scholarly journals Chemical Potentials of Light Flavor Quarks from Yield Ratios of Negative to Positive Particles in Au+Au Collisions at RHIC

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Ya-Qin Gao ◽  
Hai-Ling Lao ◽  
Fu-Hu Liu
Keyword(s):  
Transverse Momentum ◽  
Collision Energy ◽  
Center Of Mass ◽  
Star Collaboration ◽  
Strange Quarks ◽  
Center Of Mass Energy ◽  
Chemical Potentials ◽  
Momentum Spectra ◽  
200 Gev ◽  
Transverse Momentum Spectra

The transverse momentum spectra of π-, π+, K-, K+, p¯, and p produced in Au+Au collisions at center-of-mass energy sNN=7.7, 11.5, 19.6, 27, 39, 62.4, 130, and 200 GeV are analyzed in the framework of a multisource thermal model. The experimental data measured at midrapidity by the STAR Collaboration are fitted by the (two-component) standard distribution. The effective temperature of emission source increases obviously with the increase of the particle mass and the collision energy. At different collision energies, the chemical potentials of up, down, and strange quarks are obtained from the antiparticle to particle yield ratios in given transverse momentum ranges available in experiments. With the increase of logarithmic collision energy, the chemical potentials of light flavor quarks decrease exponentially.

pT spectra of charged hadrons in proton–proton collisions at s = 200 GeV

2019 ◽  
Vol 34 (19) ◽  
pp. 1950148 ◽  
Author(s):  
M. Ajaz ◽  
Maryam
Keyword(s):  
Transverse Momentum ◽  
Star Collaboration ◽  
Hadron Production ◽  
Proton Proton ◽  
Proton Collisions ◽  
Production Models ◽  
Momentum Spectra ◽  
200 Gev ◽  
Transverse Momentum Spectra ◽  
Proton Proton Collisions

The transverse momentum spectra of [Formula: see text] mesons, protons and antiprotons produced in proton–proton collisions at 200 GeV with hadron production models are reported. Two tunes of EPOS (EPOS1.99 and EPOS-LHC), three tunes of QGSJET (QGSJETI, QGSJETII-03, QGSJETII-04), DPMJET and HIJING models are used to obtain the spectra. The results are compared with the measurements of STAR collaboration obtained at mid-rapidity of [Formula: see text] in [Formula: see text] range of [Formula: see text]. All models reproduce the ratios [Formula: see text] and [Formula: see text] at low [Formula: see text] but could not predict well at high [Formula: see text]. In addition, EPOS tunes and QGSJET tunes predict well the spectra of [Formula: see text] meson and the ratios [Formula: see text] and [Formula: see text] at low [Formula: see text]. The HIJING and the QGSJET (tune I only) could reproduce all the spectra and all the ratios at a satisfactory level of precision and were found good among the models considered in the current study at RHIC energy.

scholarly journals Rapidity Dependent Transverse Momentum Spectra of Heavy Quarkonia Produced in Small Collision Systems at the LHC

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Li-Na Gao ◽  
Fu-Hu Liu ◽  
Bao-Chun Li
Keyword(s):  
Transverse Momentum ◽  
Hadron Collider ◽  
Center Of Mass ◽  
Lhcb Collaboration ◽  
Heavy Quarkonia ◽  
Proton Proton ◽  
Center Of Mass Energy ◽  
Inverse Power Law ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra

The rapidity dependent transverse momentum spectra of heavy quarkonia (J/ψ and Υ mesons) produced in small collision systems such as proton-proton (pp) and proton-lead (p-Pb) collisions at center-of-mass energy (per nucleon pair) s (sNN) = 5-13 TeV are described by a two-component statistical model which is based on the Tsallis statistics and inverse power-law. The experimental data measured by the LHCb Collaboration at the Large Hadron Collider (LHC) are well fitted by the model results. The related parameters are obtained and the dependence of parameters on rapidity is analyzed.

scholarly journals A New Description of Transverse Momentum Spectra of Identified Particles Produced in Proton-Proton Collisions at High Energies

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Pei-Pin Yang ◽  
Fu-Hu Liu ◽  
Raghunath Sahoo
Keyword(s):  
Transverse Momentum ◽  
Center Of Mass ◽  
High Energy ◽  
Momentum Spectrum ◽  
Transverse Momentum Spectrum ◽  
Proton Proton ◽  
Center Of Mass Energy ◽  
Momentum Spectra ◽  
Quark Level ◽  
Transverse Momentum Spectra

The transverse momentum spectra of identified particles produced in high energy proton-proton p + p collisions are empirically described by a new method with the framework of the participant quark model or the multisource model at the quark level, in which the source itself is exactly the participant quark. Each participant (constituent) quark contributes to the transverse momentum spectrum, which is described by the TP-like function, a revised Tsallis–Pareto-type function. The transverse momentum spectrum of the hadron is the convolution of two or more TP-like functions. For a lepton, the transverse momentum spectrum is the convolution of two TP-like functions due to two participant quarks, e.g., projectile and target quarks, taking part in the collisions. A discussed theoretical approach seems to describe the p + p collisions data at center-of-mass energy s = 200     GeV , 2.76 TeV, and 13 TeV very well.

scholarly journals Analysis of kinetic freeze-out temperature and transverse flow velocity in nucleus–nucleus and proton–proton collisions at same center-of-mass energy

2021 ◽  
pp. 2150061
Author(s):  
M. Waqas ◽  
G. X. Peng ◽  
Z. Wazir ◽  
Hai-Ling Lao
Keyword(s):  
Transverse Momentum ◽  
Flow Velocity ◽  
Center Of Mass ◽  
Transverse Flow ◽  
Proton Proton ◽  
Center Of Mass Energy ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
Proton Proton Collisions ◽  
Transverse Flow Velocity

Transverse momentum spectra of different types of identified charged particles in central Gold–Gold (Au–Au) collisions and inelastic (INEL) or nonsingle diffractive (NSD) proton–proton (pp) collisions at the Relativistic Heavy Ion Collider (RHIC), as well as in central and peripheral Lead–Lead (Pb–Pb) collisions, and INEL or NSD pp collisions at the Large Hadron Collider (LHC) are analyzed by the blast-wave model with Tsallis statistics. The model results are approximately in agreement with the experimental data measured by STAR, PHENIX and ALICE Collaborations in special transverse momentum ranges. Kinetic freeze-out (KFO) temperature and transverse flow velocity are extracted from the transverse momentum spectra of the particles. It is shown that KFO temperature of the emission source depends on mass of the particles, which reveals the mass-dependent KFO scenario in collisions at RHIC and LHC. Furthermore, the KFO temperature and transverse flow velocity in central nucleus–nucleus (AA) collisions are larger than in peripheral collisions, and both of them are slightly larger in peripheral nucleus–nucleus collisions or almost equivalent to that in proton–proton collisions at the same center-of-mass energy which shows their similar thermodynamic nature.

scholarly journals Study of Dependence of Kinetic Freezeout Temperature on the Production Cross-Section of Particles in Various Centrality Intervals in Au–Au and Pb–Pb Collisions at High Energies

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 488
Author(s):  
Muhammad Waqas ◽  
Guang-Xiong Peng
Keyword(s):  
Transverse Momentum ◽  
Flow Velocity ◽  
Production Cross ◽  
Center Of Mass ◽  
Wave Model ◽  
Transverse Flow ◽  
Peripheral Collisions ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
Transverse Flow Velocity

Transverse momentum spectra of π+, p, Λ, Ξ or Ξ¯+, Ω or Ω¯+ and deuteron (d) in different centrality intervals in nucleus–nucleus collisions at the center of mass energy are analyzed by the blast wave model with Boltzmann Gibbs statistics. We extracted the kinetic freezeout temperature, transverse flow velocity and kinetic freezeout volume from the transverse momentum spectra of the particles. It is observed that the non-strange and strange (multi-strange) particles freezeout separately due to different reaction cross-sections. While the freezeout volume and transverse flow velocity are mass dependent, they decrease with the resting mass of the particles. The present work reveals the scenario of a double kinetic freezeout in nucleus–nucleus collisions. Furthermore, the kinetic freezeout temperature and freezeout volume are larger in central collisions than peripheral collisions. However, the transverse flow velocity remains almost unchanged from central to peripheral collisions.

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.

scholarly journals Energy dependence of π±, p and p¯ transverse momentum spectra for Au+Au collisions at sNN=62.4 and 200 GeV

2007 ◽  
Vol 655 (3-4) ◽  
pp. 104-113 ◽  
Author(s):  
B.I. Abelev ◽  
M.M. Aggarwal ◽  
Z. Ahammed ◽  
B.D. Anderson ◽  
D. Arkhipkin ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Energy Dependence ◽  
Momentum Spectra ◽  
200 Gev ◽  
Transverse Momentum Spectra

scholarly journals Study of Proton, Deuteron, and Triton at 54.4 GeV

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
M. Waqas ◽  
G. X. Peng
Keyword(s):  
Transverse Momentum ◽  
Flow Velocity ◽  
Star Collaboration ◽  
Wave Model ◽  
Transverse Flow ◽  
Peripheral Collisions ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
Transverse Flow Velocity ◽  
Freeze Out

Transverse momentum spectra of proton, deuteron, and triton in gold-gold (Au-Au) collisions at 54.4 GeV are analyzed in different centrality bins by the blast wave model with Tsallis statistics. The model results are approximately in agreement with the experimental data measured by STAR Collaboration in special transverse momentum ranges. We extracted the kinetic freeze-out temperature, transverse flow velocity, and freeze-out volume from the transverse momentum spectra of the particles. It is observed that the kinetic freeze-out temperature is increasing from the central to peripheral collisions. However, the transverse flow velocity and freeze-out volume decrease from the central to peripheral collisions. The present work reveals the mass dependent kinetic freeze-out scenario and volume differential freeze-out scenario in collisions at STAR Collaboration. In addition, parameter q characterizes the degree of nonequilibrium of the produced system, and it increases from the central to peripheral collisions and increases with mass .

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