Mixed Quark-Gluon Condensate Beyond Chiral Limit

Using the Dyson-Schwinger equation and perturbation theory, we calculate the mixed quark-gluon condensates in the chiral limit and in the case of nonzero quark current mass for the light quark u/d and strange quark s. The results show that the mixed quark-gluon condensate will decrease when the quark mass increases. For the quark with zero mass, we obtain mo2 = g（qσuvGuvq）/（qq） 0.68 GeV2, which is in good agreement with the QCD sum rules estimate mo2=（0.8± 0.2） GeV2.

Calculation of Dielectric Function of a Quark-Gluon Plasma

With the hard thermal loop （HTL） resummation technique, we calculate the dielectric function excited by hard gluon in quark-gluon plasma （QCP）. We find that in a section of the space-like region po/p ∈ [0.78, 0.95], there are two extremum structures on the dielectric function curve, while the dielectric function in the HTL approximation decreases monotonously without these properties. Through the analyses of the imaginary part of the dielectric function, we conclude that the character of the dielectric function in this region reflects effects of the Landau damping.

Interpretation of Dark Matter and Quark-Gluon Plasma: The Generation of the Periodic Table Elements and Its Phase Diagram: A Novel Millennium Power Plant

This paper presents a novel physical interpretation of the state of matter of the quark-gluon as the most fundamental building blocks in nature. Such a model is derived based on the assumption that dark matter and dark energy behave as a perfect ideal fluid at extremely high temperature. By the virtue of Boltzmann constant of the ideal gas law and NASA’s Cosmic Microwave Background Explorer (CMB) which estimate that the space has an average temperature close to 2.7251 Kelvin, then the equivalent mass-energy of the fundamental particle of the dark matter/dark energy is determined. Moreover, assuming a uniform space dark energy/dark matter density, then the critical temperature at which the dark matter has a unity entity per volume is identified as 64 × 1012 K. The calculated critical temperature of the quark-gluon plasma is found to be proportional to the temperature generated by colliding heavy ions at the Relativistic Heavy Ion Collider (RHIC) and European Organization for Nuclear Research (CERN). Moreover, the individual critical temperatures of the quark-gluon plasma matter at which the elements of the Periodic Table are generated are explicitly determined. The generation temperature trend of the elements of the Periodic Table groups and Periods is then demonstrated. Accordingly, the phase diagram of the quark-gluon state matter is proposed. Finally, a new model of quark-gluon power generation plant is proposed and aims to serve humanity with new energy sources in the new millennium.

Dilepton Emission at Temperature Dependent Baryonic Quark-Gluon Plasma

Dilepton emission is calculated from quark-gluon plasma (QGP) with the consideration of temperature dependent chemical potential (TDCP). The model is considered to be quasi-model and hence take the dynamical quark mass as a finite value dependence on temperature. The temperature in quark mass enhances in the growth of dilepton emission rates. The emission rate of dilepton spectrum is shown in the intermediate mass region (IMR) of 1.0 - 4.0 GeV and its rate is observed to be a strong increasing function of the temperature dependent chemical potential for quark and anti-quark annihilation.

Incident energy dependence of dilepton production in an expanding baryon-rich quark-gluon fireball

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Production of dileptons with intermediate masses in an expanding quark-gluon matter

A study of dilepton spectra, in intermediate mass region (IMR), from main background sources, quark phase, and secondary processes in hadronic phase on the basis of a relativistic hydrodynadric model has been carried out. The comparison between these results indicates that in this mass region the contribution from the background sources dominates, and due to the effect of the phase boundary on the evolution of the system the contribution from the quark phase becomes more important than that from secondary processes.

Criterion for reducible hydrodynamic equations of baryon-rich quark-gluon plasma

Besides the state equation there exists another cubic algebraic equation about μf in the form of μf3 + pμf + q = 0, which relates parameters, temperature T, chemical potential μf, and net quark number nff （flavor f） for a baryon-rich quark-gluon plasma （QGP）. A criterion may be acquired simply according to Cardan formula of the solution of the above equation, which gives naturally a condition: if n << 2πT3/3, one may approximately use the conservation of specific entropy, and then the set of hydrodynamic equation of baryon-rich QGP may be reduced to the set of hydrodynamic equation for baryon-free QGP.

Transverse momentum balance of dijets in Xe+Xe collisions at the LHC

We present a theoretical study of the medium modifications of the p_(T)balance (x_(J)) of dijets in Xe+Xe collisions at■.The initial production of dijets was carried out using the POWHEG+PYTHIA8 prescription,which matches the next-toleading-order (NLO) QCD matrix elements with the parton shower (PS) effect.The SHELL model described the in-medium evolution of nucleus–nucleus collisions using a transport approach.The theoretical results of the dijet xJin the Xe+Xe collisions exhibit more imbalanced distributions than those in the p+p collisions,consistent with recently reported ATLAS data.By utilizing the Interleaved Flavor Neutralisation,an infrared-and-collinear-safe jet flavor algorithm,to identify the flavor of the reconstructed jets,we classify dijets processes into three categories:gluon–gluon (gg),quark–gluon (qg),and quark–quark (qq),and investigated the respective medium modification patterns and fraction changes of the gg,qg,and qq components of the dijet sample in Xe+Xe collisions.It is shown that the increased fraction of qg component at a small x_(J)contributes to the imbalance of the dijet;in particular,the q_(1)g_(2)(quark-jet-leading) dijets experience more significant asymmetric energy loss than the g_(1)q_(2)(gluon-jet-leading) dijets traversing the QGP.By comparing the■of inclusive,■ dijets in Xe+Xe collisions,we observe■.Moreover,ρ_(Xe),P_(b),the ratios of the nuclear modification factors of dijets in Xe+Xe to those in Pb+Pb,were calculated,which indicates that the yield suppression of dijets in Pb+Pb is more pronounced than that in Xe+Xe owing to the larger radius of the lead nucleus.

对超高能宇宙线大气簇射中μ子超出的探讨

近年来,一些大气簇射观测数据表明,超高能大气簇射中产生的μ子数比模型预测的要多,现有的理论模型都不能很好地解释此现象.研究指出了,当超高能宇宙射线与大气粒子发生碰撞时,可能会发生胶子凝聚,此时奇异夸克的产生会大大增强,从而在碎裂产物中产生更多的K介子;大气簇射的能量更多地分配到强子级联过程,有可能解释μ子超出现象.

Modification of the spectra of correlated charm-anticharm quark pairs in the quark-gluon plasma

Heavy quarks play an important role in probing the properties of strongly interacting quark-gluon plasma(QGP)created in ultra-relativistic heavy-ion collisions.We study the interactions of single heavy(charm)quarks and correlated charm and anticharm(ccˉ)quark pairs with the medium constituents of QGP by performing fireball+Langevin simulations of the pertinent Brownian motion with elastic collisions.Besides studying the traditional observables,the nuclear modification factor and the elliptic flow of single heavy quarks in QGP for different thermal relaxation rates,we also study the broadening of the azimuthal correlations of charm and anticharm quark pairs in the QGP medium for different relaxation rates and transverse momenta classes.We quantified the smearing of ccˉpair azimuthal correlations with an increasing thermal relaxation rate:while the(nearly)back-to-back correlations among ccˉpairs are almost completely washed out at low transverse momentum(pT),these correlations at high pT largely survive the pair diffusion.This provides a novel observable for diagnosing the properties of QGP.

Color-electric conductivity in a viscous quark-gluon plasma

Several different transport processes, such as heat, momentum, and charge transports, may occur simultaneously in a thermal plasma system. The corresponding transport coefficients are heat conductivity, shear viscosity, and electric conductivity. In the present study, we investigate the color-electric conductivity of the quark-gluon plasma(QGP) in the presence of shear viscosity, focusing on the connection between the charge transport and momentum transport. To achieve this goal, we solve the viscous chromohydrodynamic equations obtained from the QGP kinetic theory associated with the distribution function modified by shear viscosity. According to the solved color fluctuations of hydrodynamic quantities, we obtain the induced color current through which the color-electric conductivity is derived. Numerical analysis shows that the conductivity properties of the QGP are mainly demonstrated by the longitudinal part of the color-electric conductivity. Shear viscosity has an appreciable impact on real and imaginary parts of the color-electric conductivity in some frequency regions.

A New Approach to the Dark Matter/Dark Energy Puzzle

The dilemmas posed by dark matter and dark energy have been with us for decades without a satisfactory resolution. We propose that both DM and DE can be explained by the existence of long-lived topological gravitational vortices that were produced in the quark-gluon epoch of cosmic inflation due to the misalignment of the gravitational and strong forces. This is analogous to the misalignment mechanism proposed for the production of axions in the early universe. The masses of these topological vortices are expected to be on the order of the nucleon mass. Possible means for their detection are discussed.

RHIC能区Au+Au碰撞中带电粒子直接流与超子整体极化的计算与分析

非对心的相对论重离子碰撞中,不参与碰撞的核子会对参与碰撞的核子产生纵向拖拽,形成一个相对于纵向倾斜的夸克胶子等离子体(QGP)火球.同时,对撞的原子核可将巨大的轨道角动量沉积于QGP中,使其中的部分子沿系统总角动量方向发生自旋极化.在光学Glauber模型基础上,本文构建了倾斜的三维QGP初态条件,并结合3+1维黏滞流体力学模型CL Visc,研究了重离子碰撞的末态带电粒子的直接流和Λ/Λ超子的整体极化.计算表明,倾斜的初态条件与流体力学模型的结合能够较好地描述RHIC-STAR实验上观测到的直接流与超子整体自旋极化的数据.这为人们利用这些观测量进一步约束重离子碰撞产生的核物质的初始几何与运动学状态提供了理论依据.

相对论重离子碰撞中光子-光子相互作用的碰撞参数依赖性

在相对论重离子碰撞中,接近光速的重离子产生的超强电磁场,由于洛伦兹收缩效应可等效为线性极化的准实光子,进而诱发光子-光子相互作用产生正负轻子对.相对论重离子对撞机RHIC和大型强子对撞机LHC上的国际合作实验在非超周边重离子碰撞中观测到相干光致产生过程,发现正负轻子对的横动量分布相比于其在超周边碰撞发生显著的展宽,为研究解禁闭物质--夸克胶子等离子体的电磁性质提供了新途径.本文主要回顾相对论重离子碰撞中光子-光子相互作用对碰撞参数依赖的实验研究,并讨论其在侦测夸克胶子等离子体电磁性质方面的重要意义.

涡旋场中的强作用物质相变

强作用物质相结构的研究是核物理里一个非常活跃的前沿领域,对于理解相对论重离子碰撞实验和中子星观测有重要意义。传统的相结构研究集中于高温度和高密度所带来的物性变化,特别是相关的相变过程,比如手征恢复相变、色超导相变等。近年的实验和理论研究表明,非对心重离子碰撞系统携带很大的初始角动量从而产生极强的流体涡旋场。这带来了涡旋场中的强作用物质性质的一系列重要问题,对它们的探索产生了许多新颖结果。特别是在强作用物质相变方面,基于转动参考系的热场计算得到了发展,并结合平均场近似对相关的手征相变、色超导相变、高同位旋下的超流相变等现象作了深入研究,发现了涡旋场对相边界的影响以及其所带来的丰富相结构。

相对论重离子碰撞中的喷注淬火效应

相对论重离子碰撞中产生了高温高密解禁闭的夸克胶子等离子体(QGP),研究QGP的性质是高能核物理目前最重要的物理目标之一.其中,应用喷注淬火作为硬探针研究QGP的性质是一个非常重要的手段.喷注淬火指的是相对论重离子碰撞中产生的高能部分子穿过QGP时,通过强相互作用导致的能量损失效应.本文主要介绍喷注淬火效应的最新研究进展,具体包含喷注淬火效应对强子、喷注和喷注子结构的介质影响,以及目前理论上面临的问题和困难.

亚经济动力学原理——经济动力学与标准模型(Ⅲ)

亚经济动力学研究人们的经济冲动结构与市场行为的关系。以布尔巴基结构主义为哲学考量,以量子色动力学为概念化手段与模型化方法,构建了亚经济动力学理论。其中,我们讨论了自由市场的深层结构并分析了米塞斯在其人类学论证中的失误。亚经济动力学是市场动力学的心理学基础。在前言的引导下,本文共分六节:(一)自由市场与冲动味荷,论题包括:自由市场的命运,食物链与心理学,以及经济冲动的味荷;(二)经济冲动的性质,论题包括:冲动与反冲动的味与代,以及冲动束缚态与分数市场荷;(三)弗洛伊德色荷空间与自旋,论题包括:泡利不相容原理与色荷,以及弗洛伊德人格论;(四)意识与胶子;(五)规范变换与SU(3)对称群;以及(六)一般讨论。

夸克胶子等离子体的2π干涉学检测

在2π干涉学中,对不同的π源,2π关联函数可以是不同的.如果在超相对论重离子碰撞中出现夸克胶子等离子体,π介子将从夸克胶子等离子体表面发射,此时2π关联函数将出现一种特殊的振荡行为.这种振荡行为可以用来探明夸克胶子等离子体的存在性,同时也是超相对论重离子碰撞中出现夸克胶子等离子体的一个信号.

关于核子-核子相互作用势能的计算

从六夸克体系p s方程出发,导出了2个核子之间的相对运动方程———共振群方程,研究了在近程范围内夸克胶子交换势对核力的贡献,并结合中长程范围单π双π介子交换对核力的影响,从而全面研究了核力的性质,给出核子-核子相互作用的解析表达式.

高能重离子碰撞实验中的软物理研究现状

高能重离子碰撞实验中的软物理研究能够帮助我们清楚认识系统的集体演化过程,并且有助于理解碰撞产生的热密系统的性质。本文介绍了高能重离子碰撞实验中软物理的研究现状及其新近取得的实验成果,包括七部分内容:1)高能重离子碰撞简介;2)碰撞几何方面的研究现状;3)粒子产生方面的研究现状;4)关联与起伏方面的研究现状;5)集体膨胀方面的研究现状;6)强子化方面的研究现状;7)LHC/ALICE实验上的软物理预期。最后,本文对高能重离子碰撞实验中的软物理研究现状进行总结。