165 research outputs found
Directed flow in Au+Au collisions from the RHIC Beam Energy Scan at the STAR experiment
We report results of and near mid-rapidity for
, , , , , ,
and from Beam Energy Scan Au+Au collisions at
7.7 - 200 GeV using the STAR detector at RHIC. The
of , and mesons remains negative over
all beam energies. The of and baryons shows a sign
change around 10 - 15 GeV, while net baryons (net p and net ) indicate
a double sign change. The of , and
show a similar trend for 14.5 GeV. For the first time,
measurements are used to test a quark coalescence hypothesis. Many
measurements are found to be consistent with the particles being formed via
coalescence of constituent quarks. The observed deviations from that
consistency offer a new approach for probing the collision process at the quark
level.Comment: 7 pages, 4 figures to appear in CPOD 2017 proceedings,
PoS(CPOD2017)00
Strange hadron and resonance production in Pb-Pb collisions at = 2.76 TeV with ALICE experiment at LHC
The ALICE experiment at the LHC has measured the production of strange
hadrons and resonances in Pb-Pb and pp collisions at unprecedented high beam
energies. The study of strange hadrons and resonances helps us to understand
the properties of the medium created in the heavy-ion collisions and its
evolution. We present the yields () at mid-rapidity for strange hadrons
(, , , their anti-particles and ) and
resonances ( and ) for several collision centrality intervals.
The results from Pb-Pb collisions at = 2.76 TeV are presented
and compared to corresponding results from pp collisions and lower energy
measurements. Baryon to meson ratios and resonance to non-resonance particle
ratios relative to pp collisions are shown as a function of collision
centrality and compared with the results at lower energies.Comment: 4 pages, 3 figures (Quark Matter 2012 proceedings
Hadronic Resonance Production with ALICE Experiment at LHC
The production of resonances in heavy-ion collisions is expected to be
sensitive to the properties of strongly interacting matter created in such
collisions. We report on the measurements of and resonances in
Pb-Pb collisions at = 2.76 TeV. The masses, widths and yields
in Pb-Pb collisions as a function of centrality are compared to that in pp
collisions to understand the role of re-scattering and regeneration. The
resonance to non-resonance particle ratios are shown as a function of collision
centrality and compared with the results at lower energies.Comment: 4 pages, 8 figures (submitted CPOD 2013 proceedings
Measurement of global spin alignment of vector mesons at RHIC
We report the measurements of spin alignment () for ,
, , and vector mesons in RHIC isobar
collisions (Zr+Zr and Ru+Ru) at = 200 GeV. We observe
the first non-zero spin alignment for in heavy-ion collisions. The
is about 3.9 larger than that of . The
observed difference and the ordering between and are
surprising, and require further inputs from theory. When comparing between the
isobar and Au+Au collisions, no significant system size dependence in
is observed within uncertainties.Comment: Quark Matter 2022 proceeding
The First Moment of Azimuthal Anisotropy in Nuclear Collisions from AGS to LHC Energies
We review topics related to the first moment of azimuthal anisotropy (),
commonly known as directed flow, focusing on both charged particles and
identified particles from heavy-ion collisions. Beam energies from the highest
available, at the CERN LHC, down to projectile kinetic energies per nucleon of
a few GeV per nucleon, as studied in experiments at the Brookhaven AGS, fall
within our scope. We focus on experimental measurements and on theoretical work
where direct comparisons with experiment have been emphasized. The physics
addressed or potentially addressed by this review topic includes the study of
Quark Gluon Plasma, and more generally, investigation of the Quantum
Chromodynamics phase diagram and the equation of state describing the
accessible phases.Comment: Accepted for publication in Advances in High Energy Physic
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