scholarly journals Addendum to strangeness production and color deconfinement

2018 ◽  
Vol 27 (04) ◽  
pp. 1891001 ◽  
Author(s):  
P. Castorina ◽  
S Plumari ◽  
H. Satz
Keyword(s):  
Beam Energy ◽  
Star Collaboration ◽  
Entropy Density ◽  
Strangeness Production ◽  
Suppression Factor ◽  
Universal Behavior ◽  
Extensive Data ◽  
Beam Energy Scan

Recent extensive data from the beam energy scan of the STAR collaboration at BNL-RHIC provide the basis for a detailed update for the universal behavior of the strangeness suppression factor [Formula: see text] as function of the initial entropy density as proposed in our recent paper (P. Castorina, S Plumari and H. Satz, Int. J. Mod. Phys. E 26 (2017) 1750081, arXiv:1709.02706 [nucl-th]).

scholarly journals Highlights from the STAR experiment

2019 ◽  
Vol 204 ◽  
pp. 01018
Author(s):  
Alexey Aparin
Keyword(s):  
Beam Energy ◽  
Star Collaboration ◽  
Fixed Target ◽  
Directed Flow ◽  
Decay Modes ◽  
Charm Quarks ◽  
Star Experiment ◽  
The One ◽  
Beam Energy Scan ◽  
Program Show

We present an overview of the recent results obtained by the STAR Collaboration at RHIC.We report the beam energy dependence of directed flow of strange particles. These results support the assumption, that directed flow is formed before hadronization and observed particles are formed via coalescence of constituent quarks. First evidence of a non-zero directed flow of D0 meson is reported. We present the precision measurement of elliptic flow of D0 meson and the first measurement of Λc baryon in Au+Au collisions at $\rad{}{s_{NN} } = 200\,{\rm{GeV}}$, which suggests thermalization of charm quarks. We report results of global Λ polarization measurements in Au+Au collisions, together with the investigation of polarization dependence of centrality and transverse momentum pT. Results from the STAR fixed-target program show good agreement with previously obtained results. A precise measurement of the $_{{\rm{\Lambda }}}^{3} H$ lifetime is presented. Mesonic decay modes are used to reconstruct the $_{{\rm{\Lambda }}}^{3} H$ from Au+Au collisions. The measured lifetime is about 50% shorter than the one of a free Λ, indicating a strong hyperon-nucleon interaction in the hypernucleus system. Finally, we give an outlook to detector upgrades for the Beam Energy Scan phase II.

scholarly journals Strangeness Suppression and Color Deconfinement

2018 ◽  
Vol 171 ◽  
pp. 02005
Author(s):  
Helmut Satz
Keyword(s):  
Initial Temperature ◽  
Strange Particle ◽  
High Energy ◽  
Universal Function ◽  
Ideal Gas ◽  
Entropy Density ◽  
Suppression Factor ◽  
Thermal Medium ◽  
High Energy Collisions ◽  
Hadronic Resonances

The relative multiplicities for hadron production in different high energy collisions are in general well described by an ideal gas of all hadronic resonances, except that under certain conditions, strange particle rates are systematically reduced. We show that the suppression factor γs, accounting for reduced strange particle rates in pp, pA and AA collisions at different collision energies, becomes a universal function when expressed in terms of the initial entropy density s0 or the initial temperature T of the produced thermal medium. It is found that γs increases from about 0.5 to 1.0 in a narrow temperature range around the quark-hadron transition temperature Tc ≃ 160 MeV. Strangeness suppression thus disappears with the onset of color deconfinement; subsequently, full equilibrium resonance gas behavior is attained.

scholarly journals MWPC Prototyping and Testing for STAR Inner TPC Upgrade

2018 ◽  
Vol 46 ◽  
pp. 1860079
Author(s):  
Shuai Wang
Keyword(s):  
Beam Energy ◽  
Qcd Phase Transition ◽  
Proportional Chamber ◽  
Physics Program ◽  
Momentum Resolution ◽  
Multiwire Proportional Chamber ◽  
Star Experiment ◽  
Transition Study ◽  
Time Projection ◽  
Beam Energy Scan

The STAR experiment at RHIC is upgrading the inner sectors of the Time Projection Chamber (iTPC) to increase the segmentation on the inner padplane from 13 to 40 rows and to replace the inner sector multiwire proportional chamber (MWPC). The upgrade will provide better momentum resolution, better dE/dx resolution, and most importantly it will provide improved acceptance at high rapidity to [Formula: see text]1.5 compared to the current TPC coverage of [Formula: see text]1.0. The enhanced TPC capabilities based on this upgrade are critical to the physics program of the Beam Energy Scan Phase II at RHIC during 2019-2020, in particular the QCD phase transition study. In this proceedings, the iTPC MWPC module fabrication and prototype testing results are discussed.

scholarly journals Mapping the phases of quantum chromodynamics with beam energy scan

2020 ◽  
Vol 853 ◽  
pp. 1-87 ◽  
Author(s):  
Adam Bzdak ◽  
ShinIchi Esumi ◽  
Volker Koch ◽  
Jinfeng Liao ◽  
Mikhail Stephanov ◽  
...  
Keyword(s):  
Quantum Chromodynamics ◽  
Beam Energy ◽  
Beam Energy Scan
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