scholarly journals The Rapidity Distributions and the Thermalization Induced Transverse Momentum Distributions in Au-Au Collisions at RHIC Energies

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Zhi-Jin Jiang ◽  
Jia-Qi Hui ◽  
Yu Zhang
Keyword(s):  
Transverse Momentum ◽  
Heavy Ion Collisions ◽  
Good Description ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Ion Collisions ◽  
Hadronic State ◽  
Momentum Distributions ◽  
Rapidity Distributions ◽  
Made In

It is widely believed that the quark-gluon plasma (QGP) might be formed in the current heavy ion collisions. It is also widely recognized that the relativistic hydrodynamics is one of the best tools for describing the process of expansion and hadronization of QGP. In this paper, by taking into account the effects of thermalization, a hydrodynamic model including phase transition from QGP state to hadronic state is used to analyze the rapidity and transverse momentum distributions of identified charged particles produced in heavy ion collisions. A comparison is made between the theoretical results and experimental data. The theoretical model gives a good description of the corresponding measurements made in Au-Au collisions at RHIC energies.

scholarly journals A Description of the Transverse Momentum Distributions of Charged Particles Produced in Heavy Ion Collisions at RHIC and LHC Energies

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Jia-Qi Hui ◽  
Zhi-Jin Jiang ◽  
Dong-Fang Xu
Keyword(s):  
Transverse Momentum ◽  
Heavy Ion Collisions ◽  
Good Description ◽  
Charged Particles ◽  
Heavy Ion ◽  
Ion Collisions ◽  
Nonextensive Statistics ◽  
Long Range Interactions ◽  
Momentum Distributions ◽  
Momentum Region

By assuming the existence of memory effects and long-range interactions, nonextensive statistics together with relativistic hydrodynamics including phase transition are used to discuss the transverse momentum distributions of charged particles produced in heavy ion collisions. It is shown that the combined contributions from nonextensive statistics and hydrodynamics can give a good description of the experimental data in Au+Au collisions at sNN=200 GeV and in Pb+Pb collisions at sNN=2.76 TeV for π± and K± in the whole measured transverse momentum region and for pp- in the region of pT≤2.0 GeV/c. This is different from our previous work using the conventional statistics plus hydrodynamics, where the describable region is only limited in pT≤1.1 GeV/c.

JET CONVERSIONS IN QGP AND SUPPRESSION OF IDENTIFIED HADRONS

2007 ◽  
Vol 16 (07n08) ◽  
pp. 1930-1936 ◽  
Author(s):  
WEI LIU ◽  
CHE MING KO ◽  
BEN-WEI ZHANG
Keyword(s):  
Transverse Momentum ◽  
Quark Gluon Plasma ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Relativistic Heavy Ion Collisions ◽  
High Transverse Momentum ◽  
Ion Collisions ◽  
Conversion Rates ◽  
Gluon Jets

A gluon or quark jet traversing through a quark-gluon plasma can be converted into a quark or gluon jet through scatterings with thermal partons. Their conversion rates due to two-body elastic and inelastic scattering as well as scatterings involving gluon radiation are evaluated in the lowest order in Quantum Chromodynamics (QCD). Including both energy loss and conversions of quark and gluon jets in the expanding quark-gluon plasma produced in relativistic heavy ion collisions, we find a net conversion of quark jets to gluon jets. This reduces the difference between the nuclear modification factors for quark and gluon jets in central heavy ion collisions and thus enhances the p/π+ and [Formula: see text] ratios at high transverse momentum. Using the larger QCD coupling constant from lattice QCD calculations than that given by the perturbative QCD further enhances the net quark to gluon jet conversion rate, leading to a closer similarity between these ratios at high transverse momentum in central Au + Au collisions at [Formula: see text] and in p + p collisions at same energy as observed in experiments.

scholarly journals Freeze-Out Parameters in Heavy-Ion Collisions at AGS, SPS, RHIC, and LHC Energies

2015 ◽  
Vol 2015 ◽  
pp. 1-20 ◽  
Author(s):  
Sandeep Chatterjee ◽  
Sabita Das ◽  
Lokesh Kumar ◽  
D. Mishra ◽  
Bedangadas Mohanty ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
High Energy ◽  
Particle Multiplicity ◽  
Charged Particle Multiplicity ◽  
Ion Collisions ◽  
Momentum Distributions ◽  
Chemical Freeze ◽  
Freeze Out

We review the chemical and kinetic freeze-out conditions in high energy heavy-ion collisions for AGS, SPS, RHIC, and LHC energies. Chemical freeze-out parameters are obtained using produced particle yields in central collisions while the corresponding kinetic freeze-out parameters are obtained using transverse momentum distributions of produced particles. For chemical freeze-out, different freeze-out scenarios are discussed such as single and double/flavor dependent freeze-out surfaces. Kinetic freeze-out parameters are obtained by doing hydrodynamic inspired blast wave fit to the transverse momentum distributions. The beam energy and centrality dependence of transverse energy per charged particle multiplicity are studied to address the constant energy per particle freeze-out criteria in heavy-ion collisions.

A hydrodynamic model including phase transition and the thermal motion-induced transverse momentum distributions in high energy heavy ion collisions

2017 ◽  
Vol 26 (07) ◽  
pp. 1750045
Author(s):  
Z. J. Jiang ◽  
J. Q. Hui ◽  
Y. Zhang
Keyword(s):  
Phase Transition ◽  
Transverse Momentum ◽  
Hydrodynamic Model ◽  
Good Description ◽  
Heavy Ion ◽  
High Energy ◽  
Thermal Motion ◽  
Ion Collisions ◽  
Momentum Distributions ◽  
Theoretical Predictions

By taking into account the effects of thermal motion, the transverse momentum distributions of identified charged particles produced in nucleus collisions are discussed in the context of a hydrodynamic model including phase transition. A comparison is made between the theoretical predictions and experimental measurements. The theoretical model gives a good description to the data collected in Au–Au collisions at RHIC energy of [Formula: see text][Formula: see text]GeV. For Pb–Pb collisions at LHC energy of [Formula: see text][Formula: see text]TeV, the model works well up to the transverse momentum of about [Formula: see text][Formula: see text]GeV/c.

scholarly journals Jets in Heavy Ion Collisions with the ATLAS Detector

2018 ◽  
Vol 46 ◽  
pp. 1860020
Author(s):  
Helena Santos
Keyword(s):  
Transverse Momentum ◽  
Heavy Ion Collisions ◽  
Statistical Significance ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Dense Medium ◽  
Momentum Balance ◽  
Ion Collisions ◽  
High Statistical Significance ◽  
Wide Range

Jets constitute a golden probe to study the quark gluon plasma produced in heavy ion collisions at the LHC. Being produced at the early stages of the collisions, they are expected to be modified as propagating through the hot and dense medium. A signature of the modification is the energy loss lowering the jet yields at a given transverse momentum. A factor of two suppression is observed in central Pb+Pb collisions with respect to [Formula: see text] collisions. Other signatures are the modification of the dijet momentum balance and the modification of fragmentation functions. These proceedings describe results on these observables from ATLAS in Runs 1 and 2. The high statistical significance of these data samples collected by ATLAS allows precision measurements of these observables in a wide range of transverse momentum and centrality.

scholarly journals Vector boson tagged jets and jet substructure

2018 ◽  
Vol 172 ◽  
pp. 05006
Author(s):  
Ivan Vitev
Keyword(s):  
Transverse Momentum ◽  
Heavy Ion Collisions ◽  
Vector Boson ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Jet Substructure ◽  
Proton Proton ◽  
Jet Production ◽  
Ion Collisions ◽  
Jet Shapes

In these proceedings, we report on recent results related to vector boson-tagged jet production in heavy ion collisions and the related modification of jet substructure, such as jet shapes and jet momentum sharing distributions. Z0-tagging and γ-tagging of jets provides new opportunities to study parton shower formation and propagation in the quark-gluon plasma and has been argued to provide tight constrains on the energy loss of reconstructed jets. We present theoretical predictions for isolated photon-tagged and electroweak boson-tagged jet production in Pb+Pb collisions at √sNN = 5.02 TeV at the LHC, addressing the modification of their transverse momentum and transverse momentum imbalance distributions. Comparison to recent ATLAS and CMS experimental measurements is performed that can shed light on the medium-induced radiative corrections and energy dissipation due to collisional processes of predominantly quark-initiated jets. The modification of parton splitting functions in the QGP further implies that the substructure of jets in heavy ion collisions may differ significantly from the corresponding substructure in proton-proton collisions. Two such observables and the implication of tagging on their evaluation is also discussed.

scholarly journals Azimuthal dependence of two-particle transverse momentum current correlations

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
Niseem Magdy ◽  
Sumit Basu ◽  
Victor Gonzalez ◽  
Ana Marin ◽  
Olga Evdokimov ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Heavy Ion Collisions ◽  
Theoretical Models ◽  
Energy System ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Entropy Density ◽  
Relativistic Heavy Ion Collisions ◽  
Azimuthal Dependence ◽  
Ion Collisions

AbstractTwo-particle transverse momentum correlation functions are a powerful technique for understanding the dynamics of relativistic heavy-ion collisions. Among these, the transverse momentum correlator $$G_{2}\left( \varDelta \eta ,\varDelta \varphi \right) $$ G 2 Δ η , Δ φ is of particular interest for its potential sensitivity to the shear viscosity per unit of entropy density $$\eta /s$$ η / s of the quark-gluon plasma formed in heavy-ion collisions. We use the UrQMD, AMPT, and EPOS models for Au–Au at $$\sqrt{s_\mathrm{NN}}$$ s NN = 200 GeV and Pb–Pb at $$\sqrt{s_\mathrm{NN}}$$ s NN = 2760 GeV to investigate the long range azimuthal dependence of $$G_{2}\left( \varDelta \eta ,\varDelta \varphi \right) $$ G 2 Δ η , Δ φ , and explore its utility to constrain $$\eta /s$$ η / s based on charged particle correlations. We find that the three models yield quantitatively distinct transverse momentum Fourier harmonics coefficients $$a^{p_\mathrm{T}}_{n}$$ a n p T . We also observe these coefficients exhibit a significant dependence on $$\eta /s$$ η / s in the context of the AMPT model. These observations suggest that exhaustive measurements of the dependence of $$G_{2}\left( \varDelta \varphi \right) $$ G 2 Δ φ with collision energy, system size, collision centrality, in particular, offer the potential to distinguish between different theoretical models and their underlying assumptions. Exhaustive analyses of $$G_{2}\left( \varDelta \varphi \right) $$ G 2 Δ φ obtained in large and small systems should also be instrumental in establishing new constraints for precise extraction of $$\eta /s$$ η / s .

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