Browsing by Author "Sosnov, D."

Now showing 1 - 3 of 3

Citation - Scopus: 1
Measurements of Inclusive and Differential Higgs Boson Production Cross Sections at √s=13.6 TeV in the H → Γγ Decay Channel
(Springer, 2025) Hayrapetyan, A.; Makarenko, V.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Benato, L.; Sosnov, D.
Inclusive and differential cross sections for Higgs boson production in proton-proton collisions at a centre-of-mass energy of 13.6TeV are measured using data collected with the CMS detector at the LHC in 2022, corresponding to an integrated luminosity of 34.7 fb(-1). Events with the diphoton final state are selected, and the measured inclusive fiducial cross section is sfid = 74 +/- 11 (stat)(-4)(+5) (syst) fb, in agreement with the standard model prediction of 67.8 +/- 3.8 fb. Differential cross sections are measured as functions of several observables: the Higgs boson transverse momentum and rapidity, the number of associated jets, and the transverse momentum of the leading jet in the event. Within the uncertainties, the differential cross sections agree with the standard model predictions.
A Method for Correcting the Substructure of Multiprong Jets using the Lund Jet Plane
(Springer Science and Business Media Deutschland GmbH, 2025) Hayrapetyan, A.; Makarenko, V.; Tumasyan, A.; Adam, W.; Andrejkovic, J.W.; Benato, L.; Sosnov, D.
Many analyses at the CERN LHC exploit the substructure of jets to identify heavy resonances produced with high momenta that decay into multiple quarks and/or gluons. This paper presents a new technique for correcting the substructure of simulated large-radius jets from multiprong decays. The technique is based on reclustering the jet constituents into several subjets such that each subjet represents a single prong, and separately correcting the radiation pattern in the Lund jet plane of each subjet using a correction derived from data. The data presented here correspond to an integrated luminosity of 138 fb−1 collected by the CMS experiment between 2016–2018 at a center-of-mass energy of 13 TeV. The correction procedure improves the agreement between data and simulation for several different substructure observables of multiprong jets. This technique establishes, for the first time, a robust calibration for the substructure of jets with four or more prongs, enabling future measurements and searches for new phenomena containing these signatures. © The Author(s) 2025.
Search for CP Violation in Events with Top Quarks and Z Bosons at √s=13 and 13.6 Tev
(Elsevier, 2025) Hayrapetyan, A.; Makarenko, V.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Benato, L.; Sosnov, D.
A search for the violation of the charge-parity (CP) symmetry in the production of top quarks in association with Z bosons is presented, using events with at least three charged leptons and additional jets. The search is performed in a sample of proton-proton collision data collected by the CMS experiment at the CERN LHC in 2016-2018 at a center-of-mass energy of 13 TeV and in 2022 at 13.6 TeV, corresponding to a total integrated luminosity of 173 fb(-1). For the first time in this final state, observables that are odd under the CP transformation are employed. Also for the first time, physics-informed machine-learning techniques are used to construct these observables. While for standard model (SM) processes the distributions of these observables are predicted to be symmetric around zero, CP-violating modifications of the SM would introduce asymmetries. Two CP-odd operators O-Wt(I) and O-tZ(I) in the SM effective field theory are considered that may modify the interactions between top quarks and electroweak bosons. The obtained results are consistent with the SM prediction within two standard deviations, and exclusion limits on the associated Wilson coefficients of -2.7 < c(tW)(I) < 2.5 and -0.2 < c(tZ)(I) < 2.0 are set at 95% confidence level. The largest discrepancy is observed in CtZI where data is consistent with positive values, with an observed local significance with respect to the SM hypothesis of 2.5 standard deviations, when only linear terms are considered.