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1.

001-es BibID:BIBFORM130574
Első szerző:CMS Collaboration
Cím:Reweighting simulated events using machine-learning techniques in the CMS experiment / CMS Collaboration
Dátum:2025
ISSN:1434-6052
Megjegyzések:Data analyses in particle physics rely on an accurate simulation of particle collisions and a detailed simulation of detector effects to extract physics knowledge from the recorded data. Event generators together with a geantbased simulation of the detectors are used to produce large samples of simulated events for analysis by the LHC experiments. These simulations come at a high computational cost, where the detector simulation and reconstruction algorithms have the largest CPU demands. This article describes how machine-learning (ML) techniques are used to reweight simulated samples obtained with a given set of parameters to samples with different parameters or samples obtained from entirely different simulation programs. The ML reweighting method avoids the need for simulating the detector response multiple times by incorporating the relevant information in a single sample through event weights. Results are presented for reweighting to model variations and higher-order calculations in simulated top quark pair production at the LHC. This ML-based reweighting is an important element of the future computing model of the CMS experiment and will facilitate precision measurements at the High-Luminosity LHC.
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:The European Physical Journal C. - 85 : 5 (2025), p. 1-35. -
További szerzők:Ujvári Balázs (1977-) (fizikus) Oláh László (1967-) (fizikus)
Internet cím:DOI
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2.

001-es BibID:BIBFORM129644
035-os BibID:(WoS)001458700100001
Első szerző:CMS Collaboration
Cím:Search for pair production of heavy particles decaying to a top quark and a gluon in the lepton+jets final state in proton-proton collisions at root{s} = 13 TeV / CMS Collaboration
Dátum:2025
ISSN:1434-6052
Megjegyzések:A search is presented for the pair production of new heavy resonances, each decaying into a top quark (t) or antiquark and a gluon (g). The analysis uses data recorded with the CMS detector from proton?proton collisions at a center-of-mass energy of 13 TeV at the LHC, corresponding to an integrated luminosity of 138 fb?1 . Events with one muon or electron, multiple jets, and missing transverse momentum are selected. After using a deep neural network to enrich the data sample with signal-like events, distributions in the scalar sum of the transverse momenta of all reconstructed objects are analyzed in the search for a signal. No significant deviations from the standard model prediction are found. Upper limits at 95% confidence level are set on the product of cross section and branching fraction squared for the pair production of excited top quarks in the t? ? tg decay channel. The upper limits range from 120 to 0.8 fb for a t? with spin-1/2 and from 15 to 1.0 fb for a t? with spin-3/2. These correspond to mass exclusion limits up to 1050 and 1700 GeV for spin-1/2 and spin-3/2 t? particles, respectively. These are the most stringent limits to date on the existence of t? ? tg resonances.
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:The European Physical Journal C. - 85 : 3 (2025), p. 1-29. -
További szerzők:Oláh László (1967-) (fizikus) Ujvári Balázs (1977-) (fizikus)
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DOI
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3.

001-es BibID:BIBFORM126854
035-os BibID:(WOS)001412679500001 (Scopus)85207098291
Első szerző:CMS Collaboration
Cím:Observation of the Lambda_b^0 --> J/[psi][Xi]^-K^+ decay / CMS Collaboration
Dátum:2024
ISSN:1434-6052
Megjegyzések:Using proton-proton collision data corresponding to an integrated luminosity of 140 fb(-1) collected by the CMS experiment at root s = 13 TeV, the Lambda(0)(b) -> J/psi Xi K--(+) decay is observed for the first time, with a statistical significance exceeding 5 standard deviations. The relative branching fraction, with respect to the Lambda(0)(b) -> psi(2S)Lambda decay, is measured to be B(Lambda(0)(b) -> J/psi Xi K--(+))/B(Lambda(0)(b) -> psi(2S)Lambda) = [3.38 +/- 1.02 +/- 0.61 +/- 0.03]%, where the first uncertainty is statistical, the second is systematic, and the third is related to the uncertainties in B(psi(2S) -> J/psi pi(+)pi(-)) and B(Xi(-) -> Lambda pi(-)).
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Branching fractions
Integrated luminosity
Proton proton collisions
Standard deviation
Statistical significance
Uncertainty
Megjelenés:The European Physical Journal C. - 84 : 10 (2024), p. 1-24. -
További szerzők:Bartók Márton (fizikus) Raics Péter (1944-) (fizikus) Ujvári Balázs (1977-) (fizikus) Zilizi Gyula (1965-) (fizikus) Karancsi János (1987-) (fizikus)
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DOI
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4.

001-es BibID:BIBFORM125680
035-os BibID:(WoS)001412661400001 (Scopus)85200553366
Első szerző:CMS Collaboration
Cím:Constraints on anomalous Higgs boson couplings from its production and decay using the WW channel in proton-proton collisions at root{s} = 13 TeV / CMS Collaboration
Dátum:2024
ISSN:1434-6052
Megjegyzések: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 138 fb(-1). The different-flavor dilepton (e mu) 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.
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:The European Physical Journal C. - 84 : 8 (2024), p. 1-42. -
További szerzők:Bartók Márton (fizikus) Raics Péter (1944-) (fizikus) Ujvári Balázs (1977-) (fizikus) Zilizi Gyula (1965-) (fizikus)
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DOI
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5.

001-es BibID:BIBFORM125656
035-os BibID:(Scopus)85201829376
Első szerző:CMS Collaboration
Cím:Measurement of multijet azimuthal correlations and determination of the strong coupling in proton-proton collisions at root{s} = 13 TeV / CMS Collaboration
Dátum:2024
ISSN:1434-6052
Megjegyzések: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 alphaS(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 alphaS in the TeV region shows no deviation from the expected NLO pQCD behaviour.
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:The European Physical Journal C. - 84 : 8 (2024), p. 1-35. -
További szerzők:Bartók Márton (fizikus) Raics Péter (1944-) (fizikus) Ujvári Balázs (1977-) (fizikus) Zilizi Gyula (1965-) (fizikus)
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DOI
Intézményi repozitóriumban (DEA) tárolt változat
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6.

001-es BibID:BIBFORM125125
035-os BibID:(Scopus)85199187251
Első szerző:CMS Collaboration
Cím:Search for ZZ and ZH production in the bbbb final state using proton-proton collisions at root{s} = 13 TeV / CMS Collaboration
Dátum:2024
ISSN:1434-6052
Megjegyzések:A search for ZZ and ZH production in the bbbb 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 bbbb 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.
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:The European Physical Journal C. - 84 : 7 (2024), p. 1-33. -
További szerzők:Bartók Márton (fizikus) Raics Péter (1944-) (fizikus) Ujvári Balázs (1977-) (fizikus) Zilizi Gyula (1965-) (fizikus)
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DOI
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Borító:

7.

001-es BibID:BIBFORM122646
035-os BibID:(Scopus)85193357686
Első szerző:CMS Collaboration
Cím:Search for exotic decays of the Higgs boson to a pair of pseudoscalars in the [mu][mu]bb and [tau][tau]bb final states / CMS Collaboration
Dátum:2024
ISSN:1434-6052
Megjegyzések:A search for exotic decays of the Higgs boson (H) with a mass of 125GeV to a pair of light pseudoscalars a1 is performed in final states where one pseudoscalar decays to two b quarks and the other to a pair of muons or tau leptons. A data sample of proton-proton collisions at root s=13TeV corresponding to an integrated luminosity of 138fb-1 recorded with the CMS detector is analyzed. No statistically significant excess is observed over the standard model backgrounds. Upper limits are set at 95% confidence level (CL) on the Higgs boson branching fraction to [mu][mu]bb and to [tau][tau]bb, via a pair of a1s. The limits depend on the pseudoscalar mass ma1 and are observed to be in the range (0.17-3.3)x10-4 and (1.7-7.7)x10-2 in the [mu][mu]bb and [tau][tau]bb final states, respectively. In the framework of models with two Higgs doublets and a complex scalar singlet (2HDM+S), the results of the two final states are combined to determine upper limits on the branching fraction B(H-->a1a1-->llbb) at 95% CL, with l being a muon or a tau lepton. For different types of 2HDM+S, upper bounds on the branching fraction B(H-->a1a1) are extracted from the combination of the two channels. In most of the Type II 2HDM+S parameter space, B(H-->a1a1) values above 0.23 are excluded at 95% CL for ma1 values between 15 and 60GeV.
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Bosons
Charged particles
Tellurium compounds
Vanadium compounds
Megjelenés:The European Physical Journal C. - 84 : 5 (2024), p. 1-38. -
További szerzők:Bartók Márton (fizikus) Raics Péter (1944-) (fizikus) Ujvári Balázs (1977-) (fizikus) Zilizi Gyula (1965-) (fizikus) Karancsi János (1987-) (fizikus)
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DOI
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8.

001-es BibID:BIBFORM122400
035-os BibID:(WoS)001093335800001 (Scopus)85174914881
Első szerző:CMS Collaboration
Cím:Measurement of the top quark mass using a profile likelihood approach with the lepton+jets final states in proton-proton collisions at root{s} = 13TeV / CMS Collaboration
Dátum:2023
ISSN:1434-6052
Megjegyzések:The mass of the top quark is measured in 36.3 fb(-1) of LHC proton-proton collision data collected with the CMS detector at root s = 13 TeV. The measurement uses a sample of top quark pair candidate events containing one isolated electron or muon and at least four jets in the final state. For each event, the mass is reconstructed from a kinematic fit of the decay products to a top quark pair hypothesis. A profile likelihood method is applied using up to four observables per event to extract the top quark mass. The top quark mass is measured to be 171.77 +/- 0.37 GeV. This approach significantly improves the precision over previous measurements.
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:The European Physical Journal C. - 83 : 10 (2023), p. 1-31. -(cikkazonosító)963. -
További szerzők:Bartók Márton (fizikus) Karancsi János (1987-) (fizikus) Raics Péter (1944-) (fizikus) Ujvári Balázs (1977-) (fizikus)
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DOI
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Borító:

9.

001-es BibID:BIBFORM119657
035-os BibID:(WoS)000850021700001 (Scopus)85131177055
Első szerző:CMS Collaboration
Cím:Observation of B^0 --> psi(2S)K_S^0[pi]^+[pi]^- and B_S^0 --> psi(2S)K_S^0 decays / CMS Collaboration
Dátum:2022
ISSN:1434-6052
Megjegyzések:Using a data sample of root s = 13 TeV protonproton collisions collected by the CMS experiment at the LHC in 2017 and 2018 with an integrated luminosity of 103 fb(-1), the B-s(0) -> psi(2S)K-S(0) and B-0 -> psi(2S)K-S(0) pi(+) pi(-) decays are observed with significances exceeding 5 standard deviations. The resulting branching fraction ratios, measured for the first time, correspond to B(B-s(0) -> psi(2S)K-S(0))/B(B-0 Zeta -> psi(2S)K-S(0)) = (3.33 +/- 0.69(stat) +/- 0.11 (syst) +/- 0.34 (f(s)/f(d))) x 10(-2) and B(B-0 -> psi(2S)K-S(0) pi(+) pi(-))/B(B-0 -> psi(2S)K-S(0)) = 0.480 +/- 0.013 (stat) +/- 0.032 (syst), where the last uncertainty in the first ratio is related to the uncertainty in the ratio of production cross sections of B-s(0) and B-0 mesons, f(s)/f(d).
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:The European Physical Journal C. - 82 : 5 (2022), p. 1-25. -
További szerzők:Bartók Márton (fizikus) Karancsi János (1987-) (fizikus) Raics Péter (1944-) (fizikus) Trócsányi Zoltán (1961-) (fizikus) Ujvári Balázs (1977-) (fizikus)
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DOI
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10.

001-es BibID:BIBFORM120967
035-os BibID:(WoS)001062453500002 (Scopus)85168638397
Első szerző:CMS Collaboration
Cím:Measurements of the Higgs boson production cross section and couplings in the W boson pair decay channel in proton-proton collisions at root{s} = 13 TeV / CMS Collaboration
Dátum:2023
ISSN:1434-6052
Megjegyzések:Production cross sections of the standard model Higgs boson decaying to a pair of W bosons are measured in proton-proton collisions at a center-of-mass energy of 13 TeV. The analysis targets Higgs bosons produced via gluon fusion, vector boson fusion, and in association with a W or Z boson. Candidate events are required to have at least two charged leptons and moderate missing transverse momentum, targeting events with at least one leptonically decaying W boson originating from the Higgs boson. Results are presented in the form of inclusive and differential cross sections in the simplified template cross section framework, as well as couplings of the Higgs boson to vector bosons and fermions. The data set collected by the CMS detector during 2016-2018 is used, corresponding to an integrated luminosity of 138 fb(-1). The signal strength modifier mu, defined as the ratio of the observed production rate in a given decay channel to the standard model expectation, is measured to be mu = 0.95(-0.09)(+0.10). All results are found to be compatible with the standard model within the uncertainties.
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:The European Physical Journal C. - 83 : 7 (2023), p. 1-52. -
További szerzők:Bartók Márton (fizikus) Karancsi János (1987-) (fizikus) Raics Péter (1944-) (fizikus) Ujvári Balázs (1977-) (fizikus)
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DOI
Intézményi repozitóriumban (DEA) tárolt változat
Borító:

11.

001-es BibID:BIBFORM118957
035-os BibID:(Scopus)85169653371 (WoS)001066617100001
Első szerző:CMS Collaboration
Cím:Measurements of Higgs boson production in the decay channel with a pair of [tau] leptons in proton-proton collisions at root{s} = 13 TeV / CMS Collaboration
Dátum:2023
ISSN:1434-6052
Megjegyzések:Measurements of Higgs boson production, where the Higgs boson decays into a pair of tau leptons, are presented, using a sample of proton-proton collisions collected with the CMS experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb(-1). Three analyses are presented. Two are targeting Higgs boson production via gluon fusion and vector boson fusion: a neural network based analysis and an analysis based on an event categorization optimized on the ratio of signal over background events. These are complemented by an analysis targeting vector boson associated Higgs boson production. Results are presented in the form of signal strengths relative to the standard model predictions and products of cross sections and branching fraction to tau leptons, in up to 16 different kinematic regions. For the simultaneous measurements of the neural network based analysis and the analysis targeting vector boson associated Higgs boson production signal strengths are found to be 0.82 +/- 0.11 for inclusive Higgs boson production, 0.67 +/- 0.19 (0.81 +/- 0.17) for the production mainly via gluon fusion (vector boson fusion), and 1.79 +/- 0.45 for vector boson associated Higgs boson production.
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:The European Physical Journal C. - 83 : 7 (2023), p. 1-50. -
További szerzők:Bartók Márton (fizikus) Karancsi János (1987-) (fizikus) Raics Péter (1944-) (fizikus) Trócsányi Zoltán (1961-) (fizikus) Ujvári Balázs (1977-) (fizikus)
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DOI
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Borító:

12.

001-es BibID:BIBFORM116502
035-os BibID:(WoS)001099632500001 (Scopus)85174582760
Első szerző:CMS Collaboration
Cím:A search for decays of the Higgs boson to invisible particles in events with a top-antitop quark pair or a vector boson in proton-proton collisions at root{s}=13 TeV / CMS Collaboration
Dátum:2023
ISSN:1434-6052
Megjegyzések:A search for decays to invisible particles of Higgs bosons produced in association with a top-antitop quark pair or a vector boson, which both decay to a fully hadronic final state, has been performed using proton-proton collision data collected at root{s}=13 TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138 fb^{-1}. The 95% confidence level upper limit set on the branching fraction of the 125 GeV Higgs boson to invisible particles, B(H-->inv), is 0.54 (0.39 expected), assuming standard model production cross sections. The results of this analysis are combined with previous B(H-->inv) searches carried out at root{s}=7 , 8, and 13 TeV in complementary production modes. The combined upper limit at 95% confidence level on B(H-->inv) is 0.15 (0.08 expected).
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Germanium alloys
Germanium compounds
Tellurium compounds
Branching fractions
Confidence levels
Final state
Hadronics
Higgs boson
Integrated luminosity
Limit sets
Proton proton collisions
Upper limits
Vector boson
Bosons
Megjelenés:The European Physical Journal C. - 83 : 10 (2023), p. 1-39. -
További szerzők:Bartók Márton (fizikus) Karancsi János (1987-) (fizikus) Raics Péter (1944-) (fizikus) Ujvári Balázs (1977-) (fizikus) Zilizi Gyula (1965-) (fizikus)
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DOI
Intézményi repozitóriumban (DEA) tárolt változat
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