重夸克偶素质量谱的相对论夸克模型研究（已撤稿）

使用量子场论中准势途径的相对论夸克模型,计算了重夸克偶素的质量谱.所采用的同味正反夸克间的有效相互作用包括通常的直接单胶子交换、单胶子湮没及具有相对论修正的标量和矢量线性禁闭的混合.得到了与实验上肯定的数据符合较好的拟合计算结果，并讨论了湮没项和相对论修正各项对能谱超精细分裂的作用. 关键词： 重夸克偶素 质量谱 相对论修正 湮没势     

相对论效应对有限温下重夸克偶素的性质的影响

考虑相对论修正对重夸克偶素结合和分解所产生的作用，计算了重夸克偶素在热力学环境中的临界性质，并与非相对论模型理论进行了比较．     

重夸克偶素产生机制对J/ψ+γ协同产生过程的影响

利用推广x重标度模型给出的胶子分布函数计算并讨论了重夸克偶素的色八重态对p-Fe碰撞中J/ψ和γ协同产生过程微分截面的影响.结果表明:色八重态的贡献不可以忽略.本文的计算结果与未来实验数据的比较,可以对重夸克偶素的色八重态产生机制进行检验.     

t夸克偶素能谱的计算

本文利用考虑胶子质量的重夸克偶素位势计算了t夸克偶素的能谱。 关键词：     

重夸克偶素中的色屏蔽效应

将夸克-反夸克的禁闭位选为含有色屏蔽效应的禁闭势,计算了它对重夸克偶素cc和bb能谱的影响.与通常选用的线性禁闭势相比,含色屏蔽效应的禁闭势对ψ(cc)的高激发能级的轨道角动量可给出不同的预言,并且对ψ能级的轻子衰变宽度有明显的改进.     

胶子遮蔽和末态作用对p—A碰撞中粲偶素和b夸克偶素产额压低的贡献

本文用胶子结构函数的遮蔽效应和末态作用分析了在p-A碰撞中粲偶素和b夸克偶素产额压低的实验数据,较好地描述了粲偶素和b夸克偶素产额的压低与A和X2的关系.     

矢量-标量混合禁闭势模型时的重夸克偶素

本文用考虑了相对论修正的势模型计算重夸克偶素的能谱、轻子宽度和辐射跃迁宽度. 在模型中我们假定: 矢量型禁闭和标量型禁闭同时存在, 在远距离标量型禁闭为主, 在近距离矢量型禁闭为主. 在这个假定下我们得到了与实验符合得较好的精细分裂值.     

胶子遮蔽和末态作用对p—A碰撞中粲偶素和b夸克偶素产额压低的贡献

本文用胶子结构函数的遮蔽效应和末态作用分析了在ｐ－Ａ碰撞中粲偶素和ｂ夸克偶素产额压低的实验数据，较好地描述了粲偶素和ｂ夸克偶素产额的压低与Ａ和Ｘ２的关系．     

强电场对夸克胶子等离子体中粲夸克偶素演化的影响(英文)

在极端相对论重离子碰撞中,高速运动的重离子会产生很强的电场。在碰撞的早期电场强度大小在eE~m_π2的量级。在夸克胶子等离子体中,强电场将会对粲夸克偶素的演化产生巨大的影响。我们用含时薛定谔方程计算夸克胶子等离子体中由高速运动电荷所产生强电场对重夸克偶素演化的影响。此电场可以导致不同角动量态之间的跃迁。为了研究此效应,比较了有电场和无电场情况下J/ψ、ψ'以及χ_c的产额。计算结果表明,在碰撞早期电场会导致J/ψ解离;同时,χ_c也由电场导致的J/ψ的跃迁而产生。     

粲夸克偶素和b夸克偶素的色屏蔽和分解

用非相对论的色屏蔽势模型研究粲夸克偶素和b夸克偶素束缚态的结合和分解.用两种参数化形式的位势,计算了在热力学环境中的色屏蔽长度.结果表明,临界屏蔽长度r与位势的形式有密切的关系.     

Quarkonium suppression

I discuss quarkonium suppression in equilibrated strongly interacting matter. After a brief review of basic features of quarkonium production I discuss the application of recent lattice data on the heavy quark potential to the problem of quarkonium dissociation as well as the problem of direct lattice determination of quarkonium properties in finite temperature lattice QCD.     

Melting temperature of heavy quarkonium with a holographic potential up to sub-leading order

A calculation of the melting temperatures of heavy quarkonium states with the holographic potential was introduced in a previous work.In this paper,we consider the holographic potential at sub-leading order,which permits finite coupling corrections to be taken into account.It is found that this correction lowers the dissociation temperatures of heavy quarkonium.     

A Test of Color-Octet Heavy Quarkonium Production Mechanism

Using the scale evolution of nuclear parton distributions,the contribution of color-octet heavy quarkonium production mechanism to the P + Fe → J/ψ + γ + X process in calculated and discussed.Comparing our theoretical results with the future experimental data,the color-octet heavy quarkonium production mechanism can be examined.     

QUANTUM CHROMODYNAMICS AS THE TRORY OF INTERACTIONS

Recent developmeht of testing QCD as the theory of strong interactions is reviewed. Emphasis is put on the success of perturbative QCD and the determination of the fundamental scale parameter scale parameter A. Recent development of heavy quarkonium physics is also reviewed from the point of view of QCD and the possibility that future heavy quarkonium experiments can provide further quantitative QCD tests is discussed.     

Entropic destruction of heavy quarkonium in a rotating hot and dense medium from holography

Previous studies have indicated that the peak of the quarkonium entropy at the deconfinement transition can be related to the entropic force, which would induce the dissociation of heavy quarkonium. In this study, we investigated the entropic force in a rotating hot and dense medium using AdS/CFT correspondence. It was found that the inclusion of angular velocity increases the entropic force, thus enhancing quarkonium dissociation, while chemical potential has the same effect. The results imply that the quarkonium dissociates easier in rotating medium compared with the static case.     

Exclusive decay of 1 heavy quarkonium into photon and two pions

We study the exclusive decay of 1⁻⁻ heavy quarkonium into one photon and two pions in the kinematic region, where the two-pion system has a invariant mass which is much smaller than the mass of heavy quarkonium. Neglecting effects suppressed by the inverse of the heavy quark mass, the decay amplitude can be factorized, in which the nonperturbative effect related to heavy quarkonium is represented by a non-relativistic QCD matrix element, and that related to the two pions is represented by a distribution amplitude of two gluons in the isoscalar pion pair. By taking the asymptotic form for the distribution amplitude and by using chiral perturbative theory we are able to obtain numerical predictions for the decay. Numerical results show that the decay of J/ψ can be observed at BEPC and at CESR. Experiment observation of this process in this kinematic region at BEPC and CESR can provide information about how gluons are converted into the two pions and may supply a unique approach to study I=0 s-wave ππ scattering.     

Dissociation of Quarkonium in a Strong Electric Field

The probability of tunnel decay of quarkonium (bond state of a heavy quark and a heavy antiquark) into free quarks in a strong electric field is estimated.     

Holographic hadro-quarkonium

We consider the recently suggested model for some resonances near the open charm threshold as bound states of charmonium inside excited light mesons. It is argued in the soft-wall holographic model of QCD that such states of heavy quarkonium necessarily exist at sufficiently large spin of the light meson. The bound state is provided by the dilaton exchange through the 5D bulk. We also argue that the decay of such bound systems into mesons with open heavy flavors due to splitting of the heavy quarkonium can be treated as semiclassical tunneling and is suppressed. This behavior is in agreement with the known relative suppression of the decay of the discussed charmonium-like resonances into channels with D mesons.     

Heavy quarkonia in a medium as a quantum dissipative system: master-equation approach

The problem of the evolution of a heavy quarkonium in a medium can be recast as that of a quantum dissipative system. Within the framework of the master-equation approach to open quantum systems, we consider the real-time dynamics of quarkonia. We find that in a plasma at fixed temperature, the populations of the various quarkonium states evolve together, while their momentum distribution satisfies a Fokker–Planck equation.     

Quarkonium formation in statistical and kinetic models

I review the present status of two related models addressing scenarios in which the formation of heavy quarkonium states in high energy heavy ion collisions proceed via “off-diagonal” combinations of a quark and an antiquark. The physical process involved belongs to a general class of quark “recombination”, although technically the recombining quarks here were never previously bound in a quarkonium state. Features of these processes relevant as a signature of color deconfinement are discussed.Arrival of the final proofs: 26 April 2005