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.

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.

NON-EXTENSIVE THERMODYNAMICS, HEAVY ION COLLISIONS AND PARTICLE PRODUCTION AT RHIC ENERGIES

2007 ◽  
Vol 16 (06) ◽  
pp. 1687-1700 ◽  
Author(s):  
BHASKAR DE ◽  
S. BHATTACHARYYA ◽  
GOUTAM SAU ◽  
S. K. BISWAS
Keyword(s):  
Transverse Momentum ◽  
Heavy Ion Collisions ◽  
Particle Production ◽  
Heavy Ion ◽  
Ion Collisions ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
Nonextensive Thermodynamics ◽  
Comparison Of The Results

In the light of ideas of the nonextensive thermodynamics, we have analyzed here the transverse momentum spectra of pions and protons produced at different centralities in the interactions of P+P, D+Au and Au+Au interactions, all of them at [Formula: see text] GeV at RHIC-BNL. Comparison of the results and the comments thereon have also been made with indications of suitable hints to the physical import and implications. The overall impact and the utility of the approach along with the obtained results are discussed in detail.

scholarly journals Centrality dependence of thermal freeze-out conditions at LHC in Pb+Pb collisions at sNN = 2.76TeV

2015 ◽  
Vol 30 (33) ◽  
pp. 1550167 ◽  
Author(s):  
Saeed Uddin ◽  
Inam-ul Bashir ◽  
Riyaz Ahmed Bhat ◽  
Waseem Bashir
Keyword(s):  
Experimental Data ◽  
Chemical Potential ◽  
Heavy Ion ◽  
Collective Flow ◽  
Flow Profile ◽  
Alice Experiment ◽  
Ion Collisions ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
Freeze Out

We have analyzed the available midrapidity [Formula: see text] transverse momentum spectra of identified particles such as protons [Formula: see text], kaons [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] for different centralities of Pb+Pb collisions at the LHC energy [Formula: see text]. We have used our earlier proposed unified statistical thermal freeze-out model. The model incorporates the effect of nuclear transparency in such energetic collisions and the resulting asymmetry in the collective-flow profile along the longitudinal and the transverse directions. Our calculated results are found to be in good agreement with the experimental data measured by the ALICE experiment. The model calculation fits the experimental data for different particle species which provide thermal freeze-out conditions in terms of temperature and collective-flow parameters. The analysis shows a rise in the thermal freeze-out temperature and a mild decrease in the transverse collective-flow velocity as we go from central to the peripheral collisions. The baryon chemical potential is assumed to be nearly zero for the bulk of the matter [Formula: see text], a situation expected in the heavy ion collisions at LHC energies in the Bjorken approach owing to nearly complete nuclear transparency. The contributions from the decay of the heavier resonances are also taken into account in our calculations.

scholarly journals Measurement of the Hadronic Resonance Production with ALICE at the CERN LHC

Universe ◽  
2018 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Maria Vasileiou On behalf of the ALICE Collaboration
Keyword(s):  
Heavy Ion Collisions ◽  
Hadron Collider ◽  
Theoretical Models ◽  
Heavy Ion ◽  
Resonance Production ◽  
Ion Collisions ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
Hadronic Resonances ◽  
Freeze Out

We present a comprehensive study of hadronic resonance production in pp, p-Pb and Pb-Pb collisions at different Large Hadron Collider (LHC) energies. In particular, the production of hadronic resonances, such as ρ(770)0, Κ*(892)0, φ(1020), Σ(1385)±, Λ(1520) and Ξ(1530)0 will be discussed in detail. In heavy-ion collisions, hadronic resonances are sensitive to the re-scattering and regeneration processes occurring between chemical freeze-out and kinetic freeze-out due to their short lifetimes. The measurements in pp and p-Pb collisions are used as a reference for heavy-ion collisions and to search for the onset of collective phenomena. We will report on the transverse momentum spectra, integrated yields, mean transverse momenta, particle ratios and nuclear modification factors of hadronic resonances. The results will be compared to those of other experiments, and to theoretical models and Monte Carlo generators.

scholarly journals IDENTICAL MESON INTERFEROMETRY IN STAR EXPERIMENT

2007 ◽  
Vol 16 (07n08) ◽  
pp. 1883-1889 ◽  
Author(s):  
◽  
DEBASISH DAS
Keyword(s):  
Particle Production ◽  
Star Collaboration ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Transverse Mass ◽  
Particle Multiplicity ◽  
Charged Particle Multiplicity ◽  
Time Dynamics ◽  
Ion Collisions ◽  
Freeze Out

The influence of Bose–Einstein statistics on multi-particle production characterized for various systems and energies by the STAR collaboration provides interesting information about the space-time dynamics of relativistic heavy-ion collisions at RHIC. We present the centrality and transverse mass dependence measurements of the two-pion interferometry in Au + Au collisions at [Formula: see text] and Cu + Cu collisions at [Formula: see text] and 200 GeV. We compare the new data with previous STAR measurements from p + p , d + Au and Au + Au collisions at [Formula: see text]. In all systems and centralities, HBT radii decrease with transverse mass in a similar manner, which is qualitatively consistent with collective flow. The scaling of the apparent freeze-out volume with the number of participants and charged particle multiplicity is studied. Measurements of Au + Au collisions at same centralities and different energies yield different freeze-out volumes, which mean that N part is not a suitable scaling variable. The multiplicity scaling of the measured HBT radii is found to be independent of colliding system and collision energy.

Combined analysis of midrapidity transverse momentum spectra of the charged pions and kaons, protons and antiprotons in p+p and Pb+Pb collisions at (snn)1/2 = 2.76 and 5.02 TeV at the LHC

2020 ◽  
Vol 35 (29) ◽  
pp. 2050237
Author(s):  
Khusniddin K. Olimov ◽  
Shakhnoza Z. Kanokova ◽  
Alisher K. Olimov ◽  
Kobil I. Umarov ◽  
Boburbek J. Tukhtaev ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Center Of Mass ◽  
Heavy Ion ◽  
Transverse Flow ◽  
Alice Collaboration ◽  
Momentum Spectra ◽  
Charged Pions ◽  
Transverse Momentum Spectra ◽  
Tsallis Distribution ◽  
Freeze Out

The experimental transverse momentum spectra of the charged pions and kaons, protons and antiprotons, produced at midrapidity in [Formula: see text] collisions at [Formula: see text] and 5.02 TeV, central (0–5%) and peripheral (60–80%) Pb[Formula: see text]+[Formula: see text]Pb collisions at [Formula: see text] TeV, central (0–5%), semicentral (40–50%) and peripheral (80–90%) Pb[Formula: see text]+[Formula: see text]Pb collisions at [Formula: see text] TeV, measured by ALICE collaboration, were analyzed using the Tsallis distribution function as well as Hagedorn formula with the embedded transverse flow. To exclude the influence (on the results) of different available fitting [Formula: see text] ranges in the analyzed collisions, we compare the results obtained from combined (simultaneous) fits of midrapidity spectra of the charged pions and kaons, protons and antiprotons with the above theoretical model functions using the identical fitting [Formula: see text] ranges in [Formula: see text] as well as Pb[Formula: see text]+[Formula: see text]Pb collisions at [Formula: see text] and 5.02 TeV. Using the combined fits with the thermodynamically consistent Tsallis distribution as well as the simple Tsallis distribution without thermodynamical description, it is obtained that the global temperature [Formula: see text] and non-extensivity parameter [Formula: see text] slightly increase (consistently for all the particle types) with an increase in center-of-mass (c.m.) energy [Formula: see text] of [Formula: see text] collisions from 2.76 TeV to 5.02 TeV, indicating that the more violent and faster [Formula: see text] collisions at [Formula: see text] TeV result in a smaller degree of thermalization (higher degree of non-equilibrium) compared to that in [Formula: see text] collisions at [Formula: see text] TeV. The [Formula: see text] values for pions and kaons proved to be very close to each other, whereas [Formula: see text] for protons and antiprotons proved to be significantly lower than that for pions and kaons, that is [Formula: see text]. The results of the combined fits using Hagedorn formula with the embedded transverse flow are consistent with practically no (zero) transverse (radial) flow in [Formula: see text] collisions at [Formula: see text] and 5.02 TeV. Using Hagedorn formula with the embedded transverse flow, it is obtained that the value of the (average) transverse flow velocity increases and the temperature [Formula: see text] decreases with an increase in collision centrality in Pb[Formula: see text]+[Formula: see text]Pb collisions at [Formula: see text] and 5.02 TeV, which is in good agreement with the results of the combined Boltzmann–Gibbs blast-wave fits to the particle spectra in Pb[Formula: see text]+[Formula: see text]Pb collisions at [Formula: see text] and 5.02 TeV in recent works of ALICE collaboration. The temperature [Formula: see text] parameter, which approximates the kinetic freeze-out temperature, was shown to coincide in central (0–5%) Pb[Formula: see text]+[Formula: see text]Pb collisions at [Formula: see text] and 5.02 TeV, which implies, taking into account the results of our previous analysis, that kinetic freeze-out temperature stays practically constant in central heavy-ion collisions in [Formula: see text] GeV energy range.

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