scholarly journals Lattice Study of QCD Phase Structure by Canonical Approach

2018 ◽  
Vol 175 ◽  
pp. 07033 ◽  
Author(s):  
V.G. Bornyakov ◽  
D. Boyda ◽  
V. Goy ◽  
A. Molochkov ◽  
A. Nakamura ◽  
...  
Keyword(s):  
Chemical Potential ◽  
Baryon Number ◽  
Heavy Ion ◽  
Partition Functions ◽  
Transition Line ◽  
Potential Region ◽  
Relativistic Heavy Ion Collision ◽  
Sign Problem ◽  
Canonical Approach ◽  
Ion Collision

The canonical approach is a powerful tool to circumvent sign problem in LQCD. Although it has its own difficulties it provides opportunity to determine QCD phase transition line. Using improved Wilson fermions we calculated number density at nonzero imaginary chemical potential for confinement and deconfinement phases, restored canonical partition functions Zn and did extrapolation into the real chemical potential region. We computed the higher moments of the baryon number including the kurtosis, and compared our results with information from relativistic heavy ion collision experiments.

scholarly journals Restoring canonical partition functions from imaginary chemical potential

2018 ◽  
Vol 175 ◽  
pp. 07027 ◽  
Author(s):  
V.G. Bornyakov ◽  
D. Boyda ◽  
V. Goy ◽  
A. Molochkov ◽  
A. Nakamura ◽  
...  
Keyword(s):  
Chemical Potential ◽  
Baryon Number ◽  
Partition Functions ◽  
Transition Line ◽  
Qcd Phase Transition ◽  
Qcd Phase Diagram ◽  
Sign Problem ◽  
Canonical Approach ◽  
Grand Canonical ◽  
Fugacity Expansion

Using GPGPU techniques and multi-precision calculation we developed the code to study QCD phase transition line in the canonical approach. The canonical approach is a powerful tool to investigate sign problem in Lattice QCD. The central part of the canonical approach is the fugacity expansion of the grand canonical partition functions. Canonical partition functions Zn(T) are coefficients of this expansion. Using various methods we study properties of Zn(T). At the last step we perform cubic spline for temperature dependence of Zn(T) at fixed n and compute baryon number susceptibility χB/T2 as function of temperature. After that we compute numerically ∂χ/∂T and restore crossover line in QCD phase diagram. We use improved Wilson fermions and Iwasaki gauge action on the 163 × 4 lattice with mπ/mρ = 0.8 as a sandbox to check the canonical approach. In this framework we obtain coefficient in parametrization of crossover line Tc(µ2B) = Tc(C−ĸµ2B/T2c) with ĸ = −0.0453 ± 0.0099.

scholarly journals STRANGENESS IN NEUTRON STARS

2007 ◽  
Vol 16 (02n03) ◽  
pp. 231-245 ◽  
Author(s):  
FRIDOLIN WEBER ◽  
ALEXANDER HO ◽  
RODRIGO P. NEGREIROS ◽  
PHILIP ROSENFIELD
Keyword(s):  
Neutron Stars ◽  
Quark Matter ◽  
Strange Quark ◽  
Baryon Number ◽  
Heavy Ion ◽  
Strange Quark Matter ◽  
Relativistic Heavy Ion Collision ◽  
Quark Deconfinement ◽  
Ion Collision ◽  
High Pressure Environment

It is generally agreed on that the tremendous densities reached in the centers of neutron stars provide a high-pressure environment in which several intriguing particles processes may compete with each other. These range from the generation of hyperons to quark deconfinement to the formation of kaon condensates and H-matter. There are theoretical suggestions of even more exotic processes inside neutron stars, such as the formation of absolutely stable strange quark matter. In the latter event, neutron stars would be largely composed of strange quark matter possibly enveloped in a thin nuclear crust. This paper gives a brief overview of these striking physical possibilities with an emphasis on the role played by strangeness in neutron star matter, which constitutes compressed baryonic matter at ultra-high baryon number density but low temperature which is not accessible to relativistic heavy ion collision experiments.

scholarly journals QCD critical end point from a realistic PNJL model

2018 ◽  
Vol 192 ◽  
pp. 00019 ◽  
Author(s):  
Kun Xu ◽  
Zhibin Li ◽  
Mei Huang
Keyword(s):  
Phase Transition ◽  
Chemical Potential ◽  
Baryon Number ◽  
Heavy Ion ◽  
Transition Line ◽  
Density Region ◽  
Chiral Phase ◽  
Chiral Phase Transition ◽  
End Point ◽  
Freeze Out

With parameters fixed by critical temperature and equation of state at zero baryon chemical potential, a realistic Polyakov-Nambu-Jona-Lasinio (rPNJL) model predicts a critical end point of chiral phase transition at (μEB = 720MeV; TE = 93MeV). The extracted freeze-out line from heavy ion collisions is close to the chiral phase transition boundary in the rPNJL model, and the kurtosis kσ2 of baryon number fluctuations from the rPNJL model along the experimental freeze-out line agrees well with the BES-I measurement. Our analysis shows that the dip structure of measured kσ2 is determined by the relationship between the freeze-out line and chiral phase transition line at low baryon density region, and the peak structure can be regarded as a clean signature for the existence of CEP.

scholarly journals Quark Number Susceptibilities and Equation of State in QCD at Finite μB

Proceedings ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 5
Author(s):  
Saumen Datta ◽  
Rajiv Gavai ◽  
Sourendu Gupta
Keyword(s):  
Equation Of State ◽  
Taylor Series ◽  
Chemical Potential ◽  
Baryon Number ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collider ◽  
Quark Number ◽  
Monte Carlo Studies ◽  
Essential Input ◽  
Beam Energy Scan

One of the main goals of the cold baryonic matter (CBM) experiment at FAIR is to explore the phases of strongly interacting matter at finite temperature and baryon chemical potential μ B . The equation of state of quantum chromodynamics (QCD) at μ B > 0 is an essential input for the CBM experiment, as well as for the beam energy scan in the Relativistic Heavy Ion Collider(RHIC) experiment. Unfortunately, it is highly nontrivial to calculate the equation of state directly from QCD: numerical Monte Carlo studies on lattice are not useful at finite μ B . Using the method of Taylor expansion in chemical potential, we estimate the equation of state, namely the baryon number density and its contribution to the pressure, for two-flavor QCD at moderate μ B . We also study the quark number susceptibilities. We examine the technicalities associated with summing the Taylor series, and explore a Pade resummation. An examination of the Taylor series can be used to get an estimate of the location of the critical point in μ B , T plane.

scholarly journals Hadron Resonance Gas EoS and the Fluidity of Matter Produced in HIC

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Guruprasad Kadam ◽  
Swapnali Pawar
Keyword(s):  
Mass Spectrum ◽  
Chemical Potential ◽  
Heavy Ion ◽  
Baryon Chemical Potential ◽  
Hadron Mass ◽  
Lattice Quantum ◽  
Hadron Gas ◽  
Ion Collision ◽  
Discrete Mass ◽  
The Ideal

We study the equation of state (EoS) of hot and dense hadron gas by incorporating the excluded volume corrections into the ideal hadron resonance gas (HRG) model. The total hadron mass spectrum of the model is the sum of the discrete mass spectrum consisting of all the experimentally known hadrons and the exponentially rising continuous Hagedorn states. We confront the EoS of the model with lattice quantum chromodynamics (LQCD) results at finite baryon chemical potential. We find that this modified HRG model reproduces the LQCD results up to T=160 MeV at zero as well as finite baryon chemical potential. We further estimate the shear viscosity within the ambit of this model in the context of heavy-ion collision experiments.

scholarly journals Bremsstrahlung pair production in relativistic heavy ion collision

1998 ◽  
Vol 2 (4) ◽  
pp. 741 ◽  
Author(s):  
Helmar Meier ◽  
Kai Hencken ◽  
Dirk Trautmann ◽  
Gerhard Baur
Keyword(s):  
Pair Production ◽  
Heavy Ion ◽  
Heavy Ion Collision ◽  
Relativistic Heavy Ion Collision ◽  
Ion Collision

scholarly journals Development of the Detector for Relativistic Heavy-Ion-Collision Experiments

2010 ◽  
Vol 19 (1/2) ◽  
pp. 32
Author(s):  
Youngil KWON ◽  
Young-Jin KIM ◽  
In-Kwon YOO ◽  
Byungsik HONG
Keyword(s):  
Heavy Ion ◽  
Heavy Ion Collision ◽  
Relativistic Heavy Ion Collision ◽  
Ion Collision

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.

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