Measurement of the dineutrino system kinematic variables in dileptonic top quark pair production in proton-proton collisions at$\sqrt{s}$ = 13 TeV

The CMS collaboration Chekhovsky, Vladimir ; Hayrapetyan, Aram ; Makarenko, Vladimir ; et al.
CMS-TOP-24-001, 2025.
Inspire Record 3006250 DOI 10.17182/hepdata.153302

Differential top quark pair production cross sections are measured in the dilepton final states e$^+$e$^-$, $μ^+μ^-$, and e$^\pmμ^\mp$, as a function of kinematic variables of the two-neutrino system: the transverse momentum $p_\mathrm{T}^{νν}$ of the dineutrino system, the minimum distance in azimuthal angle between $\vec{p}_\mathrm{T}^{\,νν}$ and leptons, and in two dimensions in bins of both observables. The measurements are performed using CERN LHC proton-proton collisions at $\sqrt{s}$ = 13 TeV, recorded by the CMS detector between 2016 and 2018, corresponding to an integrated luminosity of 138 fb$^{-1}$. The measured cross sections are unfolded to the particle level using an unregularized least squares method. Results are compared with predictions by the standard model of particle physics, and found to be in agreement with theoretical calculations as well as Monte Carlo simulations.

0 data tables

Search for heavy pseudoscalar and scalar bosons decaying to a top quark pair in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Hayrapetyan, Aram ; Makarenko, Vladimir ; Tumasyan, Armen ; et al.
CMS-HIG-22-013, 2025.
Inspire Record 2942928 DOI 10.17182/hepdata.159298

A search for pseudoscalar or scalar bosons decaying to a top quark pair ($\mathrm{t\bar{t}}$) in final states with one or two charged leptons is presented. The analyzed proton-proton collision data was recorded at $\sqrt{s}$ = 13 TeV by the CMS experiment at the CERN LHC and corresponds to an integrated luminosity of 138 fb$^{-1}$. The invariant mass $m_\mathrm{t\bar{t}}$ of the reconstructed $\mathrm{t\bar{t}}$ system and variables sensitive to its spin and parity are used to discriminate against the standard model $\mathrm{t\bar{t}}$ background. Interference between pseudoscalar or scalar boson production and the standard model $\mathrm{t\bar{t}}$ continuum is included, leading to peak-dip structures in the $m_\mathrm{t\bar{t}}$ distribution. An excess of the data above the background prediction, based on perturbative quantum chromodynamics (QCD) calculations, is observed near the kinematic $\mathrm{t\bar{t}}$ production threshold, while good agreement is found for high $m_\mathrm{t\bar{t}}$. The data are consistent with the background prediction if the contribution from the production of a color-singlet ${}^1\mathrm{S}_0^{[1]}$$\mathrm{t\bar{t}}$ quasi-bound state $η_\mathrm{t}$, predicted by nonrelativistic QCD, is added. Upper limits at 95% confidence level are set on the coupling between the pseudoscalar or scalar bosons and the top quark for boson masses in the range 365$-$1000 GeV, relative widths between 0.5 and 25%, and two background scenarios with or without $η_\mathrm{t}$ contribution.

997 data tables

Observed values of twice the negative log-likelihood with respect to the SM (corresponding to $g_{A t \bar t} = g_{H t \bar t} = 0$) for the simultaneous presence of A, $m_A = 1000$ GeV, $\Gamma_A/m_A = 5.0$% and H, $m_H = 550$ GeV, $\Gamma_H/m_H = 21.0$% as a function of the coupling modifiers $g_{A t \bar t}$ and $g_{H t \bar t}$.

Observed values of twice the negative log-likelihood with respect to the SM (corresponding to $g_{A t \bar t} = g_{H t \bar t} = 0$) for the simultaneous presence of A, $m_A = 1000$ GeV, $\Gamma_A/m_A = 2.0$% and H, $m_H = 800$ GeV, $\Gamma_H/m_H = 2.0$% as a function of the coupling modifiers $g_{A t \bar t}$ and $g_{H t \bar t}$.

Observed values of twice the negative log-likelihood with respect to the SM (corresponding to $g_{A t \bar t} = g_{H t \bar t} = 0$) for the simultaneous presence of A, $m_A = 1000$ GeV, $\Gamma_A/m_A = 5.0$% and H, $m_H = 550$ GeV, $\Gamma_H/m_H = 2.0$% as a function of the coupling modifiers $g_{A t \bar t}$ and $g_{H t \bar t}$.

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Observation of a pseudoscalar excess at the top quark pair production threshold

The CMS collaboration Hayrapetyan, Aram ; Makarenko, Vladimir ; Tumasyan, Armen ; et al.
Rept.Prog.Phys. 88 (2025) 087801, 2025.
Inspire Record 2905701 DOI 10.17182/hepdata.156815

A search for resonances in top quark pair ($\text{t}\bar{\text{t}}$) production in final states with two charged leptons and multiple jets is presented, based on proton-proton collision data collected by the CMS experiment at the CERN LHC at $\sqrt{s}$ = 13 TeV, corresponding to 138 fb$^{-1}$. The analysis explores the invariant mass of the $\text{t}\bar{\text{t}}$ system and two angular observables that provide direct access to the correlation of top quark and antiquark spins. A significant excess of events is observed near the kinematic $\text{t}\bar{\text{t}}$ threshold compared to the nonresonant production predicted by fixed-order perturbative quantum chromodynamics (pQCD). The observed enhancement is consistent with the production of a color-singlet pseudoscalar ($^1$S$^{[1]}_0$) quasi-bound toponium state, as predicted by nonrelativistic quantum chromodynamics. Using a simplified model for $^1$S$^{[1]}_0$ toponium, the cross section of the excess above the pQCD prediction is measured to be 8.8 $^{+1.2}_{-1.4}$ pb.

0 data tables

Angular analysis of the decay B$^+$$\to$ K$^+\mu^+\mu^-$ in proton-proton collisions at $\sqrt{s} =$ 8 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.D 98 (2018) 112011, 2018.
Inspire Record 1676212 DOI 10.17182/hepdata.85741

The angular distribution of the flavor-changing neutral current decay B$^+$$\to$ K$^+\mu^+\mu^-$ is studied in proton-proton collisions at a center-of-mass energy of 8 TeV. The analysis is based on data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 20.5 fb$^{-1}$. The forward-backward asymmetry $A_{\mathrm{FB}}$ of the dimuon system and the contribution $F_{\mathrm{H}}$ from the pseudoscalar, scalar, and tensor amplitudes to the decay width are measured as a function of the dimuon mass squared. The measurements are consistent with the standard model expectations.

3 data tables

Figure 5a. Results of the $A_{FB}$ measurements in ranges of q2. 0 ≤ $F_{H}$ ≤ 3 and |$A_{FB}$| ≤ min(1, $F_{H}$/2).

Figure 5b. Results of the $F_{H}$ measurements in ranges of q2. 0 ≤ $F_{H}$ ≤ 3 and |$A_{FB}$| ≤ min(1, $F_{H}$/2).

Table 2. Results of the fit for each q2 range, together with several SM predictions. The inclusive $q^{2}$ = 1.00–22.00 $GeV^{2}$ range in the bottom line does not include events from the J/ψ and ψ(2S) resonance regions.