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.

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 Finite-volume effects on phase transition in the Polyakov-loop extended Nambu–Jona-Lasinio model with a chiral chemical potential

2017 ◽  
Vol 32 (13) ◽  
pp. 1750067 ◽  
Author(s):  
Zan Pan ◽  
Zhu-Fang Cui ◽  
Chao-Hsi Chang ◽  
Hong-Shi Zong
Keyword(s):  
Finite Volume ◽  
Chemical Potential ◽  
System Size ◽  
Heavy Ion ◽  
Polyakov Loop ◽  
End Point ◽  
Chemical Potentials ◽  
Ion Collision ◽  
Quark Flavors ◽  
Volume Effects

To investigate the finite-volume effects on the chiral symmetry restoration and the deconfinement transition for a quantum chromodynamics (QCD) system with [Formula: see text] (two quark flavors), we apply the Polyakov-loop extended Nambu–Jona-Lasinio model by introducing a chiral chemical potential [Formula: see text] artificially. The final numerical results indicate that the introduced chiral chemical potential does not change the critical exponents, but shifts the location of critical end point (CEP) significantly; the ratios for the chiral chemical potentials and temperatures at CEP, [Formula: see text] and [Formula: see text], are significantly affected by the system size [Formula: see text]. The behavior is that [Formula: see text] increases slowly with [Formula: see text] when [Formula: see text] is “large” and [Formula: see text] decreases first and then increases with [Formula: see text] when [Formula: see text] is “small.” It is also found that for a fixed [Formula: see text], there is a [Formula: see text], where the critical end point vanishes and the whole phase diagram becomes a crossover when [Formula: see text]. Therefore, we suggest that for the heavy-ion collision experiments, which is to study the possible location of CEP, the finite-volume behavior should be taken into account.

scholarly journals Chiral phase transition and kaon-to-pion ratios in the entanglement SU(3) PNJL model

2020 ◽  
Vol 229 (22-23) ◽  
pp. 3517-3536
Author(s):  
D. Blaschke ◽  
A. V. Friesen ◽  
Yu. L. Kalinovsky ◽  
A. Radzhabov
Keyword(s):  
Chemical Potential ◽  
Pion Mass ◽  
Heavy Ion ◽  
Bose Condensation ◽  
Chiral Phase ◽  
Qcd Phase Diagram ◽  
Scattering States ◽  
Meson Pole ◽  
Quark Models ◽  
Ion Collision

AbstractWithin the three-flavor PNJL and EPNJL chiral quark models we have obtained pseudoscalar meson properties in quark matter at finite temperature T and baryochemical potential μB. We compare the meson pole (Breit-Wigner) approximation with the Beth-Uhlenbeck (BU) approach that takes into account the continuum of quark-antiquark scattering states when determining the partial densities of pions and kaons. We evaluate the kaon-to-pion ratios along the (pseudo-)critical line in the T − μB plane as a proxy for the chemical freezeout line, whereby the variable x = T∕μB is introduced that corresponds to the conserved entropy per baryon as initial condition for the heavy-ion collision experiments. We present a comparison with the experimental pattern of kaon-to-pion ratios within the BU approach and using x-dependent pion and strange quark potentials. A sharp “horn” effect in the energy dependence K+∕π+ ratio is explained by the enhanced pion production at energies above √sNN=8 GeV, when the system enters the regime of meson dominance. This effect is in line with the enhancement of low-momentum pion spectra that is discussed as a precursor of the pion Bose condensation and entails the occurrence of a nonequilibrium pion chemical potential of the order of the pion mass. We elucidate that the horn effect is not related to the existence of a critical endpoint in the QCD phase diagram.

scholarly journals Effects of Superstatistics on the Location of the Effective QCD Critical End Point

2019 ◽  
Vol 64 (8) ◽  
pp. 665
Author(s):  
A. Ayala ◽  
M. Hentschinski ◽  
L. A. Hernández ◽  
M. Loewe ◽  
R. Zamora
Keyword(s):  
Phase Diagram ◽  
Chemical Potential ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Chiral Symmetry Restoration ◽  
Interaction Volume ◽  
Qcd Phase Diagram ◽  
End Point ◽  
Ion Collisions ◽  
Effective Description

Effects of the partial thermalization during the chiral symmetry restoration at the finite temperature and quark chemical potential are considered for the position of the critical end point in an effective description of the QCD phase diagram. We find that these effects cause the critical end point to be displaced toward larger values of the temperature and lower values of the quark chemical potential, as compared to the case where the system can be regarded as completely thermalized. These effects may be important for relativistic heavy ion collisions, where the number of subsystems making up the whole interaction volume can be linked to the finite number of participants in the reaction.

scholarly journals Fluctuations of conserved charges from imaginary chemical potential

2018 ◽  
Vol 175 ◽  
pp. 07036
Author(s):  
Jana N. Guenther ◽  
Szabolcs Borsányi ◽  
Zoltan Fodor ◽  
Sandor D. Katz ◽  
Attila Pásztor ◽  
...  
Keyword(s):  
Experimental Data ◽  
Chemical Potential ◽  
Heavy Ion ◽  
Higher Order ◽  
Order Derivative ◽  
Heavy Ion Collision ◽  
Lattice Calculation ◽  
Eighth Order ◽  
Conserved Charges ◽  
Ion Collision

When comparing lattice calculation to experimental data from heavy ion collision experiments, the higher order fluctuations of conserved charges are important observables. An efficient way to study these fluctuations is to determine them from simulations at imaginary chemical potential. In this talk we present results up to the six order derivative in μB (with up to eighth order included in the fit), calculated on a 483 × 12 lattice with staggered fermions using different values of μB while μS = μQ = 0.

scholarly journals CHIRALLY SYMMETRIC BUT CONFINED HADRONS AT FINITE DENSITY

2008 ◽  
Vol 23 (27n30) ◽  
pp. 2385-2388 ◽  
Author(s):  
L. YA. GLOZMAN ◽  
R. F. WAGENBRUNN
Keyword(s):  
Phase Transition ◽  
Phase Diagram ◽  
Low Temperature ◽  
Quark Matter ◽  
Chemical Potential ◽  
Heavy Ion ◽  
Finite Density ◽  
Qcd Phase Diagram

At a critical finite chemical potential and low temperature QCD undergoes the chiral restoration phase transition. The folklore tradition is that simultaneously hadrons are deconfined and there appears the quark matter. We demonstrate that it is possible to have confined but chirally symmetric hadrons at a finite chemical potential and hence beyond the chiral restoration point at a finite chemical potential and low temperature there could exist a chirally symmetric matter consisting of chirally symmetric but confined hadrons. If it does happen in QCD, then the QCD phase diagram should be reconsidered with obvious implications for heavy ion programs and astrophysics.

scholarly journals Exploring hot and dense QCD matter with HADES

2020 ◽  
Vol 1643 (1) ◽  
pp. 012012
Author(s):  
Georgy Kornakov
Keyword(s):  
Chemical Potential ◽  
Thermal Emission ◽  
Heavy Ion ◽  
Nucleon Nucleon ◽  
Baryon Chemical Potential ◽  
Qcd Phase Diagram ◽  
Test Models ◽  
Particle Spectra ◽  
Strangeness Content ◽  
Dilepton Spectrum

Abstract Experiments at snn s NN = 2 − 3 3 GeV provide the lowest energy point of the global effort made by the heavy-ion community in order to map the QCD phase diagram. This correspond to the highest baryon chemical potential, 700-900 MeV according to the universal freeze-out curve, and temperatures of the fireball of 60-80 MeV. The formed matter can be characterized in terms of particle spectra, fluctuations and correlations. The dilepton spectrum is dominated by thermal emission from the medium and it is sensitive to in medium hadron properties. Strangeness production occurs below the free nucleon-nucleon threshold and it is a sensitive probe to test models of strangeness propagation in matter and its coupling to baryons. Data show a common scaling of measured yields as a function of number of participating nucleons independently on the strangeness content or mass of the hadron. Strangeness propagation in cold nuclear matter produced in pion induced reactions on heavy and light targets shows a significant absorption of negative kaons in heavy targets as well as a similar behaviour of ϕ indicating a strong coupling of ϕ with nucleons. Two-pion correlations, flow harmonics, fluctuations are explored as well in order to further pin down the properties of the created matter.

PRODUCTION RATE OF PARTICLE PAIRS FROM A HOT QUANTUM-FIELD PLASMA WITH FINITE VOLUME

1994 ◽  
Vol 09 (04) ◽  
pp. 355-363
Author(s):  
A. NIÉGAWA ◽  
K. TAKASHIBA
Keyword(s):  
Production Rate ◽  
Finite Volume ◽  
Scalar Particle ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Volume Effect ◽  
Dirichlet Boundary Conditions ◽  
Massless Scalar ◽  
Ion Collisions ◽  
Particle Pairs

The production rate of scalar-particle pairs from finite temperature (T) plasma of massless-scalar particles confined in a cubic box of volume V is calculated. The Dirichlet boundary conditions are imposed on the wall of the box. The finite volume effect is found to be quite large at T=(2−3)×102 MeV and V=[(1−5)×10−13 cm ]3, the numerical values which have been estimated for the quark-gluon plasma produced in heavy-ion collisions at CERN SPS and LHC energies.

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