a mediator mass of 1 TeV and a dark pion proper decay length of 25 mm, for various dark pion masses.

Distributions of $\alpha_\mathrm{3D}$ for background (black) and for signals with a mediator mass of 1 TeV and a dark pion mass of 5 GeV for dark pion proper decay lengths ranging from 1 to 300 mm.

The signal acceptance A, defined as the fraction of simulated signal events passing the selection criteria, for models with a dark pion mass $m_{\pi_\mathrm{DK}}$ of 5 GeV as a function of the mediator mass $m_{\mathrm{X_{DK}}}$ and the dark pion proper decay length $c\tau_{\pi_\mathrm{DK}}$. The corresponding selection set number for each model is indicated as text on the plot.

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Search for a heavy resonance decaying to a pair of vector bosons in the lepton plus merged jet final state at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 05 (2018) 088, 2018.
Inspire Record 1657397 DOI 10.17182/hepdata.85739

A search for a new heavy particle decaying to a pair of vector bosons (WW or WZ) is presented using data from the CMS detector corresponding to an integrated luminosity of 35.9 fb$^{-1}$ collected in proton-proton collisions at a centre-of-mass energy of 13 TeV in 2016. One of the bosons is required to be a W boson decaying to e$\nu$ or $\mu\nu$, while the other boson is required to be reconstructed as a single massive jet with substructure compatible with that of a highly-energetic quark pair from a W or Z boson decay. The search is performed in the resonance mass range between 1.0 and 4.5 TeV. The largest deviation from the background-only hypothesis is observed for a mass near 1.4 TeV and corresponds to a local significance of 2.5 standard deviations. The result is interpreted as an upper bound on the resonance production cross section. Comparing the excluded cross section values and the expectations from theoretical calculations in the bulk graviton and heavy vector triplet models, spin-2 WW resonances with mass smaller than 1.07 TeV and spin-1 WZ resonances lighter than 3.05 TeV, respectively, are excluded at 95% confidence level.

3 data tables

Exclusion limits on the product of the production cross section and the branching fraction for a new spin-2 resonance decaying to WW, as a function of the resonance mass hypothesis.

Exclusion limits on the product of the production cross section and the branching fraction for a new spin-1 resonance decaying to WZ, as a function of the resonance mass hypothesis.

Signal selection efficiency times acceptance as a function of resonance mass for a spin-2 bulk graviton decaying to WW and a spin-1 W' decaying to WZ.