作者：
Jiang, Ze-Fang*;She, Duan;Yang, C. B.（杨纯斌）;Hou, Defu
期刊：
中国物理C,2020年44(8):084107 ISSN：1674-1137
通讯作者：
Jiang, Ze-Fang
作者机构：
[Jiang, Ze-Fang] Hubei Engn Univ, Dept Phys & Elect Informat Engn, Xiaogan 432000, Peoples R China.;[Yang, C. B.; Hou, Defu; She, Duan; Jiang, Ze-Fang] Cent China Normal Univ, Inst Particle Phys, MOE, Wuhan 430079, Peoples R China.;[Yang, C. B.; Hou, Defu; She, Duan; Jiang, Ze-Fang] Cent China Normal Univ, MOE, Key Lab Quark & Lepton Phys, Wuhan 430079, Peoples R China.;[Yang, C. B.; She, Duan] Indiana Univ, Dept Phys, 2401 N Milo B Sampson Lane, Bloomington, IN 47408 USA.;[Yang, C. B.; She, Duan] Indiana Univ, Ctr Explorat Energy & Matter, 2401 N Milo B Sampson Lane, Bloomington, IN 47408 USA.
通讯机构：
[Jiang, Ze-Fang] H;[Jiang, Ze-Fang] C;Hubei Engn Univ, Dept Phys & Elect Informat Engn, Xiaogan 432000, Peoples R China.;Cent China Normal Univ, Inst Particle Phys, MOE, Wuhan 430079, Peoples R China.;Cent China Normal Univ, MOE, Key Lab Quark & Lepton Phys, Wuhan 430079, Peoples R China.
关键词：
heavy ion collision;longitudinal expanding fireball;viscous hydrodynamics;Rindler coordinate
摘要：
The solutions of the relativistic viscous hydrodynamics for longitudinally expanding fireballs are investigated with the Navier-Stokes theory and Israel-Stewart theory. The energy and the Euler conservation equations for the viscous fluid are derived in Rindler coordinates, by assuming that the longitudinal expansion effect is small. Under the perturbation assumption, an analytical perturbation solution for the Navier-Stokes approximation and numerical solutions for the Israel-Stewart approximation are presented. The temperature evolution with both shear viscous effect and longitudinal acceleration effect in the longitudinal expanding framework are presented. The specific temperature profile shows symmetric Gaussian shape in the Rindler coordinates. Further, we compare the results from the Israel-Stewart approximation with the results from the Bjorken and the Navier-Stokes approximations, in the presence of the longitudinal acceleration expansion effect. We found that the Israel-Stewart approximation gives a good description of the early stage evolutions than the Navier-Stokes theory.
作者机构：
[Yang, C. B.; Jiang, ZF; Yang, CB; Gong, Xiong-Tao; She, Duan; Jiang, Ze-Fang] Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Hubei, Peoples R China.;[Gong, Xiong-Tao] Hubei Polytech Inst, Xiaogan 432000, Peoples R China.;[Jiang, Ze-Fang] Hubei Engn Univ, Dept Phys & Elect Informat Engn, Xiaogan 432000, Peoples R China.;[Yang, C. B.; Jiang, ZF; Yang, CB; She, Duan; Jiang, Ze-Fang] Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;[Yang, C. B.; Jiang, ZF; Yang, CB; She, Duan; Jiang, Ze-Fang] Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Jiang, ZF; Yang, CB] C;[Jiang, Ze-Fang] H;[Jiang, ZF; Yang, CB] K;[Jiang, ZF; Yang, CB] I;Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Hubei, Peoples R China.
关键词：
viscous hydrodynamics;pseudorapidity distribution;energy density estimation
摘要：
Based on the analytical solution of accelerating relativistic viscous fluid hydrodynamics and Buda–Lund model, the pseudorapidity distributions of the most central Pb+Pb and Xe+Xe collisions are presented. Inspired by the CNC model, a modified energy density estimation formula is presented to investigate the dependence of the initial energy density estimation on the viscous effect. This new energy density estimation formula shows that the bulk energy is deposited to the neighboring fluid cells in the presence of the shear viscosity and bulk viscosity. In contrast to the well-known CNC energy density estimation formula, a 4.9% enhancement of the estimated energy density at the LHC kinematics is shown.
作者机构：
[Yang, C. B.; Hou, Defu; Jiang, Ze Fang; She, Duan] Minist Educ, Key Lab Quark & Lepton Phys, Wuhan 430079, Hubei, Peoples R China.;[Yang, C. B.; Hou, Defu; Jiang, Ze Fang; She, Duan] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Jiang, Ze Fang] Hubei Engn Univ, Dept Phys & Elect Informat Engn, Xiaogan 432000, Peoples R China.
通讯机构：
[Hou, Defu] M;[Hou, Defu] C;Minist Educ, Key Lab Quark & Lepton Phys, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.
摘要：
Nonentral heavy-ion collisions generate the strongest magnetic field of the order of 1018–1019 Gauss due to the electric current produced by the positively charged spectators that travel at nearly the speed of light. Such transient electromagnetic fields may induce various novel effects in the hydrodynamic description of the quark gluon plasma for noncentral heavy-ion collisions. We investigate the longitudinal acceleration effects on the 1+1 dimensional relativistic magnetohydrodynamics (MHD) with homogenous transverse magnetic fields. Exact solution of such MHD with a special equation of state (EoS) is presented, and we analyze the proper time evolution of the system energy density for general EoS. We find that the longitudinal acceleration parameter λ*, magnetic field decay parameter a, equation of state κ, and initial magnetization σ0 have nontrivial effects on the evolutions of the system energy density and temperature profile.
摘要：
A quark coalescence model, based on semi-relativistic molecular dynamics with color interactions among quarks, is presented and applied to pp collisions. A phenomenological potential with two tunable parameters is introduced to describe the color interactions between quarks and antiquarks. The interactions drive the process of hadronization that finally results in different color neutral clusters, which can be identified as hadrons based on some criteria. A Monte Carlo generator PYTHIA is used to generate quarks in the initial state of hadronization, and different values of tunable parameters are used to study the final state distributions and correlations. Baryon-to-meson ratio, transverse momentum spectra, pseudorapidity distributions and forward-backward multiplicity correlations of hadrons produced in the hadronization process, obtained from this model with different parameters, are compared with those from PYTHIA.
期刊：
JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS,2019年46(3):035006 ISSN：0954-3899
通讯作者：
Li, G. L.
作者机构：
[Li, G. L.] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Li, G. L.] C;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.
作者机构：
[Yang Chun-Bin; Jiang Ze-Fang] Minist Educ, Key Lab Quark & Lepton Phys, Wuhan 430079, Hubei, Peoples R China.;[Yang Chun-Bin; Jiang Ze-Fang] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Csanad, Mate] Eotvos Lorand Univ, ELTE, Pazmany Ps 1-A, H-1117 Budapest, Hungary.;[Csorgo, Tamas] Hungarian Acad Sci, Wigner Res Ctr Phys, POB 49, H-1525 Budapest, Hungary.;[Csorgo, Tamas] Eszterhazy Karoly Univ, Karoly Robert Campus,Matrai Ut 36, H-3200 Gyongyos, Hungary.
通讯机构：
[Jiang Ze-Fang] M;[Jiang Ze-Fang] C;Minist Educ, Key Lab Quark & Lepton Phys, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.
摘要：
A known class of analytic, exact, accelerating solutions of prefect relativistic hydrodynamics with longitudinal acceleration is utilized to describe results on the pseudorapidity distributions for different collision systems. These results include dN/dη measured in p+p, Cu+Cu, Au+Au, and Pb+Pb collisions at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider, in a broad centrality range. Going beyond the traditional Bjorken model, from the accelerating hydrodynamic description we determine the initial energy density and other thermodynamic quantities in those collisions.
作者机构：
[Yang, C. B.] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Yang, C. B.] C;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.
摘要：
Results from the Relativistic Heavy Ion Colloder (RHIC) and the Large Hadron Collider (LHC) experiments show that in relativistic heavy ion collisions, a new state of matter, a strongly interacting perfect fluid, is created. Accelerating, exact and explicit solutions of relativistic hydrodynamics allow for a simple and natural description of this medium. A finite rapidity distribution arises from these solutions, leading to an advanced estimate of the initial energy density of high energy collisions. These solutions can be utilized to describe various aspects of proton–proton collisions, as originally suggested by Landau. We show that an advanced estimate based on hydrodynamics yields an initial energy density in s = 7 and 8 TeV proton–proton (p–p) collisions at the LHC on the same order as the critical energy density from lattice Quantum Chromodynamics (QCD). The advanced estimate yields a corresponding initial temperature that is around the critical temperature from QCD and the Hagedorn temperature. The multiplicity dependence of the estimated initial energy density suggests that in high multiplicity p–p collisions at the LHC, there is large enough initial energy density to create a non-hadronic perfect fluid.
作者机构：
[Yang, Chunbin; Zhao, Longfeng; Li, W; Zou, Yijiang; Li, Wei; Su, Zhu; Han, Jihui] Hua Zhong Cent China Normal Univ, Complex Sci Ctr, Wuhan 430079, Peoples R China.;[Yang, Chunbin; Zhao, Longfeng; Li, W; Zou, Yijiang; Li, Wei; Su, Zhu; Han, Jihui] Hua Zhong Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[Li, Wei] Max Planck Inst Math Sci, D-04103 Leipzig, Germany.
通讯机构：
[Zhao, LF; Li, W] H;[Li, Wei] M;Hua Zhong Cent China Normal Univ, Complex Sci Ctr, Wuhan 430079, Peoples R China.;Hua Zhong Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;Max Planck Inst Math Sci, D-04103 Leipzig, Germany.
关键词：
Complex systems;Fractals;Autocorrelation;Monte Carlo method;Probability density;Fluctuation analysis;Skewness;Scale-free networks
摘要：
Many models and real complex systems possess critical thresholds at which the systems shift dramatically from one sate to another. The discovery of early-warnings in the vicinity of critical points are of great importance to estimate how far the systems are away from the critical states. Multifractal Detrended Fluctuation analysis (MF-DFA) and visibility graph method have been employed to investigate the multifractal and geometrical properties of the magnetization time series of the two-dimensional Ising model. Multifractality of the time series near the critical point has been uncovered from the generalized Hurst exponents and singularity spectrum. Both long-term correlation and broad probability density function are identified to be the sources of multifractality. Heterogeneous nature of the networks constructed from magnetization time series have validated the fractal properties. Evolution of the topological quantities of the visibility graph, along with the variation of multifractality, serve as new early-warnings of phase transition. Those methods and results may provide new insights about the analysis of phase transition problems and can be used as early-warnings for a variety of complex systems.
作者机构：
[Hwa, Rudolph C.] Univ Oregon, Inst Theoret Sci, Eugene, OR 97403 USA.;[Hwa, Rudolph C.] Univ Oregon, Dept Phys, Eugene, OR 97403 USA.;[Yang, C. B.] Cent China Normal Univ, Key Lab Quark & Lepton Phys, Minist Educ, Wuhan, Peoples R China.
通讯机构：
[Hwa, Rudolph C.] U;Univ Oregon, Inst Theoret Sci, Eugene, OR 97403 USA.;Univ Oregon, Dept Phys, Eugene, OR 97403 USA.
摘要：
Quark-hadron phase transition at the end of evolution of the dense matter created in heavy-ion collisions is studied with particular attention given to the fluctuation of spatial patterns that is expected in a second-order phase transition, as found in the Ising model. Since QCD thermodynamics cannot easily be applied at low temperature and density, an event generator is constructed to simulate the dynamical properties of contraction due to confinement forces, and randomization due to the thermal behavior of a large quark system on the edge of hadronization. Fluctuations of the positions of emitted pions in the (η, ψ) space are analyzed using normalized factorial moments in a wide range of bin sizes. The scaling index v is found to be very close to the predicted value in the Ginzburg-Landau formalism. The erraticity indices μq are determined in a number of ways that lead to the same consistent values. They are compared to the values from the Ising model, showing significant difference in a transparent plot. Experimental determination of v and μq at the LHC are now needed to check the reality of the theoretical study, and to provide guidance for improving the model description of quark-hadron phase transition.
作者机构：
[Yang, Chun-Bin; Zhong, Yang; Cai, Xu] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[Zhong, Yang; Feng, Sheng-Qin] China Three Gorges Univ, Coll Sci, Yichang 443002, Peoples R China.;[Yang, Chun-Bin; Feng, Sheng-Qin; Cai, Xu] Cent China Normal Univ, Key Lab Quark & Lepton Phys, MOE, Wuhan 430079, Peoples R China.
通讯机构：
[Zhong, Yang] C;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;China Three Gorges Univ, Coll Sci, Yichang 443002, Peoples R China.
关键词：
spatial distribution of electric field;chiral electric field
摘要：
It has been proposed that electric fields may lead to chiral separation in quark-gluon plasma (QGP). This is called the chiral electric separation effect. The strong electromagnetic field and the QCD vacuum can both be completely produced in off-central nuclear-nuclear collision. We use the Woods-Saxon nucleon distribution to calculate the electric field distributions of off-central collisions. The chiral electric field spatial distribution at Relativistic Heavy-Ion Collider (RHIC) and Large Hadron Collider (LHC) energy regions are systematically studied in this paper. The dependence of the electric field produced by the thermal quark in the central position with different impact parameters on the proper time with different collision energies in the RHIC and LHC energy regions are studied in this paper.
作者机构：
[Yang, Chun-Bin] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Yang, Chun-Bin] C;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.
摘要：
Within the framework of Ginzburg-Landau theory, the effect of multiplicity correlation between the dynamical multiplicity fluctuations is analyzed for a first-order phase transition from quark-gluon plasma to hadrons. Normalized factorial correlators are used to study the correlated dynamical fluctuations. A scaling behavior is found among the factorial correlators, and an approximate universal exponent, which is weakly dependent on the details of the phase transition, is obtained.
作者机构：
[Yang, C. B.] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;[Yang, C. B.] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Yang, C. B.] C;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.
期刊：
International Journal of Modern Physics E,2015年24(6):1550044 ISSN：0218-3013
通讯作者：
Tan, Z. G.
作者机构：
[Tan, Z. G.] Changsha Univ, Dept Elect & Commun Engn, Changsha 410003, Hunan, Peoples R China.;[Yang, C. B.; Tan, Z. G.] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;[Yang, C. B.; Tan, Z. G.] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Tan, Z. G.] C;Changsha Univ, Dept Elect & Commun Engn, Changsha 410003, Hunan, Peoples R China.
关键词：
Color;interaction;hadronization;multi-quark
摘要：
This paper deals with the hadronization process of quark system. A phenomenological potential is introduced to describe the interaction between a quark pair. The potential depends on the color charge of those quarks and their relative distances. Those quarks move according to classical equations of motion. Due to the color interaction, coloring quarks are separated to form color neutral clusters which are supposed to be the hadrons.
作者机构：
[Yang Chun-Bin; Zhong Yang; Cai Xu] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[Zhong Yang; Feng Sheng-Qin] China Three Gorges Univ, Coll Sci, Yichang 443002, Peoples R China.;[Yang Chun-Bin; Cai Xu; Feng Sheng-Qin] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.
通讯机构：
[Zhong Yang] C;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
关键词：
the distribution of magnetic field;non-central collision
摘要：
Relativistic heavy-ion collisions can produce extremely strong magnetic fields in the collision regions.The spatial variation features of the magnetic fields are analyzed in detail for non-central Pb–Pb collisions at LHC at√s NN = 900, 2760 and 7000 Ge V and Au–Au collisions at RHIC at√s NN=62.4, 130 and 200 Ge V. The dependencies of magnetic field on proper time, collision energies and impact parameters are investigated in this paper. It is shown that an enormous and highly inhomogeneous spatial distribution magnetic field can indeed be created in off-centre relativistic heavy-ion collisions in RHIC and LHC energy regions. The enormous magnetic field is produced just after the collision, and the magnitude of magnetic field of the LHC energy region is larger than that of the RHIC energy region at small proper time. It is found that the magnetic field in the LHC energy region decreases more quickly with the increase of proper time than that of the RHIC energy region.
期刊：
JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS,2014年41(10):105006 ISSN：0954-3899
通讯作者：
Zhang, W. C.
作者机构：
[Zhang, W. C.] Shaanxi Normal Univ, Sch Phys & Informat Technol, Xian 710119, Peoples R China.;[Yang, C. B.] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[Yang, C. B.] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.
通讯机构：
[Zhang, W. C.] S;Shaanxi Normal Univ, Sch Phys & Informat Technol, Xian 710119, Peoples R China.
摘要：
We report on a scaling behaviour in the transverse momentum (p(T)) distributions for charged hadrons produced in proton-proton (pp) collisions with different centre of mass energies (root s = 0.9, 2.76 and 7 TeV) at the Compact Muon Solenoid detector. This scaling behaviour appears when the p(T) is replaced by p(T)/K, where K is a parameter and depends on root s. A similar scaling behaviour is observed in the p(T) distributions of charged hadrons produced in proton-antiproton (p (p) over bar) collisions with root s = 0.63, 1.8 and 1.96 TeV at the Collider Detector at Fermilab. The particle production mechanism behind the scaling behaviour in the pp or p (p) over bar collisions could be explained by the model of percolation of strings.
