5 research outputs found
Insight from the elliptic flow of identified hadrons measured in relativistic heavy-ion collisions
In this paper, we have discussed the transverse momentum dependence of
elliptic flow measured in relativistic heavy-ion collisions. The transverse
momentum dependence of the number of constituent quarks () scaled
is obtained for all the measured identified hadrons. The scaled
is found to be similar to scaled . This
indicates that both and are produced through quark
recombination at RHIC energies. We also find scaled proton
( of light quarks) is higher than scaled and
( of strange quarks) at 1.0 GeV/c. This can be
explained by considering quark is proportional to its transverse
kinetic energy considering mass of deconfined light and strange quarks equal to
4 MeV and 140 MeV, respectively.Comment: 8 pages, 6 figure
Azimuthal anisotropy measurement of multi-strange hadrons in Au+Au collision at √
In these proceedings, we present the second order (ν2) and the third order (ν3) azimuthal anisotropy measurements of strange and multi-strange hadrons such as in Au+Au collisions at at STAR. The centrality dependence of ν2 and ν3 as well as the number of constituent quark scaling (NCQ scaling) for all the particles mentioned above are discussed. The ratio of ν2 of ϕ mesons to that of is presented at which gives a hint of mass ordering violation at low pT
Examining the influence of hadronic interactions on the directed flow of identified particles in RHIC Beam Energy Scan energies using UrQMD model
The directed flow of identified particles can serve as a sensitive tool for
investigating the interactions during initial and final states in heavy ion
collisions. This study examines the rapidity-odd directed flow () and
its slope () for , , p, and in
Au+Au collisions at different collision centralities and beam energies
( = 7.7, 11.5, 14.5, 19.6, 27, and 39 GeV) using the
UrQMD model. We investigate the impact of late-stage hadronic interactions on
charge dependent and its slope by modifying the duration of the
hadronic cascade lifetime (). The energy dependence of for p
() exhibits distinct pattern compared to and
. Notably, we observe a change in the sign reversal position of proton
at different beam energies with varying in central and
mid-central collisions. Moreover, the difference in between
positively and negatively charged hadrons () demonstrates a
stark centrality dependence for different particle species. The deuteron
displays a significant increase in with increasing compared
to p and n. This investigation underscores the importance of considering the
temporal evolution and duration of the hadronic phase when interpreting the
sign reversal, charge splitting of and light nuclei formation at lower
RHIC energies.Comment: 12 pages, 8 figure
Hyperon Polarization along the Beam Direction Relative to the Second and Third Harmonic Event Planes in Isobar Collisions at <math display="inline"><mrow><msqrt><mrow><msub><mrow><mi>s</mi></mrow><mrow><mi>N</mi><mi>N</mi></mrow></msub></mrow></msqrt><mo>=</mo><mn>200</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></math>
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 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 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.The polarization of and 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 = 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 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 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