Search for pair production of scalar leptoquarks decaying into first- or second-generation leptons and top quarks in proton-proton collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
CERN-EP-2020-160, 2020.
Inspire Record 1821703 DOI 10.17182/hepdata.96389

A search for pair production of scalar leptoquarks, each decaying into either an electron or a muon and a top quark, is presented. This is the first leptoquark search using ATLAS data to investigate top-philic cross-generational couplings that could provide explanations for recently observed anomalies in $B$ meson decays. This analysis targets high leptoquark masses which cause the decay products of each resultant top quark to be contained within a single high-$p_{\mathrm{T}}$ large-radius jet. The full Run 2 dataset is exploited, consisting of 139 fb$^{-1}$ of data collected from proton-proton collisions at $\sqrt{s}=13$ TeV from 2015 to 2018 with the ATLAS detector at the CERN Large Hadron Collider. In the absence of any significant deviation from the background expectation, lower limits on the leptoquark masses are set at 1480 GeV and 1470 GeV for the electron and muon channel, respectively.

4 data tables

Expected and observed upper limits at the 95% CL on the leptoquark pair production cross section as a function of leptoquark mass under the assumption of $\mathcal{B}$(LQ->$te$)=1.

Expected and observed upper limits at the 95% CL on the leptoquark pair production cross section as a function of leptoquark mass under the assumption of $\mathcal{B}$(LQ->$t\mu$)=1.

Expected and observed 95% CL lower limits on the leptoquark mass as a function of the branching ratio $\mathcal{B}$(LQ->$te$).

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W$^+$W$^-$ boson pair production in proton-proton collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
CMS-SMP-18-004, 2020.
Inspire Record 1814328 DOI 10.17182/hepdata.94259

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.

8 data tables

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.

Expected and observed 68% and 95% confidence intervals on the measurement of the Wilson coefficients associated with the three CP-preserving, dimension-6 operators.

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Evidence for electroweak production of four charged leptons and two jets in proton-proton collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
CMS-SMP-20-001, 2020.
Inspire Record 1811911 DOI 10.17182/hepdata.95433

Evidence is presented for the electroweak (EW) production of two jets (jj) in association with two Z bosons and constraints on anomalous quartic gauge couplings are set. The analysis is based on a data sample of proton-proton collisions at $\sqrt{s}= $ 13 TeV collected with the CMS detector in 2016-2018, and corresponding to an integrated luminosity of 137 fb$^{-1}$. The search is performed in the fully leptonic final state ZZ$\to\ell\ell\ell'\ell'$, where $\ell,\ell' = $ e, $\mu$. The EW production of two jets in association with two Z bosons is measured with an observed (expected) significance of 4.0 (3.5) standard deviations. The cross sections for the EW production are measured in three fiducial volumes and the result is $\sigma_{\mathrm{EW}}$(pp $\to$ ZZjj $\to\ell\ell\ell'\ell'$jj) = 0.33$^{+0.11}_{-0.10}$ (stat) $^{+0.04}_{-0.03}$ (syst) fb in the most inclusive volume, in agreement with the standard model prediction of 0.275 $\pm$ 0.021 fb. Limits on anomalous quartic gauge couplings are derived in terms of the effective field theory operators T0, T1, T2, T8, and T9.

5 data tables

Data from paper Table 3. Measured and expected fiducial cross-sections in the ZZjj inclusive fiducial region.

Data from paper Table 3. Measured and expected fiducial cross-sections in the VBS-enriched loose fiducial region.

Data from paper Table 3. Measured and expected fiducial cross-sections in the VBS-enriched tight fiducial region.

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Search for heavy resonances decaying into a photon and a hadronically decaying Higgs boson in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
Phys.Rev.Lett., 2020.
Inspire Record 1811594 DOI 10.17182/hepdata.95538

This Letter presents a search for the production of new heavy resonances decaying into a Higgs boson and a photon using proton-proton collision data at $\sqrt{s}=13$ TeV collected by the ATLAS detector at the LHC. The data correspond to an integrated luminosity of 139 fb$^{-1}$. The analysis is performed by reconstructing hadronically decaying Higgs boson $(H\to b\bar{b})$ candidates as single large-radius jets. A novel algorithm using information about the jet constituents in the center-of-mass frame of the jet is implemented to identify the two $b$-quarks in the single jet. No significant excess of events is observed above the expected background. Upper limits are set on the production cross-section times branching fraction for narrow spin-1 resonances decaying into a Higgs boson and a photon in the resonance mass range from 0.7 to 4 TeV, cross-sections times branching fraction are excluded between 11.6 fb and 0.11 fb at a 95% confidence level.

5 data tables

Data distribution of the reconstructed $m_{J\gamma}$ and background only fitting in the single-b-tagged category. Background and signal fit functions are provided in Table 3. Background event yields are calculated using the fitted background function.

Data distribution of the reconstructed $m_{J\gamma}$ and background only fitting in the double-b-tagged category. Background and signal fit functions are provided in Table 3. Background event yields are calculated using the fitted background function.

Background and signal functions, with their fit parameters. For the background function, the parameters are fitted from the data distribution. The "Yield" is the total number of events in data in the single-b-tagged or double-b-tagged fitting range. For the single-b-tagged category, the fitting range is [1400GeV, 4200GeV], and for the double-b-tagged category, it is [600GeV, 4200GeV]. The background event yields per bin in Table 1 and Table 2 are calculated using the data yield multiplied by the integral of the normalized background function in that bin. For the signal function, the value for the parameters are from parametrisation studies and CB stands for a Crystal-Ball function. Signal distributions in Figure 1a and Figure 1b are normalized to an arbitrary yield, for illustration purpose.

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Measurement of light-by-light scattering and search for axion-like particles with 2.2 nb$^{-1}$ of Pb+Pb data with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
CERN-EP-2020-135, 2020.
Inspire Record 1811464 DOI 10.17182/hepdata.95747

This paper describes a measurement of light-by-light scattering based on Pb+Pb collision data recorded by the ATLAS experiment during Run 2 of the LHC. The study uses $2.2$ nb$^{-1}$ of integrated luminosity collected in 2015 and 2018 at $\sqrt{s_\mathrm{NN}}=5.02$ TeV. Light-by-light scattering candidates are selected in events with two photons produced exclusively, each with transverse energy $E_{\mathrm{T}}^{\gamma} > 2.5$ GeV, pseudorapidity $|\eta_{\gamma}| < 2.37$, diphoton invariant mass $m_{\gamma\gamma} > 5$ GeV, and with small diphoton transverse momentum and diphoton acoplanarity. The integrated and differential fiducial cross sections are measured and compared with theoretical predictions. The diphoton invariant mass distribution is used to set limits on the production of axion-like particles. This result provides the most stringent limits to date on axion-like particle production for masses in the range 6-100 GeV. Cross sections above 2 to 70 nb are excluded at the 95% CL in that mass interval.

11 data tables

Measured differential fiducial cross sections of $\gamma\gamma \rightarrow \gamma\gamma$ production in Pb+Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV for diphoton invariant mass are shown as points with error bars giving the statistical uncertainty and grey bands indicating the size of the total uncertainty. The results are compared with the prediction from the SuperChic v3.0 MC generator (solid line) with bands denoting the theoretical uncertainty.

Measured normalised differential fiducial cross sections of $\gamma\gamma \rightarrow \gamma\gamma$ production in Pb+Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV for diphoton invariant mass are shown as points with error bars giving the statistical uncertainty and grey bands indicating the size of the total uncertainty. The results are compared with the prediction from the SuperChic v3.0 MC generator (solid line).

Measured differential fiducial cross sections of $\gamma\gamma \rightarrow \gamma\gamma$ production in Pb+Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV for diphoton $|cos(\theta*)|$ are shown as points with error bars giving the statistical uncertainty and grey bands indicating the size of the total uncertainty. The results are compared with the prediction from the SuperChic v3.0 MC generator (solid line) with bands denoting the theoretical uncertainty.

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Search for supersymmetry in proton-proton collisions at $\sqrt{s} =$ 13 TeV in events with high-momentum Z bosons and missing transverse momentum

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 09 (2020) 149, 2020.
Inspire Record 1811111 DOI 10.17182/hepdata.96235

A search for new physics in events with two highly Lorentz-boosted Z bosons and large missing transverse momentum is presented. The analyzed proton-proton collision data, corresponding to an integrated luminosity of 137 fb$^{-1}$, were recorded at $\sqrt{s} =$ 13 TeV by the CMS experiment at the CERN LHC. The search utilizes the substructure of jets with large radius to identify quark pairs from Z boson decays. Backgrounds from standard model processes are suppressed by requirements on the jet mass and the missing transverse momentum. No significant excess in the event yield is observed beyond the number of background events expected from the standard model. For a simplified supersymmetric model in which the Z bosons arise from the decay of gluinos, an exclusion limit of 1920 GeV on the gluino mass is set at 95% confidence level. This is the first search for beyond-standard-model production of pairs of boosted Z bosons plus large missing transverse momentum.

14 data tables

Cross section upper limit vs m(GLUINO) for SMS model T5ZZ.

Cross section upper limit vs m(GLUINO) for SMS model T5ZZ.

Cross section upper limit vs m(GLUINO) for SMS model T5ZZ.

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Measurement of the associated production of a Higgs boson decaying into $b$-quarks with a vector boson at high transverse momentum in $pp$ collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
2020.
Inspire Record 1810348 DOI 10.17182/hepdata.94801

The associated production of a Higgs boson with a $W$ or $Z$ boson decaying into leptons and where the Higgs boson decays to a $b\bar{b}$ pair is measured in the high vector-boson transverse momentum regime, above 250 GeV, with the ATLAS detector. The analysed data, corresponding to an integrated luminosity of 139 fb$^{-1}$, were collected in proton-proton collisions at the Large Hadron Collider between 2015 and 2018 at a centre-of-mass energy of $\sqrt{s} = 13$ TeV. The measured signal strength, defined as the ratio of the measured signal yield to that predicted by the Standard Model, is $0.72 ^{+0.39}_{-0.36}$ corresponding to an observed (expected) significance of 2.1 (2.7) standard deviations. Cross-sections of associated production of a Higgs boson decaying into $b$ quark pairs with a $W$ or $Z$ gauge boson, decaying into leptons, are measured in two exclusive transverse momentum regions, 250-400 GeV and above 400 GeV, and interpreted as constraints on anomalous couplings in the framework of a Standard Model effective field theory.

3 data tables

Observed correlations between the measured reduced stage-1.2 simplified template VH, V->leptons and H->bb cross sections, including both the statistical and systematic uncertainties.

Measured and predicted VH, V->leptons reduced stage-1.2 simplified template cross sections times the H->bb and V->leptons branching fractions with corresponding uncertainties. All possible Z decays into neutral and charged leptons are considered.

Linear combinations of Wilson coefficients corresponding to the principal component decomposition eigenvectors. The corresponding eigenvalues, representing in the gaussian approximation the inverse uncertainty square of the measured eigenvector, is also indicated.


Reconstruction and identification of boosted di-$\tau$ systems in a search for Higgs boson pairs using 13 TeV proton$-$proton collision data in ATLAS

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
2020.
Inspire Record 1809175 DOI 10.17182/hepdata.95432

In this paper, a novel technique, referred to as the di-$\tau$ tagger, is designed to reconstruct and identify hadronically decaying $\tau^+\tau^-$ pairs with a large Lorentz boost in the ATLAS experiment at the Large Hadron Collider. A benchmark di-$\tau$ tagging selection is employed in the search for resonant Higgs boson pair production, where one Higgs boson decays into a boosted $b\bar{b}$ pair and the other into a boosted $\tau^+\tau^-$ pair, with two hadronically decaying $\tau$-leptons in the final state. Using 139 fb$^{-1}$ of proton$-$proton collision data recorded at a centre-of-mass energy of 13 TeV, the efficiency of the di-$\tau$ tagger is determined and the background with quark- or gluon-initiated jets misidentified as di-$\tau$ objects is estimated. The search for a heavy, narrow, scalar resonance produced via gluon$-$gluon fusion and decaying into two Higgs bosons is carried out in the mass range 1$-$3 TeV using the same dataset. No deviations from the Standard Model predictions are observed, and 95% confidence-level exclusion limits are set on this model.

4 data tables

Signal acceptance times selection efficiency as a function of the resonance mass, at various stages of the event selection. From top to bottom: an event pre-selection (trigger, object definitions and $E_{T}^{miss}>10$ GeV) is performed first; the requirements on the di-$\tau$ object and large-$R$ jet detailed in the text are then applied; finally, the $HH$ SR definition must be satisfied.

Distribution of $m^{vis}_{HH}$ after applying all the event selection that define the $HH$ SR, except the requirement on $m^{vis}_{HH}$. The background labelled as "Others" contains $W$+jets, diboson, $t\bar{t}$ and single-top-quark processes. The $X\rightarrow HH \rightarrow b\bar{b}\tau^{+}\tau^{-}$ signal is overlaid for two resonance mass hypotheses with a cross-section set to the expected limit, while all backgrounds are pre-fit. The first and the last bins contains the under-flow and over-flow bin entries, respectively. The hatched bands represent combined statistical and systematic uncertainties.

Event yields of the various estimated backgrounds and data, computed in the signal region of the search for $X\rightarrow HH \rightarrow b\bar{b}\tau^{+}\tau^{-}$. The background labelled as "Others" contains $W$+jets, diboson, $t\bar{t}$ and single-top-quark processes. Statistical and systematic uncertainties are quoted. The background yields and uncertainties are pre-fit and are found to be similar to those post-fit.

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Search for resonances decaying into a weak vector boson and a Higgs boson in the fully hadronic final state produced in proton$-$proton collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
2020.
Inspire Record 1806507 DOI 10.17182/hepdata.94788

A search for heavy resonances decaying into a $W$ or $Z$ boson and a Higgs boson produced in proton$-$proton collisions at the Large Hadron Collider at $\sqrt{s} = 13$ TeV is presented. The analysis utilizes the dominant $W \to q \bar{q}^\prime$ or $Z \to q \bar{q}$ and $H \to b \bar{b}$ decays with substructure techniques applied to large-radius jets. A sample corresponding to an integrated luminosity of 139 fb$^{-1}$ collected with the ATLAS detector is analyzed and no significant excess of data is observed over the background prediction. The results are interpreted in the context of the Heavy Vector Triplet model with spin-1 $W^\prime$ and $Z^\prime$ bosons. Upper limits on the cross section are set for resonances with mass between 1.5 and 5.0 TeV, ranging from 6.8 to 0.53 fb for $W^\prime \to WH$ and from 8.7 to 0.53 fb for $Z^\prime \to ZH$ at the 95 % confidence level.

4 data tables

Observed and expected 95% CL upper limits on the cross section in the WH channel.

Observed and expected 95% CL upper limits on the cross section in the ZH channel.

Signal acceptance times efficiency of HVT WH(qqbb) events as a function of the resonance mass at different cut stages. Auxiliary table attached for 2 TeV mass point.

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Measurements of inclusive and differential cross-sections of combined $t\bar{t}\gamma$ and $tW\gamma$ production in the $e\mkern-2mu\mu$ channel at 13 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
JHEP 09 (2020) 049, 2020.
Inspire Record 1806806 DOI 10.17182/hepdata.94915

Inclusive and differential cross-sections for the production of top quarks in association with a photon are measured with proton$-$proton collision data corresponding to an integrated luminosity of 139 fb$^{-1}$. The data were collected by the ATLAS detector at the LHC during Run 2 between 2015 and 2018 at a centre-of-mass energy of 13 TeV. The measurements are performed in a fiducial volume defined at parton level. Events with exactly one photon, one electron and one muon of opposite sign, and at least two jets, of which at least one is $b$-tagged, are selected. The fiducial cross-section is measured to be $39.6\,^{+2.7}_{-2.3}\,\textrm{fb}$. Differential cross-sections as functions of several observables are compared with state-of-the-art Monte Carlo simulations and next-to-leading-order theoretical calculations. These include cross-sections as functions of photon kinematic variables, angular variables related to the photon and the leptons, and angular separations between the two leptons in the event. All measurements are in agreement with the predictions from the Standard Model.

24 data tables

The measured fiducial cross-section in the electron-muon channel. The first uncertainty is the statistical uncertainty and the second one is the systematic uncertainty.

The absolute differential cross-section measured in the fiducial phase-space as a function of the photon pT in the electron-muon channel. The uncertainty is decomposed into four components which are the signal modelling uncertainty, the background modelling uncertainty, the experimental uncertainty, and the data statistical uncertainty.

The absolute differential cross-section measured in the fiducial phase-space as a function of the photon $|\eta|$ in the electron-muon channel. The uncertainty is decomposed into four components which are the signal modelling uncertainty, the background modelling uncertainty, the experimental uncertainty, and the data statistical uncertainty.

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Search for decays of the 125 GeV Higgs boson into a Z boson and a $\rho$ or $\phi$ meson

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/HIG-19-012 (CMS Public Pages), 2020.
Inspire Record 1806506 DOI 10.17182/hepdata.95908

Decays of the 125 GeV Higgs boson into a Z boson and a $\rho^0$(770) or $\phi$(1020) meson are searched for using proton-proton collision data collected by the CMS experiment at the LHC at $\sqrt{s}= $ 13 TeV. The analysed data set corresponds to an integrated luminosity of 137 fb$^{-1}$. Events are selected in which the Z boson decays into a pair of electrons or a pair of muons, and the $\rho$ and $\phi$ mesons decay into pairs of pions and kaons, respectively. No significant excess above the background model is observed. As different polarization states are possible for the decay products of the Z boson and $\rho$ or $\phi$ mesons, affecting the signal acceptance, scenarios in which the decays are longitudinally or transversely polarized are considered. Upper limits at the 95% confidence level on the Higgs boson branching fractions into Z$\rho$ and Z$\phi$ are determined to be 1.04-1.31% and 0.31-0.40%, respectively, where the ranges reflect the considered polarization scenarios; these values are 740-940 and 730-950 times larger than the respective standard model expectations. These results constitute the first experimental limits on the two decay channels.

2 data tables

Observed and expected 95% CL upper limits on B(H $\rightarrow$ Z$\rho$), for different polarizations.

Observed and expected 95% CL upper limits on B(H $\rightarrow$ Z$\phi$), for different polarizations.


Measurements of $WH$ and $ZH$ production in the $H \rightarrow b\bar{b}$ decay channel in $pp$ collisions at 13 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
2020.
Inspire Record 1805282 DOI 10.17182/hepdata.94800

Measurements of the Standard Model Higgs boson decaying into a $b\bar{b}$ pair and produced in association with a $W$ or $Z$ boson decaying into leptons, using proton-proton collision data collected between 2015 and 2018 by the ATLAS detector, are presented. The measurements use collisions produced by the Large Hadron Collider at a centre-of-mass energy of $\sqrt{s} = $13 TeV, corresponding to an integrated luminosity of 139 fb$^{-1}$. The production of a Higgs boson in association with a $W$ or $Z$ boson is established with observed (expected) significances of 4.0 (4.1) and 5.3 (5.1) standard deviations, respectively. Cross-sections of associated production of a Higgs boson decaying into bottom quark pairs with an electroweak gauge boson, $W$ or $Z$, decaying into leptons are measured as a function of the gauge boson transverse momentum in kinematic fiducial volumes. The cross-section measurements are all consistent with the Standard Model expectations, and the total uncertainties vary from 30% in the high gauge boson transverse momentum regions to 85% in the low regions. Limits are subsequently set on the parameters of an effective Lagrangian sensitive to modifications of the $WH$ and $ZH$ processes as well as the Higgs boson decay into $b\bar{b}$.

3 data tables

Best-fit values and uncertainties for $VH, V\rightarrow\mathrm{leptons}$ for the cross-section times the $H\rightarrow b\bar{b}$ branching fraction, in the reduced stage-1.2 simplififed template cross-sections (STXS) scheme. The SM predictions for each region is also shown. They are obtained from the samples of simulated events scaled to the inclusive cross-sections calculated at NNLO(QCD)+NLO(EW) accuracy for the $qq\rightarrow WH$ and $qq\rightarrow ZH$ processes, and at NLO+NLL accuracy for the $gg\rightarrow ZH$ process. The contributions to the total uncertainty in the measurements from statistical (Stat.) or systematic uncertainties in the signal modelling (Th. sig.), background modelling (Th. bkg.) and in experimental performance (Exp.) are given separately. All leptonic decays of the $V$ bosons (including those to $\tau$ leptons, $\ell = e, \mu, \tau$) are considered.

Observed correlations between the measured reduced stage-1.2 simplified template $VH, H \rightarrow b\bar{b}$ cross-sections (STXS), including both the statistical and systematic uncertainties. All leptonic decays of the $V$ bosons (including those to $\tau$ leptons, $\ell = e, \mu, \tau$) are considered.

Linear combination of Wilson coefficients corresponding to SMEFT operators in the Warsaw basis for which this analysis provides orthogonal constraints (eigenvectors). Eigenvalues are shown for each eigenvector, which provides a measure of the experimental sensitivity to that linear combination. The modifications to the $qq\rightarrow ZH$ and $qq\rightarrow WH$ processes due to SMEFT operators are computed at LO, and changes to the $gg\rightarrow ZH$ process are neglected.


Differential cross-section measurements for the electroweak production of dijets in association with a $Z$ boson in proton-proton collisions at ATLAS

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
2020.
Inspire Record 1803608 DOI 10.17182/hepdata.94218

Differential cross-section measurements are presented for the electroweak production of two jets in association with a $Z$ boson. These measurements are sensitive to the vector-boson fusion production mechanism and provide a fundamental test of the gauge structure of the Standard Model. The analysis is performed using proton-proton collision data collected by ATLAS at $\sqrt{s}$=13 TeV and with an integrated luminosity of 139 fb$^{-1}$. The differential cross-sections are measured in the $Z\rightarrow \ell^+\ell^-$ decay channel ($\ell=e,\mu$) as a function of four observables: the dijet invariant mass, the rapidity interval spanned by the two jets, the signed azimuthal angle between the two jets, and the transverse momentum of the dilepton pair. The data are corrected for the effects of detector inefficiency and resolution and are sufficiently precise to distinguish between different state-of-the-art theoretical predictions calculated using Powheg+Pythia8, Herwig7+Vbfnlo and Sherpa 2.2. The differential cross-sections are used to search for anomalous weak-boson self-interactions using a dimension-six effective field theory. The measurement of the signed azimuthal angle between the two jets is found to be particularly sensitive to the interference between the Standard Model and dimension-six scattering amplitudes and provides a direct test of charge-conjugation and parity invariance in the weak-boson self-interactions.

21 data tables

Differential cross-sections for EW $Zjj$ production as a function of $m_{jj}$ with breakdown of associated uncertainties. The statistical uncertainty is correlated across bins according to the statistical cross correlation matrix presented in Table 21.

Differential cross-sections for EW $Zjj$ production as a function of $|\Delta y_{jj}|$ with breakdown of associated uncertainties. The statistical uncertainty is correlated across bins according to the statistical cross correlation matrix presented in Table 21.

Differential cross-sections for EW $Zjj$ production as a function of $p_{\mathrm{T},\ell\ell}$ with breakdown of associated uncertainties. The statistical uncertainty is correlated across bins according to the statistical cross correlation matrix presented in Table 21.

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Search for new non-resonant phenomena in high-mass dilepton final states with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
2020.
Inspire Record 1802523 DOI 10.17182/hepdata.94786

A search for new physics with non-resonant signals in dielectron and dimuon final states in the mass range above 2 TeV is presented. This is the first search for non-resonant signals in dilepton final states at the LHC to use a background estimate from the data. The data, corresponding to an integrated luminosity of 139 fb$^{-1}$, were recorded by the ATLAS experiment in proton-proton collisions at a centre-of-mass energy of $\sqrt{s} = 13$ TeV during Run 2 of the Large Hadron Collider. The benchmark signal signature is a two-quark and two-lepton contact interaction, which would enhance the dilepton event rate at the TeV mass scale. To model the contribution from background processes a functional form is fit to the dilepton invariant-mass spectra in data in a mass region below the region of interest. It is then extrapolated to a high-mass signal region to obtain the expected background there. No significant deviation from the expected background is observed in the data. Upper limits at 95% CL on the number of events and the visible cross-section times branching fraction for processes involving new physics are provided. Observed (expected) 95% CL lower limits on the contact interaction energy scale reach 35.8(37.6) TeV.

7 data tables

Expected and observed event yields in each signal bin.

Model-independent upper limits at 95% CL on the number of signal events in the (constructive/destructive interference) SRs used in the analysis for dielectrons and dimuons.

Lower limits at 95$\%$ CL on $\Lambda$ for the dielectron channel for different signal chiralities in the (constructive/destructive interference) SRs of the analysis.

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Measurement of the $t\bar{t}$ production cross-section in the lepton+jets channel at $\sqrt{s}=13$ TeV with the ATLAS experiment

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
Phys.Lett.B 810 (2020) 135797, 2020.
Inspire Record 1802524 DOI 10.17182/hepdata.95748

The $t\bar{t}$ production cross-section is measured in the lepton+jets channel using proton$-$proton collision data at a centre-of-mass energy of $\sqrt{s}=13$ TeV collected with the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 139 fb$^{-1}$. Events with exactly one charged lepton and four or more jets in the final state, with at least one jet containing $b$-hadrons, are used to determine the $t\bar{t}$ production cross-section through a profile-likelihood fit. The inclusive cross-section is measured to be ${\sigma_{\text{inc}} = 830 \pm 0.4~\text{(stat.)}\pm 36~\text{(syst.)}\pm 14~\text{(lumi.)}~\mathrm{pb}}$ with a relative uncertainty of 4.6%. The result is consistent with theoretical calculations at next-to-next-to-leading order in perturbative QCD.

5 data tables

The results of fitted inclusive and fiducial ${t\bar{t}}$ cross-sections

Ranking of the systematic uncertainties on the measured cross-section, normalised to the predicted value, in the inclusive fit to data. The impact of each nuisance parameter, $\Delta \sigma_{\text{inc}}/\sigma^{\text{pred.}}_{\text{inc}}$, is computed by comparing the nominal best-fit value of $\sigma_{\text{inc}}/\sigma^{\text{pred}}_{\text{inc}}$ with the result of the fit when fixing the considered nuisance parameter to its best-fit value, $\theta$, shifted by its pre-fit (post-fit) uncertainties $\pm \Delta \theta$ ($\pm \Delta \hat{\theta}$). The figure shows the effect of the ten most significant uncertainties.

Ranking of the systematic uncertainties on the measured cross-section, normalised to the predicted value, in the fiducial fit to data. The impact of each nuisance parameter, $\Delta \sigma_{\text{fid}}/\sigma^{\text{pred.}}_{\text{fid}}$, is computed by comparing the nominal best-fit value of $\sigma_{\text{fid}}/\sigma^{\text{pred}}_{\text{fid}}$ with the result of the fit when fixing the considered nuisance parameter to its best-fit value, $\theta$, shifted by its pre-fit (post-fit) uncertainties $\pm \Delta \theta$ ($\pm \Delta \hat{\theta}$). The figure shows the effect of the ten most significant uncertainties.

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Evidence for top quark production in nucleus-nucleus collisions

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Nature Physics and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/HIN-19-001 (CMS Public Pages), 2020.
Inspire Record 1802092 DOI 10.17182/hepdata.93878

Ultrarelativistic heavy ion collisions recreate in the laboratory the thermodynamical conditions prevailing in the early universe up to 10$^{-6}$ seconds, thereby allowing the study of the quark-gluon plasma (QGP), a state of quantum chromodynamics (QCD) matter with deconfined partons. The top quark, the heaviest elementary particle known, is accessible in nucleus-nucleus collisions at the CERN LHC, and constitutes a novel probe of the QGP. Here, we report the first-ever evidence for the production of top quarks in nucleus-nucleus collisions, using lead-lead collision data at a nucleon-nucleon centre-of-mass energy of 5.02 TeV recorded by the CMS experiment. Two methods are used to measure the cross section for top quark pair production ($\sigma_\mathrm{t\bar{t}}$) via the decay into charged leptons (electrons or muons) and bottom quarks. One method relies on the leptonic information alone, and the second one exploits, in addition, the presence of bottom quarks. The measured cross sections, $\sigma_\mathrm{t\bar{t}} = $ 2.54$^{+0.84}_{-0.74}$ and 2.03$^{+0.71}_{-0.64}$ $\mu$b, respectively, are compatible with expectations from scaled proton-proton data and QCD predictions.

1 data table

Inclusive $\mathrm{t\bar{t}}$ cross sections measured with two methods, relying on the leptonic information alone ($2\ell_{\mathrm{OS}}$), and the second one exploits, in addition, the presence of bottom quarks ($2\ell_{\mathrm{OS}}+N_{\mathrm{b-tag}}$), in the combined $\mathrm{e}^+\mathrm{e}^-$, $\mu^+\mu^-$, and $\mathrm{e}^\pm\mu^\mp$ final states in PbPb collisions at 5.02 TeV, and pp results at $\sqrt{\smash[b]{s}}=5.02$ TeV (scaled by $A^2$) from JHEP 03 (2018) 115. The measurements are compared with theoretical predictions at NNLO+NNLL accuracy in QCD. The inner (outer) experimental uncertainty bars include statistical (statistical and systematic, added in quadrature) uncertainties. The inner (outer) theoretical uncertainty bands correspond to nuclear or free-nucleon PDF (PDF and scale, added in quadrature) uncertainties.


Measurement of the azimuthal anisotropy of $\Upsilon$(1S) and $\Upsilon$(2S) mesons in PbPb collisions at $\sqrt{s_\mathrm{NN}} =$ 5.02 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys. Lett. B and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/HIN-19-002 (CMS Public Pages), 2020.
Inspire Record 1801111 DOI 10.17182/hepdata.93880

The second-order Fourier coefficients ($v_2$) characterizing the azimuthal distribution of $\Upsilon$(1S) and $\Upsilon$(2S) mesons arising from PbPb collisions at $\sqrt{s_\mathrm{NN}} =$ 5.02 TeV are studied. The $\Upsilon$ mesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The data set was collected in 2018 and corresponds to an integrated luminosity of 1.7 nb$^{-1}$. The scalar product method is used to extract the $v_2$ coefficients of the azimuthal distribution. Results are reported for the rapidity range $|y|\lt$ 2.4, with the transverse momentum 0 $\lt p_\mathrm{T} \lt$ 50 GeV/$c$, and in three centrality ranges of 10-30, 30-50 and 50-90%. In contrast to the J/$\psi$ mesons, no azimuthal anisotropy is observed for the $\Upsilon$ mesons.

5 data tables

$v_{2}$ of $\Upsilon(\mathrm{1S})$ mesons as a function of collision centrality.

$v_{2}$ of $\Upsilon(\mathrm{1S})$ and $\Upsilon(\mathrm{2S})$ mesons integrated for 10-90% centrality range.

$v_{2}$ of $\Upsilon(\mathrm{1S})$ as a function of $p_{\mathrm{T}}$ in 10-90% centrality range.

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Search for pairs of scalar leptoquarks decaying into quarks and electrons or muons in $\sqrt{s}=13$ TeV pp collisions with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
CERN-EP-2020-084, 2020.
Inspire Record 1800410 DOI 10.17182/hepdata.95211

A search for new-physics resonances decaying into a lepton and a jet performed by the ATLAS experiment is presented. Scalar leptoquarks pair-produced in pp collisions at $\sqrt{s}=13$ TeV at the Large Hadron Collider are considered using an integrated luminosity of 139 fb$^{-1}$, corresponding to the full Run 2 dataset. They are searched for in events with two electrons or two muons and two or more jets, including jets identified as arising from the fragmentation of $c$- or $b$-quarks. The observed yield in each channel is consistent with the Standard Model background expectation. Leptoquarks with masses below 1.8 TeV and 1.7 TeV are excluded in the electron and muon channels, respectively, assuming a branching ratio into a charged lepton and a quark of 100%, with minimal dependence on the quark flavour. Upper limits on the aforementioned branching ratio are also given as a function of the leptoquark mass.

30 data tables

Distribution of the resonance mass in the pretag Signal Region of the $ qe$ channel for the post-fit background, the observed data, and the expected signal with $m_{LQ} = 1$ TeV.

Distribution of the resonance mass in the pretag Signal Region of the $ q\mu$ channel for the post-fit background, the observed data, and the expected signal with $m_{LQ} = 1$ TeV.

Distribution of the resonance mass in the untagged Signal Region of the $ ce$ channel for the post-fit background, the observed data, and the expected signal with $m_{LQ} = 1$ TeV.

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Search for Higgs boson decays into two new low-mass spin-0 particles in the 4$b$ channel with the ATLAS detector using $pp$ collisions at $\sqrt{s}= 13$ TeV

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
2020.
Inspire Record 1797642 DOI 10.17182/hepdata.94383

This paper describes a search for beyond the Standard Model decays of the Higgs boson into a pair of new spin-0 particles subsequently decaying into $b$-quark pairs, $H \rightarrow aa \rightarrow (b\bar{b})(b\bar{b})$, using proton-proton collision data collected by the ATLAS detector at the Large Hadron Collider at center-of-mass energy $\sqrt{s}=13$ TeV. This search focuses on the regime where the decay products are collimated and in the range $15 \leq m_a \leq 30$ GeV and is complementary to a previous search in the same final state targeting the regime where the decay products are well separated and in the range $20 \leq m_a \leq 60$ GeV. A novel strategy for the identification of the $a \rightarrow b\bar{b}$ decays is deployed to enhance the efficiency for topologies with small separation angles. The search is performed with 36 fb$^{-1}$ of integrated luminosity collected in 2015 and 2016 and sets upper limits on the production cross-section of $H \rightarrow aa \rightarrow (b\bar{b})(b\bar{b})$, where the Higgs boson is produced in association with a $Z$ boson.

5 data tables

Summary of the 95% CL upper limits on $\sigma_{ZH} BR(H\rightarrow aa \rightarrow (b\bar{b})(b\bar{b}))$. Both observed and expected limits are listed. In the case of the expected limits, one- and two-standard-deviation uncertainty bands are also listed.

Summary of the observed 95% CL upper limits on $\sigma_{ZH} BR(H\rightarrow aa \rightarrow (b\bar{b})(b\bar{b}))$ for the resolved analysis.

Efficiency and acceptance for simulated $ZH(\rightarrow aa\rightarrow (b\bar{b})(b\bar{b}))$ samples in two signal regions (SR) of the analysis, one with two $a\to b\bar{b}$ candidates in the High Purity Category (HPC), and the other with one $a\to b\bar{b}$ candidate in the High Purity Category (HPC) and one in the Low Purity Category (LPC).

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Search for a light charged Higgs boson in the H$^\pm$ $\to $ cs channel in proton-proton collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.D 102 (2020) 072001, 2020.
Inspire Record 1796727 DOI 10.17182/hepdata.94261

A search is conducted for a low-mass charged Higgs boson produced in a top quark decay and subsequently decaying into a charm and a strange quark. The data sample was recorded in proton-proton collisions at $\sqrt{s} =$ 13 TeV by the CMS experiment at the LHC and corresponds to an integrated luminosity of 35.9 fb$^{-1}$. The search is performed in the process of top quark pair production, where one top quark decays to a bottom quark and a charged Higgs boson, and the other to a bottom quark and a W boson. With the W boson decaying to a charged lepton (electron or muon) and a neutrino, the final state comprises an isolated lepton, missing transverse momentum, and at least four jets, of which two are tagged as b jets. To enhance the search sensitivity, one of the jets originating from the charged Higgs boson is required to satisfy a charm tagging selection. No significant excess beyond standard model predictions is found in the dijet invariant mass distribution. An upper limit in the range 1.68-0.25% is set on the branching fraction of the top quark decay to the charged Higgs boson and bottom quark for a charged Higgs boson mass between 80 and 160 GeV.

3 data tables

Expected and observed 95% CL exclusion limits in % on BR(t->H+ b) for the muon channel after the individual charm tagging categories have been combined.

Expected and observed 95% CL exclusion limits in % on BR(t->H+ b) for the electron channel after the individual charm tagging categories have been combined.

Expected and observed 95% CL exclusion limits in % on BR(t->H+ b) after the individual charm tagging categories and the muon and electron channels have been combined.


Dependence of inclusive jet production on the anti-$k_\mathrm{T}$ distance parameter in pp collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/SMP-19-003 (CMS Public Pages), 2020.
Inspire Record 1795080 DOI 10.17182/hepdata.95241

The dependence of inclusive jet production in proton-proton collisions with a center-of-mass energy of 13 TeV on the distance parameter $R$ of the anti-$k_\mathrm{T}$ algorithm is studied using data corresponding to integrated luminosities up to 35.9 fb$^{-1}$ collected by the CMS experiment in 2016. The ratios of the inclusive cross sections as functions of transverse momentum $p_\mathrm{T}$ and rapidity $y$, for $R$ in the range 0.1 to 1.2 to those using $R=$ 0.4 are presented in the region 84 $\lt p_\mathrm{T} \lt$ 1588 GeV and $|y|\lt$ 2.0. The results are compared to calculations at leading and next-to-leading order in the strong coupling constant using different parton shower models. The variation of the ratio of cross sections with $R$ is well described by calculations including a parton shower model, but not by a leading-order quantum chromodynamics calculation including nonperturbative effects. The agreement between the data and the theoretical predictions for the ratios of cross sections is significantly improved when next-to-leading order calculations with nonperturbative effects are used.

88 data tables

Ratio of differential cross section of AK1 jets with respect to AK4 jets a function of jet PT in the rapidity range |y|<0.5. The nonperturbative correction can be used to scale fixed-order theory prediction to compare to data at particle level.

Ratio of differential cross section of AK1 jets with respect to AK4 jets a function of jet PT in the rapidity range 0.5<|y|<1.0. The nonperturbative correction can be used to scale fixed-order theory prediction to compare to data at particle level.

Ratio of differential cross section of AK1 jets with respect to AK4 jets a function of jet PT in the rapidity range 1.0<|y|<1.5. The nonperturbative correction can be used to scale fixed-order theory prediction to compare to data at particle level.

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A search for the $Z\gamma$ decay mode of the Higgs boson in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
Phys.Lett.B 809 (2020) 135754, 2020.
Inspire Record 1795890 DOI 10.17182/hepdata.94315

A search for the $Z\gamma$ decay of the Higgs boson, with $Z$ boson decays into pairs of electrons or muons is presented. The analysis uses proton$-$proton collision data at $\sqrt{s}$ = 13 TeV corresponding to an integrated luminosity of 139 fb$^{-1}$ recorded by the ATLAS detector at the Large Hadron Collider. The observed data are consistent with the expected background with a $p$-value of 1.3%. An upper limit at 95% confidence level on the production cross-section times the branching ratio for $pp\to H\to Z\gamma$ is set at 3.6 times the Standard Model prediction while 2.6 times is expected in the presence of the Standard Model Higgs boson. The best-fit value for the signal yield normalised to the Standard Model prediction is $2.0^{+1.0}_{-0.9}$ where the statistical component of the uncertainty is dominant.

4 data tables

The number of data events selected in each category, and in the $Z\gamma$ mass range of 105--160 GeV. In addition, the following numbers are given: the expected number of Higgs boson signal events in an interval around the peak position for a signal of $m_{H}=125.09$ GeV containing 68% of the SM signal ($S_{68}$), the mass resolution quantified by the width of the $S_{68}$ interval ($w_{68}$) defined by the difference between the 84th and the 16th percentile of the signal mass distribution, the background in the $S_{68}$ interval ($B_{68}$) is estimated from fits to the data using the background models described in paper, the observed number of events in the $S_{68}$ interval ($N_{68}$), the expected signal-to-background ratio in the $S_{68}$ window ($S_{68}/B_{68}$), and the expected significance estimate defined as $S_{68}/\sqrt{S_{68}+B_{68}}$. The final row of the table displays the expected number of events for an analysis performed in a single inclusive category.

Upper limit at 95% confidence level on the signal yield normalised to the Standard Model prediction (signal strength) for $pp \to H \to Z+\gamma$

The best fit value for the signal yield normalised to the Standard Model prediction (signal strength) for $pp \to H \to Z+\gamma$

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Search for $t\bar{t}$ resonances in fully hadronic final states in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
JHEP 10 (2020) 061, 2020.
Inspire Record 1795076 DOI 10.17182/hepdata.94415

This paper presents a search for new heavy particles decaying into a pair of top quarks using 139 fb$^{-1}$ of proton$-$proton collision data recorded at a centre-of-mass energy of $\sqrt{s}=13$ TeV with the ATLAS detector at the Large Hadron Collider. The search is performed using events consistent with pair production of high-transverse-momentum top quarks and their subsequent decays into the fully hadronic final states. The analysis is optimized for resonances decaying into a $t\bar{t}$ pair with mass above 1.4 TeV, exploiting a dedicated multivariate technique with jet substructure to identify hadronically decaying top quarks using large-radius jets and evaluating the background expectation from data. No significant deviation from the background prediction is observed. Limits are set on the production cross-section times branching fraction for the new $Z'$ boson in a topcolor-assisted-technicolor model. The $Z'$ boson masses below 3.9 and 4.7 TeV are excluded at 95% confidence level for the decay widths of 1% and 3%, respectively.

6 data tables

Acceptance and acceptance times selection efficiency as a function of $m^{gen}_{t\bar{t}}$ in SR$1b$. The acceptance is measured as the fraction of events with two leading truth-contained large-$R$ jets, both satisfying the kinematic requirements, but not containing generator-level electrons or muons, as described in the paper. The acceptance $\times$ efficiency is calculated with respect to the full analysis selections including top- and $b$-tagging requirements on the two leading large-$R$ jets. The $m^{gen}_{t\bar{t}}$ is calculated from the momenta of top and anti-top quarks at the generator level before final-state radiation. The branching fractions of the $t \bar{t}$ into all possible final states are included in the acceptance calculation.

Acceptance and acceptance times selection efficiency as a function of $m^{gen}_{t\bar{t}}$ in SR$2b$. The acceptance is measured as the fraction of events with two leading truth-contained large-$R$ jets, both satisfying the kinematic requirements, but not containing generator-level electrons or muons, as described in the paper. The acceptance $\times$ efficiency is calculated with respect to the full analysis selections including top- and $b$-tagging requirements on the two leading large-$R$ jets. The $m^{gen}_{t\bar{t}}$ is calculated from the momenta of top and anti-top quarks at the generator level before final-state radiation. The branching fractions of the $t \bar{t}$ into all possible final states are included in the acceptance calculation.

Observed $m_{t\bar{t}}^{reco}$ distributions in data for SR$1b$, shown together with the result of the fit with the three-shape-parameter function. The error bars indicate the effect of the fit parameter uncertainty on the background prediction. The bin width of the distributions is chosen to be the same as that used in the background parameterization.

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Observation of the B$^0_\mathrm{s}\to $X(3872)$\phi$ decay

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett. 125 (2020) 152001, 2020.
Inspire Record 1795066 DOI 10.17182/hepdata.94444

Using a data sample of proton-proton collisions at $\sqrt{s} =$ 13 TeV, corresponding to an integrated luminosity of 140 fb$^{-1}$ collected by the CMS experiment in 2016-2018, the B$^0_\mathrm{s}$ $\to$ X(3872)$\phi$ decay is observed. Decays into J/$\psi\,\pi^+\pi^-$ and K$^+$K$^-$ are used to reconstruct, respectively, the X(3872) and $\phi$. The ratio of the product of branching fractions $\mathcal{B}($B$^0_\mathrm{s}$ $\to$ X(3872)$\phi)\,\mathcal{B}($X(3872) $\to$ J$/\psi\,\pi^+\pi^-)$ to the product $\mathcal{B}($B$^0_\mathrm{s}$ $\to$ $\psi$(2S)$\phi)\,\mathcal{B}(\psi$(2S) $\to$ J/$\psi\,\pi^+\pi^-)$ is measured to be (2.21 $\pm$ 0.29 (stat) $\pm$ 0.17 (syst))%. The ratio $\mathcal{B}($B$^0_\mathrm{s}$ $\to$ X(3872)$\phi) / \mathcal{B}($B$^{0}$ $\to$ X(3872)K$^0)$ is found to be consistent with one, while the ratio $\mathcal{B}($B$^0_\mathrm{s}$ $\to$ X(3872)$\phi) / \mathcal{B}($B$^+$ $\to$ X(3872)K$^+)$ is two times smaller. This suggests a difference in the production dynamics of the X(3872) in B$^0$ and B$^0_\mathrm{s}$ meson decays compared to B$^+$. The reported observation may shed new light on the nature of the X(3872) particle.

1 data table

The measured ratio of branching fraction products


Measurements of production cross sections of WZ and same-sign WW boson pairs in association with two jets in proton-proton collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Lett.B 809 (2020) 135710, 2020.
Inspire Record 1794169 DOI 10.17182/hepdata.94181

Measurements of production cross sections of WZ and same-sign WW boson pairs in association with two jets in proton-proton collisions at $\sqrt{s} =$ 13 TeV at the LHC are reported. The data sample corresponds to an integrated luminosity of 137 fb$^{-1}$, collected with the CMS detector during 2016-2018. The measurements are performed in the leptonic decay modes W$^\pm$Z $\to$ $\ell^\pm\nu\ell'^\pm\ell'^\mp$ and WW $\to$ $\ell^\pm\nu\ell'^\pm\nu$, where $\ell, \ell' = $ e, $\mu$. Differential fiducial cross sections as functions of the invariant masses of the jet and charged lepton pairs, as well as of the leading-lepton transverse momentum, are measured for WW production and are consistent with the standard model predictions. The dependence of differential cross sections on the invariant mass of the jet pair is also measured for WZ production. An observation of electroweak production of WZ boson pairs is reported with an observed (expected) significance of 6.8 (5.3) standard deviations. Constraints are obtained on the structure of quartic vector boson interactions in the framework of effective field theory.

20 data tables

Relative systematic uncertainties in the EW $W^\pm W^\pm$ and WZ cross section measurements in units of percent.

Expected and observed yields from the standard model processeses in the WW signal region. The combination of the statistical and systematic uncertainties are shown. The predicted yields are shown with their best-fit normalizations from the simultaneous fit.

Expected and observed yields from the standard model processeses in the WZ signal region. The combination of the statistical and systematic uncertainties are shown. The predicted yields are shown with their best-fit normalizations from the simultaneous fit.

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