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Брандин, Андрей Владимирович

Организационные подразделения

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Другие подразделения НИЯУ МИФИ

Структурные подразделения НИЯУ МИФИ, не включенные в состав институтов и факультетов.

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Брандин

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Андрей Владимирович

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Теперь показываю 1 - 10 из 43

Только метаданные
Upsilon measurements in Au plus Au collisions at root S-NN=200 GeV with the STAR experiment
(2019) Wang, P. F.; Adam, J.; Adamczyk, L.; Adams, J. R.; Alekseev, I.; Brandin, A. V.; Kochenda, L.; Kravtsov, P.; Nigmatkulov, G.; Okorokov, V. A.; Strikhanov, M.; Taranenko, A.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович
We present the latest measurements of Upsilon production in Au+Au collisions at root S-NN = 200 GeV via both di-muon and di-electron decay channels by the STAR experiment at RHIC. With the addition of the 2016 data set to those taken in 2011 and 2014, the precision of Upsilon measurements is significantly improved compared to previous preliminary results, especially for the excited Upsilon states. The nuclear modification factors for the ground and excited Upsilon states are shown as a functions of transverse momentum or centrality, and are compared to results from the LHC as well as to theoretical calculations.
Только метаданные
Measurements of open charm production in Au plus Au collisions at root s(NN)=200 GeV with the STAR experiment at RHIC
(2019) Radhakrishnan, S.; Adam, J.; Adamczyk, L.; Adams, J. R.; Alekseev, I.; Brandin, A. V.; Kochenda, L.; Kravtsov, P.; Nigmatkulov, G.; Okorokov, V. A.; Strikhanov, M.; Taranenko, A.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович
We report in these proceedings on the measurements of collision centrality and transverse momentum (p(T)) dependences of the Lambda(+/-)(c) production in Au+Au collisions at root s(NN) = 200 GeV, using the STAR Heavy Flavor Tracker (HFT). The Lambda(+/-)(c) signal significance is greatly improved with the addition of the high-statistics data set collected in 2016 and the use of a supervised machine learning method for topological reconstruction of the decay vertices. The measured Lambda(+/-)(c)/D-0 ratio shows a significant enhancement compared to the PYTHIA prediction for p+p collisions, across the measured p(T) range. We also report on the updated measurements of D-0 nuclear modification factors R-AA and R-CP using the 2014 data with the HFT. The measured D-0 R-AA in central collisions is lower than unity across the p(T) interval of the measurement. The D-0 yields show strong suppression at high p(T) (> 6 GeV/c) in central collisions, consistent with that of light flavor hadrons. The c (c) over bar production cross section per binary nucleon collision at midrapidity in Au+Au collisions at 200 GeV is extracted based on the various charm hadron measurements by STAR. It is observed that while the charm hadrochemistry is significantly modified in Au+Au collisions compared to p+p collisions, the c (c) over bar production cross section at midrapidity remains consistent between Au+Au and p+p collisions.
Только метаданные
Global and local polarization of A hyperons in Au plus Au collisions at 200 GeV from STAR
(2019) Niida, T.; Adam, J.; Adamczyk, L.; Adams, J. R.; Alekseev, I.; Brandin, A. V.; Kochenda, L.; Kravtsov, P.; Nigmatkulov, G.; Okorokov, V. A.; Strikhanov, M.; Taranenko, A.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович
New results on global polarization of A hyperons in Au+Au collisions at root s(NN) = 200 GeV reveal non-zero signal on the order of a few tenths of a percent. Compared with lower energy results, the current measurement shows that the polarization decreases at higher collision energy, the trend being well reproduced by theoretical calculations. The polarization is found to be larger in more peripheral collisions, as well as in the in-plane than in the out-of-plane direction. The signal seems to depend on the asymmetry between positive and negative charge in each event, which may indicate an influence of the axial current induced by the magnetic field. In addition, the first measurement of a local polarization along the beam direction was performed. The results show a quadrupole modulation relative to the second-order event plane, as expected from the elliptic flow.
Только метаданные
The STAR BES-II and Forward Rapidity Physics and Upgrades
(2019) Yang, Q.; Adam, J.; Adamczyk, L.; Adams, J. R.; Alekseev, I.; Brandin, A. V.; Kochenda, L.; Kravtsov, P.; Nigmatkulov, G.; Okorokov, V. A.; Strikhanov, M.; Taranenko, A.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович
The second phase of the Beam Energy Scan at RHIC, BES-II, is scheduled to start in 2019 and will explore the high baryon density region of the QCD phase diagram with precision measurements. The detector upgrades will enhance some of the key measurements by extending STAR's kinematic reach, like the kurtosis of net-protons distribution which could pinpoint the position of a critical point. The upgrades currently under way comprise: the replacement of the inner TPC sectors, the Event Plane Detector (EPD) and the end-cap TOR Building on these upgrades STAR is planning to further enhance its detector capabilities by installing a Forward Calorimeter System (FCS) integrating an electromagnetic and hadronic calorimeter and a Forward Tracking System (FTS) combining 3 Silicon mini-strip disks and 4 Small-Strip Thin Gap Chamber (sTGC) wheels. The forward upgrades are motivated by studying the initial state of nucleons and nuclei and the exploration of cold QCD physics in the very high and low x regions. This contribution will highlight these upgrades and some of the physics opportunities that they allow.
Только метаданные
The production of triton and reconstruction of H-3(Lambda) with the Heavy Flavor Tracker in Au plus Au collisions at STAR
(2019) Liu, P.; Adam, J.; Adamczyk, L.; Adams, J. R.; Alekseev, I.; Brandin, A. V.; Kochenda, L.; Kravtsov, P.; Nigmatkulov, G.; Okorokov, V. A.; Strikhanov, M.; Taranenko, A.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович
The transverse momentum spectra of triton with STAR Beam Energy Scan data from Au+Au collisions at root N-SS = 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, 200 GeV in the centrality classes 0 - 10%, 10 - 20%, 20 - 40% and 40 - 80% are reported. The centrality dependence of the coalescence parameter B-3 of triton and the collision energy dependence of the relative neutron density fluctuation are then calculated. The results indicate that the B-3 decreases from peripheral to central collisions and the neutron density fluctuation shows a non-monotonic collision energy dependence with a peak around collision energy of 20-30 GeV. In addition, we report details about the reconstruction method of H-3(Lambda) via H-3(Lambda) -> 4 He-3 + pi(-) and H-3(Lambda) -> + p + pi(-) using high statistics data in Au+Au collisions at root S-NN = 200 GeV collected in 2014 and 2016 with the Heavy Flavor Tracker.
Только метаданные
Collision system and beam energy dependence of anisotropic flow fluctuations
(2019) Magdy, N.; Adam, J.; Adamczyk, L.; Adams, J. R.; Alekseev, I.; Brandin, A. V.; Kochenda, L.; Kravtsov, P.; Nigmatkulov, G.; Okorokov, V. A.; Strikhanov, M.; Taranenko, A.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович
New measurements of elliptic flow from two- and four-particle correlations are used to investigate flow fluctuations in collisions of U+U at root s(NN) = 193 GeV, Cu+Au at root s(NN) = 200 GeV and Au+Au at several beam energies. These measurements highlight the dependence of these fluctuations on the event shape, system size and beam energy and indicate a dominant role for initial-state-driven fluctuations. These measurements could provide further constraints for initial-state models, as well as for precision extraction of the temperature-dependent specific shear viscosity eta/s(T).
Только метаданные
Measurements of directed and elliptic flow for D-0 and <(D-0)over bar> mesons using the STAR detector at RHIC
(2019) Singha, S.; Adam, J.; Adamczyk, L.; Adams, J. R.; Alekseev, I.; Brandin, A. V.; Kochenda, L.; Kravtsov, P.; Nigmatkulov, G.; Okorokov, V. A.; Strikhanov, M.; Taranenko, A.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович
We report on the first evidence for a non-zero rapidity-odd directed flow (nu(1)) for D-0 and (D-0) over bar mesons in 10-80% centrality Au+Au collisions at root S-NN = 200 GeV measured with the STAR detector at RHIC. The slope of the v1 rapidity dependence (d nu(1)/dy) averaged over D-0 and (D-0) over bar mesons is -0.081 +/- 0.021 +/- 0.017, while that of charged kaons is -0.0030 +/- 0.0001 +/- 0.0002, suggesting significantly larger slope for the D-0 mesons. Models indicate that the large d nu(1)/dy of D-0 mesons is sensitive to the initially tilted source. We also present a new measurement of the D-0 meson elliptic flow (v(2)) as a function of transverse momentum (P-T) in Au+Au collisions at root S-NN = 200 GeV with an improved precision with respect to the previously published results. The D-0 nu(2) results are compared to those of light-flavor hadrons to test the number-of-constituent-quark (NCQ) scaling. Both the nu(1) and nu(2) results are compared to recent hydrodynamic and transport model calculations.
Только метаданные
Measurements of hadron production in π++ C and π++Be interactions at 60 GeV/c
(2019) Aduszkiewicz, A.; Andronov, E. V.; Anticic, T.; Babkin, V.; Brandin, A.; Golosov, O.; Kargin, N. I.; Kashirin, E.; Morozov, S.; Selyuzhenkov, I.; Strikhanov, M.; Taranenko, A.; Брандин, Андрей Владимирович; Голосов, Олег Владимирович; Каргин, Николай Иванович; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович
© 2019 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/" Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Precise knowledge of hadron production rates in the generation of neutrino beams is necessary for accelerator-based neutrino experiments to achieve their physics goals. NA61/SHINE, a large-acceptance hadron spectrometer, has recorded hadron+nucleus interactions relevant to ongoing and future long-baseline neutrino experiments at Fermi National Accelerator Laboratory. This paper presents three analyses of interactions of 60 GeV/c π+ with thin, fixed carbon and beryllium targets. Integrated production and inelastic cross sections were measured for both of these reactions. In an analysis of strange, neutral hadron production, differential production multiplicities of KS0, Λ and Λ were measured. Lastly, in an analysis of charged hadron production, differential production multiplicities of π+, π-, K+, K- A nd protons were measured. These measurements will enable long-baseline neutrino experiments to better constrain predictions of their neutrino flux in order to achieve better precision on their neutrino cross section and oscillation measurements.
Только метаданные
Long-range collectivity in small collision systems with two- and four-particle correlations at STAR
(2019) Huang, S. L.; Adam, J.; Adamczyk, L.; Adams, J. R.; Alekseev, I.; Brandin, A. V.; Kochenda, L.; Kravtsov, P.; Nigmatkulov, G.; Okorokov, V. A.; Strikhanov, M.; Taranenko, A.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович
New STAR measurements of two- and four-particle (c(2){4}) azimuthal angle correlations are reported for p+Au collisions at 200 GeV and d+Au collisions from 19.6 to 200 GeV. A negative c(2){4), consistent with collective anisotropic flow, is observed in high multiplicity d+Au events at 62.4 and 200 GeV where the statistical significance of the data allows an analysis. A template fitting method, employed to subtract non-flow contributions to the two-particle correlations, allows the extraction of the anisotropy coefficients (v(2)) for these systems at their respective energies. The v(2) results for different energies show a common dependence on the charged particle multiplicity density << dN(ch)/d eta >>, which provide important insight on the nature of collective behavior in small collision systems.
Только метаданные
Search for the Chiral Magnetic Wave with Anisotropic Flow of Identified Particles at RHIC-STAR
(2019) Shou, Q. Y.; Adam, J.; Adamczyk, L.; Adams, J. R.; Alekseev, I.; Brandin, A. V.; Kochenda, L.; Kravtsov, P.; Nigmatkulov, G.; Okorokov, V. A.; Strikhanov, M.; Taranenko, A.; Алексеев, Игорь Геннадьевич; Брандин, Андрей Владимирович; Нигматкулов, Григорий Александрович; Окороков, Виталий Алексеевич; Стриханов, Михаил Николаевич; Тараненко, Аркадий Владимирович
The chiral magnetic wave (CMW) has been theorized to propagate in the Quark-Gluon Plasma formed in high-energy heavy-ion collisions. It could cause a finite electric quadrupole moment of the collision system, and may be observed as a dependence of elliptic flow, v(2), on the asymmetry between positively and negatively charged hadrons, A(ch). However, non-CMW mechanisms, such as local charge conservation (LCC) and hydrodynamics with isospin effect, could also contribute to the experimental observations. Here we present the STAR measurements of elliptic flow v(2) and triangular flow v(3) of charged pions, along with v(2) of charged kaons and protons, as functions of A(ch) in Au+Au collisions root S-NN = 200 GeV. The slope parameters of Delta v(2)(A(ch)) and Delta v(3)(Ach) are reported and compared to investigate the LCC background. The similarity between pion and kaon slopes suggests that the hydrodynamics is not the dominant mechanism. The difference between the normalized Delta v(2) and Delta v(3) slopes, together with the small slopes in p+Au and d+Au collisions at root S-NN = 200 GeV, suggest that the CMW picture remains a viable interpretation at RHIC.