CMS Publications#CMSPAS: Measurement of single top and ttbar production cross sections in association with a photon in proton-proton collisions at sqrt(s) = 13 TeV (CMS-PAS-TOP-25-003) https://cds.cern.ch/record/2957059 #TopQuark
#CMSPAS: Combination of ATLAS and CMS measurements of the azimuthal spin correlation variable in dilepton top quark pair events at 13 TeV (CMS-PAS-TOP-22-004) https://cds.cern.ch/record/2952446 #TopQuark
#CMSpaper: Characterization of the quantum state of top quark pairs produced in proton-proton collisions at √s = 13 TeV using the beam and helicity bases (arXiv:2512.17557) https://arxiv.org/abs/2512.17557 #TopQuark
#CMSpaper soon on arXiv: Characterization of the quantum state of top quark pairs produced in proton-proton collisions at √s = 13 TeV using the beam and helicity bases (CERN-EP-2025-287) https://cds.cern.ch/record/2951662 #TopQuark
Characterization of the quantum state of top quark pairs produced in proton-proton collisions at $ \sqrt{s}= $ 13 TeV using the beam and helicity bases
Measurements of the spin correlation coefficients in the beam basis are presented for top quark-antiquark ($ \mathrm{t} \overline{\mathrm{t}} $) systems produced in proton-proton collisions at $ \sqrt{s}= $ 13 TeV collected by the CMS experiment in 2016-2018, and corresponding to an integrated luminosity of 138 fb$ ^{-1} $. The $ \mathrm{t} \overline{\mathrm{t}} $ system is reconstructed from final states containing an electron or muon, and jets. Together with the previously reported results in the helicity basis, these measurements are used to decompose the system into the Bell and spin eigenstates in various kinematic regions. The spin correlation coefficients are also used to evaluate properties of the $ \mathrm{t} \overline{\mathrm{t}} $ quantum state, such as the purity, von Neumann entropy, and entanglement. All results are consistent with standard model predictions.
#CMSpaper: Inclusive and differential measurements of the ttγ cross section and the ttγ/tt cross section ratio in proton-proton collisions at √s = 13 TeV (arXiv:2511.01995) https://arxiv.org/abs/2511.01995 #TopQuark
#CMSpaper soon on arXiv: Inclusive and differential measurements of the ttγ cross section and the ttγ/tt cross section ratio in proton-proton collisions at √s = 13 TeV (CERN-EP-2025-240) https://cds.cern.ch/record/2947763 #TopQuark
Inclusive and differential measurements of the $ {\mathrm{t}\overline{\mathrm{t}}} \gamma $ cross section and the $ {\mathrm{t}\overline{\mathrm{t}}} \gamma/{\mathrm{t}\overline{\mathrm{t}}} $ cross section ratio in proton-proton collisions at $ \sqrt{s}= $ 13 TeV
Inclusive and differential cross section measurements of top quark pair ($ \mathrm{t} \overline{\mathrm{t}} $) production in association with a photon ($ \gamma $) are performed as a function of lepton, photon, top quark, and $ \mathrm{t} \overline{\mathrm{t}} $ kinematic observables, using data from proton-proton collisions at $ \sqrt{s}= $ 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$. Events containing two leptons (electrons or muons) and a photon in the final state are considered. The fiducial cross section of $ {\mathrm{t}\overline{\mathrm{t}}} \gamma $ is measured to be 137 $ \pm $ 8 fb, in a phase space including events with a high momentum, isolated photon. The fiducial cross section of $ {\mathrm{t}\overline{\mathrm{t}}} \gamma $ is also measured to be 56 $ \pm $ 5 fb when considering only events where the photon is emitted in the production part of the process. Both measurements are in agreement with the theoretical predictions, of 126 $ \pm $ 19 fb and 57 $ \pm $ 5 fb, respectively. Differential measurements are performed at the particle and parton levels. Additionally, inclusive and differential ratios between the cross sections of $ {\mathrm{t}\overline{\mathrm{t}}} \gamma $ and $ \mathrm{t} \overline{\mathrm{t}} $ production are measured. The inclusive ratio is found to be 0.0133 $ \pm $ 0.0005, in agreement with the standard model prediction of 0.0127 $ \pm $ 0.0008. The top quark charge asymmetry in $ {\mathrm{t}\overline{\mathrm{t}}} \gamma $ production is also measured to be $-$0.012 $ \pm $ 0.042, compatible with both the standard model prediction and with no asymmetry.
#CMSPAS: Measurement of top quark charge asymmetries in jet-associated top quark pair production at √s 13 TeV (CMS-PAS-TOP-24-015) https://cds.cern.ch/record/2947613 #TopQuark
#CMSpaper: Observation of tWZ production at the CMS experiment (arXiv:2510.19080) https://arxiv.org/abs/2510.19080 #TopQuark
#CMSpaper soon on arXiv: Observation of tWZ production at the CMS experiment (CERN-EP-2025-205) https://cds.cern.ch/record/2946717 #TopQuark
Observation of tWZ production at the CMS experiment
The first observation of single top quark production in association with a W and a Z boson in proton-proton collisions is reported. The analysis uses data at center-of-mass energies of 13 and 13.6 TeV recorded with the CMS detector at the CERN LHC, corresponding to a total integrated luminosity of 200 fb$ ^{-1} $. Events with three or four charged leptons, which can be electrons or muons, are selected. Advanced machine-learning algorithms and improved reconstruction methods, compared to an earlier analysis, result in an unprecedented sensitivity to tWZ production. The measured cross sections for tWZ production are 248 $ \pm $ 52 fb and 244 $ \pm $ 74 fb for $ \sqrt{s}= $ 13 and 13.6 TeV, respectively. The signal is established with a statistical significance of 5.8 standard deviations, with 3.5 expected, compared to the background-only hypothesis.
#CMSpaper: Measurement of the dineutrino system kinematic variables in dileptonic top quark pair production in proton-proton collisions at √s = 13 TeV (arXiv:2510.00160) https://arxiv.org/abs/2510.00160 #TopQuark