ISENTROPIC QUARK HADRON PHASE BOUNDARY AND STRANGENESS ENHANCEMENT

2000 ◽  
Vol 15 (22) ◽  
pp. 3563-3575
Author(s):  
B. K. PATRA ◽  
C. P. SINGH ◽  
F. C. KHANNA
Keyword(s):  
Phase Boundary ◽  
Chemical Potential ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Strange Particle ◽  
Phase Boundaries ◽  
Two Phase ◽  
Hadron Phase ◽  
Particle Ratios ◽  
Strangeness Enhancement

We develop a phenomenological equation of state for the quark–gluon plasma containing nf flavors when the entropy per baryon ratio remains continuous across the phase boundary and thus derive a generalized expression for the temperature and baryon chemical potential dependent bag constant. The phase boundaries are obtained for an isentropic quark–hadron phase transition after using Gibbs' criteria and the transition to an ideal QGP from the solution of the condition B(μ,T)=0. The variation of critical temperature Tc with nf and the temperature variation of the quantity (ε-4P)/T4 which measures the interaction present in QGP are obtained and compared with the results from lattice calculations. Finally we obtain the strange particle ratios on the two phase boundaries which will be useful in identifying deconfined and/or ideal QGP formation in the heavy-ion experiments.

EVIDENCE FOR A QUARK-GLUON PLASMA AT RHIC

2007 ◽  
Vol 16 (03) ◽  
pp. 643-659 ◽  
Author(s):  
JOHN W. HARRIS
Keyword(s):  
Chemical Potential ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Heavy Nuclei ◽  
Relativistic Heavy Ion Collider ◽  
Heavy Ion Physics ◽  
Strongly Coupled ◽  
Hadron Phase ◽  
B Hadrons ◽  
Quark Level

This presentation is given in honor of Walter Greiner's 70th birthday, in recognition of the pioneering work of his "Frankfurt School" and their contributions to the field of heavy ion physics. Ultra-relativistic collisions of heavy nuclei at the Relativistic Heavy Ion Collider (RHIC) form an extremely hot system at energy densities greater than 5 GeV/fm3, where normal hadrons cannot exist. Upon rapid cooling of the system to a temperature T ~ 175 MeV and vanishingly small baryo-chemical potential, hadrons coalesce from quarks at the quark-hadron phase boundary predicted by lattice QCD. A large amount of collective (elliptic) flow at the quark level provides evidence for strong pressure gradients in the initial partonic stage of the collision when the system is dense and highly interacting prior to coalescence into hadrons. The suppression of both light (u,d,s) and heavy (c,b) hadrons at large transverse momenta, that form from fragmentation of hard-scattered partons, and the quenching of di-jets provide evidence for extremely large energy loss of partons as they attempt to propagate through the dense, strongly-coupled, colored medium created at RHIC.

scholarly journals Strange hadron production in pp, pPb, and PbPb collisions at LHC energies

2018 ◽  
Vol 171 ◽  
pp. 13008
Author(s):  
Hong Ni
Keyword(s):  
Particle Production ◽  
Dynamical Evolution ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Strange Particle ◽  
Relativistic Heavy Ion Collisions ◽  
High Multiplicity ◽  
Collective Effects ◽  
Additional Information ◽  
Particle Ratios

Identified particle spectra provide an important tool for understanding the particle production mechanism and the dynamical evolution of the medium created in relativistic heavy ion collisions. Studies involving strange and multi-strange hadrons, such as K0S, Λ, and Ξ−, carry additional information since there is no net strangeness content in the initial colliding system. Strangeness enhancement in AA collisions with respect to pp and pA collisions has long been considered as one of the signatures for quark-gluon plasma (QGP) formation. Recent observations of collective effects in high-multiplicity pp and pA collisions raise the question of whether QGP can also be formed in the smaller systems. Systematic studies of strange particle abundance, particle ratios, and nuclear modification factors can shed light on this issue. The CMS experiment has excellent strange-particle reconstruction capabilities over a broad kinematic range, and dedicated high-multiplicity triggers in pp and pPb collisions. The spectra of K0S, Λ, and Ξ− hadrons have been measured in various multiplicity and rapidity regions as a function of pT in pp, pPb, and PbPb collisions for several collision energies. The spectral shapes and particle ratios are compared in the different collision systems for events that have the same multiplicity and interpreted in the context of hydrodynamics models.

scholarly journals Influence of Finite Volume Effect on the Polyakov Quark–Meson Model

Universe ◽  
2019 ◽  
Vol 5 (4) ◽  
pp. 94 ◽  
Author(s):  
Niseem Magdy
Keyword(s):  
Phase Boundary ◽  
Finite Volume ◽  
Chemical Potential ◽  
Heavy Ion ◽  
Volume Effect ◽  
Order Parameters ◽  
Model Order ◽  
Conserved Charges ◽  
Qcd Phase Diagram ◽  
Hadron Phase

In the current work, we study the influence of a finite volume on 2 + 1 S U ( 3 ) Polyakov Quark–Meson model (PQM) order parameters, (fluctuations) correlations of conserved charges and the quark–hadron phase boundary. Our study of the PQM model order parameters and the (fluctuations) correlations of conserved charges indicates a sizable shift of the quark–hadron phase boundary to higher values of baryon chemical potential ( μ B ) and temperature (T) for decreasing the system volume. The detailed study of such effect could have important implications for the extraction of the (fluctuations) correlations of conserved charges of the QCD phase diagram from heavy ion data.

scholarly journals Strangeness chemical potential from the baryons relative to the kaons particle ratios

2017 ◽  
Vol 26 (07) ◽  
pp. 1750046
Author(s):  
Abdel Nasser Tawfik ◽  
Magda Abdel Wahab ◽  
Hayam Yassin ◽  
Eman R. Abo Elyazeed ◽  
Hadeer M. Nasr El Din
Keyword(s):  
Strange Quark ◽  
Collision Energy ◽  
Chemical Potential ◽  
Entropy Density ◽  
Baryon Chemical Potential ◽  
Systematic Analysis ◽  
Particle Ratios ◽  
Alternative Approach ◽  
Strangeness Enhancement ◽  
Thermal Calculations

From a systematic analysis of the energy-dependence of four antibaryon-to-baryon ratios relative to the antikaon-to-kaon ratio, we propose an alternative approach determining the strange-quark chemical potential ([Formula: see text]). It is found that [Formula: see text] generically genuinely equals one-fifth the baryon chemical potential ([Formula: see text]). An additional quantity depending on [Formula: see text] and the freezeout temperature ([Formula: see text]) should be added in order to assure averaged strangeness conversation. This quantity gives a genuine estimation for the possible strangeness enhancement with the increase in the collision energy. At the chemical freezeout conditioned to constant entropy density normalized to temperature cubed, various particle ratios calculated at [Formula: see text] and [Formula: see text] and the resultant [Formula: see text] excellently agree with the statistical-thermal calculations.

scholarly journals An estimate of the thermodynamic pressure in high-energy collisions

2015 ◽  
Vol 30 (07) ◽  
pp. 1550027 ◽  
Author(s):  
Abdel Nasser Tawfik
Keyword(s):  
Energy Density ◽  
Chemical Potential ◽  
Lattice Energy ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
High Energy ◽  
Order Moment ◽  
Particle Multiplicity ◽  
The Mean ◽  
Thermodynamic Pressure

We introduce a novel approach to estimate the thermodynamic pressure from heavy-ion collisions based on recently measured higher-order moments of particle multiplicities by the STAR experiment. We start with fitting the experimental results in the most-central collisions. Then, we integrate them back to lower ones. For example, we find that the first-order moment, the mean multiplicity, is exactly reproduced from the integral of variance, the second-order moment. Therefore, the zeroth-order moment, the thermodynamic pressure, can be estimated from the integral of the mean multiplicity. The possible comparison between such a kind of pressure (deduced from the integral of particle multiplicity) and the lattice pressure and the relating of Bjorken energy density to the lattice energy density are depending on lattice QCD at finite baryon chemical potential and first-principle estimation of the formation time of the quark–gluon plasma (QGP).

scholarly journals Strangeness Enhancement at LHC Energies Using the Thermal Model and EPOSLHC Event Generator

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mahmoud Hanafy ◽  
Omnia S. A. Qandil ◽  
Asmaa G. Shalaby
Keyword(s):  
Cosmic Ray ◽  
Heavy Ion ◽  
Event Generator ◽  
Relativistic Heavy Ion Collider ◽  
Model Calculations ◽  
High Energies ◽  
Particle Ratios ◽  
Strangeness Enhancement ◽  
The Mean ◽  
Good Agreement

The strangeness enhancement signature of QGP formation at LHC energies is carefully tackled in the present study. Based on HRG, the particle ratios of mainly strange and multistrange particles are studied at energies from lower s ~ 0.001 up to 13 TeV. The strangeness enhancement clearly appeared at more high energies, and the ratios are confronted to the available experimental data. The particle ratios are also studied using the Cosmic Ray Monte Carlo (CRMC) interface model with its two different event generators, namely, EPOS 1.99 and EPOSlhc, which show a good agreement with the model calculations at the whole range of the energy. We utilize them to produce some particles ratios. EPOS 1.99 is used to estimate particle ratios at lower energies from AGS up to the Relativistic Heavy Ion Collider (RHIC) while EPOSlhc is used at LHC energies. The production of kaons and lambda particles is studied in terms of the mean multiplicity in p-p collisions at energies ranging from 4 to 26 GeV. We find that both HRG model and the used event generators, EPOS 1.99 and EPOSlhc, can describe the particle ratios very well. Additionally, the freeze-out parameters are estimated for different collision systems, such as p-p and Pb-Pb, at LHC energies using both models.

scholarly journals Strangeness Production in pp, p–Pb and Pb–Pb Collisions at the LHC Energies Measured with ALICE

2018 ◽  
Vol 46 ◽  
pp. 1860017
Author(s):  
D. Colella
Keyword(s):  
Particle Production ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Strange Particle ◽  
Weak Decay ◽  
Relativistic Heavy Ion Collisions ◽  
Strangeness Production ◽  
Heavy Ion Physics ◽  
Ion Collisions ◽  
Increasing Trend

The main goal of heavy-ion physics is to study the properties of the deconfined state of matter known as the Quark-Gluon Plasma (QGP) created in ultra-relativistic heavy-ion collisions. A systematic study of strangeness production is of fundamental importance for determining the thermal properties of the system created in such collisions. In the central barrel of the ALICE detector, K[Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] can be identified reconstructing their weak decay topology. It will be shown that the relative production (to pions) of strange particles follows a continuous increasing trend from low multiplicity pp to peripheral Pb–Pb collisions, above which a saturation is visible for central Pb–Pb collisions. This increasing trend is similar for pp and p–Pb collisions. Moreover, comparison of strange particle production in pp collisions at two different energies ([Formula: see text] = 7 TeV and 13 TeV) will be used to demonstrate that the observed trend in multiplicity is also energy independent.

Phenomenological modeling of the photon production rate from the QGP at finite quark chemical potential

2015 ◽  
Vol 30 (33) ◽  
pp. 1550196 ◽  
Author(s):  
Yogesh Kumar ◽  
Poonam Jain
Keyword(s):  
Significant Contribution ◽  
Chemical Potential ◽  
Emission Rate ◽  
Photon Emission ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
High Energy ◽  
Photon Production ◽  
Phenomenological Parameter ◽  
Ion Collisions

We show the extended calculation of leading order process for photon production from Quark–Gluon Plasma (QGP) using a finite quark mass incorporating phenomenological parameter of quarks and gluons with the effect of quark chemical potential. The photon emission rate is observed in the range of low and intermediate transverse momentum. Our modified results of photon production give significant contribution in the range of quark phenomenological parameter, i.e. [Formula: see text] of high-energy heavy-ion collisions. The results obtained are compared with other results.

scholarly journals Energy Dependence of Particle Ratios in High Energy Nucleus-Nucleus Collisions: A USTFM Approach

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Inam-ul Bashir ◽  
Rameez Ahmad Parra ◽  
Hamid Nanda ◽  
Saeed Uddin
Keyword(s):  
Particle Production ◽  
Chemical Potential ◽  
Heavy Ion ◽  
High Energy ◽  
Ion Collisions ◽  
System A ◽  
Particle Ratios ◽  
High Degree ◽  
Chemical Freeze ◽  
Freeze Out

We study the identified particle ratios produced at mid-rapidity (y<0.5) in heavy-ion collisions, along with their correlations with the collision energy. We employ our earlier proposed unified statistical thermal freeze-out model (USTFM), which incorporates the effects of both longitudinal and transverse hydrodynamic flow in the hot hadronic system. A fair agreement seen between the experimental data and our model results confirms that the particle production in these collisions is of statistical nature. The variation of the chemical freeze-out temperature and the baryon chemical potential with respect to collision energies is studied. The chemical freeze-out temperature is found to be almost constant beyond the RHIC energy and is found to be close to the QCD predicted phase-transition temperature suggesting that the chemical freeze-out occurs soon after the hadronization takes place. The vanishing value of chemical potential at LHC indicates very high degree of nuclear transparency in the collision.

scholarly journals Polarization tensor of magnetized quark-gluon plasma at nonzero baryon density

2021 ◽  
Vol 81 (10) ◽  
Author(s):  
Xinyang Wang ◽  
Igor Shovkovy
Keyword(s):  
Quark Gluon Plasma ◽  
Chemical Potential ◽  
Photon Emission ◽  
Absorptive Part ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Photon Production ◽  
Polarization Tensor ◽  
Baryon Chemical Potential ◽  
Wide Range

AbstractWe derive a general expression for the absorptive part of the one-loop photon polarization tensor in a strongly magnetized quark-gluon plasma at nonzero baryon chemical potential. To demonstrate the application of the main result in the context of heavy-ion collisions, we study the effect of a nonzero baryon chemical potential on the photon emission rate. The rate and the ellipticity of photon emission are studied numerically as a function the transverse momentum (energy) for several values of temperature and chemical potential. When the chemical potential is small compared to the temperature, the rates of the quark and antiquark splitting processes (i.e., $$q\rightarrow q +\gamma $$ q → q + γ and $${\bar{q}}\rightarrow {\bar{q}} +\gamma $$ q ¯ → q ¯ + γ , respectively) are approximately the same. However, the quark splitting gradually becomes the dominant process with increasing the chemical potential. We also find that increasing the chemical potential leads to a growing total photon production rate but has only a small effect on the ellipticity of photon emission. The quark-antiquark annihilation ($$q+{\bar{q}}\rightarrow \gamma $$ q + q ¯ → γ ) also contributes to the photon production, but its contribution remains relatively small for a wide range of temperatures and chemical potentials investigated.

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