Персона: Болоздыня, Александр Иванович
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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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Руководитель научной группы"Межкафедральная лаборатория экспериментальной ядерной физики"
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Болоздыня
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Александр Иванович
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187 results
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- ПубликацияТолько метаданныеϒ production and nuclear modification at forward rapidity in Pb–Pb collisions at sNN=5.02TeV(2021) Acharya, S.; Adamova, D.; Adler, A.; Adolfsson, J.; Belyaev, V.; Bogdanov, A.; Bolozdynya, A.; Borissov, A.; Grigoriev, V.; Kaplin, V.; Kondratyeva, N.; Loginov, V.; Samsonov, V.; Selyuzhenkov, I.; Беляев, Владимир Никитич; Богданов, Алексей Александрович; Болоздыня, Александр Иванович; Григорьев, Владислав Анатольевич; Кондратьева, Наталья Викторовна; Логинов, Виталий Александрович© 2021 European Organization for Nuclear Research, ALICEThe production of ϒ mesons in Pb–Pb collisions at a centre-of-mass energy per nucleon pair sNN=5.02 TeV is measured with the muon spectrometer of the ALICE detector at the LHC. The yields as well as the nuclear modification factors are determined in the forward rapidity region 2.5
- ПубликацияТолько метаданныеMeasurement of D , D + , D ∗ + and Ds+ production in pp collisions at √s=5.02TeV with ALICE(2019) Acharya, S.; Adamova, D.; Adhya, S. P.; Adler, A.; Belyaev, V.; Bogdanov, A.; Bolozdynya, A.; Grigoriev, V.; Kaplin, V.; Kondratyeva, N.; Loginov, V.; Melikyan, Y.; Samsonov, V.; Selyuzhenkov, I.; Беляев, Владимир Никитич; Богданов, Алексей Александрович; Болоздыня, Александр Иванович; Григорьев, Владислав Анатольевич; Кондратьева, Наталья Викторовна; Логинов, Виталий Александрович© 2019, CERN for the benefit of the ALICE collaboration. The measurements of the production of prompt D , D + , D ∗ + , and Ds+ mesons in proton–proton (pp) collisions at s=5.02TeV with the ALICE detector at the Large Hadron Collider (LHC) are reported. D mesons were reconstructed at mid-rapidity (| y| < 0.5) via their hadronic decay channels D → K - π + , D + → K - π + π + , D ∗ + → D π + → K - π + π + , Ds+→ϕπ+→K+K-π+, and their charge conjugates. The production cross sections were measured in the transverse momentum interval 0
- ПубликацияТолько метаданныеNon-linear flow modes of identified particles in Pb-Pb collisions at √sNN = 5.02 TeV(2020) Acharya, S.; Adamova, D.; Adler, A.; Adolfsson, J.; Belyaev, V.; Bogdanov, A.; Bolozdynya, A.; Borissov, A.; Grigoriev, V.; Kaplin, V.; Kondratyeva, N.; Loginov, V.; Melikyan, Y.; Samsonov, V.; Selyuzhenkov, I.; Беляев, Владимир Никитич; Богданов, Алексей Александрович; Болоздыня, Александр Иванович; Григорьев, Владислав Анатольевич; Кондратьева, Наталья Викторовна; Логинов, Виталий Александрович© 2020, The Author(s).The pT-differential non-linear flow modes, v4,22, v5,32, v6,33 and v6,222 for π±, K±, KS0 , p + p ¯ , Λ + Λ ¯ and ϕ-meson have been measured for the first time at sNN = 5.02 TeV in Pb-Pb collisions with the ALICE detector at the Large Hadron Collider. The results were obtained with a multi-particle technique, correlating the identified hadrons with reference charged particles from a different pseudorapidity region. These non-linear observables probe the contribution from the second and third order initial spatial anisotropy coefficients to higher flow harmonics. All the characteristic features observed in previous pT-differential anisotropic flow measurements for various particle species are also present in the non-linear flow modes, i.e. increase of magnitude with increasing centrality percentile, mass ordering at low pT and particle type grouping in the intermediate pT range. Hydrodynamical calculations (iEBE-VISHNU) that use different initial conditions and values of shear and bulk viscosity to entropy density ratios are confronted with the data at low transverse momenta. These calculations exhibit a better agreement with the anisotropic flow coefficients than the non-linear flow modes. These observations indicate that non-linear flow modes can provide additional discriminatory power in the study of initial conditions as well as new stringent constraints to hydrodynamical calculations. [Figure not available: see fulltext.].
- ПубликацияТолько метаданныеFirst constraint on coherent elastic neutrino-nucleus scattering in argon(2019) Akimov, D. Y.; Albert, J. B.; An, P.; Awe, C.; Belov, V. A.; Bolozdynya, A. I.; Khromov, A. V.; Konovalov, A. M.; Kozlova, E. S.; Kumpan, A. V.; Razuvaeva, O.; Rudik, D. G.; Shakirov, A. V.; Simakov, G.; Sosnovtsev, V. V.; Акимов, Дмитрий Юрьевич; Белов, Владимир Александрович; Болоздыня, Александр Иванович; Хромов, Александр Владимирович; Коновалов, Алексей Михайлович; Козлова, Екатерина Сергеевна; Кумпан, Александр Вячеславович; Разуваева, Ольга Евгеньевна; Рудик, Дмитрий Геннадьевич; Шакиров, Алексей Вячеславович; Симаков, Григорий Евгеньевич; Сосновцев, Валерий ВитальевичCoherent elastic neutrino-nucleus scattering (CEvNS) is calculated to be the dominant neutrino scattering channel for neutrinos of energy E-nu < 100 MeV. We report a limit for this process from data collected in an engineering run of the 29 kg CENNS-10 liquid argon detector located 27.5 m from the pion decay-at-rest neutrino source at the Oak Ridge National Laboratory Spallation Neutron Source (SNS) with 4.2 x 10(22) protons on target. The dataset provided constraints on beam-related backgrounds critical for future measurements and yielded < 7.4 candidate CEvNS events which implies a cross section for the process, averaged over the SNS pion decay-at-rest flux, of < 3.4 x 10(-39) cm(2), a limit within twice the Standard Model prediction. This is the first limit on CEvNS from an argon nucleus and confirms the earlier CsI[Na] nonstandard neutrino interaction constraints from the collaboration. This run demonstrated the feasibility of the ongoing experimental effort to detect CEvNS with liquid argon.
- ПубликацияТолько метаданныеProduction of muons from heavy-flavour hadron decays at high transverse momentum in Pb–Pb collisions at sNN=5.02 and 2.76 TeV(2021) Acharya, S.; Adamova, D.; Adler, A.; Adolfsson, J.; Belyaev, V.; Bogdanov, A.; Bolozdynya, A.; Borissov, A.; Grigoriev, V.; Kaplin, V.; Kondratyeva, N.; Loginov, V.; Samsonov, V.; Selyuzhenkov, I.; Беляев, Владимир Никитич; Богданов, Алексей Александрович; Болоздыня, Александр Иванович; Григорьев, Владислав Анатольевич; Кондратьева, Наталья Викторовна; Логинов, Виталий Александрович© 2021 European Organization for Nuclear Research, ALICEMeasurements of the production of muons from heavy-flavour hadron decays in Pb–Pb collisions at sNN=5.02 and 2.76 TeV using the ALICE detector at the LHC are reported. The nuclear modification factor RAA at sNN=5.02 TeV is measured at forward rapidity (2.57 GeV/c). The RAA shows an increase of the suppression of the yields of muons from heavy-flavour hadron decays with increasing centrality. A suppression by a factor of about three is observed in the 10% most central collisions. The RAA at sNN=5.02 TeV is similar to that at sNN=2.76 TeV. The precise RAA measurements have the potential to distinguish between model predictions implementing different mechanisms of parton energy loss in the high-density medium formed in heavy-ion collisions. They place important constraints for the understanding of the heavy-quark interaction with the hot and dense QCD medium.
- ПубликацияТолько метаданныеMeasurement of jet radial profiles in Pb–Pb collisions at sNN=2.76 TeV(2019) Acharya, S.; Adamova, D.; Adhya, S. P.; Adler, A.; Belyaev, V.; Bogdanov, A.; Bolozdynya, A.; Borissov, A.; Grigoriev, V.; Kaplin, V.; Kondratyeva, N.; Loginov, V.; Melikyan, Y.; Samsonov, V.; Selyuzhenkov, I.; Беляев, Владимир Никитич; Богданов, Алексей Александрович; Болоздыня, Александр Иванович; Григорьев, Владислав Анатольевич; Кондратьева, Наталья Викторовна; Логинов, Виталий Александрович© 2019 The Author(s)The jet radial structure and particle transverse momentum (pT) composition within jets are presented in centrality-selected Pb–Pb collisions at sNN=2.76 TeV. Track-based jets, which are also called charged jets, were reconstructed with a resolution parameter of R=0.3 at midrapidity |ηch jet|<0.6 for transverse momenta pT,ch jet=30–120 GeV/c. Jet–hadron correlations in relative azimuth and pseudorapidity space (Δφ,Δη) are measured to study the distribution of the associated particles around the jet axis for different pT,assoc-ranges between 1 and 20 GeV/c. The data in Pb–Pb collisions are compared to reference distributions for pp collisions, obtained using embedded PYTHIA simulations. The number of high-pT associate particles (4
- ПубликацияТолько метаданныеPseudorapidity distributions of charged particles as a function of mvid- and forward rapidity multiplicities in pp collisions at root s=5.02, 7 and 13 TeV(2021) Acharya, S.; Adamova, D.; Adler, A.; Adolfsson, J.; Belyaev, V.; Bogdanov, A.; Bolozdynya, A.; Borissov, A.; Grigoriev, V.; Kaplin, V.; Kondratyeva, N.; Loginov, V.; Samsonov, V.; Selyuzhenkov, I.; Беляев, Владимир Никитич; Богданов, Алексей Александрович; Болоздыня, Александр Иванович; Григорьев, Владислав Анатольевич; Кондратьева, Наталья Викторовна; Логинов, Виталий АлександровичThemultiplicity dependence of the pseudorapidity density of charged particles in proton-proton (pp) collisions at centre-of-mass energies root s = 5.02, 7 and 13 TeV measured by ALICE is reported. The analysis relies on track segments measured in the midrapidity range (|eta| < 1.5). Results are presented for inelastic events having at least one charged particle produced in the pseudorapidity interval |eta| < 1. The multiplicity dependence of the pseudorapidity density of charged particles is measured with midand forward rapidity multiplicity estimators, the latter being less affected by autocorrelations. Adetailed comparison with predictions from the PYTHIA 8 and EPOS LHC event generators is also presented. The results can be used to constrain models for particle production as a function of multiplicity in pp collisions.
- ПубликацияТолько метаданныеInclusive J/psi production at midrapidity in pp collisions at root s=13 Tev(2021) Acharya, S.; Adamova, D.; Adler, A.; Rinella, G. A.; Belyaev, V.; Bogdanov, A.; Bolozdynya, A.; Grigoriev, V.; Kaplin, V.; Kondratyeva, N.; Loginov, V.; Okorokov, V. A.; Samsonov, V.; Selyuzhenkov, I.; Беляев, Владимир Никитич; Богданов, Алексей Александрович; Болоздыня, Александр Иванович; Григорьев, Владислав Анатольевич; Кондратьева, Наталья Викторовна; Логинов, Виталий Александрович; Окороков, Виталий АлексеевичWe report on the inclusive J/psi production cross section measured at the CERN Large Hadron Collider in proton-proton collisions at a center-of-mass energy root s = 13 TeV. The J/psi mesons are reconstructed in the e(+)e(-) decay channel and the measurements are performed at midrapidity (vertical bar y vertical bar < 0.9) in the transverse-momentum interval 0 < p(T) < 40 GeV/c, using a minimum-bias data sample corresponding to an integrated luminosity L-i(nt) = 32.2 nb(-1) and an Electromagnetic Calorimeter triggered data sample with L-i(nt) = 8.3 pb(-1). The p(T)-integrated J/psi production cross section at midrapidity, computed using the minimumbias data sample, is d sigma/dy vertical bar(y) =0 = 8.97 +/- 0.24 (stat) 0.48 (syst) +/- 0.15 (lumi) mu b. An approximate logarithmic dependence with the collision energy is suggested by these results and available world data, in agreement with model predictions. The integrated and p(T)-differential measurements are compared with measurements in pp collisions at lower energies and with several recent phenomenological calculations based on the non-relativistic QCD and Color Evaporation models.
- ПубликацияТолько метаданныеFirst Observation of an Attractive Interaction between a Proton and a Cascade Baryon(2019) Acharya, S.; Adamova, D.; Adhya, S. P.; Adler, A.; Belyaev, V.; Bogdanov, A.; Bolozdynya, A.; Borissov, A.; Grigoriev, V.; Kaplin, V.; Kondratyeva, N.; Loginov, V.; Melikyan, Y.; Samsonov, V.; Selyuzhenkov, I.; Беляев, Владимир Никитич; Богданов, Алексей Александрович; Болоздыня, Александр Иванович; Григорьев, Владислав Анатольевич; Кондратьева, Наталья Викторовна; Логинов, Виталий АлександровичThis Letter presents the first experimental observation of the attractive strong interaction between a proton and a multistrange baryon (hyperon) Xi(-). The result is extracted from two-particle correlations of combined p-Xi(-) circle plus (p) over bar-(Xi) over bar (+) pairs measured in p-Pb collisions at root S-NN = 5.02 TeV at the LHC with ALICE. The measured correlation function is compared with the prediction obtained assuming only an attractive Coulomb interaction and a standard deviation in the range [3.6, 5.3] is found. Since the measured p-Xi(-)circle plus(p) over bar-(Xi) over bar (+) correlation is significantly enhanced with respect to the Coulomb prediction, the presence of an additional, strong, attractive interaction is evident. The data are compatible with recent lattice calculations by the HAL-QCD Collaboration, with a standard deviation in the range [1.8, 3.7]. The lattice potential predicts a shallow repulsive Xi(-). interaction within pure neutron matter and this implies stiffer equations of state for neutron-rich matter including hyperons. Implications of the strong interaction for the modeling of neutron stars are discussed.
- ПубликацияТолько метаданныеFirst measurement of Lambda(+)(c) production down to p(T)=0 in pp and p-Pb collisions at root s(NN)=5.02 TeV(2023) Belyaev, V.; Bogdanov, A.; Bolozdynya, A.; Grigoriev, V.; Kaplin, V.; Kondratyeva, N.; Okorokov, V. A.; Selyuzhenkov, I.; Беляев, Владимир Никитич; Богданов, Алексей Александрович; Болоздыня, Александр Иванович; Григорьев, Владислав Анатольевич; Кондратьева, Наталья Викторовна; Окороков, Виталий АлексеевичThe production of prompt Lambda(+)(c) baryons has been measured at midrapidity in the transverse momentum interval 0 < pT < 1 GeV/c for the first time, in pp and p-Pb collisions at a center-of-mass energy per nucleon-nucleon collision root s(NN) = 5.02 TeV. The measurement was performed in the decay channel Lambda(+)(c) . pK0 S by applying new decay reconstruction techniques using a Kalman-Filter vertexing algorithm and adopting a machine-learning approach for the candidate selection. The pT -integrated Lambda(+)(c) production cross sections in both collision systems were determined and used along with the measured yields in Pb-Pb collisions to compute the pT -integrated nuclear modification factors RpPb and RAA of Lambda(+)(c) baryons, which are compared to model calculations that consider nuclear modification of the parton distribution functions. The Lambda(+)(c) /D0 baryon-to-meson yield ratio is reported for pp and p-Pb collisions. Comparisons with models that include modified hadronization processes are presented, and the implications of the results on the understanding of charm hadronization in hadronic collisions are discussed. A significant (3.7s) modification of the mean transverse momentum of Lambda(+)(c) baryons is seen in p-Pb collisions with respect to pp collisions, while the pT -integrated Lambda(+)(c) /D0 yield ratio was found to be consistent between the two collision systems within the uncertainties.