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Алексеев, Игорь Геннадьевич

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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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Алексеев

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Игорь Геннадьевич

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Теперь показываю 1 - 10 из 14

Только метаданные
Projections of two-particle correlations onto transverse rapidity in Au+Au collisions at sNN =200 GeV at STAR
(2022) Alekseev I.; Brandin A. V.; Kochenda L.; Kravtsov P.; Nigmatkulov G.; Okorokov V. A.; Parfenov P.; Strikhanov M.; Taranenko A.; Vasiliev A. N.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Парфенов, Петр Евгеньевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович; Васильев, Александр Николаевич
Two-particle correlation measurements projected onto two-dimensional, transverse rapidity coordinates (yT1,yT2) provide an independent, orthogonal view of the multidimensional correlation distribution that is most often studied via angular projections. As such, these independent transverse projections allow access to manifestations of dynamical fluctuations in relativistic heavy-ion collisions that angular-correlation measurements may not be sensitive to. We report nonidentified charged-particle correlations for Au+Au minimum-bias collisions at sNN=200 GeV taken by the STAR experiment at the Relativistic Heavy-Ion Collider (RHIC). Correlations are presented as two-dimensional functions of transverse rapidity for like-sign, unlike-sign, and all charged-particle pairs, as well as for particle pairs whose relative azimuthal angles lie on the near-side, the away-side, or at all relative azimuth. The correlations are constructed using charged particles with transverse momentum pT≥0.15 GeV/c, pseudorapidity from -1 to 1, and azimuthal angles from -π to π. The significant correlation structures that are observed evolve smoothly with collision centrality. The major correlation features include a saddle shape plus a broad peak with maximum near yT≈3, corresponding to pT≈1.5 GeV/c. The broad peak is observed in both like- and unlike-sign charge combinations and in near- and away-side relative azimuthal angles. The all-charge, all-azimuth correlation measurements are compared with the predictions of hijing and epos to provide theoretical context for these new measurements. The results indicate that the correlations for peripheral to mid-central collisions can be approximately described as a superposition of nucleon + nucleon collisions with minimal effects from the quantum chromodynamics medium. Strong medium effects are indicated in mid- to most-central collisions. © 2022 American Physical Society.
Только метаданные
Centrality and transverse-momentum dependence of higher-order flow harmonics of identified hadrons in Au+Au collisions at sNN =200 GeV
(2022) Alekseev I.; Brandin A. V.; Khyzhniak E.; Kochenda L.; Kravtsov P.; Nigmatkulov G.; Okorokov V. A.; Parfenov P.; Strikhanov M.; Taranenko A.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Парфенов, Петр Евгеньевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович
We present high-precision measurements of elliptic, triangular, and quadrangular flow v2, v3, and v4, respectively, at midrapidity for identified hadrons π, p, K, φ, Ks, Λ as a function of centrality and transverse momentum in Au+Au collisions at the center-of-mass energy sNN=200 GeV. We observe similar vn trends between light and strange mesons which indicates that the heavier strange quarks flow as strongly as the lighter up and down quarks. The number-of-constituent-quark scaling for v2, v3, and v4 is found to hold within statistical uncertainty for 0-10%, 10-40%, and 40-80% collision centrality intervals. The results are compared to several viscous hydrodynamic calculations with varying initial conditions, and could serve as an additional constraint to the development of hydrodynamic models. © 2022 American Physical Society.
Только метаданные
Pair invariant mass to isolate background in the search for the chiral magnetic effect in Au + Au collisions at sNN =200 GeV
(2022) Alekseev I.; Brandin A. V.; Khyzhniak E.; Kochenda L.; Kravtsov P.; Nigmatkulov G.; Okorokov V. A.; Parfenov P.; Strikhanov M.; Taranenko A.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Парфенов, Петр Евгеньевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович
Только метаданные
Evidence for Nonlinear Gluon Effects in QCD and Their Mass Number Dependence at STAR
(2022) Alekseev I.; Brandin A. V.; Khyzhniak E.; Kochenda L.; Kravtsov P.; Nigmatkulov G.; Okorokov V. A.; Parfenov P.; Strikhanov M.; Taranenko A.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Парфенов, Петр Евгеньевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович
The STAR Collaboration reports measurements of back-to-back azimuthal correlations of di-π0s produced at forward pseudorapidities (2.6<η<4.0) in p+p, p+Al, and p+Au collisions at a center-of-mass energy of 200 GeV. We observe a clear suppression of the correlated yields of back-to-back π0 pairs in p+Al and p+Au collisions compared to the p+p data. The observed suppression of back-to-back pairs as a function of transverse momentum suggests nonlinear gluon dynamics arising at high parton densities. The larger suppression found in p+Au relative to p+Al collisions exhibits a dependence of the saturation scale Qs2 on the mass number A. A linear scaling of the suppression with A1/3 is observed with a slope of -0.09±0.01. © 2022 American Physical Society.
Только метаданные
Collision-System and Beam-Energy Dependence of Anisotropic Flow Fluctuations
(2022) Abdallah, M. S.; Adam, J.; Adamczyk, L.; Adams, J. R.; Alekseev I.; Brandin A. V.; Khyzhniak Y. V.; Kochenda L.; Kravtsov P.; Nigmatkulov G.; Okorokov V.; Parfenov P.; Strikhanov M.; Taranenko A.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Парфенов, Петр Евгеньевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович
Elliptic flow measurements from two-, four-, and six-particle correlations are used to investigate flow fluctuations in collisions of U + U at root S-NN = 193 GeV, Cu thorn Au at root S-NN = 200 GeV and Au thorn Au spanning the range root S-NN = 11.5-200 GeV. The measurements show a strong dependence of the flow fluctuations on collision centrality, a modest dependence on system size, and very little if any, dependence on particle species and beam energy. The results, when compared to similar LHC measurements, viscous hydrodynamic calculations, and TRENTO model eccentricities, indicate that initial-state-driven fluctuations predominate the flow fluctuations generated in the collisions studied.
Только метаданные
Measurements of the Elliptic and Triangular Azimuthal Anisotropies in Central He+Au, 4+Au and p+Au Collisions at & RADIC;SNN=200 GeV br
(2023) Alekseev I.; Brandin A. V.; Kochenda L.; Kravtsov P.; Nigmatkulov G.; Okorokov V. A.; Parfenov P.; Strikhanov M.; Taranenko A.; Vasiliev A. N.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Парфенов, Петр Евгеньевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович; Васильев, Александр Николаевич
The elliptic (v2) and triangular (v3) azimuthal anisotropy coefficients in central 3He thorn Au, d thorn Au, and p thorn Au collisions atffiffiffiffiffiffiffi p 1/4 200 GeV are measured as a function of transverse momentum (pT) at sNN midrapidity (j and eta;j < 0.9), via the azimuthal angular correlation between two particles both at j and eta;j < 0.9. While the v2opT thorn values depend on the colliding systems, the v3 opT thorn values are system independent within the uncertainties, suggesting an influence on eccentricity from subnucleonic fluctuations in these small -sized systems. These results also provide stringent constraints for the hydrodynamic modeling of these systems.
Только метаданные
Search for the chiral magnetic wave using anisotropic flow of identified particles at energies available at the BNL Relativistic Heavy Ion Collider
(2023) Abdulhamid, M. I.; Aboona, B. E.; Adam, J.; Adams, J. R.; Alekseev I.; Brandin A. V.; Kochenda L.; Kravtsov P.; Nigmatkulov G.; Okorokov V. A.; Parfenov P.; Strikhanov M.; Taranenko A.; Vasiliev A. N.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Парфенов, Петр Евгеньевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович; Васильев, Александр Николаевич
Открытый доступ
Beam energy dependence of the linear and mode-coupled flow harmonics in Au+Au collisions
(2023) Aboona, B. E.; Adam, J.; Adams, J. R.; Agakishiev, G.; Alekseev I.; Brandin A. V.; Kochenda L.; Kravtsov P.; Nigmatkulov G.; Okorokov V. A.; Parfenov P.; Strikhanov M.; Taranenko A.; Vasiliev A. N.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Парфенов, Петр Евгеньевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович; Васильев, Александр Николаевич
The linear and mode-coupled contributions to higher-order anisotropic flow are presented for Au+Au collisions at sNN = 27, 39, 54.4, and 200 GeV and compared to similar measurements for Pb+Pb collisions at the Large Hadron Collider (LHC). The coefficients and the flow harmonics correlations, which characterize the linear and mode-coupled response to the lower-order anisotropies, indicate a beam energy dependence consistent with an influence from the specific shear viscosity (О·/s). In contrast, the dimensionless coefficients, mode-coupled response coefficients, and normalized symmetric cumulants are approximately beam-energy independent, consistent with a significant role from initial-state effects. These measurements could provide unique supplemental constraints to (i) distinguish between different initial-state models and (ii) delineate the temperature (T) and baryon chemical potential (ОјB) dependence of the specific shear viscosity О·s(T,ОјB).
Открытый доступ
Pattern of global spin alignment of ϕ and K*0 mesons in heavy-ion collisions
(2023) Abdallah, M. S.; Aboona, B. E.; Adam, J.; Adamczyk, L.; Alekseev I.; Brandin A. V.; Kochenda L.; Kravtsov P.; Nigmatkulov G.; Okorokov V. A.; Parfenov P.; Strikhanov M.; Taranenko A.; Vasiliev A. N.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Парфенов, Петр Евгеньевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович; Васильев, Александр Николаевич
Notwithstanding decades of progress since Yukawa first developed a description of the force between nucleons in terms of meson exchange1, a full understanding of the strong interaction remains a considerable challenge in modern science. One remaining difficulty arises from the non-perturbative nature of the strong force, which leads to the phenomenon of quark confinement at distances on the order of the size of the proton. Here we show that, in relativistic heavy-ion collisions, in which quarks and gluons are set free over an extended volume, two species of produced vector (spin-1) mesons, namely П• and K*0, emerge with a surprising pattern of global spin alignment. In particular, the global spin alignment for П• is unexpectedly large, whereas that for K*0 is consistent with zero. The observed spin-alignment pattern and magnitude for П• cannot be explained by conventional mechanisms, whereas a model with a connection to strong force fields2вЂ“6, that is, an effective proxy description within the standard model and quantum chromodynamics, accommodates the current data. This connection, if fully established, will open a potential new avenue for studying the behaviour of strong force fields. At the Relativistic Heavy Ion Collider, observations of two meson species produced by heavy-ion collisions, П• and K*0, show surprising patterns of global spin alignment, being unexpectedly large and consistent with zero, respectively.
Открытый доступ
Beam Energy Dependence of Triton Production and Yield Ratio (Nt×Np/ Nd2) in Au+Au Collisions at RHIC
(2023) Abdulhamid, M. I.; Aboona, B. E.; Adam, J.; Adams, J. R.; Alekseev I.; Brandin A. V.; Kochenda L.; Kravtsov P.; Nigmatkulov G.; Okorokov V. A.; Parfenov P.; Strikhanov M.; Taranenko A.; Vasiliev A. N.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Парфенов, Петр Евгеньевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович; Васильев, Александр Николаевич