Constraints on Higgs boson production with large transverse momentum using $H\rightarrow b\bar{b}$ decays in the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, Dale ; et al.
CERN-EP-2021-185, 2021.
Inspire Record 1969589 DOI 10.17182/hepdata.102183

This paper reports constraints on Higgs boson production with transverse momentum above 1 TeV. The analyzed data from proton-proton collisions at a center-of-mass energy of 13 TeV were recorded with the ATLAS detector at the Large Hadron Collider from 2015 to 2018 and correspond to an integrated luminosity of 136 fb$^{-1}$. Higgs bosons decaying into $b\bar{b}$ are reconstructed as single large-radius jets recoiling against a hadronic system and identified by the experimental signature of two $b$-hadron decays. The experimental techniques are validated in the same kinematic regime using the $Z\rightarrow b\bar{b}$ process. The 95% confidence-level upper limit on the cross section for Higgs boson production with transverse momentum above 450 GeV is 115 fb, and above 1 TeV it is 9.6 fb. The Standard Model predictions in the same kinematic regions are 18.4 fb and 0.13 fb, respectively.

11 data tables

- - - - - - - - Overview of HEPData Record - - - - - - - - <br/><br/> <b>Standard Model cross sections:</b> <a href="102183?table=SMcrosssections">table</a><br/><br/> <b>Cutflow ggF:</b> <a href="102183?table=CutflowggF">table</a><br/><br/> <b>Cutflow VBF:</b> <a href="102183?table=CutflowVBF">table</a><br/><br/> <b>Cutflow VH:</b> <a href="102183?table=CutflowVH">table</a><br/><br/> <b>Cutflow ttH:</b> <a href="102183?table=CutflowttH">table</a><br/><br/> <b>Production mode fractional contributions::</b> <a href="102183?table=Fractionalcontribution">table</a><br/><br/> <b>Acceptance times efficiency - fiducial:</b> <a href="102183?table=Acceptancetimesefficiency-fiducial">table</a><br/><br/> <b>Acceptance times efficiency - differential:</b> <a href="102183?table=Acceptancetimesefficiency-differential">table</a><br/><br/> <b>Yield table - fiducial:</b> <a href="102183?table=Eventyields-fiducial">table</a><br/><br/> <b>Yield table - differential:</b> <a href="102183?table=Eventyields-differential">table</a><br/><br/>

Predicted Higgs boson production cross sections within fiducial volumes obtained from the four production mode MC samples (ggF, VBF, VH, and ttH) described in Section 3 with and without higher order electroweak (EW) corrections. All μH values reported are with respect to cross section with EW corrections.

The efficiency for simulated ggF events to pass each analysis cut.

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Search for associated production of a $Z$ boson with an invisibly decaying Higgs boson or dark matter candidates at $\sqrt{s}=13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, Dale ; et al.
CERN-EP-2021-204, 2021.
Inspire Record 1969392 DOI 10.17182/hepdata.114363

A search for invisible decays of the Higgs boson as well as searches for dark matter candidates, produced together with a leptonically decaying $Z$ boson, are presented. The analysis is performed using proton-proton collisions at a centre-of-mass energy of 13 TeV, delivered by the LHC, corresponding to an integrated luminosity of 139 fb$^{-1}$ and recorded by the ATLAS experiment. Assuming Standard Model cross-sections for $ZH$ production, the upper limit on the branching ratio of the Higgs boson to invisible particles is found to be 19% at the 95% confidence level. Exclusion limits are also set for simplified dark matter models and 2HDM$+a$ models.

28 data tables

The expected exclusion contours as a function of (m(med), m($\chi$)), with Axial-vector mediator)

The observed exclusion contours as a function of (m(med), m($\chi$)), with Axial-vector mediator)

The expected exclusion contours as a function of (m(med), m($\chi$)), with Vector mediator)

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Measurement of Higgs boson decay into $b$-quarks in associated production with a top-quark pair in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, Dale ; et al.
CERN-EP-2021-202, 2021.
Inspire Record 1967501 DOI 10.17182/hepdata.114360

The associated production of a Higgs boson and a top-quark pair is measured in events characterised by the presence of one or two electrons or muons. The Higgs boson decay into a $b$-quark pair is used. 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 $0.35^{+0.36}_{-0.34}$. This result is compatible with the Standard Model prediction and corresponds to an observed (expected) significance of 1.0 (2.7) standard deviations. The signal strength is also measured differentially in bins of the Higgs boson transverse momentum in the simplified template cross-section framework, including a bin for specially selected boosted Higgs bosons with transverse momentum above 300 GeV.

74 data tables

Comparison between data and prediction for the DNN $P(H)$ output for the Higgs boson candidate prior to any fit to the data in the single-lepton boosted channel for $300\le p_T^H<450$ GeV. The dashed line shows the ${t\bar {t}H}$ signal distribution normalised to the total background prediction. The uncertainty band includes all uncertainties and their correlations.

Comparison between data and prediction for the DNN $P(H)$ output for the Higgs boson candidate prior to any fit to the data in the single-lepton boosted channel for $p_{{T}}^{H}\ge 450$ GeV. The dashed line shows the ${t\bar {t}H}$ signal distribution normalised to the total background prediction. The uncertainty band includes all uncertainties and their correlations.

Performance of the Higgs boson reconstruction algorithms. For each row of `truth' ${\hat{p}_{{T}}^{H}}$, the matrix shows (in percentages) the fraction of all Higgs boson candidates with reconstructed $p_T^H$ in the various bins of the dilepton (left), single-lepton resolved (middle) and boosted (right) channels.

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Study of dijet events with large rapidity separation in proton-proton collisions at $\sqrt{s}$ = 2.76 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
CMS-FSQ-13-004, 2021.
Inspire Record 1963239 DOI 10.17182/hepdata.113660

The cross sections for inclusive and Mueller-Navelet dijet production are measured as a function of the rapidity separation between the jets in proton-proton collisions at $\sqrt{s}$ = 2.76 TeV for jets with transverse momentum $p_\mathrm{T} \gt $ 35 GeV and rapidity $\vert y\vert\lt $ 4.7. Various dijet production cross section ratios are also measured. A veto on additional jets with $p_\mathrm{T} \gt $ 20 GeV is introduced to improve the sensitivity to the effects of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) evolution. The measurement is compared with the predictions of various Monte Carlo models based on leading-order and next-to-leading-order calculations including the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi leading-logarithm (LL) parton shower as well as the LL BFKL resummation.

24 data tables

Summary of the systematic uncertainties on the cross section dσincl/d∆y.

Summary of the systematic uncertainties on the cross section dσMN/d∆y.

Summary of the systematic uncertainties on the ratio Rincl.

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Search for Higgs bosons decaying into new spin-0 or spin-1 particles in four-lepton final states with the ATLAS detector with 139 fb$^{-1}$ of $pp$ collision data at $\sqrt{s}=13$ TeV

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, Dale ; et al.
CERN-EP-2021-193, 2021.
Inspire Record 1954278 DOI 10.17182/hepdata.111057

Searches are conducted for new spin-0 or spin-1 bosons using events where a Higgs boson with mass $125$ GeV decays into four leptons ($\ell =$$e$,$\mu$). This decay is presumed to occur via an intermediate state which contains two on-shell, promptly decaying bosons: $H \rightarrow XX/ZX \rightarrow 4\ell$, where the new boson $X$ has a mass between 1 and 60 GeV. The search uses $pp$ collision data collected with the ATLAS detector at the LHC with an integrated luminosity of 139 fb$^{-1}$ at a centre-of-mass energy $\sqrt{s}=13$ TeV. The data are found to be consistent with Standard Model expectations. Limits are set on fiducial cross sections and on the branching ratio of the Higgs boson to decay into $XX/ZX$, improving those from previous publications by a factor between two and four. Limits are also set on mixing parameters relevant in extensions of the Standard Model containing a dark sector where $X$ is interpreted to be a dark boson.

31 data tables

Distribution of $\langle m_{\ell\ell}\rangle$ for events selected in the HM $H\to XX \to 4\ell$ $\, ( 15 \,\text{GeV} < m_{X} < 60 \,\text{GeV})$ analysis. (Pre-fit background expectations and signal templates for $m_{Z_d} = 20 \,\text{GeV}$, $35 \,\text{GeV}$, and $55 \,\text{GeV}$ are given. The latter's yields are normalized with $\sigma(pp\to H\to Z_dZ_d\to 4\ell) =\frac{1}{10}\sigma_{\textrm{SM}}(pp\to H\to ZZ^*\to 4\ell)$.

Distribution of $\langle m_{\ell\ell}\rangle$ for events selected in the LM $H\to XX \to 4\mu$ $( 1 \,\text{GeV} < m_{X} < 15 \, \text{GeV} )$ analysis. The regions of 2 GeV to 4.4 GeV, and 8 GeV to 12 GeV are each excluded by the quarkonia veto. No data events pass this selection. Background expectations are pre-fit. Signal templates for $m_{Z_d} = 2 \,\text{GeV}$, $6 \,\text{GeV}$, and $15 \,\text{GeV}$ are given. All signal yields are normalized with $\sigma(pp\to H\to aa\to 4\mu) = \frac{1}{10}\sigma_{\textrm{SM}}(pp\to H\to ZZ^*\to 4\mu) = 0.15 \text{ fb}$ .

Distribution of $m_{34}$ for data and background events in the mass range $115 \,\text{GeV} < m_{4\ell} < 130 \,\text{GeV}$ after the $H\to ZX\to 4\ell$ selection. The background yield for the $H \to ZZ^* \to 4\ell$ process is post-fit and constrained to $1.2 \pm 0.16$ times the Standard Model expectation. Three $H \to ZZ_d \to 4\ell$ signal templates are shown for $Z_d$ masses of $m_{Z_d} = 20 \,\text{GeV}$, $35 \,\text{GeV}$, and $55 \,\text{GeV}$. They are normalized to a branching ratio of $\textrm{BR}(H\rightarrow ZZ_d \rightarrow 4\ell) = \frac{1}{10}\textrm{BR}(H\rightarrow ZZ^*\rightarrow 4\ell)$.

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Search for long-lived particles produced in association with a Z boson in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
CMS-EXO-20-003, 2021.
Inspire Record 1954276 DOI 10.17182/hepdata.114366

A search for long-lived particles (LLPs) produced in association with a Z boson is presented. The study is performed using data from proton-proton collisions with a center-of-mass energy of 13 TeV recorded by the CMS experiment during 2016-2018, corresponding to an integrated luminosity of 117 fb$^{-1}$. The LLPs are assumed to decay to a pair of standard model quarks that are identified as displaced jets within the CMS tracker system. Triggers and selections based on Z boson decays to electron or muon pairs improve the sensitivity to light LLPs (down to 15 GeV). This search provides sensitivity to beyond the standard model scenarios which predict LLPs produced in association with a Z boson. In particular, the results are interpreted in the context of exotic decays of the Higgs boson to a pair of scalar LLPs (H $\to$ SS). The Higgs boson decay branching fraction is constrained to values less than 6% for proper decay lengths of 10-100 mm and for LLP masses between 40 and 55 GeV. In the case of low-mass ($\approx$15 GeV) scalar particles that subsequently decay to a pair of b quarks, the search is sensitive to branching fractions $\mathcal{B}$(H $\to$ SS) $\lt$ 20% for proper decay lengths of 10-50 mm. The use of associated production with a Z boson increases the sensitivity to low-mass LLPs of this analysis with respect to gluon fusion searches. In the case of 15 GeV scalar LLPs, the improvement corresponds to a factor of 2 at a proper decay length of 30 mm.

10 data tables

Distributions of the median-log10 impact parameter significance tagging variable for data and for four signal samples, where the decay lengths of the signal range from 1 to 1000 mm.

Distributions of the median-log10 track angle tagging variable for data and for four signal samples, where the decay lengths of the signal range from 1 to 1000 mm.

Distributions of the alpha max tagging variable for data and for four signal samples, where the decay lengths of the signal range from 1 to 1000 mm.

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First search for exclusive diphoton production at high mass with tagged protons in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The TOTEM & CMS collaborations Tumasyan, Armen ; Adam, Wolfgang ; Bergauer, Thomas ; et al.
CMS-EXO-18-014, 2021.
Inspire Record 1942141 DOI 10.17182/hepdata.113659

A search for exclusive two-photon production via photon exchange in proton-proton collisions, pp $\to$ p$\gamma\gamma$p with intact protons, is presented. The data correspond to an integrated luminosity of 9.4 fb$^{-1}$ collected in 2016 using the CMS and TOTEM detectors at a center-of-mass energy of 13 TeV at the LHC. Events are selected with a diphoton invariant mass above 350 GeV and with both protons intact in the final state, to reduce backgrounds from strong interactions. The events of interest are those where the invariant mass and rapidity calculated from the momentum losses of the forward-moving protons matches the mass and rapidity of the central, two-photon system. No events are found that satisfy this condition. Interpreting this result in an effective dimension-8 extension of the standard model, the first limits are set on the two anomalous four-photon coupling parameters. If the other parameter is constrained to its standard model value, the limits at 95% CL are $\lvert\zeta_1\rvert\lt$ 2.88$\times$10$^{-13}$ GeV$^{-4}$ and $\lvert\zeta_2\rvert\lt$6.02$\times$10$^{-13}$GeV$^{-4}$.

6 data tables

Cut flow for the diphoton selection stages defined in the text (signal contribution is magnified by a factor 5000).

Invariant mass distribution of the diphoton pairs for the elastic selection region with events satisfying a < 0.005 (signal contribution is magnified by a factor 5000).

Predicted number of events having an elastic diphoton pair in association with a pair of protons observed within the range where the proton detectors have a radiation inefficiency less than 10%. The yields where the two-photon and two-proton systems mass and rapidity are matching at 2 and 3$\sigma$ are also quoted. This corresponds to a search region of $m_{\gamma\gamma} > 350$ GeV, $0.070 < \xi^+ < 0.111$, and $0.070 < \xi^- < 0.138$.

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Measurement of the energy asymmetry in $t\bar{t}j$ production at 13 TeV with the ATLAS experiment and interpretation in the SMEFT framework

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, Dale ; et al.
CERN-EP-2021-181, 2021.
Inspire Record 1941095 DOI 10.17182/hepdata.111348

A measurement of the energy asymmetry in jet-associated top-quark pair production is presented using 139 $\mathrm{fb}^{-1}$ of data collected by the ATLAS detector at the Large Hadron Collider during $pp$ collisions at $\sqrt{s}=13$ TeV. The observable measures the different probability of top and antitop quarks to have the higher energy as a function of the jet scattering angle with respect to the beam axis. The energy asymmetry is measured in the semileptonic $t\bar{t}$ decay channel, and the hadronically decaying top quark must have transverse momentum above $350$ GeV. The results are corrected for detector effects to particle level in three bins of the scattering angle of the associated jet. The measurement agrees with the SM prediction at next-to-leading-order accuracy in quantum chromodynamics in all three bins. In the bin with the largest expected asymmetry, where the jet is emitted perpendicular to the beam, the energy asymmetry is measured to be $-0.043\pm0.020$, in agreement with the SM prediction of $-0.037\pm0.003$. Interpreting this result in the framework of the Standard Model effective field theory (SMEFT), it is shown that the energy asymmetry is sensitive to the top-quark chirality in four-quark operators and is therefore a valuable new observable in global SMEFT fits.

6 data tables

Data Measurements and predictions of the energy asymmetry in three bins of the jet angle $\theta_j$. The SM prediction was obtained from simulations of $t\bar{t}j$ events with MadGraph5_aMC@NLO + Pythia 8 at NLO in QCD for $t\bar{t}j$ + PS, including MC statistical and scale uncertainties.

Correlation coefficients $\rho_{i,j}$ for the statistical and systematic uncertainties between the $i$-th and $j$-th bin of the differential $A_E$ measurement as a function of the jet scattering angle $\theta_j$

The effects on the energy asymmetry of $1\sigma$ variations in its influencing nuisance parameters for the three $\theta_j$ bins. These are extracted from the samples of the posterior distribution with $\sigma_i^{(j)} = c_{ij}/\sqrt{c_{jj}}$ being the estimated shift of bin $i$ in conjunction with a shift $\Delta\theta_j$ of nuisance parameter $j$. The data statistical (Data stat.) uncertainty is obtained from running the unfolding with all nuisance parameters being fixed to their post-marginalised values, the MC statistical uncertainty on the response matrix ($t\bar{t}$ response MC stat.) is evaluated using a bootstrapping method from the covariance matrix of the ensemble of repeated unfolding results with varied response matrices. The $\gamma$ variations denote the statistical uncertainties of the background predictions in the corresponding bin of the $\Delta E$ vs $\theta_{j}$ distribution. The numbers appended to the $W$+jets PDF variations denote the corresponding NNPDF3.0 PDF sets.

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Search for long-lived particles decaying to leptons with large impact parameter in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
CMS-EXO-18-003, 2021.
Inspire Record 1940976 DOI 10.17182/hepdata.113658

A search for new long-lived particles decaying to leptons using proton-proton collision data produced by the CERN LHC at $\sqrt{s}$ = 13 TeV is presented. Events are selected with two leptons (an electron and a muon, two electrons, or two muons) that both have transverse impact parameter values between 0.01 and 10 cm and are not required to form a common vertex. Data used for the analysis were collected with the CMS detector in 2016, 2017, and 2018, and correspond to an integrated luminosity of 118 (113) fb$^{-1}$ in the ee channel (e$\mu$ and $\mu\mu$ channels). The search is designed to be sensitive to a wide range of models with displaced e$\mu$, ee, and $\mu\mu$ final states. The results constrain several well-motivated models involving new long-lived particles that decay to displaced leptons. For some areas of the available phase space, these are the most stringent constraints to date.

30 data tables

The distribution of electron $|d_0|$ for the events in data and signal that pass the e$\mu$ preselection. In all of the histograms, the last bin includes the overflow. The electron $|d_0|$ distributions have a longer tail than those of muons because the muon $|d_0|$ values are measured more precisely.

The distribution of muon $|d_0|$ for the events in data and signal that pass the e$\mu$ preselection. In all of the histograms, the last bin includes the overflow. The electron $|d_0|$ distributions have a longer tail than those of muons because the muon $|d_0|$ values are measured more precisely.

Two-dimensional distribution of $|d_{0}^{a}|$ vs $|d_{0}^{b}|$, for simulated background events passing the e$\mu$ preselection with 2018 conditions. In each $|d_{0}^{a}|$-$|d_{0}^{b}|$ bin, the number of events divided by the bin area is plotted. The inclusive signal region covers the region between 100 $\mu$m and 10 cm in each $|d_{0}|$ variable shown.

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Analysis of the CP structure of the Yukawa coupling between the Higgs boson and $\tau$ leptons in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
CMS-HIG-20-006, 2021.
Inspire Record 1940967 DOI 10.17182/hepdata.104978

The first measurement of the CP structure of the Yukawa coupling between the Higgs boson and $\tau$ leptons is presented. The measurement is based on data collected in proton-proton collisions at $\sqrt{s}$ =13 TeV by the CMS detector at the LHC, corresponding to an integrated luminosity of 137 fb$^{-1}$. The analysis uses the angular correlation between the decay planes of $\tau$ leptons produced in Higgs boson decays. The effective mixing angle between CP-even and CP-odd $\tau$ Yukawa couplings is found to be $-$1$\pm$19$^\circ$, compared to an expected value of 0$\pm$21$^\circ$ at the 68.3% confidence level. The data disfavour the pure CP-odd scenario at 3.0 standard deviations. The results are compatible with predictions for the standard model Higgs boson.

7 data tables

Observed likelihood scan of $\alpha^{\mathrm{H}\tau\tau}$.

Expected likelihood scan of $\alpha^{\mathrm{H}\tau\tau}$.

Observed likelihood scan in the ($\alpha^{\mathrm{H}\tau\tau}$, $\mu$) plane.

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