Average transverse expansion velocities and global freeze-out temperatures in central Cu + Cu, Au + Au, and Pb + Pb collisions at high energies at RHIC and LHC

2020 ◽  
Vol 35 (14) ◽  
pp. 2050115 ◽  
Author(s):  
Khusniddin K. Olimov ◽  
Shakhnoza Z. Kanokova ◽  
Kosim Olimov ◽  
Kadyr G. Gulamov ◽  
Bekhzod S. Yuldashev ◽  
...  
Keyword(s):  
Blast Wave ◽  
Heavy Ion Collisions ◽  
Wave Model ◽  
Heavy Ion ◽  
Transverse Flow ◽  
Collision System ◽  
Transverse Expansion ◽  
Ion Collisions ◽  
Charged Pions ◽  
Freeze Out

The experimental invariant transverse momentum [Formula: see text] spectra of the charged pions and kaons, protons and antiprotons, produced at midrapidity in central (0–10%) Au[Formula: see text]Au collisions at [Formula: see text], central (0–10%) Cu[Formula: see text]Cu collisions at [Formula: see text], central (0–10%) Au[Formula: see text]Au collisions at [Formula: see text], and central (0–5%) Pb[Formula: see text]Pb collisions at [Formula: see text], measured by BRAHMS, STAR and ALICE collaborations, were analyzed using three different transverse expansion (blast-wave) models: Siemens–Rasmussen blast-wave model, Simple transverse flow model, and Simplified (hydro-inspired) blast-wave model of Schnedermann et al. Combined (simultaneous) minimum [Formula: see text] fits of the experimental invariant [Formula: see text] spectra of the charged pions and kaons, protons and antiprotons with the above three model functions were conducted, using the identical selected optimal fitting ranges in [Formula: see text] in each studied collision system, and the values of the average transverse expansion velocity [Formula: see text] and global kinetic freeze-out temperature [Formula: see text] and their dependencies on the collision system [Formula: see text] and [Formula: see text] were extracted. The combined (simultaneous) fits using Hagedorn formula with the (embedded) simple transverse flow describe well the experimental invariant [Formula: see text] spectra of the charged pions, kaons, protons and antiprotons in the whole measured range in region [Formula: see text] in the analyzed central heavy ion collisions at RHIC and LHC, reproducing qualitatively well all the established dependencies of the parameters [Formula: see text] and [Formula: see text] on the collision system [Formula: see text] and [Formula: see text]. The obtained results were compared with those of the previous analyses of high energy heavy ion collisions.

scholarly journals Production of Kaon andΛin Nucleus-Nucleus Collisions at Ultrarelativistic Energy from a Blast-Wave Model

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
S. Zhang ◽  
Y. G. Ma ◽  
J. H. Chen ◽  
C. Zhong
Keyword(s):  
Blast Wave ◽  
Particle Production ◽  
Wave Model ◽  
Heavy Ion ◽  
Relativistic Energy ◽  
Ion Collisions ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
Good Agreement ◽  
Freeze Out

The particle production of Kaon andΛis studied in nucleus-nucleus collisions at relativistic energy based on a chemical equilibrium blast-wave model. The transverse momentum spectra of Kaon andΛat the kinetic freeze-out stage from our model are in good agreement with the experimental results. The kinetic freeze-out parameters of temperatureTkinand radial flow parameterρ0are presented for the FOPI, RHIC, and LHC energies. And the resonance decay effect is also discussed. The systematic study for beam energy dependence of the strangeness particle production will help us to better understand the properties of the matter created in heavy-ion collisions at the kinetic freeze-out stage.

scholarly journals Analyzing Transverse Momentum Spectra of Pions, Kaons and Protons in p–p, p–A and A–A Collisions via the Blast-Wave Model with Fluctuations

Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 803
Author(s):  
Hai-Ling Lao ◽  
Fu-Hu Liu ◽  
Bo-Qiang Ma
Keyword(s):  
Transverse Momentum ◽  
Flow Velocity ◽  
Blast Wave ◽  
Proper Time ◽  
Wave Model ◽  
Transverse Flow ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
Transverse Flow Velocity ◽  
Freeze Out

The transverse momentum spectra of different types of particles, π±, K±, p and p¯, produced at mid-(pseudo)rapidity in different centrality lead–lead (Pb–Pb) collisions at 2.76 TeV; proton–lead (p–Pb) collisions at 5.02 TeV; xenon–xenon (Xe–Xe) collisions at 5.44 TeV; and proton–proton (p–p) collisions at 0.9, 2.76, 5.02, 7 and 13 TeV, were analyzed by the blast-wave model with fluctuations. With the experimental data measured by the ALICE and CMS Collaborations at the Large Hadron Collider (LHC), the kinetic freeze-out temperature, transverse flow velocity and proper time were extracted from fitting the transverse momentum spectra. In nucleus–nucleus (A–A) and proton–nucleus (p–A) collisions, the three parameters decrease with the decrease of event centrality from central to peripheral, indicating higher degrees of excitation, quicker expansion velocities and longer evolution times for central collisions. In p–p collisions, the kinetic freeze-out temperature is nearly invariant with the increase of energy, though the transverse flow velocity and proper time increase slightly, in the considered energy range.

Freeze-out in relativistic heavy ion collisions at AGS energies

1995 ◽  
Vol 354 (3-4) ◽  
pp. 196-201 ◽  
Author(s):  
L.V. Bravina ◽  
I.N. Mishustin ◽  
N.S. Amelin ◽  
J.P. Bondorf ◽  
L.P. Csernai
Keyword(s):  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Ion Collisions ◽  
Freeze Out

Collision centrality dependencies of charged pion production in 12C+ 181 Ta collisions at 4.2 A GeV/c

2018 ◽  
Vol 27 (11) ◽  
pp. 1850092 ◽  
Author(s):  
Akhtar Iqbal ◽  
Khusniddin K. Olimov ◽  
Kosim Olimov ◽  
Mushtaq Ahmad ◽  
Sh. Z. Kanokova ◽  
...  
Keyword(s):  
Simple Model ◽  
Pion Production ◽  
Charged Pion ◽  
Heavy Ion ◽  
Emission Angle ◽  
Collision System ◽  
High Energies ◽  
Collision Centrality ◽  
Ion Collisions ◽  
Charged Pions

The collision centrality dependencies of the average kinematical characteristics of the negative and positive pions, produced in [Formula: see text] collisions at [Formula: see text], were investigated. The ratio [Formula: see text] proved to be [Formula: see text], [Formula: see text] and [Formula: see text] in the peripheral, semicentral, and central [Formula: see text] collision events, respectively, decreasing noticeably with increasing collision centrality. The suppression (decrease) of the ratio [Formula: see text] was observed in the semicentral and central [Formula: see text] collisions as compared to the ratio [Formula: see text], estimated using the simple model for [Formula: see text] collision system. The ratio [Formula: see text] estimated using the simple model agreed well with the corresponding ratio [Formula: see text], estimated for [Formula: see text] collisions at [Formula: see text] based on the Wounded Nucleon Model (WNM). Comparison of the emission angle as well as momentum distributions of the charged pions in the peripheral and central [Formula: see text] collisions revealed the significant decrease of the fraction of the relatively fast charged pions (with smaller emission angles) and increase of the fraction of the relatively slow charged pions (with larger emission angles) with an increase in collision centrality. The results of the present analysis can be useful for analysis of the centrality dependence of the charged pion production in heavy ion collisions at high energies.

scholarly journals Collision system size scan of collective flows in relativistic heavy-ion collisions

2020 ◽  
Vol 804 ◽  
pp. 135366
Author(s):  
S. Zhang ◽  
Y.G. Ma ◽  
G.L. Ma ◽  
J.H. Chen ◽  
Q.Y. Shou ◽  
...  
Keyword(s):  
Heavy Ion Collisions ◽  
System Size ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Collision System ◽  
Ion Collisions
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