Browsing by Author "Gomez,G."

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Constraints on anomalous Higgs boson couplings from its production and decay using the WW channel in proton–proton collisions at s=13TeV
(Springer Nature, 2024) Hayrapetyan,A.; Tumasyan,A.; Adam,W.; Andrejkovic,J.W.; Bergauer,T.; Chatterjee,S.; Gomez,G.
A study of the anomalous couplings of the Higgs boson to vector bosons, including CP-violation effects, has been conducted using its production and decay in the WW channel. This analysis is performed on proton–proton collision data collected with the CMS detector at the CERN LHC during 2016–2018 at a center-of-mass energy of 13 TeV, and corresponds to an integrated luminosity of 138fb-1. The different-flavor dilepton (eμ) final state is analyzed, with dedicated categories targeting gluon fusion, electroweak vector boson fusion, and associated production with a W or Z boson. Kinematic information from associated jets is combined using matrix element techniques to increase the sensitivity to anomalous effects at the production vertex. A simultaneous measurement of four Higgs boson couplings to electroweak vector bosons is performed in the framework of a standard model effective field theory. All measurements are consistent with the expectations for the standard model Higgs boson and constraints are set on the fractional contribution of the anomalous couplings to the Higgs boson production cross section. © The Author(s) 2024.
Citation Count: 0
Measurement of multijet azimuthal correlations and determination of the strong coupling in proton-proton collisions at s=13TeV
(Springer Nature, 2024) Hayrapetyan,A.; Tumasyan,A.; Adam,W.; Andrejkovic,J.W.; Bergauer,T.; Chatterjee,S.; Gomez,G.
A measurement is presented of a ratio observable that provides a measure of the azimuthal correlations among jets with large transverse momentum pT. This observable is measured in multijet events over the range of pT=360–3170GeV based on data collected by the CMS experiment in proton-proton collisions at a centre-of-mass energy of 13TeV, corresponding to an integrated luminosity of 134fb-1. The results are compared with predictions from Monte Carlo parton-shower event generator simulations, as well as with fixed-order perturbative quantum chromodynamics (pQCD) predictions at next-to-leading-order (NLO) accuracy obtained with different parton distribution functions (PDFs) and corrected for nonperturbative and electroweak effects. Data and theory agree within uncertainties. From the comparison of the measured observable with the pQCD prediction obtained with the NNPDF3.1 NLO PDFs, the strong coupling at the Z boson mass scale is αS(mZ)=0.1177±0.0013(exp)-0.0073 +0.0116(theo)=0.1177-0.0074 +0.0117, where the total uncertainty is dominated by the scale dependence of the fixed-order predictions. A test of the running of αS in the TeV region shows no deviation from the expected NLO pQCD behaviour. © The Author(s) 2024.
Citation Count: 0
Search for ZZ and ZH production in the bb¯bb¯ final state using proton-proton collisions at s=13TeV
(Springer Nature, 2024) Hayrapetyan,A.; Tumasyan,A.; Adam,W.; Andrejkovic,J.W.; Bergauer,T.; Chatterjee,S.; Gomez,G.
A search for ZZ and ZH production in the bb¯bb¯ final state is presented, where H is the standard model (SM) Higgs boson. The search uses an event sample of proton-proton collisions corresponding to an integrated luminosity of 133fb-1 collected at a center-of-mass energy of 13TeV with the CMS detector at the CERN LHC. The analysis introduces several novel techniques for deriving and validating a multi-dimensional background model based on control samples in data. A multiclass multivariate classifier customized for the bb¯bb¯ final state is developed to derive the background model and extract the signal. The data are found to be consistent, within uncertainties, with the SM predictions. The observed (expected) upper limits at 95% confidence level are found to be 3.8 (3.8) and 5.0 (2.9) times the SM prediction for the ZZ and ZH production cross sections, respectively. © The Author(s) 2024.