Measurements of the Elliptic and Triangular Azimuthal Anisotropies in Central

The elliptic (v_{2}) and triangular (v_{3}) azimuthal anisotropy coefficients in central ^{3}He+Au, d+Au, and p+Au collisions at sqrt[s_{NN}]=200 GeV are measured as a function of transverse momentum (p_{T}) at midrapidity (|η|<0.9), via the azimuthal angular correlation between two particles both at |η|<0.9. While the v_{2}(p_{T}) values depend on the colliding systems, the v_{3}(p_{T}) 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.

Observation of Directed Flow of Hypernuclei _{Λ}

We report here the first observation of directed flow (v_{1}) of the hypernuclei _{Λ}^{3}H and _{Λ}^{4}H in mid-central Au+Au collisions at sqrt[s_{NN}]=3 GeV at RHIC. These data are taken as part of the beam energy scan program carried out by the STAR experiment. From 165×10^{6} events in 5%-40% centrality, about 8400 _{Λ}^{3}H and 5200 _{Λ}^{4}H candidates are reconstructed through two- and three-body decay channels. We observe that these hypernuclei exhibit significant directed flow. Comparing to that of light nuclei, it is found that the midrapidity v_{1} slopes of _{Λ}^{3}H and _{Λ}^{4}H follow baryon number scaling, implying that the coalescence is the dominant mechanism for these hypernuclei production in the 3 GeV Au+Au collisions.

Hyperon Polarization along the Beam Direction Relative to the Second and Third Harmonic Event Planes in Isobar Collisions at sqrt[s_{NN}]=200 GeV.

The polarization of Λ and Λ[over ¯] hyperons along the beam direction has been measured relative to the second and third harmonic event planes in isobar Ru+Ru and Zr+Zr collisions at sqrt[s_{NN}]=200 GeV. This is the first experimental evidence of the hyperon polarization by the triangular flow originating from the initial density fluctuations. The amplitudes of the sine modulation for the second and third harmonic results are comparable in magnitude, increase from central to peripheral collisions, and show a mild p_{T} dependence. The azimuthal angle dependence of the polarization follows the vorticity pattern expected due to elliptic and triangular anisotropic flow, and qualitatively disagrees with most hydrodynamic model calculations based on thermal vorticity and shear induced contributions. The model results based on one of existing implementations of the shear contribution lead to a correct azimuthal angle dependence, but predict centrality and p_{T} dependence that still disagree with experimental measurements. Thus, our results provide stringent constraints on the thermal vorticity and shear-induced contributions to hyperon polarization. Comparison to previous measurements at RHIC and the LHC for the second-order harmonic results shows little dependence on the collision system size and collision energy.

Beam Energy Dependence of Triton Production and Yield Ratio (N_{t}×N_{p}/N_{d}

We report the triton (t) production in midrapidity (|y|<0.5) Au+Au collisions at sqrt[s_{NN}]=7.7-200 GeV measured by the STAR experiment from the first phase of the beam energy scan at the Relativistic Heavy Ion Collider. The nuclear compound yield ratio (N_{t}×N_{p}/N_{d}^{2}), which is predicted to be sensitive to the fluctuation of local neutron density, is observed to decrease monotonically with increasing charged-particle multiplicity (dN_{ch}/dη) and follows a scaling behavior. The dN_{ch}/dη dependence of the yield ratio is compared to calculations from coalescence and thermal models. Enhancements in the yield ratios relative to the coalescence baseline are observed in the 0%-10% most central collisions at 19.6 and 27 GeV, with a significance of 2.3σ and 3.4σ, respectively, giving a combined significance of 4.1σ. The enhancements are not observed in peripheral collisions or model calculations without critical fluctuation, and decreases with a smaller p_{T} acceptance. The physics implications of these results on the QCD phase structure and the production mechanism of light nuclei in heavy-ion collisions are discussed.

Probing the Gluonic Structure of the Deuteron with J/ψ Photoproduction in d+Au Ultraperipheral Collisions.

Understanding gluon density distributions and how they are modified in nuclei are among the most important goals in nuclear physics. In recent years, diffractive vector meson production measured in ultraperipheral collisions (UPCs) at heavy-ion colliders has provided a new tool for probing the gluon density. In this Letter, we report the first measurement of J/ψ photoproduction off the deuteron in UPCs at the center-of-mass energy sqrt[s_{NN}]=200 GeV in d+Au collisions. The differential cross section as a function of momentum transfer -t is measured. In addition, data with a neutron tagged in the deuteron-going zero-degree calorimeter is investigated for the first time, which is found to be consistent with the expectation of incoherent diffractive scattering at low momentum transfer. Theoretical predictions based on the color glass condensate saturation model and the leading twist approximation nuclear shadowing model are compared with the data quantitatively. A better agreement with the saturation model has been observed. With the current measurement, the results are found to be directly sensitive to the gluon density distribution of the deuteron and the deuteron breakup process, which provides insights into the nuclear gluonic structure.

[The characteristics of the lipid-hormonal interrelations in young men with a history of myocardial infarct (based on family registry data in Novosibirsk and Bishkek)]. / Osobennosti lipidno-gormonal'nykh vzaimosviazei u molodykh muzhchin, perenesshikh infarkt miokarda (po materialam semeinykh registrov v Novosibirske i Bishkeke).

Altogether 226 male probands who suffered large-focal or transmural myocardial infarction (MI) before reaching 50 years were examined in Novosibirsk and Bishkek in one stage according to the unified program. In Novosibirsk all the probands were Russians whereas in Bishkek 75 probands were Kirghizs and 71 were Russians. The probands were examined within a period of 1 to 3 years after MI. The lipid and lipoprotein plasma content was determined by standardized methods on a Tekhnikon AAP autoanalyzer. The content of thyroid hormones, insulin and cortisol was measured by means of RIA-kits and that of apolipoprotein B (ApoB) by radial immunodiffusion. It turned out that the patients from Novosibirsk demonstrated the highest content of cholesterol, low density lipoprotein cholesterol, the highest index of atherogenicity, the highest concentration of ApoB, and hyperinsulinemia. In the probands of both nationalities from Bishkek, the lipid spectrum did not differ substantially from the populational norm, the content of ApoB in the Russian probands was slightly lower than in those from Novosibirsk whereas in Kirghizs, the least content of thyroxin was recorded.

[The prevalence of the main risk factors among probands who have had a myocardial infarct at a young age and among their relatives (based on family registry data in Bishkek and Novosibirsk)]. / Rasprostranennost' osnovnykh faktorov riska sredi probandov, perenesshikh infarkt miokarda v molodom vozraste, i ikh rodstvennikov (po materialam semeinykh registrov v Bishkeke i Novosibirske).

Macrofocal or transmural myocardial infarction at the age under 50 in probands served the criterion for selection of 136 families in Bishkek and Novosibirsk (66 Kirghiz and 70 Russian families, respectively). Main risk factors in probands and their families were determined according to WHO methodological recommendations. Essential hypertension was more prevalent in probands and their families in Bishkek, while hypercholesterolemia was more common in Novosibirsk families. Smoking was documented in Bishkek and Novosibirsk probands in equal proportions, though there were more smokers among probands' sons in Bishkek. Overweight occurred with equal frequency in probands' wives and daughters in both cities, but in probands and their sons in Novosibirsk this risk factor appeared more prevalent. Novosibirsk cases of reduced levels of high-density lipoproteins cholesterol and triiodothyronine, elevated concentrations of apolipoprotein B and immunoreactive insulin outnumbered those in Bishkek.