Refine
Language
- English (42)
Has Fulltext
- yes (42)
Is part of the Bibliography
- no (42)
Keywords
- Collectivity (2)
- Correlation (2)
- Diffraction (2)
- Elastic scattering (2)
- Shear viscosity (2)
- B-slope (1)
- Charm quark spatial diffusion coefficient (1)
- Coalescence (1)
- Cold nuclear matter effects (1)
- Critical point (1)
- Deuteron production (1)
- Elliptic flow (1)
- Groomed jet radius (1)
- Heavy Ion Experiments (1)
- Heavy Quark Production (1)
- Heavy-Ion Collision (1)
- Heavy-flavor decay electron (1)
- Heavy-ion collisions (1)
- Higher moments (1)
- J/ψ suppression (1)
- Jet substructure (1)
- Proton-proton collisions (1)
- Proton–proton collisions (1)
- RHIC (1)
- SoftDrop (1)
- Splitting function (1)
- Thermal model (1)
Institute
We report the first measurements of cumulants, up to 4𝑡ℎ order, of deuteron number distributions and protondeuteron correlations in Au+Au collisions recorded by the STAR experiment in phase-I of Beam Energy Scan (BES) program at the Relativistic Heavy Ion Collider. Deuteron cumulants, their ratios, and proton-deuteron mixed cumulants are presented for different collision centralities covering a range of center-of-mass energy per nucleon pair √𝑠NN = 7.7 to 200 GeV. It is found that the cumulant ratios at lower collision energies favor a canonical ensemble over a grand canonical ensemble in thermal models. An anti-correlation between proton and deuteron multiplicity is observed across all collision energies and centralities, consistent with the expectation from global baryon number conservation. The UrQMD model coupled with a phase-space coalescence mechanism qualitatively reproduces the collision-energy dependence of cumulant ratios and proton-deuteron correlations.
The polarization of Λ and Λ¯ 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 √sNN = 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 pT dependence. The azimuthal angle dependence of the polarization follows the vorticity pattern expected due to elliptic and triangular anisotropic flow, and qualitatively disagree 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 pT 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.