Equilibrium and Nonequilibrium Signatures of the Quark Gluon Plasma at High Temperature and Density

新一代的超相对论重离子对撞机，布鲁克海文的RHIC和欧洲核子研究中心的大型强子对撞机，将打开一扇通往早期宇宙的窗口，当时宇宙只有一微秒大。在这些实验中，一种新的物质状态——夸克胶子等离子体——将会形成。当宇宙小于一微秒，温度大于1012k时，这种状态盛行。这种新状态也被推测存在于宇宙中密度最大的恒星——中子星的核心，并且是假想的夸克星的主要组成部分。这些天体的密度约为1015gr/cc，这些恒星是当前宇宙中最强大事件——超新星爆炸的残余。中子星的特性和夸克星的存在目前正在由许多卫星任务进行研究：HST， Rosat，钱德拉，xmm -牛顿和即将到来的中微子望远镜。评估夸克胶子等离子体的潜在观测值和实验特征需要在前所未有的温度和密度下研究强相互作用。此外，在超相对论性重离子碰撞中，夸克胶子等离子体预计将是一个短暂的态，其寿命史无前例的短，约为10-22秒，经历一个相变到夸克和胶子在强子内部结合的阶段。因此，我们面临的挑战是如何从短暂且快速演化的等离子体中提取观测特征。本提案的重点和目标是实施我们在过去几年中开发的方法来研究夸克胶子等离子体的平衡和非平衡实验特征以及超相对论性重离子碰撞和致密恒星中的相变。我们特别关注：i)电磁特征（光子和轻子对），ii)的输运现象和性质。作为相变的潜在观测值的波动，iii)导致强磁化中子星和夸克恒星中夸克物质观测信号的天体物理过程：光子和中微子发射。智力挑战：这是一个真正的跨学科项目，处于核与粒子物理、天体物理学和宇宙学的前沿。许多方法，特别是强烈不平衡的输运现象，也与凝聚态物理中的及时问题重叠：半导体中的飞秒弛豫。因此，我们预计该计划也将在许多领域产生广泛的影响。利用地球上的加速器打开一扇通往早期宇宙的窗户，研究密度最大的恒星，宇宙中能量最大的事件——超新星爆炸的残余——显然是最令人着迷的努力之一。广泛的兴趣：研究早期宇宙和目前宇宙中一些最奇特的物体的吸引力超出了在这些领域工作的科学家的范围，并且达到了广泛的受众。公众对宇宙学和粒子物理学的最新发现很感兴趣，渴望倾听和了解更多。宇宙学、天体物理学、核物理和粒子物理学之间的共生关系使其成为一种有效的工具，可以传递新的、迷人的发现，并突出宇宙的重要性。来解开宇宙的终极奥秘。本提案中描述的项目是在之前的资助下进行的研究的延续：N.S.F. PHY-9988720(5/31/00-5/31/03)，预计为期三年。

The new generation of ultrarelativistic heavy ion colliders, RHIC at Brookhaven and LHC at CERNwill open a window to the Early Universe when it was one microsecond old. In these experimentsa new state of matter-the quark gluon plasma- will be formed. This state prevailed when theUniverse was younger than a microsecond with temperatures larger than 1012 K. This novel stateis also conjectured to exist at the core of the densest stars in the Universe-neutron stars- and to bethe primary constituent of hypothetical quark stars. The density in these astrophysical objects isabout 1015gr/cc, these stars are the remnant of the most powerful events in the present Universesupernovaeexplosions. The properties of neutron stars and the existence of quark stars is currentlybeing studied by a host of satellite missions: HST, Rosat, Chandra, XMM-Newton and forthcomingneutrino telescopes.Assessing potential observables and experimental signatures of the quark gluon plasma requiresstudying the strong interactions in an unprecedented regime of temperatures and densities. Furthermore,in ultrarelativistic heavy ion collisions the quark gluon plasma is expected to be a transientstate with an unprecedented short lifetime of the order of 10-22 seconds, undergoing a phase transitionto a phase in which quarks and gluons are con.ned inside hadrons. Thus the challenge is toextract observational signatures fromthe short-lived and rapidly evolving plasma. The focus andgoal of this proposal is to implement the methods that we developed during the last several yearsto study equilibriumand non-equilibriumexp erimental signatures of the quark gluon plasma andthe phase transitions in ultrarelativistic heavy ion collisions and in compact stars. In particularwe focus on: i) electromagnetic signatures (photons and lepton pairs), ii) transport phenomenaand properties of .uctuations as potential observables of the phase transitions, iii) astrophysicalprocesses that lead to observational signals of quark matter in strongly magnetized neutron starsand quark stars: photon and neutrino emissions.Intellectual challenge: This is a truly interdisciplinary programat the forefront of nuclearand particle physics and astrophysics and cosmology. Many of the methods, in particular transportphenomena strongly out of equilibrium also overlaps with timely problems in condensed matterphysics: femtosecond relaxation in semiconductors. Thus we expect that the program will alsohave a broad impact in many areas. The possibility of opening a window to the Early Universewith earth-bound accelerators and studying the densest stars, the remnants of the most energeticevents in the Universe-Supernovae explosions-is clearly one of the most fascinating endeavors.Broad interest: The appeal of studying the Early Universe and some of the most exoticobjects in the present Universe goes beyond the scientists working in these areas, and reaches tothe broad audience. The general public is fascinated about the latest discoveries in cosmology andparticle physics, and eager to listen and learn more. The symbiosis between cosmology, astrophysicsand nuclear and particle physics lends itself to being an e.ective vehicle to transmit the new andfascinating discoveries and to highlight the importance of the di.erent areas to unravel the ultimatemysteries of the Universe.The projects described in this proposal are a continuation of the research done under theprevious Grant: N.S.F. PHY-9988720 (5/31/00-5/31/03) and is estimated for a period of threeyears.