Date

Determination of the relative sign of the Higgs boson couplings to $W$ and $Z$ bosons using $WH$ production via vector-boson fusion with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abeling, Kira ; et al.
Phys.Rev.Lett. 133 (2024) 141801, 2024.
Inspire Record 2753923 DOI 10.17182/hepdata.145856

The associated production of Higgs and $W$ bosons via vector-boson fusion (VBF) is highly sensitive to the relative sign of the Higgs boson couplings to $W$ and $Z$ bosons. In this Letter, two searches for this process are presented, using 140 fb$^{-1}$ of proton-proton collision data at $\sqrt{s}$ = 13 TeV recorded by the ATLAS detector at the LHC. The first search targets scenarios with opposite-sign couplings of the $W$ and $Z$ bosons to the Higgs boson, while the second targets Standard Model-like scenarios with same-sign couplings. Both analyses consider Higgs decays into a pair of $b$-quarks and $W$ decays with an electron or muon. The opposite-sign coupling hypothesis is excluded with significance much greater than $5\sigma$, and the observed (expected) upper limit set on the cross-section for VBF $WH$ production is 9.0 (8.7) times the Standard Model value.

5 data tables

Data compared to the background prediction in each region of the negative $\lambda_{WZ}$ analysis, before the fit to data. The signal prediction with $\kappa_{W} = +1$, $\kappa_{Z} = -1$ is shown overlaid. The predicted signal yield with $\kappa_{W} = +1$, $\kappa_{Z} = +1$ in SR$^{-}$ is 2.93 events, which is not shown in the figure. The shaded bands represent the total pre-fit uncertainty on the prediction. The uncertainty does not include the normalization of the main backgrounds, which is unconstrained in the fit.

Data compared to the background prediction in each region of the negative $\lambda_{WZ}$ analysis, after the fit to data. The fitted signal strength is $\hat{\mu} = -0.027$, corresponding to $-8$ events. This contribution is not shown in the figure. The predicted signal yield with $\kappa_{W} = +1$, $\kappa_{Z} = +1$ in SR$^{-}$ is 2.93 events, which is also not shown in the figure. The shaded bands represent the total post-fit uncertainty on the prediction.

Data compared to the SM prediction in each region of the positive \lam{} analysis, before the fit to data. The shaded bands represent the total pre-fit uncertainty on the prediction. The uncertainty does not include the normalization of the main backgrounds, which is unconstrained in the fit.

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Multiplicities of positive and negative pions, kaons and unidentified hadrons from deep-inelastic scattering of muons off a liquid hydrogen target

The COMPASS collaboration Alexeev, G.D. ; Alexeev, M.G. ; Alice, C. ; et al.
Phys.Rev.D 112 (2025) 012002, 2025.
Inspire Record 2840545 DOI 10.17182/hepdata.159544

The multiplicities of positive and negative pions, kaons and unidentified hadrons produced in deep-inelastic scattering are measured in bins of the Bjorken scaling variable $x$, the relative virtual-photon energy $y$ and the fraction of the virtual-photon energy transferred to the final-state hadron $z$. Data were obtained by the COMPASS Collaboration using a 160 GeV muon beam of both electric charges and a liquid hydrogen target. These measurements cover the kinematic domain with photon virtuality $Q^2 > 1$ (GeV/$c)^2$, $0.004 < x < 0.4$, $0.1 < y < 0.7$ and $0.2 < z < 0.85$, in accordance with the kinematic domain used in earlier published COMPASS multiplicity measurements with an isoscalar target. The calculation of radiative corrections was improved by using the Monte Carlo generator DJANGOH, which results in up to 12% larger corrections in the low-$x$ region.

3 data tables

h+/h- multiplicities in (x, y, z) bins with corrections, applied corrections for VM and RC are provided in the table

pi+/pi- multiplicities in (x, y, z) bins with corrections, applied corrections for VM and RC are provided in the table

K+/K- multiplicities in (x, y, z) bins with corrections, applied corrections for VM and RC are provided in the table


Search for the nonresonant and resonant production of a Higgs boson in association with an additional scalar boson in the $γγττ$ final state in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
CMS-HIG-22-012, 2025.
Inspire Record 2940190 DOI 10.17182/hepdata.158371

The results of a search for the production of two scalar bosons in final states with two photons and two tau leptons are presented. The search considers both nonresonant production of a Higgs boson pair, HH, and resonant production via a new boson X which decays either to HH or to H and a new scalar Y. The analysis uses up to 138 fb$^{-1}$ of proton-proton collision data, recorded between 2016 and 2018 by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV. No evidence for signal is found in the data. For the nonresonant production, the observed (expected) upper limit at 95% confidence level (CL) on the HH production cross section is set at 930 (740) fb, corresponding to 33 (26) times the standard model prediction. At 95% CL, HH production is observed (expected) to be excluded for values of $κ_λ$ outside the range between $-$12 ($-$9.4) and 17 (15). Observed (expected) upper limits at 95% CL for the XHH cross section are found to be within 160 to 2200 (200 to 1800) fb, depending on the mass of X. In the X $\to$ Y($γγ$)H($ττ$) search, the observed (expected) upper limits on the product of the production cross section and decay branching fractions vary between 0.059$-$1.2 fb (0.087$-$0.68 fb). For the X $\to$ Y($γγ$)H($ττ$) search the observed (expected) upper limits on the product of the production cross section and Y $to$ $γγ$ branching fraction vary between 0.69$-$15 fb (0.73$-$8.3 fb) in the low Y mass search, tightening constraints on the next-to-minimal supersymmetric standard model, and between 0.64$-$10 fb (0.70$-$7.6 fb) in the high Y mass search.

13 data tables

Observed and expected 95% CL upper limits on the nonresonant $\mathrm{HH}$ production cross section, $\sigma(\mathrm{pp} \to \mathrm{HH})$, as a function of the Higgs boson self-coupling strength modifier $\kappa_\lambda$. All Higgs boson couplings other than $\lambda$ are assumed to have the values predicted in the SM.

Observed and expected 95% CL upper limits on the nonresonant $\mathrm{HH}$ production cross section, $\sigma(\mathrm{pp} \to \mathrm{HH})$, for thirteen different BSM benchmark scenarios from [arXiv:1507.02245, arXiv:1806.05162] which consider different values of the couplings, $\kappa_\lambda$, $\kappa_t$, $c_{2g}$, $c_g$, and $c_2$ (defined in Table 1).

Observed and expected 95% CL upper limits on the cross section for the resonant production of a new spin-0 particle $\mathrm{X}^{(0)}$ which decays to Higgs boson pairs, $\sigma(\mathrm{pp} \to \mathrm{X}^{(0)} \to \mathrm{HH})$, given for different values of $m_\mathrm{X}$ in the range 260-1000 GeV.

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Version 2
Measurements of the production cross-section for a $Z$ boson in association with $b$- or $c$-jets in proton-proton collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
Eur.Phys.J.C 84 (2024) 984, 2024.
Inspire Record 2771257 DOI 10.17182/hepdata.151815

This paper presents a measurement of the production cross-section of a $Z$ boson in association with $b$- or $c$-jets, in proton-proton collisions at $\sqrt{s} = 13$ TeV with the ATLAS experiment at the Large Hadron Collider using data corresponding to an integrated luminosity of 140 fb$^{-1}$. Inclusive and differential cross-sections are measured for events containing a $Z$ boson decaying into electrons or muons and produced in association with at least one $b$-jet, at least one $c$-jet, or at least two $b$-jets with transverse momentum $p_\textrm{T} > 20$ GeV and rapidity $|y| < 2.5$. Predictions from several Monte Carlo generators based on next-to-leading-order matrix elements interfaced with a parton-shower simulation, with different choices of flavour schemes for initial-state partons, are compared with the measured cross-sections. The results are also compared with novel predictions, based on infrared and collinear safe jet flavour dressing algorithms. Selected $Z + \ge 1 c$-jet observables, optimized for sensitivity to intrinsic-charm, are compared with benchmark models with different intrinsic-charm fractions.

29 data tables

Figure 6(left) of the article. Measured fiducial cross sections for events with $Z \left( \rightarrow \ell \ell \right) \geq 1 b$-jet. The thin inner band corresponds to the statistical uncertainty of the data, and the outer band to statistical and systematic uncertainties of the data, added in quadrature.

Figure 6(right) of the article. Measured fiducial cross sections for events with $Z \left( \rightarrow \ell \ell \right) \geq 2 b$-jets. The thin inner band corresponds to the statistical uncertainty of the data, and the outer band to statistical and systematic uncertainties of the data, added in quadrature.

Figure 7 of the article. Measured fiducial cross sections for events with $Z \left( \rightarrow \ell \ell \right) \geq 1 c$-jet. The thin inner band corresponds to the statistical uncertainty of the data, and the outer band to statistical and systematic uncertainties of the data, added in quadrature.

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Version 2
Search for vector-like leptons with long-lived particle decays in the CMS muon system in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Chekhovsky, Vladimir ; Hayrapetyan, Aram ; Makarenko, Vladimir ; et al.
CMS-EXO-23-015, 2025.
Inspire Record 2902874 DOI 10.17182/hepdata.156846

A first search is presented for vector-like leptons (VLLs) decaying into a light long-lived pseudoscalar boson and a standard model $\tau$ lepton. The pseudoscalar boson is assumed to have a mass of 2 GeV and to decay exclusively into a pair of photons. It is identified using the CMS muon system. The analysis is carried out using a data set of proton-proton collisions at a center-of-mass energy of 13 TeV collected by the CMS experiment in 2016-2018, corresponding to an integrated luminosity of 138 fb$^{-1}$. Selected events contain at least one pseudoscalar boson decaying electromagnetically in the muon system and at least one hadronically decaying $\tau$ lepton. No significant excess of data events is observed compared to the background expectation. Upper limits are set at 95% confidence level on the vector-like lepton production cross section as a function of the VLL mass and the pseudoscalar boson mean proper decay length. The observed and expected exclusion ranges of the VLL mass extend up to 700 and 670 GeV, respectively, depending on the pseudoscalar boson lifetime.

13 data tables

The cluster reconstruction efficiency, including both DT and CSC clusters, as a function of the simulated r and |z| decay positions of the pseudoscalar into photons in events with MET > 200 GeV, for a VLL mass of 700 GeV and a pseudoscalar mass of 2 GeV, and a range of ctau values uniformly distributed between 0.01 and 0.1 m.

Distributions of the number of hits in the cluster (Nhits) for the DT category in the signal region (SR). The last histogram bin contains all overflow events.

Distributions of the number of hits in the cluster (Nhits) for the CSC category in the signal region (SR). The last histogram bin contains all overflow events.

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Version 2
Search for a common baryon source in high-multiplicity pp collisions at the LHC

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
Phys.Lett.B 811 (2020) 135849, 2020.
Inspire Record 1791631 DOI 10.17182/hepdata.98857

We report on the measurement of the size of the particle-emitting source from two-baryon correlations with ALICE in high-multiplicity pp collisions at $\sqrt{s}$ = 13 TeV. The source radius is studied with low relative momentum p-p, $\bar{\rm{p}}$-$\bar{\rm{p}}$, p-$Λ$ and $\bar{\rm{p}}$-$\barΛ$ pairs as a function of the pair transverse mass $m_{\rm{T}}$ considering for the first time in a quantitative way the effect of strong resonance decays. After correcting for this effect, the radii extracted for pairs of different particle species agree. This indicates that protons, antiprotons, $Λ$, and $\barΛ$ originate from the same source. Within the measured $m_{\rm{T}}$ range (1.1-2.2) GeV/$c^{2}$ the invariant radius of this common source varies between 0.85 and 1.3 fm. These results provide a precise reference for studies of the strong hadron-hadron interactions and for the investigation of collective properties in small colliding systems.

9 data tables

Source radius $r_{0}$ as a function of〈$m_{T}$〉for the assumption of a purely Gaussian source. The blue crosses result from fitting the p–p correlation function with the strong Argonne v18 potential. The green squared crosses (red triangular crosses) result from fitting the p–Λ correlation functions with the strong χEFT LO (NLO) potential. Statistical (lines) and systematic (boxes) uncertainties are shown separately.

Source radius $r_0$ as a function of〈$m_\mathrm{T}$〉for the assumption of a purely Gaussian source. The blue crosses result from fitting the p–p correlation function with the strong Argonne v18 potential. The green squared crosses (red triangular crosses) result from fitting the p–Λ correlation functions with the strong χEFT LO (NLO) potential. Statistical (lines) and systematic (boxes) uncertainties are shown separately.

Source radius $r_{0}$ as a function of〈$m_{T}$〉for the assumption of a purely Gaussian source. The blue crosses result from fitting the p–p correlation function with the strong Argonne v18 potential. The green squared crosses (red triangular crosses) result from fitting the p–Λ correlation functions with the strong χEFT LO (NLO) potential. Statistical (lines) and systematic (boxes) uncertainties are shown separately.

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Jet modification via $\pi^0$-hadron correlations in Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV

The PHENIX collaboration Abdulameer, N.J. ; Acharya, U. ; Adare, A. ; et al.
Phys.Rev.C 110 (2024) 044901, 2024.
Inspire Record 2797343 DOI 10.17182/hepdata.159378

High-momentum two-particle correlations are a useful tool for studying jet-quenching effects in the quark-gluon plasma. Angular correlations between neutral-pion triggers and charged hadrons with transverse momenta in the range 4--12~GeV/$c$ and 0.5--7~GeV/$c$, respectively, have been measured by the PHENIX experiment in 2014 for Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$~GeV. Suppression is observed in the yield of high-momentum jet fragments opposite the trigger particle, which indicates jet suppression stemming from in-medium partonic energy loss, while enhancement is observed for low-momentum particles. The ratio and differences between the yield in Au$+$Au collisions and $p$$+$$p$ collisions, $I_{AA}$ and $\Delta_{AA}$, as a function of the trigger-hadron azimuthal separation, $\Delta\phi$, are measured for the first time at the Relativistic Heavy Ion Collider. These results better quantify how the yield of low-$p_T$ associated hadrons is enhanced at wide angle, which is crucial for studying energy loss as well as medium-response effects.

29 data tables

Per-trigger jet-pair yield as a function of $\Delta\phi$ for selected $\pi^0$ trigger and charged-hadron-associated $p_T$ combinations (${{p_{T,\pi^0}} \otimes p_{T,h}}$) in Au$+$Au collisions. Systematic uncertainties for background subtraction and global scale uncertainties are given.

Integrated away-side $I_{AA}$ as a function of $p_T^h$. Systematic uncertainties for background subtraction and global scale uncertainties are given.

Differential away-side a function of Deltaphi 0%-20% collisions. Systematic uncertainties for background subtraction and global scale uncertainties are given.

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Measurement of WWZ and ZH production cross sections at $\sqrt{s}$ = 13 and 13.6 TeV

The CMS collaboration Hayrapetyan, Aram ; Makarenko, Vladimir ; Tumasyan, Armen ; et al.
CMS-SMP-24-015, 2025.
Inspire Record 2925580 DOI 10.17182/hepdata.158280

A measurement is presented of the cross section in proton-proton collisions for the production of two W bosons and one Z boson. It is based on data recorded by the CMS experiment at the CERN LHC at center-of-mass energies $\sqrt{s}$ = 13 and 13.6 TeV, corresponding to an integrated luminosity of 200 fb$^{-1}$. Events with four charged leptons (electrons or muons) in the final state are selected. Both nonresonant WWZ production and ZH production, with the Higgs boson decaying into two W bosons, are reported. For the first time, the two processes are measured separately in a simultaneous fit. Combining the two modes, signal strengths relative to the standard model (SM) predictions of 0.75$^{+0.34}_{-0.29}$ and 1.74$^{+0.71}_{-0.60}$ are measured for $\sqrt{s}$ = 13 and 13.6 TeV, respectively. The observed (expected) significance for the triboson signal is 3.8 (2.5) standard deviations for $\sqrt{s}$ = 13.6 TeV, thus providing the first evidence for triboson production at this center-of-mass energy. Combining the two modes and the two center-of-mass energies, the inclusive signal strength relative to the SM prediction is measured to be 1.03$^{+0.31}_{-0.28}$, with an observed (expected) significance of 4.5 (5.0) standard deviations.

3 data tables

Two-dimensional likelihood scan as a function of the individual WWZ and ZH signal strength parameters for the combined Run 2 and Run 3 datasets

One-dimensional likelihood scan as a function of the inclusive (WWZ + ZH) signal strength parameter for the combined Run 2 and Run 3 datasets

Comparison of the observed number of events to the SM-predicted number of events for each of the bins included in the fit for Run 2 (upper row) and Run 3 (lower row). The SM expectations are shown before performing the fit. The horizontal axis legend also indicates "WWZ-like" and "ZH-like" bins defined based on whether the WWZ BDT score is higher or lower than the ZH score.


Measurement of event shapes in minimum-bias events from proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Chekhovsky, Vladimir ; Hayrapetyan, Aram ; Makarenko, Vladimir ; et al.
CMS-SMP-23-008, 2025.
Inspire Record 2924533 DOI 10.17182/hepdata.157862

A measurement of event-shape variables is presented, using a data sample produced in a special run with approximately one inelastic proton-proton collision per bunch crossing. The data were collected with the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 64 $\mu$b$^{-1}$. A number of observables related to the overall distribution of charged particles in the collisions are corrected for detector effects and compared with simulations. Inclusive event-shape distributions, as well as differential distributions of event shapes as functions of charged-particle multiplicity, are studied. None of the models investigated is able to satisfactorily describe the data. Moreover, there are significant features common amongst all generator setups studied, particularly showing data being more isotropic than any of the simulations. Multidimensional unfolded distributions are provided, along with their correlations.

65 data tables

The unfolded charged particle multiplicity distribution of inelastic proton-proton collisions with at least three charged particles with transverse momentum higher than 0.5 GeV and pseudorapidity between -2.4 and 2.4. The total area of the histogram is normalised to 1.

The unfolded charged particle invariant mass distribution of inelastic proton-proton collisions with at least three charged particles with transverse momentum higher than 0.5 GeV and pseudorapidity between -2.4 and 2.4. The total area of the histogram is normalised to 1.

The unfolded charged particle sphericity distribution of inelastic proton-proton collisions with at least three charged particles with transverse momentum higher than 0.5 GeV and pseudorapidity between -2.4 and 2.4. The total area of the histogram is normalised to 1.

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Version 2
Measurement of the Drell--Yan forward-backward asymmetry and of the effective leptonic weak mixing angle in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Lett.B 866 (2025) 139526, 2025.
Inspire Record 2818125 DOI 10.17182/hepdata.153661

The forward-backward asymmetry in Drell-Yan production and the effective leptonic electroweak mixing angle are measured in proton-proton collisions at $\sqrt{s}$ = 13 TeV, collected by the CMS experiment and corresponding to an integrated luminosity of 138 fb$^{-1}$. The measurement uses both dimuon and dielectron events, and is performed as a function of the dilepton mass and rapidity. The unfolded angular coefficient $A_4$ is also extracted, as a function of the dilepton mass and rapidity. Using the CT18Z set of parton distribution functions, we obtain $\sin\theta^\ell_\text{eff}$ = 0.23152 $\pm$ 0.00031, where the uncertainty includes the experimental and theoretical contributions. The measured value agrees with the standard model fit result to global experimental data. This is the most precise $\sin\theta^\ell_\text{eff}$ measurement at a hadron collider, with a precision comparable to the results obtained at LEP and SLD.

2 data tables

Measured $A_4(|Y|,M))$ distribution for the combined Run 2 data.

Correlation coefficients for the $A_4(|Y|,M)$ values among different $|Y|-M$ bins. The $A_4(|Y|,M)$ values and total uncertainties are shown in Figure 8 in the paper.