Observation of the $\Lambda_\text{b}^0$$\to$ J/$\psi\Xi^-$K$^+$ decay

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
CMS-BPH-22-002, 2024.
Inspire Record 2752469 DOI 10.17182/hepdata.145642

Using proton-proton collision data corresponding to an integrated luminosity of 140 fb$^{-1}$ collected by the CMS experiment at $\sqrt{s}$ = 13 TeV, the $\Lambda_\text{b}^0$$\to$ J/$\psi\Xi^-$K$^+$ decay is observed for the first time, with a statistical significance exceeding 5 standard deviations. The relative branching fraction, with respect to the $\Lambda_\text{b}^0$$\to$$\psi$(2S)$\Lambda$ decay, is measured to be $\mathcal{B}$($\Lambda_\text{b}^0$$\to$ J/$\psi\Xi^-$K$^+$)/$\mathcal{B}$( $\Lambda_\text{b}^0$$\to$$\psi$(2S)$\Lambda$) = [3.38 $\pm$ 1.02 $\pm$ 0.61 $\pm$ 0.03]%, where the first uncertainty is statistical, the second is systematic, and the third is related to the uncertainties in $\mathcal{B}$($\psi$(2S) $\to$ J/$\psi\pi^+\pi^-$) and $\mathcal{B}$($\Xi^-$ $\to$ $\Lambda\pi^-$).

1 data table

The measured branching fraction ratio


Measurement of multidifferential cross sections for dijet production in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
CMS-SMP-21-008, 2023.
Inspire Record 2741343 DOI 10.17182/hepdata.146075

A measurement of the dijet production cross section is reported based on proton-proton collision data collected in 2016 at $\sqrt{s}$ = 13 TeV by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of up to 36.3 fb$^{-1}$. Jets are reconstructed with the anti-$k_\mathrm{T}$ algorithm for distance parameters of $R$ = 0.4 and 0.8. Cross sections are measured double-differentially (2D) as a function of the largest absolute rapidity $\lvert y_\text{max}\rvert$ of the two jets with the highest transverse momenta $p_\mathrm{T}$ and their invariant mass $m_{1,2}$, and triple-differentially (3D) as a function of the rapidity separation $y^*$, the total boost $y_\mathrm{b}$, and either $m_{1,2}$ or the average $p_\mathrm{T}$ of the two jets. The cross sections are unfolded to correct for detector effects and are compared with fixed-order calculations derived at next-to-next-to-leading order in perturbative quantum chromodynamics. The impact of the measurements on the parton distribution functions and the strong coupling constant at the mass of the Z boson is investigated, yielding a value of $\alpha_\mathrm{S}$ = 0.1179 $\pm$ 0.0019.

24 data tables

Double-differential dijet cross section for anti-$k_\text{T}$ jets with R = 0.4 as a function of the dijet invariant mass ($m_{1,2}$) and the absolute rapidity of the outermost jet ($\left| y \right|_\text{max}$)

Electroweak corrections to double-differential dijet cross section for anti-$k_\text{T}$ jets with R = 0.4 as a function of the dijet invariant mass ($m_{1,2}$) and the absolute rapidity of the outermost jet ($\left| y \right|_\text{max}$)

Nonperturbative corrections to double-differential dijet cross section for anti-$k_\text{T}$ jets with R = 0.4 as a function of the dijet invariant mass ($m_{1,2}$) and the absolute rapidity of the outermost jet ($\left| y \right|_\text{max}$)

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Version 2
Inclusive and differential cross section measurements of $\mathrm{t\bar{t}b\bar{b}}$ production in the lepton+jets channel at $\sqrt{s}$ = 13 TeV

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
CMS-TOP-22-009, 2023.
Inspire Record 2703254 DOI 10.17182/hepdata.138416

Measurements of inclusive and normalized differential cross sections of the associated production of top quark-antiquark and bottom quark-antiquark pairs, ttbb, are presented. The results are based on data from proton-proton collisions collected by the CMS detector at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$. The cross sections are measured in the lepton+jets decay channel of the top quark pair, using events containing exactly one isolated electron or muon and at least five jets. Measurements are made in four fiducial phase space regions, targeting different aspects of the ttbb process. Distributions are unfolded to the particle level through maximum likelihood fits, and compared with predictions from several event generators. The inclusive cross section measurements of this process in the fiducial phase space regions are the most precise to date. In most cases, the measured inclusive cross sections exceed the predictions with the chosen generator settings. The only exception is when using a particular choice of dynamic renormalization scale, $\mu_\mathrm{R}=\frac{1}{2} \prod_{i=\mathrm{t, \bar{t}, b, \bar{b}}} m_{\mathrm{T},i}^{1/4}$, where $m_{\mathrm{T},i}^2=m_i^2+p^2_{\mathrm{T},i}$ are the transverse masses of top and bottom quarks. The differential cross sections show varying degrees of compatibility with the theoretical predictions, and none of the tested generators with the chosen settings simultaneously describe all the measured distributions.

114 data tables

Fiducial cross sections from the measurements of all observables, compared to predictions from different ttbb simulation approaches. For each of the normalized differential measurements the fiducial cross section in the respective phase space is also determined. In the paper only one representative observable is quoted for each fiducial phase space, while here the measured cross section with the uncertainties from the fit to the respective observable is summarized.

Compatibility of normalized differential cross section measurements with modeling predictions. The compatibility is quantified with z scores for each of the theoretical predictions, given the unfolded normalized differential cross sections and their covariances. A lower value indicates a better agreement between prediction and measurement. A value of z = 2 indicates a p-value of 5%. In the calculation of the z score only the measurement uncertainties and the statistical uncertainties of the modeling predictions are taken into account

Normalized differential cross section of $|\eta(\mathrm{b}^{\mathrm{add.}}_{1})|$ in $\geq 6$ jets: $\geq 4 \mathrm{b}$ phase space.

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Search for fractionally charged particles in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
CMS-EXO-19-006, 2024.
Inspire Record 2758805 DOI 10.17182/hepdata.146758

A search is presented for fractionally charged particles with charge below 1$e$, using their small energy loss in the tracking detector as a key variable to observe a signal. The analyzed data set corresponds to an integrated luminosity of 138 fb$^{-1}$ of proton-proton collisions collected at $\sqrt{s}$ = 13 TeV in 2016-2018 at the CERN LHC. This is the first search at the LHC for new particles with charges between $e/$3 and $e$. Masses up to 640 GeV and charges as low as $e/$3 are excluded at 95% confidence level. These are the most stringent limits to date for the considered Drell-Yan-like production mode.

9 data tables

Signal yields for two charge scenarios considered in the analysis, as well as their associated uncertainties.

Signal yields for two charge scenarios considered in the analysis, as well as their associated uncertainties.

Signal yields for two charge scenarios considered in the analysis, as well as their associated uncertainties.

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Evidence for tWZ production in proton-proton collisions at $\sqrt{s}$ = 13 TeV in multilepton final states

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
CMS-TOP-22-008, 2023.
Inspire Record 2738533 DOI 10.17182/hepdata.138419

The first evidence for the standard model production of a top quark in association with a W boson and a Z boson is reported. The measurement is performed in multilepton final states, where the Z boson is reconstructed via its decays to electron or muon pairs and the W boson decays either to leptons or hadrons. The analysed data were recorded by the CMS experiment at the CERN LHC in 2016-2018 in proton-proton collisions at $\sqrt{s}$ = 13 TeV, and correspond to an integrated luminosity of 138 fb$^{-1}$. The measured cross section is 354 $\pm$ 54 (stat) $\pm$ 95 (syst) fb, and corresponds to a statistical significance of 3.4 standard deviations.

11 data tables

Expected yields for signal and background processes and observed number of events in the signal and control regions

Postfit b jet multiplicity distribution in the $\text{SR}_\text{4l}$

Postfit score of the tWZ output node from the multiclass classifier in $\text{SR}_\text{3l,3j}$ for events with exactly 1 b jet

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Search for scalar leptoquarks produced in lepton-quark collisions and coupled to $\tau$ leptons

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett. 132 (2024) 061801, 2024.
Inspire Record 2687527 DOI 10.17182/hepdata.141335

The first search for scalar leptoquarks produced in $\tau$-lepton-quark collisions is presented. It is based on a set of proton-proton collision data recorded with the CMS detector at the LHC at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 138 fb$^{-1}$. The reconstructed final state consists of a jet, significant missing transverse momentum, and a $\tau$ lepton reconstructed through its hadronic or leptonic decays. Limits are set on the product of the leptoquark production cross section and branching fraction and interpreted as exclusions in the plane of the leptoquark mass and the leptoquark-$\tau$-quark coupling strength.

33 data tables

Observed and expected distributions of the collinear mass in the $\tau_\mathrm{h}$+jet btag category with the BDT requirements selecting the most signal-like events. The signal hypothesis corresponds to a scalar leptoquark coupled to u quarks and $\tau$ leptons with a coupling strength $\lambda$ equal to 1.5.

Observed and expected distributions of the collinear mass in the e+jet btag category with the BDT requirements selecting the most signal-like events. The signal hypothesis corresponds to a scalar leptoquark coupled to u quarks and $\tau$ leptons with a coupling strength $\lambda$ equal to 1.5.

Observed and expected distributions of the collinear mass in the $\mu$+jet btag category with the BDT requirements selecting the most signal-like events. The signal hypothesis corresponds to a scalar leptoquark coupled to u quarks and $\tau$ leptons with a coupling strength $\lambda$ equal to 1.5.

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Search for inelastic dark matter in events with two displaced muons and missing transverse momentum in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett. 132 (2024) 041802, 2024.
Inspire Record 2661228 DOI 10.17182/hepdata.140434

A search for dark matter in events with a displaced nonresonant muon pair and missing transverse momentum is presented. The analysis is performed using an integrated luminosity of 138 fb$^{-1}$ of proton-proton (pp) collision data at a center-of-mass energy of 13 TeV produced by the LHC in 2016-2018. No significant excess over the predicted backgrounds is observed. Upper limits are set on the product of the inelastic dark matter production cross section $\sigma$(pp $\to$ A' $\to$$\chi_1$$\chi_2$) and the decay branching fraction $\mathcal{B}$($\chi_2$$\to$$\chi_1 \mu^+ \mu^-$), where A' is a dark photon and $\chi_1$ and $\chi_2$ are states in the dark sector with near mass degeneracy. This is the first dedicated collider search for inelastic dark matter.

6 data tables

Definition of ABCD bins and yields in data, per match category. The predicted yield in the bin with the smallest backgrounds (bin D) is extracted from the simultaneous four-bin fit by assuming zero signal, which corresponds to $(\text{Obs. B} \times \text{Obs. C}) / (\text{Obs. A})$ in this limit.

Systematic uncertainties in the analysis. The jet uncertainties are larger in 2017 because of noise issues with the ECAL endcap. The tracking inefficiency in 2016 is caused by the unexpected saturation of photodiode signals in the tracker.

Simulated muon reconstruction efficiency of standard (blue squares) and displaced (red circles) reconstruction algorithms as a function of transverse vertex displacement $v_{xy}$. The two dashed vertical gray lines denote the ends of the fiducial tracker and muon detector regions, respectively.

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Observation of the $\Xi^-_\mathrm{b}$$\to$$\psi$(2S)$\Xi^-$ decay and studies of the $\Xi_\mathrm{b}^{\ast{}0}$ baryon in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
CMS-BPH-23-002, 2024.
Inspire Record 2762139 DOI 10.17182/hepdata.146756

The first observation of the decay $\Xi^-_\mathrm{b}$$\to$$\psi$(2S)$\Xi^-$ and measurement of the branching ratio of $\Xi^-_\mathrm{b}$$\to$$\psi$(2S)$\Xi^-$ to $\Xi^-_\mathrm{b}$$\to$ J/$\psi$$\Xi^-$ are presented. The J/$\psi$ and $\psi$(2S) mesons are reconstructed using their dimuon decay modes. The results are based on proton-proton colliding beam data from the LHC collected by the CMS experiment at $\sqrt{s}$ = 13 TeV in 2016-2018, corresponding to an integrated luminosity of 140 fb$^{-1}$. The branching fraction ratio is measured to be $\mathcal{B}$($\Xi^-_\mathrm{b}$$\to$$\psi$(2S)$\Xi^-$)/$\mathcal{B}$($\Xi^-_\mathrm{b}$$\to$ J/$\psi$$\Xi^-$) = 0.84$^{+0.21}_{-0.19}$ (stat) $\pm$ 0.10 (syst) $\pm$ 0.02 ($\mathcal{B}$), where the last uncertainty comes from the uncertainties in the branching fractions of the charmonium states. New measurements of the $\Xi_\mathrm{b}^{\ast{}0}$ baryon mass and natural width are also presented, using the $\Xi_\mathrm{b}^-\pi^+$ final state, where the $\Xi^-_\mathrm{b}$ baryon is reconstructed through the decays J/$\psi \Xi^-$, $\psi$(2S)$\Xi^-$, J/$\psi \Lambda$K$^-$, and J/$\psi \Sigma^0$K$^-$. Finally, the fraction of the $\Xi^-_\mathrm{b}$ baryons produced from $\Xi_\mathrm{b}^{\ast{}0}$ decays is determined.

5 data tables

The measured ratio of branching fractions

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Search for long-lived particles using displaced vertices and missing transverse momentum in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
CMS-EXO-22-020, 2024.
Inspire Record 2761908 DOI 10.17182/hepdata.147272

A search for the production of long-lived particles in proton-proton collisions at a center-of-mass energy of 13 TeV at the CERN LHC is presented. The search is based on data collected by the CMS experiment in 2016-2018, corresponding to a total integrated luminosity of 137 fb$^{-1}$. This search is designed to be sensitive to long-lived particles with mean proper decay lengths between 0.1 and 1000 $\mu$m, whose decay products produce a final state with at least one displaced vertex and missing transverse momentum. A machine learning algorithm, which improves the background rejection power by more than an order of magnitude, is applied to improve the sensitivity. The observation is consistent with the standard model background prediction, and the results are used to constrain split supersymmetry (SUSY) and gauge-mediated SUSY breaking models with different gluino mean proper decay lengths and masses. This search is the first CMS search that shows sensitivity to hadronically decaying long-lived particles from signals with mass differences between the gluino and neutralino below 100 GeV. It sets the most stringent limits to date for split-SUSY models and gauge-mediated SUSY breaking models with gluino proper decay length less than 6 $\mu$m.

17 data tables

Distributions of $S_{\mathrm{ML}}$ for data, simulated background and signal events with $n_{\mathrm{track}}$ of 3. The distributions are shown for split-SUSY signals with a gluino mass of 2000 GeV and neutralino mass of 1900 GeV. Different gluino proper decay lengths are shown as $c\tau$ in the legend. All distributions are normalized to unity.

Distributions of $S_{\mathrm{ML}}$ for data, simulated background and signal events with $n_{\mathrm{track}}$ of 3. The distributions are shown for split-SUSY signals with a gluino mass of 2000 GeV and neutralino mass of 1800 GeV. Different gluino proper decay lengths are shown as $c\tau$ in the legend. All distributions are normalized to unity.

Distributions of $S_{\mathrm{ML}}$ for data, simulated background and signal events with $n_{\mathrm{track}}$ of 4. The distributions are shown for split-SUSY signals with a gluino mass of 2000 GeV and neutralino mass of 1900 GeV. Different gluino proper decay lengths are shown as $c\tau$ in the legend. All distributions are normalized to unity.

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Constraints on anomalous Higgs boson couplings from its production and decay using the WW channel in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
CMS-HIG-22-008, 2024.
Inspire Record 2764172 DOI 10.17182/hepdata.146013

A study of the anomalous couplings of the Higgs boson to vector bosons, including $CP$-violation effects, has been conducted using its production and decay in the WW channel. This analysis is performed on proton-proton collision data collected with the CMS detector at the CERN LHC during 2016-2018 at a center-of-mass energy of 13 TeV, and corresponds to an integrated luminosity of 138 fb$^{-1}$. The different-flavor dilepton (e$\mu$) final state is analyzed, with dedicated categories targeting gluon fusion, electroweak vector boson fusion, and associated production with a W or Z boson. Kinematic information from associated jets is combined using matrix element techniques to increase the sensitivity to anomalous effects at the production vertex. A simultaneous measurement of four Higgs boson couplings to electroweak vector bosons is performed in the framework of a standard model effective field theory. All measurements are consistent with the expectations for the standard model Higgs boson and constraints are set on the fractional contribution of the anomalous couplings to the Higgs boson production cross section.

30 data tables

Expected profiled likelihood on $f_{a2}$ using Approach 1. The signal strength modifiers are treated as free parameters. Axis scales are varied to improve the visibility of important features.

Observed profiled likelihood on $f_{a2}$ using Approach 1. The signal strength modifiers are treated as free parameters. Axis scales are varied to improve the visibility of important features.

Expected profiled likelihood on $f_{\Lambda1}$ using Approach 1. The signal strength modifiers are treated as free parameters. Axis scales are varied to improve the visibility of important features.

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