Персона: Блау, Дмитрий Сергеевич
Загружается...
Email Address
Birth Date
Научные группы
Научная группа
Научная группа
Организационные подразделения
Организационная единица
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.
Статус
Фамилия
Блау
Имя
Дмитрий Сергеевич
Имя
47 results
Результаты поиска
Теперь показываю 1 - 10 из 47
- ПубликацияТолько метаданныеNuclear-modification factor of charged hadrons at forward and backward rapidity in p plus Al and p plus Au collisions at root S-NN=200 GeV(2020) Aidala, C.; Akiba, Y.; Alfred, M.; Andrieux, V.; Blau, D. S.; Riabov, V.; Samsonov, V.; Taranenko, A.; Блау, Дмитрий Сергеевич; Рябов, Виктор Германович; Тараненко, Аркадий ВладимировичThe PHENIX experiment has studied nuclear effects in p + Al and p + Au collisions at root S-NN = 200GeV on charged hadron production at forward rapidity (1.4 < eta < 2.4, p-going direction) and backward rapidity (-2.2 < eta < -1.2, A-going direction). Such effects are quantified by measuring nuclear modification factors as a function of transverse momentum and pseudorapidity in various collision multiplicity selections. In central p + Al and p + Au collisions, a suppression (enhancement) is observed at forward (backward) rapidity compared to the binary scaled yields in p + p collisions. The magnitude of enhancement at backward rapidity is larger in p + Au collisions than in p + Al collisions, which have a smaller number of participating nucleons. However, the results at forward rapidity show a similar suppression within uncertainties. The results in the integrated centrality are compared with calculations using nuclear parton distribution functions, which show a reasonable agreement at the forward rapidity but fail to describe the backward rapidity enhancement.
- ПубликацияТолько метаданныеMeasurement of J/Psi at forward and backward rapidity in p plus p, p plus Al, p + Au, and He-3+Au collisions at root s(NN)=200 GeV(2020) Acharya, U.; Adare, A.; Aidala, C.; Ajitanand, N. N.; Blau, D. S.; Riabov, V.; Samsonov, V.; Taranenko, A.; Блау, Дмитрий Сергеевич; Рябов, Виктор Германович; Тараненко, Аркадий ВладимировичCharmonium is a valuable probe in heavy-ion collisions to study the properties of the quark gluon plasma, and is also an interesting probe in small collision systems to study cold nuclear matter effects, which are also present in large collision systems. With the recent observations of collective behavior of produced particles in small system collisions, measurements of the modification of charmonium in small systems have become increasingly relevant. We present the results of J/Psi measurements at forward and backward rapidity in various small collision systems, p + p, p + Al, p + Au, and He-3+Au, at root s(NN) = 200 GeV. The results are presented in the form of the observable RAB, the nuclear modification factor, a measure of the ratio of the J/Psi invariant yield compared to the scaled yield in p + p collisions. We examine the rapidity, transverse momentum, and collision centrality dependence of nuclear effects on J/Psi production with different projectile sizes p and He-3, and different target sizes Al and Au. The modification is found to be strongly dependent on the target size, but to be very similar for p + Au and He-3+Au. However, for 0%-20% central collisions at backward rapidity, the modification factor for He-3+Au is found to be smaller than that for p + Au, with a mean fit to the ratio of 0.89 +/- 0.03(stat)+/- 0.08(syst), possibly indicating final state effects due to the larger projectile size.
- ПубликацияТолько метаданныеMeasurement of jet-medium interactions via direct photon-hadron correlations in Au+Au and d+Au collisions at sNN =200 GeV(2020) Acharya, U.; Adare, A.; Afanasiev, S.; Aidala, C.; Blau, D. S.; Riabov, V.; Samsonov, V.; Taranenko, A.; Блау, Дмитрий Сергеевич; Рябов, Виктор Германович; Тараненко, Аркадий Владимирович© 2020 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the 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. Funded by SCOAP3.We present direct photon-hadron correlations in 200 GeV/A Au+Au, d+Au, and p+p collisions, for direct photon pT from 5-12 GeV/c, collected by the PHENIX Collaboration in the years from 2006 to 2011. We observe no significant modification of jet fragmentation in d+Au collisions, indicating that cold nuclear matter effects are small or absent. Hadrons carrying a large fraction of the quark's momentum are suppressed in Au+Au compared to p+p and d+Au. As the momentum fraction decreases, the yield of hadrons in Au+Au increases to an excess over the yield in p+p collisions. The excess is at large angles and at low hadron pT and is most pronounced for hadrons associated with lower momentum direct photons. Comparison to theoretical calculations suggests that the hadron excess arises from medium response to energy deposited by jets.
- ПубликацияТолько метаданныеNuclear Dependence of the Transverse Single-Spin Asymmetry in the Production of Charged Hadrons at Forward Rapidity in Polarized p plus p, p plus Al, and p plus Au Collisions at root s(NN)=200 GeV(2019) Aidala, C.; Akiba, Y.; Alfred, M.; Andrieux, V.; Blau, D. S.; Riabov, V.; Samsonov, V.; Taranenko, A.; Блау, Дмитрий Сергеевич; Рябов, Виктор Германович; Тараненко, Аркадий ВладимировичWe report on the nuclear dependence of transverse single-spin asymmetries (TSSAs) in the production of positively charged hadrons in polarized p(up arrow) + p, p(up arrow) + Al, and p(up arrow) + Au collisions at root s(NN) = 200 GeV. The measurements have been performed at forward rapidity (1.4 < eta < 2.4) over the range of transverse momentum (1.8 < p(T) < 7.0 GeV/c) and Feynman x (0.1 < x(F) < 0.2). We observed positive asymmetries for positively charged hadrons in p(up arrow) + p collisions, and significantly reduced asymmetries in p(up arrow) + A collisions. These results reveal a nuclear dependence of TSSAs for charged-hadron production in a regime where perturbative techniques are applicable. These results provide new opportunities to use p(up arrow) + A collisions as a tool to investigate the rich phenomena behind TSSAs in hadronic collisions and to use TSSAs as a new handle in studying small-system collisions.
- ПубликацияТолько метаданныеMeasurement of charm and bottom production from semileptonic hadron decays in p plus p collisions at root s=200 GeV(2019) Aidala, C.; Akiba, Y.; Alfred, M.; Andrieux, V.; Blau, D. S.; Riabov, V.; Samsonov, V.; Taranenko, A.; Блау, Дмитрий Сергеевич; Рябов, Виктор Германович; Тараненко, Аркадий ВладимировичMeasurements of the differential production of electrons from open-heavy-flavor hadrons with charm-and bottom-quark content in p + p collisions at root s = 200 GeV are presented. The measurements proceed through displaced-vertex analyses of electron tracks from the semileptonic decay of charm and bottom hadrons using the PHENIX silicon-vertex detector. The relative contribution of electrons from bottom decays to inclusive heavy-flavor-electron production is found to be consistent with fixed-order-plus-next-to-leading-log perturbative-QCD calculations within experimental and theoretical uncertainties. These new measurements in p + p collisions provide a precision baseline for comparable forthcoming measurements in A + A collisions.
- ПубликацияТолько метаданныеImplications for small-system collectivity from a comprehensive set of soft physics measurements in 200 GeV p plus Au collisions by PHENIX(2019) Xu, Q.; Adare, A.; Afanasiev, S.; Aidala, C.; Blau, D. S.; Riabov, V.; Samsonov, V.; Taranenko, A.; Блау, Дмитрий Сергеевич; Рябов, Виктор Германович; Тараненко, Аркадий ВладимировичProton-nucleus (p+A) collisions play an important role as a control system for interpreting hot nuclear matter effects in nucleus-nucleus (A+A) collisions. There is a large amount of data from both RHIC and the LHC that indicate that collective effects are also present in small systems. Understanding the origin of these effects is still incomplete, since a variety of models with very different underlying physics have been shown to describe p+A data. We present a comprehensive set of measurements of soft-physics observables and comparisons with theoretical models. These measurements include multi-particle correlations as a function of event multiplicity, v(2)(p(T)) and v(3)(p(T)) for inclusive charged particles at mid-rapidity, v(2)(p(T)) for hadrons at forward/backward rapidities, and the centrality and pseudorapidity dependence of inclusive v(2). The implications for the origin of collectivity in p+Au collisions at RHIC is discussed.
- ПубликацияТолько метаданныеPHENIX results on jet modification with pi(0)- and photon-triggered two particle correlations in p plus p, p(d) plus Au, and Au plus Au collisions(2019) Osborn, J. D.; Adare, A.; Afanasiev, S.; Aidala, C.; Blau, D. S.; Riabov, V.; Samsonov, V.; Taranenko, A.; Блау, Дмитрий Сергеевич; Рябов, Виктор Германович; Тараненко, Аркадий ВладимировичAs a colorless probe, direct photons balance the p(T) of the away-side jet at leading order. Direct photon-hadron correlations are thus an excellent probe for nuclear structure and QCD effects, including parton energy loss in the Quark-Gluon Plasma. PHENIX has measured pi(0) and direct photon-triggered two-particle azimuthal correlations in a variety of collision systems ranging from p+p to Au+Au at 200 GeV. In p+Au and d+Au collisions, no modification of the per-trigger jet yield or away-side correlation width compared to p+p collisions is observed for direct photon triggered correlations while an increase in the away-side width for pi(0) triggered correlations in p+Au has been measured. In Au+Au collisions, direct photons have been identified statistically as well as using an isolation cut. Combining data sets from different collision systems allows us to quantify the transition from suppression at high z(T) (P-T,P-h/P-T,P-gamma) to the enhancement of low z(T) particles relative to p+p, and to study this transition as a function of trigger p(T).
- ПубликацияТолько метаданныеPHENIX results on elliptic and triangular flow from the small-system geometry scan at 200 GeV(2019) Morrow, S.; Adare, A.; Afanasiev, S.; Aidala, C.; Blau, D. S.; Riabov, V.; Samsonov, V.; Taranenko, A.; Блау, Дмитрий Сергеевич; Рябов, Виктор Германович; Тараненко, Аркадий ВладимировичUsing the extraordinary versatility of RHIC in selecting different colliding species, the PHENIX experiment has collected data in p+Al, p+Au, d+Au, and He-3+Au collisions at 200 GeV center-of-mass energy and conducted a comprehensive set of anisotropic flow measurements. These geometry-controlled experiments provide a unique testing ground for theoretical models that produce azimuthal particle correlations based on initial- and/or final-state effects. A complete set of triangular anisotropies of inclusive charged particles and final results on identified pion and proton v(2)(p(T)) are shown. The mass-ordered splitting in v(2)(p(T)) provides information about the role of early-stage collective flow and late-stage hadronic rescattering. Detailed model comparisons with all observables are discussed.
- ПубликацияТолько метаданныеPHENIX measurements of low momentum direct photon radiation(2019) Khachatryan, V.; Adare, A.; Afanasiev, S.; Aidala, C.; Blau, D. S.; Riabov, V.; Samsonov, V.; Taranenko, A.; Блау, Дмитрий Сергеевич; Рябов, Виктор Германович; Тараненко, Аркадий ВладимировичThe versatility of RHIC allowed the PHENIX collaboration to measure low momentum direct photons from small systems, such as p+p, p+A, d+Au at root s(NN) = 200 GeV as well as from large A+A systems, such as Au+Au and Cu+Cu at 200 GeV and Au+Au at 62.4 GeV and 39 GeV. In these measurements PHENIX has discovered a large excess over the scaled p+p yield of direct photons in A+A collisions, and a non-zero excess over the scaled p+p yield in central p+A collisions. Another PHENIX discovery is that at low-p(T) the integrated yield of direct photons, dN(gamma)/dy, from large systems follows a universal scaling as a function of the charged-particle multiplicity, (dN(ch)/d eta)(alpha), with alpha = 1.25. The observed scaling properties of direct photons from these systems show that the photon production yield increases faster than the charged-particle multiplicity.
- ПубликацияТолько метаданныеMeasurements of charm, bottom, and Drell-Yan via dimuons in p plus p and p plus Au collisions at root S-NN=200 GeV with PHENIX at RHIC(2019) Leung, Y. H.; Adare, A.; Afanasiev, S.; Aidala, C.; Blau, D. S.; Riabov, V.; Samsonov, V.; Taranenko, A.; Блау, Дмитрий Сергеевич; Рябов, Виктор Германович; Тараненко, Аркадий ВладимировичDilepton spectra are a classic probe to study ultra-relativistic heavy ion collisions. At RHIC energies, the dimuon continuum is dominated by correlated pairs from semi-leptonic decays of charm and bottom hadrons and the Drell-Yan process. The dimuon spectra contain information on heavy flavor angular correlations, which can constrain the relative contributions from different heavy flavor production mechanisms. Studying heavy flavor correlations in p+Au collisions may provide further insight on cold nuclear matter effects. Measurements of the Drell-Yan cross-section can provide constraints to PDFs, as well as further our understanding in initial state interactions in p+Au collisions. In this talk, we report measurements of pp pairs from charm, bottom, and Drell-Yan in p+p and p+Au collisions at root S-NN = 200 GeV. A further shape analysis is applied to the heavy flavor pair correlations to extract the relative contributions to heavy flavor production mechanisms.