Персона: Булеков, Олег Владимирович
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Институт ядерной физики и технологий
Цель ИЯФиТ и стратегия развития - создание и развитие научно-образовательного центра мирового уровня в области ядерной физики и технологий, радиационного материаловедения, физики элементарных частиц, астрофизики и космофизики.
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Олег Владимирович
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- ПубликацияТолько метаданныеMeasurement of the tt¯ production cross-section in the lepton+jets channel at s=13 TeV with the ATLAS experiment(2020) Aad, G.; Abbott, B.; Abbott, D. C.; Abed, Abud, A.; Belotskiy, K.; Belyaev, N. L.; Bulekov, O.; Kurova, A.; Ponomarenko, D.; Proklova, N.; Pyatiizbyantseva, D.; Romaniouk, A.; Smirnov, N.; Smirnov, S. Y.; Smirnov, Y.; Soldatov, E. Y.; Tikhomirov, V. O.; Timoshenko, S.; Vorobev, K.; Белоцкий, Константин Михайлович; Булеков, Олег Владимирович; Курова, Анастасия Сергеевна; Пятиизбянцева, Диана Николаевна; Романюк, Анатолий Самсонович; Смирнов, Сергей Юрьевич; Смирнов, Юрий Сергеевич; Солдатов, Евгений Юрьевич; Тихомиров, Владимир Олегович; Тимошенко, Сергей Леонидович; Воробьёв, Константин Александрович© 2020 The Author(s)The top anti-top quark production cross-section is measured in the lepton+jets channel using proton–proton collision data at a centre-of-mass energy of s=13 TeV collected with the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 139 fb−1. Events with exactly one charged lepton and four or more jets in the final state, with at least one jet containing b-hadrons, are used to determine the tt¯ production cross-section through a profile-likelihood fit. The inclusive cross-section is measured to be σinc=830±0.4(stat.)±36(syst.)±14(lumi.)pb with a relative uncertainty of 4.6%. The result is consistent with theoretical calculations at next-to-next-to-leading order in perturbative QCD. The fiducial tt¯ cross-section within the experimental acceptance is also measured.
- ПубликацияТолько метаданныеSearch for type-III seesaw heavy leptons in leptonic final states in pp collisions at √s=13TeV with the ATLAS detector(2022) Belotskiy, K.; Belyaev, N. L.; Bulekov, O.; Kurova, A.; Ponomarenko, D.; Proklova, N.; Pyatiizbyantseva, D.; Romaniouk, A.; Smirnov, S. Y.; Smirnov, Y.; Soldatov, E. Y.; Tikhomirov, V. O.; Timoshenko, S.; Vorobev, K.; Белоцкий, Константин Михайлович; Булеков, Олег Владимирович; Курова, Анастасия Сергеевна; Пятиизбянцева, Диана Николаевна; Романюк, Анатолий Самсонович; Смирнов, Сергей Юрьевич; Смирнов, Юрий Сергеевич; Солдатов, Евгений Юрьевич; Тихомиров, Владимир Олегович; Тимошенко, Сергей Леонидович; Воробьёв, Константин АлександровичA search for the pair production of heavy leptons as predicted by the type-III seesaw mechanism is presented. The search uses proton–proton collision data at a centre-of-mass energy of 13 TeV, corresponding to 139fb-1 of integrated luminosity recorded by the ATLAS detector during Run 2 of the Large Hadron Collider. The analysis focuses on final states with three or four electrons or muons from the possible decays of new heavy leptons via intermediate electroweak bosons. No significant deviations above the Standard Model expectation are observed; upper and lower limits on the heavy lepton production cross-section and masses are derived respectively. These results are then combined for the first time with the ones already published by ATLAS using the channel with two leptons in the final state. The observed lower limit on the mass of the type-III seesaw heavy leptons combining two, three and four lepton channels together is 910 GeV at the 95% confidence level. © 2022, CERN for the benefit of the ATLAS Collaboration.
- ПубликацияТолько метаданныеMeasurements of differential cross-sections in top-quark pair events with a high transverse momentum top quark and limits on beyond the Standard Model contributions to top-quark pair production with the ATLAS detector at √s = 13 TeV(2022) Aad, G.; Abbott, B.; Abbott, D. C.; Abed, Abud A.; Belotskiy, K.; Belyaev, N. L.; Bulekov, O.; Kurova, A.; Ponomarenko, D.; Proklova, N.; Pyatiizbyantseva, D.; Romaniouk, A.; Smirnov, S. Y.; Smirnov, Y.; Soldatov, E. Y.; Tikhomirov, V. O.; Timoshenko, S.; Vorobev, K.; Белоцкий, Константин Михайлович; Булеков, Олег Владимирович; Курова, Анастасия Сергеевна; Пятиизбянцева, Диана Николаевна; Романюк, Анатолий Самсонович; Смирнов, Сергей Юрьевич; Смирнов, Юрий Сергеевич; Солдатов, Евгений Юрьевич; Тихомиров, Владимир Олегович; Тимошенко, Сергей Леонидович; Воробьёв, Константин Александрович© 2022, The Author(s).Cross-section measurements of top-quark pair production where the hadronically decaying top quark has transverse momentum greater than 355 GeV and the other top quark decays into ℓνb are presented using 139 fb−1 of data collected by the ATLAS experiment during proton-proton collisions at the LHC. The fiducial cross-section at s = 13 TeV is measured to be σ = 1.267 ± 0.005 ± 0.053 pb, where the uncertainties reflect the limited number of data events and the systematic uncertainties, giving a total uncertainty of 4.2%. The cross-section is measured differentially as a function of variables characterising the tt¯ system and additional radiation in the events. The results are compared with various Monte Carlo generators, including comparisons where the generators are reweighted to match a parton-level calculation at next-to-next-to-leading order. The reweighting improves the agreement between data and theory. The measured distribution of the top-quark transverse momentum is used to search for new physics in the context of the effective field theory framework. No significant deviation from the Standard Model is observed and limits are set on the Wilson coefficients of the dimension-six operators OtG and Otq(8), where the limits on the latter are the most stringent to date. [Figure not available: see fulltext.].
- ПубликацияТолько метаданныеSearch for high-mass dilepton resonances using 139 fb−1 of pp collision data collected at s=13 TeV with the ATLAS detector(2019) Aad, G.; Abbott, B.; Abbott, D. C.; Abdinov, O.; Belotskiy, K.; Belyaev, N. L.; Bulekov, O.; Kantserov, V. A.; Kurova, A.; Ponomarenko, D.; Proklova, N.; Romaniouk, A.; Smirnov, N.; Smirnov, S. Y.; Smirnov, Y.; Soldatov, E. Y.; Timoshenko, S.; Vorobev, K.; Tikhomirov, V. O.; Белоцкий, Константин Михайлович; Булеков, Олег Владимирович; Курова, Анастасия Сергеевна; Романюк, Анатолий Самсонович; Смирнов, Сергей Юрьевич; Смирнов, Юрий Сергеевич; Солдатов, Евгений Юрьевич; Тимошенко, Сергей Леонидович; Воробьёв, Константин Александрович; Тихомиров, Владимир Олегович© 2019 The AuthorA search for high-mass dielectron and dimuon resonances in the mass range of 250 GeV to 6 TeV is presented. The data were recorded by the ATLAS experiment in proton–proton collisions at a centre-of-mass energy of s=13 TeV during Run 2 of the Large Hadron Collider and correspond to an integrated luminosity of 139 fb−1. A functional form is fitted to the dilepton invariant-mass distribution to model the contribution from background processes, and a generic signal shape is used to determine the significance of observed deviations from this background estimate. No significant deviation is observed and upper limits are placed at the 95% confidence level on the fiducial cross-section times branching ratio for various resonance width hypotheses. The derived limits are shown to be applicable to spin-0, spin-1 and spin-2 signal hypotheses. For a set of benchmark models, the limits are converted into lower limits on the resonance mass and reach 4.5 TeV for the E6-motivated Zψ ′ boson. Also presented are limits on Heavy Vector Triplet model couplings.
- ПубликацияТолько метаданныеMeasurement of isolated-photon plus two-jet production in pp collisions at √s = 13 TeV with the ATLAS detector(2020) Aad, G.; Abbott, B.; Abbott, D. C.; Abed, Abud, A.; Belotskiy, K.; Belyaev, N. L.; Bulekov, O.; Kantserov, V. A.; Kurova, A.; Ponomarenko, D.; Proklova, N.; Romaniouk, A.; Smirnov, N.; Smirnov, S. Y.; Smirnov, Y.; Soldatov, E. Y.; Tikhomirov, V. O.; Timoshenko, S.; Vorobev, K.; Белоцкий, Константин Михайлович; Булеков, Олег Владимирович; Курова, Анастасия Сергеевна; Романюк, Анатолий Самсонович; Смирнов, Сергей Юрьевич; Смирнов, Юрий Сергеевич; Солдатов, Евгений Юрьевич; Тихомиров, Владимир Олегович; Тимошенко, Сергей Леонидович; Воробьёв, Константин Александрович© 2020, The Author(s).The dynamics of isolated-photon plus two-jet production in pp collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset corresponding to an integrated luminosity of 36.1 fb−1. Cross sections are measured as functions of a variety of observables, including angular correlations and invariant masses of the objects in the final state, γ + jet + jet. Measurements are also performed in phase-space regions enriched in each of the two underlying physical mechanisms, namely direct and fragmentation processes. The measurements cover the range of photon (jet) transverse momenta from 150 GeV (100 GeV) to 2 TeV. The tree-level plus parton-shower predictions from Sherpa and Pythia as well as the next-to-leading-order QCD predictions from Sherpa are compared with the measurements. The next-to-leading-order QCD predictions describe the data adequately in shape and normalisation except for regions of phase space such as those with high values of the invariant mass or rapidity separation of the two jets, where the predictions overestimate the data. [Figure not available: see fulltext.]
- ПубликацияОткрытый доступSearch for light resonances decaying to boosted quark pairs and produced in association with a photon or a jet in proton–proton collisions at √s=13TeV with the ATLAS detector(2019) Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.; Antonov, A.; Belotskiy, K.; Belyaev, N. L.; Bulekov, O.; Kantserov, V. A.; Krasnopevtsev, D.; Ponomarenko, D.; Proklova, N.; Romaniouk, A.; Shulga, E.; Smirnov, N.; Smirnov, S. Y.; Smirnov, Y.; Soldatov, E. Y.; Timoshenko, S.; Tikhomirov, V. O.; Vorobev, K.; Белоцкий, Константин Михайлович; Булеков, Олег Владимирович; Романюк, Анатолий Самсонович; Смирнов, Сергей Юрьевич; Смирнов, Юрий Сергеевич; Солдатов, Евгений Юрьевич; Тимошенко, Сергей Леонидович; Тихомиров, Владимир Олегович; Воробьёв, Константин Александрович© 2018 The Author(s) This Letter presents a search for new light resonances decaying to pairs of quarks and produced in association with a high-pT photon or jet. The dataset consists of proton–proton collisions with an integrated luminosity of 36.1 fb−1 at a centre-of-mass energy of s=13 TeV recorded by the ATLAS detector at the Large Hadron Collider. Resonance candidates are identified as massive large-radius jets with substructure consistent with a particle decaying into a quark pair. The mass spectrum of the candidates is examined for local excesses above background. No evidence of a new resonance is observed in the data, which are used to exclude the production of a lepto-phobic axial-vector Z′ boson.
- ПубликацияТолько метаданныеObservation of electroweak W ± Z boson pair production in association with two jets in pp collisions at s=13 TeV with the ATLAS detector(2019) Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.; Belotskiy, K.; Belyaev, N. L.; Bulekov, O.; Kantserov, V. A.; Kurova, A.; Ponomarenko, D.; Proklova, N.; Romaniouk, A.; Shulga, E.; Smirnov, N.; Smirnov, S. Y.; Smirnov, Y.; Soldatov, E. Y.; Tikhomirov, V. O.; Timoshenko, S.; Vorobev, K.; Белоцкий, Константин Михайлович; Булеков, Олег Владимирович; Курова, Анастасия Сергеевна; Романюк, Анатолий Самсонович; Смирнов, Сергей Юрьевич; Смирнов, Юрий Сергеевич; Солдатов, Евгений Юрьевич; Тихомиров, Владимир Олегович; Тимошенко, Сергей Леонидович; Воробьёв, Константин Александрович© 2019 The Author(s) An observation of electroweak W ± Z production in association with two jets in proton–proton collisions is presented. The data collected by the ATLAS detector at the Large Hadron Collider in 2015 and 2016 at a centre-of-mass energy of s=13 TeV are used, corresponding to an integrated luminosity of 36.1fb −1 . Events containing three identified leptons, either electrons or muons, and two jets are selected. The electroweak production of W ± Z bosons in association with two jets is measured with an observed significance of 5.3 standard deviations. A fiducial cross-section for electroweak production including interference effects and for a single leptonic decay mode is measured to be σ WZjj−EW =0.57 −0.13 +0.14 (stat.) −0.06 +0.07 (syst.)fb. Total and differential fiducial cross-sections of the sum of W ± Zjj electroweak and strong productions for several kinematic observables are also measured.
- ПубликацияТолько метаданныеCombination of searches for Higgs boson pairs in pp collisions at s=13TeV with the ATLAS detector(2020) Aad, G.; Abbott, B.; Abbott, D. C.; Abed, Abud, A.; Belotskiy, K.; Belyaev, N. L.; Bulekov, O.; Kantserov, V. A.; Kurova, A.; Ponomarenko, D.; Proklova, N.; Romaniouk, A.; Smirnov, N.; Smirnov, S. Y.; Smirnov, Y.; Soldatov, E. Y.; Timoshenko, S.; Vorobev, K.; Tikhomirov, V. O.; Белоцкий, Константин Михайлович; Булеков, Олег Владимирович; Курова, Анастасия Сергеевна; Романюк, Анатолий Самсонович; Смирнов, Сергей Юрьевич; Смирнов, Юрий Сергеевич; Солдатов, Евгений Юрьевич; Тимошенко, Сергей Леонидович; Воробьёв, Константин Александрович; Тихомиров, Владимир Олегович© 2019 The Author(s)This letter presents a combination of searches for Higgs boson pair production using up to 36.1 fb−1 of proton–proton collision data at a centre-of-mass energy s=13 TeV recorded with the ATLAS detector at the LHC. The combination is performed using six analyses searching for Higgs boson pairs decaying into the bb¯bb¯, bb¯W+W−, bb¯τ+τ−, W+W−W+W−, bb¯γγ and W+W−γγ final states. Results are presented for non-resonant and resonant Higgs boson pair production modes. No statistically significant excess in data above the Standard Model predictions is found. The combined observed (expected) limit at 95% confidence level on the non-resonant Higgs boson pair production cross-section is 6.9 (10) times the predicted Standard Model cross-section. Limits are also set on the ratio (κλ) of the Higgs boson self-coupling to its Standard Model value. This ratio is constrained at 95% confidence level in observation (expectation) to −5.0<κλ<12.0 (−5.8<κλ<12.0). In addition, limits are set on the production of narrow scalar resonances and spin-2 Kaluza–Klein Randall–Sundrum gravitons. Exclusion regions are also provided in the parameter space of the habemus Minimal Supersymmetric Standard Model and the Electroweak Singlet Model.
- ПубликацияОткрытый доступMeasurement of the nuclear modification factor for inclusive jets in Pb+Pb collisions at sNN=5.02 TeV with the ATLAS detector(2019) Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.; Belotskiy, K.; Belyaev, N. L.; Bulekov, O.; Kantserov, V. A.; Ponomarenko, D.; Proklova, N.; Romaniouk, A.; Shulga, E.; Smirnov, N.; Smirnov, S. Y.; Smirnov, Y.; Soldatov, E. Y.; Timoshenko, S.; Vorobev, K.; Tikhomirov, V. O.; Белоцкий, Константин Михайлович; Булеков, Олег Владимирович; Романюк, Анатолий Самсонович; Смирнов, Сергей Юрьевич; Смирнов, Юрий Сергеевич; Солдатов, Евгений Юрьевич; Тимошенко, Сергей Леонидович; Воробьёв, Константин Александрович; Тихомиров, Владимир Олегович© 2019 The Author Measurements of the yield and nuclear modification factor, RAA, for inclusive jet production are performed using 0.49 nb−1 of Pb+Pb data at sNN=5.02TeV and 25 pb−1 of Pb+Pb data at s=5.02TeV with the ATLAS detector at the LHC. Jets are reconstructed with the anti-kt algorithm with radius parameter R=0.4 and are measured over the transverse momentum range of 40–1000 GeV in six rapidity intervals covering |y|<2.8. The magnitude of RAA increases with increasing jet transverse momentum, reaching a value of approximately 0.6 at 1 TeV in the most central collisions. The magnitude of RAA also increases towards peripheral collisions. The value of RAA is independent of rapidity at low jet transverse momenta, but it is observed to decrease with increasing rapidity at high transverse momenta.
- ПубликацияТолько метаданныеProperties of g -> b(b)over-bar at small opening angles in pp collisions with the ATLAS detector at root s=13 TeV(2019) Aaboud, M.; Aad, G.; Abbott, B.; Abbott, D. C.; Belotskiy, K.; Belyaev, N. L.; Bulekov, O.; Kantserov, V. A.; Kurova, A.; Ponomarenko, D.; Proklova, N.; Romaniouk, A.; Shulga, E.; Smirnov, N.; Smirnov, S. Yu.; Smirnov, Y. u.; Soldatov, E. Yu.; Tikhomirov, V. O.; Timoshenko, S.; Vorobev, K.; Белоцкий, Константин Михайлович; Булеков, Олег Владимирович; Курова, Анастасия Сергеевна; Романюк, Анатолий Самсонович; Смирнов, Сергей Юрьевич; Смирнов, Юрий Сергеевич; Солдатов, Евгений Юрьевич; Тихомиров, Владимир Олегович; Тимошенко, Сергей Леонидович; Воробьёв, Константин АлександровичThe fragmentation of high-energy gluons at small opening angles is largely unconstrained by present measurements. Gluon splitting to b-quark pairs is a unique probe into the properties of gluon fragmentation because identified b-tagged jets provide a proxy for the quark daughters of the initial gluon. In this study, key differential distributions related to the g -> b (b) over bar process are measured using 33 fb(-1) of root s = 13 TeV pp collision data recorded by the ATLAS experiment at the LHC in 2016. Jets constructed from charged-particle tracks, clustered with the anti-k(t) jet algorithm with radius parameter R = 0.2, are used to probe angular scales below the R = 0.4 jet radius. The observables are unfolded to particle level in order to facilitate direct comparisons with predictions from present and future simulations. Multiple significant differences are observed between the data and parton shower Monte Carlo predictions, providing input to improve these predictions of the main source of background events in analyses involving boosted Higgs bosons decaying into b-quarks.